Investigative Ophthalmology & Visual Science, May 14, 2008
Riboflavin/ultraviolet A (UVA) cross-linking (CXL) of corneal collagen is a novel method of stabi... more Riboflavin/ultraviolet A (UVA) cross-linking (CXL) of corneal collagen is a novel method of stabilizing corneal mechanical properties and preventing progression of keratectasias. This study was conducted to investigate whether CXL influences ablation rate, flap thickness, and refractive results of excimer laser procedures ex vivo. Corneal epithelium was removed from enucleated porcine eyes, and CXL was performed with riboflavin 0.1% and UVA radiation (365 nm, 3 mW/cm(2)) for 30 minutes. Control eyes received epithelial abrasion only. Diffusion of riboflavin through the cornea was assessed by using infrared-excited, two-photon microscopy of riboflavin autofluorescence, combined with second-harmonic generation of fibrillar collagen. During phototherapeutic keratectomy, corneal thickness was measured by optical coherence pachymetry. During LASIK for myopia, the flap thickness of microkeratome cuts was measured and the induced refractive change assessed by Placido topography. Data were analyzed by Shapiro-Wilk test and Student's t-test. Multiphoton imaging showed a rapid (30-minute) and even distribution of riboflavin throughout the corneal stroma. No difference in ablation rate was measured in treated and untreated corneas (P = 0.90). Mean flap thickness was increased by 44% in cross-linked corneas (P < 0.01). After LASIK for myopia of 4 to 25 D, the mean corneal refractive change was reduced in CXL-treated eyes by 20.1% (P < 0.05). This effect was less pronounced in thinner flaps. CXL reduces the amount of refractive change after LASIK for myopia. Although the laser ablation rate is unaffected, CXL results in an increased flap thickness. This study suggests the need for adjustment of microkeratome and laser parameters for LASIK after CXL and indirectly endorses the theory of a direct stiffening effect of CXL.
Doctoral thesis, UCL (University College London)., Jun 28, 2017
Gene therapy of the eye has made huge advances in recent years, which led to first clinical trial... more Gene therapy of the eye has made huge advances in recent years, which led to first clinical trials. While these were aimed at replacing a defective gene in inherited disease, research is now expanding to using augmentation gene therapy where a gene is used to modulate the course of disease. We investigated the possibilities of gene transfer of cell cycle modulating genes to induce proliferation in two amitotic tissues essential for vision, the corneal endothelium and retinal pigment epithelium. Corneal endothelial cells (CEC) maintain the water content of the cornea and thereby its clarity. Low CEC density in corneal diseases causes blindness and requires corneal transplantation. Transfer of E2F2, a transcription factor regulating G1 to S phase progression, increases CEC density in human ex vivo cultivated corneas, but only when transferred by adenoviral vector, not lentiviral vector. Instead, lentiviral overexpression of ZONAB, a transcription factor normally inactivated by tight junction protein ZO-1, increased CEC density. Lentiviral downregulation of ZO-1, mimicking loss of cell-cell contacts and loss of contact inhibition, led to CEC proliferation. However, CEC density increase was only achieved in young corneas up to ~60 years-of-age, indicating loss of proliferative capacity with age. RPE loss, as seen in age related macular degeneration (AMD), causes photoreceptor loss and blindness. RPE proliferation could be induced using non-integrating lentiviral vectors delivering E2F2. We showed this in vitro and in vivo after subretinal injection of vector in normal RPE of wildtype mice. To a certain extent, the proliferative effect could also be seen in a transgenic mouse model with degenerated RPE. This concept of in situ regeneration by induction of proliferation could lead to new strategies for CEC loss, especially in donor corneas stored in eye banks. For the RPE, it could be used for treatment of early stages of AMD.
Background: To present a case of conjunctival lymphangioma in a 4-year-old girl with tuberous scl... more Background: To present a case of conjunctival lymphangioma in a 4-year-old girl with tuberous sclerosis complex. Methods/results: A 4-year-old girl presented with a relapsing cystic lesion of the bulbar conjunctiva in the right eye with string-of-pearl-like dilation of lymphatic vessels and right-sided facial swelling with mild pain. Best-corrected vision was not impaired. Examination of the skin revealed three hypomelanotic macules and a lumbal Shagreen patch. Magnetic resonance imaging (MRI) findings displayed minimal enhancement of buccal fat on the right side. Cranial and orbital MRI showed signal enhancement in the right cortical and subcortical areas. Genetic analysis revealed a heterozygous deletion encompassing exon 1 and 2 of the TSC1 gene (tuberous sclerosis complex 1 gene), confirming the diagnosis of tuberous sclerosis complex. Conclusion: In conjunctival lymphangioma, tuberous sclerosis complex should be considered as the primary disease.
Phototherapeutic keratectomy (PTK) has become established as a successful therapy for recurrent c... more Phototherapeutic keratectomy (PTK) has become established as a successful therapy for recurrent corneal erosions. After epithelial debridement, Bowman's lamella and anterior stroma are ablated by the Excimer laser. We have evaluated two alternative stroma-sparing treatment options, intraepithelial PTK, and alcohol delamination. All treatments were performed in the relapse-free period. 17 eyes with recurrent corneal erosions were treated with intraepithelial PTK: from the intact epithelium, 12 - 25 microm of tissue were ablated by the Excimer laser (group I). Alcohol delamination was performed in 13 eyes (group II). Follow-up time was between 6 months and 7 years (mean 4.2 years). Both methods turned out to be safe, no refractive changes were detectable. After intraepithelial PTK, we saw a cumulative recurrence rate of 12 % after 1 year, 18 % after 2 years, and 24 % after 3 years, and a temporary subepithelial scaring was seen. Alcohol delamination resulted in a recurrence rate of 15 % during the whole follow-up time (no statistically significant difference compared to intraepithelial PTK), showing no haze or scarring. Both minimally invasive, stroma-sparing methods were effective for the treatment of trauma-associated recurrent erosion. The ablation of Bowman's lamella or anterior stroma does not seem to be necessary. However, for basal membrane dystrophy, we recommend PTK after epithelial debridement for the partial ablation of Bowman's lamella.
