An overview of scaffolds for corneal endothelial tissue engineering, their properties and materia... more An overview of scaffolds for corneal endothelial tissue engineering, their properties and materials starting from the Descemet's membrane and evaluating the scaffolds from a materials scientist perspective.
Eye & Contact Lens: Science & Clinical Practice, 2020
OBJECTIVES To report the clinical outcome of hybrid contact lens fitting in keratoconus. METHODS ... more OBJECTIVES To report the clinical outcome of hybrid contact lens fitting in keratoconus. METHODS A retrospective chart review was performed of keratoconus patients who had been fitted with hybrid contact lenses in one or both eyes. Patients with a history of previous intraocular surgery (except for corneal crosslinking) and relevant concurrent ocular disease limiting visual outcome were excluded. The outcome data at 6-month follow-up included hybrid lens-corrected visual acuity, wearing time, and lens discontinuation. RESULTS Fifty-four keratoconus patients (102 eyes) were included. Mean visual acuity with habitual correction before hybrid lens fitting was 0.63±0.29 (decimal Snellen). Eyes were fitted with Eyebrid lenses (LCS Laboratories, Caen, France) and SynergEyes lenses (SynergEyes Inc., Carlsbad, CA). Refits were necessary in 13 eyes, because of poor fitting (76.9%) or suboptimal refraction (23.1%). Visual acuity had significantly improved with hybrid lenses (0.93±0.14; P<0.0001). In 37 eyes (37.8%), hybrid lens wear was discontinued within 6 months after lens fitting. Reported issues were discomfort in 27 eyes (73%), handling difficulties in 14 eyes (37.8%) and poor vision in 1 eye (2.7%). Success rate of lens fitting was significantly correlated to cone morphology (P=0.01). CONCLUSIONS New generation hybrid lenses are an appropriate, safe therapeutic option for keratoconus patients. Excellent visual outcomes are achieved in successful fittings, yet a dropout rate of 37.8%-mainly occurring in sagging, more peripheral, cones - still limit their clinical success.
Eye & Contact Lens: Science & Clinical Practice, 2020
OBJECTIVES To report the clinical outcome of hybrid contact lens fitting in keratoconus. METHODS ... more OBJECTIVES To report the clinical outcome of hybrid contact lens fitting in keratoconus. METHODS A retrospective chart review was performed of keratoconus patients who had been fitted with hybrid contact lenses in one or both eyes. Patients with a history of previous intraocular surgery (except for corneal crosslinking) and relevant concurrent ocular disease limiting visual outcome were excluded. The outcome data at 6-month follow-up included hybrid lens-corrected visual acuity, wearing time, and lens discontinuation. RESULTS Fifty-four keratoconus patients (102 eyes) were included. Mean visual acuity with habitual correction before hybrid lens fitting was 0.63±0.29 (decimal Snellen). Eyes were fitted with Eyebrid lenses (LCS Laboratories, Caen, France) and SynergEyes lenses (SynergEyes Inc., Carlsbad, CA). Refits were necessary in 13 eyes, because of poor fitting (76.9%) or suboptimal refraction (23.1%). Visual acuity had significantly improved with hybrid lenses (0.93±0.14; P<0.0001). In 37 eyes (37.8%), hybrid lens wear was discontinued within 6 months after lens fitting. Reported issues were discomfort in 27 eyes (73%), handling difficulties in 14 eyes (37.8%) and poor vision in 1 eye (2.7%). Success rate of lens fitting was significantly correlated to cone morphology (P=0.01). CONCLUSIONS New generation hybrid lenses are an appropriate, safe therapeutic option for keratoconus patients. Excellent visual outcomes are achieved in successful fittings, yet a dropout rate of 37.8%-mainly occurring in sagging, more peripheral, cones - still limit their clinical success.