To evaluate the morphological macular changes and fluid dynamics under brolucizumab treatment in ... more To evaluate the morphological macular changes and fluid dynamics under brolucizumab treatment in eyes refractory to previous anti-vascular endothelial growth factor (anti-VEGF) treatment for neovascular age-related macular degeneration (nAMD) compared with treatment-naive eyes. Methods: Retrospective study of all eyes treated with brolucizumab for nAMD between 2020 and 2021 with a fixed injection regimen and one year follow-up. Treatment-naive eyes (TN) were compared with eyes refractory to previous treatment with bevacizumab, ranibizumab, or aflibercept (RT). The primary outcome measure was change of best-corrected visual acuity (BCVA). Secondary outcome measures included foveal central thickness (FCT), presence of intra-or subretinal fluid (IRF, SRF) and presence of pigment epithelial detachment (PED) at any time point during treatment in both groups. Results: Seventeen TN eyes and 17 RT eyes were included. Mean BCVA and mean FCT in TN eyes had significantly improved after 3 months and continued to improve during treatment (p<0.05 and p=0.001, respectively). In RT eyes, mean BCVA did not change significantly while mean FCT had improved after 3 months of treatment and remained stable thereafter. SRF or PED were more frequent in RT eyes compared with TN eyes (p=0.003 and p=0.005, respectively). Conclusion: After 3 months of treatment, the BCVA increased significantly only in TN eyes, while the FCT was significantly reduced in both groups. IRF appears to be similarly seen in both groups after the loading phase; however, SRF and PED appear to be more frequent in the RT eyes compared with TN eyes.
SummaryThe retinal pigment epithelium (RPE) interacts closely with photoreceptors and is importan... more SummaryThe retinal pigment epithelium (RPE) interacts closely with photoreceptors and is important for maintaining visual function. In degenerative diseases such as age‐related macular degeneration (AMD), the leading cause of blindness in the developed world, RPE cell loss is followed by photoreceptor cell death. RPE cells can proliferate under certain conditions, suggesting an intrinsic regenerative potential, but so far this has not been utilised therapeutically. Here we use E2F2, a potent transcriptional regulator of cell proliferation, to induce RPE regeneration in vitro and in vivo. Gene transfer of E2F2 induced upregulation of Ki67 and uptake of BrdU in growth arrested ARP19 cells in vitro. In both, young and old C57Bl/6 mice, subretinal lentiviral delivery of E2F2 to the RPE caused a 40‐fold ±27.2 increase in E2F2 positive RPE cells that correlated with a 10‐fold ±4.7 increase in BrdU positive cells and a mean increase of RPE cell density. E2F2 also induced BrdU uptake and increased cell density in the central RPE of RPECreER/DTA mice, where pathology, induced by the activation of diphtheria toxin‐A, was strongest. These results provide proof of concept for a strategy to treat progressive RPE cell loss by in situ regeneration.
American Journal of Ophthalmology Case Reports, Dec 1, 2022
To report two cases of acute corneal melting and perforation requiring emergency penetrating kera... more To report two cases of acute corneal melting and perforation requiring emergency penetrating keratoplasty after corneal crosslinking (CXL) in advanced keratoconus. Observations: Case 1 was a 34 and case 2 was a 16-year old male, both with progressive keratoconus, who underwent CXL (Dresden protocol). After riboflavin imbibition, patients had a minimal pachymetry of 337 μm and 347 μm, and therefore required stromal swelling by hypoosmolar riboflavin resulting in pachymetries of 470 μm and 422 μm, prior to the 30 minute UV-irradiation with 3mW/cm 2. In case 1, on the 7th postoperative day a 4mm linear perforation occurred. Extensive post-hoc examinations revealed no infectious cause. In case 2, a corneal melting developed within 24 hours, from which Staphylococcus aureus was cultured. Conclusions and importance: Acute corneal melting and perforation may occur after CXL. Dysfunctional collagen metabolism, atopia, thin preoperative pachymetry and the use of hypoosmolar substances may have initiated this complication in our cases.
... Kampik, D and Smith, A and Luhmann, UFO and Buch, P and Larkin, DFP and Ali, RR (2010) Non-In... more ... Kampik, D and Smith, A and Luhmann, UFO and Buch, P and Larkin, DFP and Ali, RR (2010) Non-Integrating Lentiviral Gene Transfer of E2F2 to Induce Corneal Endothelial Cell Replication. In: HUMAN GENE THERAPY. (pp. 1200 - 1200). MARY ANN LIEBERT INC. ...
SummaryThe retinal pigment epithelium (RPE) interacts closely with photoreceptors and is importan... more SummaryThe retinal pigment epithelium (RPE) interacts closely with photoreceptors and is important for maintaining visual function. In degenerative diseases such as age‐related macular degeneration (AMD), the leading cause of blindness in the developed world, RPE cell loss is followed by photoreceptor cell death. RPE cells can proliferate under certain conditions, suggesting an intrinsic regenerative potential, but so far this has not been utilised therapeutically. Here we use E2F2, a potent transcriptional regulator of cell proliferation, to induce RPE regeneration in vitro and in vivo. Gene transfer of E2F2 induced upregulation of Ki67 and uptake of BrdU in growth arrested ARP19 cells in vitro. In both, young and old C57Bl/6 mice, subretinal lentiviral delivery of E2F2 to the RPE caused a 40‐fold ±27.2 increase in E2F2 positive RPE cells that correlated with a 10‐fold ±4.7 increase in BrdU positive cells and a mean increase of RPE cell density. E2F2 also induced BrdU uptake and in...
Purpose To evaluate efficacy, durability, and safety of faricimab in Japanese patients with diabe... more Purpose To evaluate efficacy, durability, and safety of faricimab in Japanese patients with diabetic macular edema (DME). Study design Subgroup analysis of 2 global, multicenter, randomized, double-masked, active-comparator-controlled, phase 3 trials (YOSEMITE, NCT03622580; RHINE, NCT03622593). Methods Patients with DME were randomized 1:1:1 to intravitreal faricimab 6.0 mg every 8 weeks (Q8W), faricimab 6.0 mg per personalized treatment interval (PTI), or aflibercept 2.0 mg Q8W through week 100. Primary endpoint was bestcorrected visual acuity (BCVA) change from baseline at 1 year, averaged over weeks 48, 52, and 56. This is the first time 1-year outcomes between Japanese patients (only enrolled into YOSEMITE) and the pooled YOSEMITE/RHINE cohort (N = 1891) have been compared. Results The YOSEMITE Japan subgroup included 60 patients randomized to faricimab Q8W (n = 21), faricimab PTI (n = 19), or aflibercept Q8W (n = 20). Consistent with global results, the adjusted mean (95.04% confidence interval) BCVA change at 1 year in the Japan subgroup was comparable with faricimab Q8W (+11.1 [7.6-14.6] letters), faricimab PTI (+8.1 [4.4-11.7] letters), and aflibercept Q8W (+6.9 [3.3-10.5] letters). At week 52, 13 (72%) patients in the faricimab PTI arm achieved ≥ Q12W dosing, including 7 (39%) patients receiving Q16W dosing. Anatomic improvements with faricimab were generally consistent between the Japan subgroup and pooled YOSEMITE/RHINE cohort. Faricimab was well tolerated; no new or unexpected safety signals were identified. Conclusion Consistent with global results, faricimab up to Q16W offered durable vision gains and improved anatomic and disease-specific outcomes among Japanese patients with DME.
To evaluate the morphological macular changes and fluid dynamics under brolucizumab treatment in ... more To evaluate the morphological macular changes and fluid dynamics under brolucizumab treatment in eyes refractory to previous anti-vascular endothelial growth factor (anti-VEGF) treatment for neovascular age-related macular degeneration (nAMD) compared with treatment-naive eyes. Methods: Retrospective study of all eyes treated with brolucizumab for nAMD between 2020 and 2021 with a fixed injection regimen and one year follow-up. Treatment-naive eyes (TN) were compared with eyes refractory to previous treatment with bevacizumab, ranibizumab, or aflibercept (RT). The primary outcome measure was change of best-corrected visual acuity (BCVA). Secondary outcome measures included foveal central thickness (FCT), presence of intra-or subretinal fluid (IRF, SRF) and presence of pigment epithelial detachment (PED) at any time point during treatment in both groups. Results: Seventeen TN eyes and 17 RT eyes were included. Mean BCVA and mean FCT in TN eyes had significantly improved after 3 months and continued to improve during treatment (p<0.05 and p=0.001, respectively). In RT eyes, mean BCVA did not change significantly while mean FCT had improved after 3 months of treatment and remained stable thereafter. SRF or PED were more frequent in RT eyes compared with TN eyes (p=0.003 and p=0.005, respectively). Conclusion: After 3 months of treatment, the BCVA increased significantly only in TN eyes, while the FCT was significantly reduced in both groups. IRF appears to be similarly seen in both groups after the loading phase; however, SRF and PED appear to be more frequent in the RT eyes compared with TN eyes.
Purpose To evaluate the standard of care, in particular the use of topical or subconjunctival int... more Purpose To evaluate the standard of care, in particular the use of topical or subconjunctival interferon-α2b, in treating ocular surface squamous neoplasia or melanocytic tumours in tertiary eye centres in Germany. Methods A survey containing 14 questions was sent to 43 tertiary eye centres in Germany. The questions addressed the surgical and medical management of ocular surface squamous neoplasia and melanocytic tumours (primary acquired melanosis and malignant melanoma), as well as the clinical experiences and difficulties in prescribing off-label interferon-α2b eye drops and subconjunctival injections. Results Twenty-four tertiary eye centres responded to the survey. Eighty-three percent of centres had used interferon-α2b in their clinical practice and 25% prescribed it as the first-line cytostatic agent following surgical excision of ocular surface squamous neoplasia, while 10% would do so for melanocytic tumours. Correspondingly, the majority of respondents selected mitomycin C...
Background To reduce treatment burden and optimise patient outcomes in diabetic macular oedema, w... more Background To reduce treatment burden and optimise patient outcomes in diabetic macular oedema, we present 1-year results from two phase 3 trials of faricimab, a novel angiopoietin-2 and vascular endothelial growth factor-A bispecific antibody. Methods YOSEMITE and RHINE were randomised, double-masked, non-inferiority trials across 353 sites worldwide. Adults with vision loss due to centre-involving diabetic macular oedema were randomly assigned (1:1:1) to intravitreal faricimab 6•0 mg every 8 weeks, faricimab 6•0 mg per personalised treatment interval (PTI), or aflibercept 2•0 mg every 8 weeks up to week 100. PTI dosing intervals were extended, maintained, or reduced (every 4 weeks up to every 16 weeks) based on disease activity at active dosing visits. The primary endpoint was mean change in best-corrected visual acuity at 1 year, averaged over weeks 48, 52, and 56. Efficacy analyses included the intention-to-treat population (non-inferiority margin 4 Early Treatment Diabetic Retinopathy Study [ETDRS] letters); safety analyses included patients with at least one dose of study treatment. These trials are registered with ClinicalTrials.gov (YOSEMITE NCT03622580 and RHINE NCT03622593). Findings 3247 patients were screened for eligibility in YOSEMITE (n=1532) and RHINE (n=1715). After exclusions, 940 patients were enrolled into YOSEMITE between
Staphylococcus epidermidis and Staphylococcus aureus are opportunistic pathogens that cause nosoc... more Staphylococcus epidermidis and Staphylococcus aureus are opportunistic pathogens that cause nosocomial and chronic biofilm-associated infections. Indwelling medical devices and contact lenses are ideal ecological niches for formation of staphylococcal biofilms. Bacteria within biofilms are known to display reduced susceptibilities to antimicrobials and are protected from the host immune system. High rates of acquired antibiotic resistances in staphylococci and other biofilm-forming bacteria further hamper treatment options and highlight the need for new anti-biofilm strategies. Here, we aimed to evaluate the potential of marine sponge-derived actinomycetes in inhibiting biofilm formation of several strains of S. epidermidis, S. aureus, and Pseudomonas aeruginosa. Results from in vitro biofilm-formation assays, as well as scanning electron and confocal microscopy, revealed that an organic extract derived from the marine sponge-associated bacterium Streptomyces sp. SBT343 significantly inhibited staphylococcal biofilm formation on polystyrene, glass and contact lens surfaces, without affecting bacterial growth. The extract also displayed similar antagonistic effects towards the biofilm formation of other S. epidermidis and S. aureus strains tested but had no inhibitory effects towards Pseudomonas biofilms. Interestingly the extract, at lower effective concentrations, did not exhibit cytotoxic effects on mouse fibroblast, macrophage and human corneal epithelial cell lines. Chemical analysis by High Resolution Fourier Transform Mass Spectrometry (HRMS) of the Streptomyces sp. SBT343 extract proportion revealed its chemical richness and complexity. Preliminary physico-chemical characterization of the extract highlighted the heat-stable and nonproteinaceous nature of the active component(s). The combined data suggest that the Streptomyces sp. SBT343 extract selectively inhibits staphylococcal biofilm formation
... Kampik, D and Smith, A and Luhmann, UFO and Buch, P and Larkin, DFP and Ali, RR (2010) Non-In... more ... Kampik, D and Smith, A and Luhmann, UFO and Buch, P and Larkin, DFP and Ali, RR (2010) Non-Integrating Lentiviral Gene Transfer of E2F2 to Induce Corneal Endothelial Cell Replication. In: HUMAN GENE THERAPY. (pp. 1200 - 1200). MARY ANN LIEBERT INC. ...
Background: To present a case of conjunctival lymphangioma in a 4-year-old girl with tuberous scl... more Background: To present a case of conjunctival lymphangioma in a 4-year-old girl with tuberous sclerosis complex. Methods/results: A 4-year-old girl presented with a relapsing cystic lesion of the bulbar conjunctiva in the right eye with string-of-pearl-like dilation of lymphatic vessels and right-sided facial swelling with mild pain. Best-corrected vision was not impaired. Examination of the skin revealed three hypomelanotic macules and a lumbal Shagreen patch. Magnetic resonance imaging (MRI) findings displayed minimal enhancement of buccal fat on the right side. Cranial and orbital MRI showed signal enhancement in the right cortical and subcortical areas. Genetic analysis revealed a heterozygous deletion encompassing exon 1 and 2 of the TSC1 gene (tuberous sclerosis complex 1 gene), confirming the diagnosis of tuberous sclerosis complex. Conclusion: In conjunctival lymphangioma, tuberous sclerosis complex should be considered as the primary disease.
PurposeTo evaluate long-term outcomes of corneal collagen crosslinking (CXL) using riboflavin and... more PurposeTo evaluate long-term outcomes of corneal collagen crosslinking (CXL) using riboflavin and UV-A irradiation and to determine when to repeat CXL.MethodsIn this retrospective consecutive interventional case series 131 eyes of 131 patients (95 male, 36 female, mean age 29.7±11.4 years) between 2006 and 2016 received standard CXL (Dresden protocol, epithelium-off) for progressive keratoconus. Corrected distance visual acuity (CDVA) and corneal tomography (K1, K2, Kmax) were repeatedly recorded 1 year (n=103 eyes) to 10 years (n=44) postoperatively. Only one eye per patient was included. Paired t-test or Wilcoxon matched-pairs signed rank test was used for parametric and nonparametric data, respectively.Results1 to 3 years preoperatively, median K2 significantly increased by 1.1D (p<0.001). Postoperatively, median K2 increased by 0.1D after 1 year, then decreased over the remaining postoperative period by 0.85D (p=0.021). Median apical corneal thickness decreased by 16µm (p=0.0...
Primary open-angle glaucoma (POAG) is a leading cause of blindness due to chronic degeneration of... more Primary open-angle glaucoma (POAG) is a leading cause of blindness due to chronic degeneration of retinal ganglion cells and their optic nerve axons. It is associated with disturbed regulation of intraocular pressure, elevated intraocular levels of TGF-β2, aberrant extracellular matrix (ECM) deposition and increased outflow resistance in the trabecular meshwork (TM). The mechanisms underlying these changes are not fully understood. Cell-matrix interactions have a decisive role in TM maintenance and it has been suggested that TGF-β-induced inhibition of matrix metalloproteases may drive aberrant ECM deposition in POAG. Invadopodia and podosomes (invadosomes) are distinct sites of cell-matrix interaction and localized matrix-metalloprotease (MMP) activity. Here, we report on the effects of TGF-β2 on invadosomes in human trabecular meshwork cells. Human TM (HTM) cells were derived from donor tissue and pretreated with vehicle or TGF-β2 (2 ng/ml) for 3d. Invadosomes were studied in ECM degradation assays, protein expression and MMP-2 activity were assessed by western blot and zymography and ECM protein transcription was detected by RT-qPCR. HTM cells spontaneously formed podosomes and invadopodia as detected by colocalization of Grb2 or Nck1 to sites of gelatinolysis. Pretreatment with TGF-β2 enhanced invadosomal proteolysis and zymographic MMP-2 activity as well as MMP-2, TIMP-2 and PAI-1 levels in HTM cell culture supernatants. Rho-kinase inhibition by H1152 blocked the effects of TGF-β2. Concomitant transcription of fibronectin and collagens-1, -4 and -6 was increased by TGF-β2 and fibrillar fibronectin deposits were observed in areas of invadosomal ECM remodelling. In contrast to a current hypothesis, our data indicate that TGF-β2 induces an active ECM remodelling process in TM cells, characterized by concurrent increases in localized ECM digestion and ECM expression, rather than a mere buildup of material due to a lack of degradation. Invadosomal cell adhesion and signaling may thus have a role in POAG pathophysiology.
Investigative Ophthalmology & Visual Science, May 14, 2008
Riboflavin/ultraviolet A (UVA) cross-linking (CXL) of corneal collagen is a novel method of stabi... more Riboflavin/ultraviolet A (UVA) cross-linking (CXL) of corneal collagen is a novel method of stabilizing corneal mechanical properties and preventing progression of keratectasias. This study was conducted to investigate whether CXL influences ablation rate, flap thickness, and refractive results of excimer laser procedures ex vivo. Corneal epithelium was removed from enucleated porcine eyes, and CXL was performed with riboflavin 0.1% and UVA radiation (365 nm, 3 mW/cm(2)) for 30 minutes. Control eyes received epithelial abrasion only. Diffusion of riboflavin through the cornea was assessed by using infrared-excited, two-photon microscopy of riboflavin autofluorescence, combined with second-harmonic generation of fibrillar collagen. During phototherapeutic keratectomy, corneal thickness was measured by optical coherence pachymetry. During LASIK for myopia, the flap thickness of microkeratome cuts was measured and the induced refractive change assessed by Placido topography. Data were analyzed by Shapiro-Wilk test and Student&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s t-test. Multiphoton imaging showed a rapid (30-minute) and even distribution of riboflavin throughout the corneal stroma. No difference in ablation rate was measured in treated and untreated corneas (P = 0.90). Mean flap thickness was increased by 44% in cross-linked corneas (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01). After LASIK for myopia of 4 to 25 D, the mean corneal refractive change was reduced in CXL-treated eyes by 20.1% (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). This effect was less pronounced in thinner flaps. CXL reduces the amount of refractive change after LASIK for myopia. Although the laser ablation rate is unaffected, CXL results in an increased flap thickness. This study suggests the need for adjustment of microkeratome and laser parameters for LASIK after CXL and indirectly endorses the theory of a direct stiffening effect of CXL.
Doctoral thesis, UCL (University College London)., Jun 28, 2017
Gene therapy of the eye has made huge advances in recent years, which led to first clinical trial... more Gene therapy of the eye has made huge advances in recent years, which led to first clinical trials. While these were aimed at replacing a defective gene in inherited disease, research is now expanding to using augmentation gene therapy where a gene is used to modulate the course of disease. We investigated the possibilities of gene transfer of cell cycle modulating genes to induce proliferation in two amitotic tissues essential for vision, the corneal endothelium and retinal pigment epithelium. Corneal endothelial cells (CEC) maintain the water content of the cornea and thereby its clarity. Low CEC density in corneal diseases causes blindness and requires corneal transplantation. Transfer of E2F2, a transcription factor regulating G1 to S phase progression, increases CEC density in human ex vivo cultivated corneas, but only when transferred by adenoviral vector, not lentiviral vector. Instead, lentiviral overexpression of ZONAB, a transcription factor normally inactivated by tight junction protein ZO-1, increased CEC density. Lentiviral downregulation of ZO-1, mimicking loss of cell-cell contacts and loss of contact inhibition, led to CEC proliferation. However, CEC density increase was only achieved in young corneas up to ~60 years-of-age, indicating loss of proliferative capacity with age. RPE loss, as seen in age related macular degeneration (AMD), causes photoreceptor loss and blindness. RPE proliferation could be induced using non-integrating lentiviral vectors delivering E2F2. We showed this in vitro and in vivo after subretinal injection of vector in normal RPE of wildtype mice. To a certain extent, the proliferative effect could also be seen in a transgenic mouse model with degenerated RPE. This concept of in situ regeneration by induction of proliferation could lead to new strategies for CEC loss, especially in donor corneas stored in eye banks. For the RPE, it could be used for treatment of early stages of AMD.
Background: To present a case of conjunctival lymphangioma in a 4-year-old girl with tuberous scl... more Background: To present a case of conjunctival lymphangioma in a 4-year-old girl with tuberous sclerosis complex. Methods/results: A 4-year-old girl presented with a relapsing cystic lesion of the bulbar conjunctiva in the right eye with string-of-pearl-like dilation of lymphatic vessels and right-sided facial swelling with mild pain. Best-corrected vision was not impaired. Examination of the skin revealed three hypomelanotic macules and a lumbal Shagreen patch. Magnetic resonance imaging (MRI) findings displayed minimal enhancement of buccal fat on the right side. Cranial and orbital MRI showed signal enhancement in the right cortical and subcortical areas. Genetic analysis revealed a heterozygous deletion encompassing exon 1 and 2 of the TSC1 gene (tuberous sclerosis complex 1 gene), confirming the diagnosis of tuberous sclerosis complex. Conclusion: In conjunctival lymphangioma, tuberous sclerosis complex should be considered as the primary disease.
Phototherapeutic keratectomy (PTK) has become established as a successful therapy for recurrent c... more Phototherapeutic keratectomy (PTK) has become established as a successful therapy for recurrent corneal erosions. After epithelial debridement, Bowman&#39;s lamella and anterior stroma are ablated by the Excimer laser. We have evaluated two alternative stroma-sparing treatment options, intraepithelial PTK, and alcohol delamination. All treatments were performed in the relapse-free period. 17 eyes with recurrent corneal erosions were treated with intraepithelial PTK: from the intact epithelium, 12 - 25 microm of tissue were ablated by the Excimer laser (group I). Alcohol delamination was performed in 13 eyes (group II). Follow-up time was between 6 months and 7 years (mean 4.2 years). Both methods turned out to be safe, no refractive changes were detectable. After intraepithelial PTK, we saw a cumulative recurrence rate of 12 % after 1 year, 18 % after 2 years, and 24 % after 3 years, and a temporary subepithelial scaring was seen. Alcohol delamination resulted in a recurrence rate of 15 % during the whole follow-up time (no statistically significant difference compared to intraepithelial PTK), showing no haze or scarring. Both minimally invasive, stroma-sparing methods were effective for the treatment of trauma-associated recurrent erosion. The ablation of Bowman&#39;s lamella or anterior stroma does not seem to be necessary. However, for basal membrane dystrophy, we recommend PTK after epithelial debridement for the partial ablation of Bowman&#39;s lamella.
To evaluate the morphological macular changes and fluid dynamics under brolucizumab treatment in ... more To evaluate the morphological macular changes and fluid dynamics under brolucizumab treatment in eyes refractory to previous anti-vascular endothelial growth factor (anti-VEGF) treatment for neovascular age-related macular degeneration (nAMD) compared with treatment-naive eyes. Methods: Retrospective study of all eyes treated with brolucizumab for nAMD between 2020 and 2021 with a fixed injection regimen and one year follow-up. Treatment-naive eyes (TN) were compared with eyes refractory to previous treatment with bevacizumab, ranibizumab, or aflibercept (RT). The primary outcome measure was change of best-corrected visual acuity (BCVA). Secondary outcome measures included foveal central thickness (FCT), presence of intra-or subretinal fluid (IRF, SRF) and presence of pigment epithelial detachment (PED) at any time point during treatment in both groups. Results: Seventeen TN eyes and 17 RT eyes were included. Mean BCVA and mean FCT in TN eyes had significantly improved after 3 months and continued to improve during treatment (p<0.05 and p=0.001, respectively). In RT eyes, mean BCVA did not change significantly while mean FCT had improved after 3 months of treatment and remained stable thereafter. SRF or PED were more frequent in RT eyes compared with TN eyes (p=0.003 and p=0.005, respectively). Conclusion: After 3 months of treatment, the BCVA increased significantly only in TN eyes, while the FCT was significantly reduced in both groups. IRF appears to be similarly seen in both groups after the loading phase; however, SRF and PED appear to be more frequent in the RT eyes compared with TN eyes.
SummaryThe retinal pigment epithelium (RPE) interacts closely with photoreceptors and is importan... more SummaryThe retinal pigment epithelium (RPE) interacts closely with photoreceptors and is important for maintaining visual function. In degenerative diseases such as age‐related macular degeneration (AMD), the leading cause of blindness in the developed world, RPE cell loss is followed by photoreceptor cell death. RPE cells can proliferate under certain conditions, suggesting an intrinsic regenerative potential, but so far this has not been utilised therapeutically. Here we use E2F2, a potent transcriptional regulator of cell proliferation, to induce RPE regeneration in vitro and in vivo. Gene transfer of E2F2 induced upregulation of Ki67 and uptake of BrdU in growth arrested ARP19 cells in vitro. In both, young and old C57Bl/6 mice, subretinal lentiviral delivery of E2F2 to the RPE caused a 40‐fold ±27.2 increase in E2F2 positive RPE cells that correlated with a 10‐fold ±4.7 increase in BrdU positive cells and a mean increase of RPE cell density. E2F2 also induced BrdU uptake and increased cell density in the central RPE of RPECreER/DTA mice, where pathology, induced by the activation of diphtheria toxin‐A, was strongest. These results provide proof of concept for a strategy to treat progressive RPE cell loss by in situ regeneration.
American Journal of Ophthalmology Case Reports, Dec 1, 2022
To report two cases of acute corneal melting and perforation requiring emergency penetrating kera... more To report two cases of acute corneal melting and perforation requiring emergency penetrating keratoplasty after corneal crosslinking (CXL) in advanced keratoconus. Observations: Case 1 was a 34 and case 2 was a 16-year old male, both with progressive keratoconus, who underwent CXL (Dresden protocol). After riboflavin imbibition, patients had a minimal pachymetry of 337 μm and 347 μm, and therefore required stromal swelling by hypoosmolar riboflavin resulting in pachymetries of 470 μm and 422 μm, prior to the 30 minute UV-irradiation with 3mW/cm 2. In case 1, on the 7th postoperative day a 4mm linear perforation occurred. Extensive post-hoc examinations revealed no infectious cause. In case 2, a corneal melting developed within 24 hours, from which Staphylococcus aureus was cultured. Conclusions and importance: Acute corneal melting and perforation may occur after CXL. Dysfunctional collagen metabolism, atopia, thin preoperative pachymetry and the use of hypoosmolar substances may have initiated this complication in our cases.
... Kampik, D and Smith, A and Luhmann, UFO and Buch, P and Larkin, DFP and Ali, RR (2010) Non-In... more ... Kampik, D and Smith, A and Luhmann, UFO and Buch, P and Larkin, DFP and Ali, RR (2010) Non-Integrating Lentiviral Gene Transfer of E2F2 to Induce Corneal Endothelial Cell Replication. In: HUMAN GENE THERAPY. (pp. 1200 - 1200). MARY ANN LIEBERT INC. ...
SummaryThe retinal pigment epithelium (RPE) interacts closely with photoreceptors and is importan... more SummaryThe retinal pigment epithelium (RPE) interacts closely with photoreceptors and is important for maintaining visual function. In degenerative diseases such as age‐related macular degeneration (AMD), the leading cause of blindness in the developed world, RPE cell loss is followed by photoreceptor cell death. RPE cells can proliferate under certain conditions, suggesting an intrinsic regenerative potential, but so far this has not been utilised therapeutically. Here we use E2F2, a potent transcriptional regulator of cell proliferation, to induce RPE regeneration in vitro and in vivo. Gene transfer of E2F2 induced upregulation of Ki67 and uptake of BrdU in growth arrested ARP19 cells in vitro. In both, young and old C57Bl/6 mice, subretinal lentiviral delivery of E2F2 to the RPE caused a 40‐fold ±27.2 increase in E2F2 positive RPE cells that correlated with a 10‐fold ±4.7 increase in BrdU positive cells and a mean increase of RPE cell density. E2F2 also induced BrdU uptake and in...
Purpose To evaluate efficacy, durability, and safety of faricimab in Japanese patients with diabe... more Purpose To evaluate efficacy, durability, and safety of faricimab in Japanese patients with diabetic macular edema (DME). Study design Subgroup analysis of 2 global, multicenter, randomized, double-masked, active-comparator-controlled, phase 3 trials (YOSEMITE, NCT03622580; RHINE, NCT03622593). Methods Patients with DME were randomized 1:1:1 to intravitreal faricimab 6.0 mg every 8 weeks (Q8W), faricimab 6.0 mg per personalized treatment interval (PTI), or aflibercept 2.0 mg Q8W through week 100. Primary endpoint was bestcorrected visual acuity (BCVA) change from baseline at 1 year, averaged over weeks 48, 52, and 56. This is the first time 1-year outcomes between Japanese patients (only enrolled into YOSEMITE) and the pooled YOSEMITE/RHINE cohort (N = 1891) have been compared. Results The YOSEMITE Japan subgroup included 60 patients randomized to faricimab Q8W (n = 21), faricimab PTI (n = 19), or aflibercept Q8W (n = 20). Consistent with global results, the adjusted mean (95.04% confidence interval) BCVA change at 1 year in the Japan subgroup was comparable with faricimab Q8W (+11.1 [7.6-14.6] letters), faricimab PTI (+8.1 [4.4-11.7] letters), and aflibercept Q8W (+6.9 [3.3-10.5] letters). At week 52, 13 (72%) patients in the faricimab PTI arm achieved ≥ Q12W dosing, including 7 (39%) patients receiving Q16W dosing. Anatomic improvements with faricimab were generally consistent between the Japan subgroup and pooled YOSEMITE/RHINE cohort. Faricimab was well tolerated; no new or unexpected safety signals were identified. Conclusion Consistent with global results, faricimab up to Q16W offered durable vision gains and improved anatomic and disease-specific outcomes among Japanese patients with DME.
To evaluate the morphological macular changes and fluid dynamics under brolucizumab treatment in ... more To evaluate the morphological macular changes and fluid dynamics under brolucizumab treatment in eyes refractory to previous anti-vascular endothelial growth factor (anti-VEGF) treatment for neovascular age-related macular degeneration (nAMD) compared with treatment-naive eyes. Methods: Retrospective study of all eyes treated with brolucizumab for nAMD between 2020 and 2021 with a fixed injection regimen and one year follow-up. Treatment-naive eyes (TN) were compared with eyes refractory to previous treatment with bevacizumab, ranibizumab, or aflibercept (RT). The primary outcome measure was change of best-corrected visual acuity (BCVA). Secondary outcome measures included foveal central thickness (FCT), presence of intra-or subretinal fluid (IRF, SRF) and presence of pigment epithelial detachment (PED) at any time point during treatment in both groups. Results: Seventeen TN eyes and 17 RT eyes were included. Mean BCVA and mean FCT in TN eyes had significantly improved after 3 months and continued to improve during treatment (p<0.05 and p=0.001, respectively). In RT eyes, mean BCVA did not change significantly while mean FCT had improved after 3 months of treatment and remained stable thereafter. SRF or PED were more frequent in RT eyes compared with TN eyes (p=0.003 and p=0.005, respectively). Conclusion: After 3 months of treatment, the BCVA increased significantly only in TN eyes, while the FCT was significantly reduced in both groups. IRF appears to be similarly seen in both groups after the loading phase; however, SRF and PED appear to be more frequent in the RT eyes compared with TN eyes.
Purpose To evaluate the standard of care, in particular the use of topical or subconjunctival int... more Purpose To evaluate the standard of care, in particular the use of topical or subconjunctival interferon-α2b, in treating ocular surface squamous neoplasia or melanocytic tumours in tertiary eye centres in Germany. Methods A survey containing 14 questions was sent to 43 tertiary eye centres in Germany. The questions addressed the surgical and medical management of ocular surface squamous neoplasia and melanocytic tumours (primary acquired melanosis and malignant melanoma), as well as the clinical experiences and difficulties in prescribing off-label interferon-α2b eye drops and subconjunctival injections. Results Twenty-four tertiary eye centres responded to the survey. Eighty-three percent of centres had used interferon-α2b in their clinical practice and 25% prescribed it as the first-line cytostatic agent following surgical excision of ocular surface squamous neoplasia, while 10% would do so for melanocytic tumours. Correspondingly, the majority of respondents selected mitomycin C...
Background To reduce treatment burden and optimise patient outcomes in diabetic macular oedema, w... more Background To reduce treatment burden and optimise patient outcomes in diabetic macular oedema, we present 1-year results from two phase 3 trials of faricimab, a novel angiopoietin-2 and vascular endothelial growth factor-A bispecific antibody. Methods YOSEMITE and RHINE were randomised, double-masked, non-inferiority trials across 353 sites worldwide. Adults with vision loss due to centre-involving diabetic macular oedema were randomly assigned (1:1:1) to intravitreal faricimab 6•0 mg every 8 weeks, faricimab 6•0 mg per personalised treatment interval (PTI), or aflibercept 2•0 mg every 8 weeks up to week 100. PTI dosing intervals were extended, maintained, or reduced (every 4 weeks up to every 16 weeks) based on disease activity at active dosing visits. The primary endpoint was mean change in best-corrected visual acuity at 1 year, averaged over weeks 48, 52, and 56. Efficacy analyses included the intention-to-treat population (non-inferiority margin 4 Early Treatment Diabetic Retinopathy Study [ETDRS] letters); safety analyses included patients with at least one dose of study treatment. These trials are registered with ClinicalTrials.gov (YOSEMITE NCT03622580 and RHINE NCT03622593). Findings 3247 patients were screened for eligibility in YOSEMITE (n=1532) and RHINE (n=1715). After exclusions, 940 patients were enrolled into YOSEMITE between
Staphylococcus epidermidis and Staphylococcus aureus are opportunistic pathogens that cause nosoc... more Staphylococcus epidermidis and Staphylococcus aureus are opportunistic pathogens that cause nosocomial and chronic biofilm-associated infections. Indwelling medical devices and contact lenses are ideal ecological niches for formation of staphylococcal biofilms. Bacteria within biofilms are known to display reduced susceptibilities to antimicrobials and are protected from the host immune system. High rates of acquired antibiotic resistances in staphylococci and other biofilm-forming bacteria further hamper treatment options and highlight the need for new anti-biofilm strategies. Here, we aimed to evaluate the potential of marine sponge-derived actinomycetes in inhibiting biofilm formation of several strains of S. epidermidis, S. aureus, and Pseudomonas aeruginosa. Results from in vitro biofilm-formation assays, as well as scanning electron and confocal microscopy, revealed that an organic extract derived from the marine sponge-associated bacterium Streptomyces sp. SBT343 significantly inhibited staphylococcal biofilm formation on polystyrene, glass and contact lens surfaces, without affecting bacterial growth. The extract also displayed similar antagonistic effects towards the biofilm formation of other S. epidermidis and S. aureus strains tested but had no inhibitory effects towards Pseudomonas biofilms. Interestingly the extract, at lower effective concentrations, did not exhibit cytotoxic effects on mouse fibroblast, macrophage and human corneal epithelial cell lines. Chemical analysis by High Resolution Fourier Transform Mass Spectrometry (HRMS) of the Streptomyces sp. SBT343 extract proportion revealed its chemical richness and complexity. Preliminary physico-chemical characterization of the extract highlighted the heat-stable and nonproteinaceous nature of the active component(s). The combined data suggest that the Streptomyces sp. SBT343 extract selectively inhibits staphylococcal biofilm formation
... Kampik, D and Smith, A and Luhmann, UFO and Buch, P and Larkin, DFP and Ali, RR (2010) Non-In... more ... Kampik, D and Smith, A and Luhmann, UFO and Buch, P and Larkin, DFP and Ali, RR (2010) Non-Integrating Lentiviral Gene Transfer of E2F2 to Induce Corneal Endothelial Cell Replication. In: HUMAN GENE THERAPY. (pp. 1200 - 1200). MARY ANN LIEBERT INC. ...
Background: To present a case of conjunctival lymphangioma in a 4-year-old girl with tuberous scl... more Background: To present a case of conjunctival lymphangioma in a 4-year-old girl with tuberous sclerosis complex. Methods/results: A 4-year-old girl presented with a relapsing cystic lesion of the bulbar conjunctiva in the right eye with string-of-pearl-like dilation of lymphatic vessels and right-sided facial swelling with mild pain. Best-corrected vision was not impaired. Examination of the skin revealed three hypomelanotic macules and a lumbal Shagreen patch. Magnetic resonance imaging (MRI) findings displayed minimal enhancement of buccal fat on the right side. Cranial and orbital MRI showed signal enhancement in the right cortical and subcortical areas. Genetic analysis revealed a heterozygous deletion encompassing exon 1 and 2 of the TSC1 gene (tuberous sclerosis complex 1 gene), confirming the diagnosis of tuberous sclerosis complex. Conclusion: In conjunctival lymphangioma, tuberous sclerosis complex should be considered as the primary disease.
PurposeTo evaluate long-term outcomes of corneal collagen crosslinking (CXL) using riboflavin and... more PurposeTo evaluate long-term outcomes of corneal collagen crosslinking (CXL) using riboflavin and UV-A irradiation and to determine when to repeat CXL.MethodsIn this retrospective consecutive interventional case series 131 eyes of 131 patients (95 male, 36 female, mean age 29.7±11.4 years) between 2006 and 2016 received standard CXL (Dresden protocol, epithelium-off) for progressive keratoconus. Corrected distance visual acuity (CDVA) and corneal tomography (K1, K2, Kmax) were repeatedly recorded 1 year (n=103 eyes) to 10 years (n=44) postoperatively. Only one eye per patient was included. Paired t-test or Wilcoxon matched-pairs signed rank test was used for parametric and nonparametric data, respectively.Results1 to 3 years preoperatively, median K2 significantly increased by 1.1D (p<0.001). Postoperatively, median K2 increased by 0.1D after 1 year, then decreased over the remaining postoperative period by 0.85D (p=0.021). Median apical corneal thickness decreased by 16µm (p=0.0...
Primary open-angle glaucoma (POAG) is a leading cause of blindness due to chronic degeneration of... more Primary open-angle glaucoma (POAG) is a leading cause of blindness due to chronic degeneration of retinal ganglion cells and their optic nerve axons. It is associated with disturbed regulation of intraocular pressure, elevated intraocular levels of TGF-β2, aberrant extracellular matrix (ECM) deposition and increased outflow resistance in the trabecular meshwork (TM). The mechanisms underlying these changes are not fully understood. Cell-matrix interactions have a decisive role in TM maintenance and it has been suggested that TGF-β-induced inhibition of matrix metalloproteases may drive aberrant ECM deposition in POAG. Invadopodia and podosomes (invadosomes) are distinct sites of cell-matrix interaction and localized matrix-metalloprotease (MMP) activity. Here, we report on the effects of TGF-β2 on invadosomes in human trabecular meshwork cells. Human TM (HTM) cells were derived from donor tissue and pretreated with vehicle or TGF-β2 (2 ng/ml) for 3d. Invadosomes were studied in ECM degradation assays, protein expression and MMP-2 activity were assessed by western blot and zymography and ECM protein transcription was detected by RT-qPCR. HTM cells spontaneously formed podosomes and invadopodia as detected by colocalization of Grb2 or Nck1 to sites of gelatinolysis. Pretreatment with TGF-β2 enhanced invadosomal proteolysis and zymographic MMP-2 activity as well as MMP-2, TIMP-2 and PAI-1 levels in HTM cell culture supernatants. Rho-kinase inhibition by H1152 blocked the effects of TGF-β2. Concomitant transcription of fibronectin and collagens-1, -4 and -6 was increased by TGF-β2 and fibrillar fibronectin deposits were observed in areas of invadosomal ECM remodelling. In contrast to a current hypothesis, our data indicate that TGF-β2 induces an active ECM remodelling process in TM cells, characterized by concurrent increases in localized ECM digestion and ECM expression, rather than a mere buildup of material due to a lack of degradation. Invadosomal cell adhesion and signaling may thus have a role in POAG pathophysiology.
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Papers by Daniel Kampik