Corneal blindness is the fourth leading cause of visual impairment. Of specific interest is blind... more Corneal blindness is the fourth leading cause of visual impairment. Of specific interest is blindness due to a dysfunctional corneal endothelium which can only be treated by transplanting healthy tissue from a deceased donor. Unfortunately, corneal supply does not meet the demand with only one donor for every 70 patients. Therefore, there is a huge interest in tissue engineering of grafts consisting of an ultra-thin scaffold seeded with cultured endothelial cells. The present research describes the fabrication of such artificial Descemet membranes based on the combination of a biodegradable amorphous polyester (poly (d,l-lactic acid)) and crosslinkable gelatins. Four different crosslinkable gelatin derivatives are compared in terms of processing, membrane quality, and function, as well as biological performance in the presence of corneal endothelial cells. The membranes are fabricated through multi-step spincoating, including a sacrificial layer to allow for straightforward membrane detachment after production. As a consequence, ultrathin (<1 µm), highly transparent (>90%), semi-permeable membranes could be obtained with high biological potential. The membranes supported the characteristic morphology and correct phenotype of corneal endothelial cells while exhibiting similar proliferation rates as the positive control. As a consequence, the proposed membranes prove to be a promising synthetic alternative to donor tissue.
Corneal blindness is the fourth leading cause of visual impairment. Of specific interest is blind... more Corneal blindness is the fourth leading cause of visual impairment. Of specific interest is blindness due to a dysfunctional corneal endothelium which can only be treated by transplanting healthy tissue from a deceased donor. Unfortunately, corneal supply does not meet the demand with only one donor for every 70 patients. Therefore, there is a huge interest in tissue engineering of grafts consisting of an ultra-thin scaffold seeded with cultured endothelial cells. The present research describes the fabrication of such artificial Descemet membranes based on the combination of a biodegradable amorphous polyester (poly (d,l-lactic acid)) and crosslinkable gelatins. Four different crosslinkable gelatin derivatives are compared in terms of processing, membrane quality, and function, as well as biological performance in the presence of corneal endothelial cells. The membranes are fabricated through multi-step spincoating, including a sacrificial layer to allow for straightforward membrane detachment after production. As a consequence, ultrathin (<1 µm), highly transparent (>90%), semi-permeable membranes could be obtained with high biological potential. The membranes supported the characteristic morphology and correct phenotype of corneal endothelial cells while exhibiting similar proliferation rates as the positive control. As a consequence, the proposed membranes prove to be a promising synthetic alternative to donor tissue.
PURPOSE To develop an objective severity scoring system for keratoconus for the use in clinical p... more PURPOSE To develop an objective severity scoring system for keratoconus for the use in clinical practice. METHODS Corneal elevation and minimum thickness data of 812 subjects were retrospectively collected and divided into two groups: one control group with normal topography in both eyes (304 eyes), and one keratoconus group (508 eyes). Keratoconus cases ranged from suspect to moderate and had at least 1 examination in 1 of 2 recruiting centres. The elevation data were fitted to Zernike polynomial functions up to 8th order. An adapted machine learning algorithm was then applied to derive a platform-independent severity scoring and identification system for keratoconus. RESULTS The resulting logistic index for keratoconus (Logik) provided consistent and progressing scoring that reflected keratoconus severity. Moreover, the system provided an accurate classification of suspect keratoconus versus normal (sensitivity of 85.2%, specificity of 70.0%) when compared with Belin/Ambrosio Display Deviation (BAD_D) (sensitivity of 75.0%, specificity of 74.4%) and the Pentacam Topographical Keratoconus Classification (TKC) (sensitivity of 9.3%, specificity of 97.0%). Logik also showed better accuracy for grading keratoconus stages with an average accuracy of 99.9% versus (98.2%, 94.7%) with BAD_D and TKC respectively. CONCLUSION Logik is a reliable index to identify suspect keratoconus and to score the severity of the disease. It shows an agreement with existing approaches while achieving better performance.
PURPOSE To assess the efficacy and safety of human leukocyte antigen-matched allogeneic cultivate... more PURPOSE To assess the efficacy and safety of human leukocyte antigen-matched allogeneic cultivated limbal epithelial stem cell grafts in the treatment of aniridia-associated keratopathy (AAK). METHODS Six eyes of 6 patients with severe AAK received an allogeneic stem cell graft between January 2010 and March 2017. Anatomical and functional results were assessed at 6 months, 1 year, 2 years, and the final follow-up visit available. Safety analysis was performed by considering all perioperative and postoperative adverse events and additional surgeries required during the follow-up period. RESULTS The mean follow-up was 53.6 months (range 24-104 months). In most patients (80%), there was an early improvement of the keratopathy postoperatively, which slowly regressed during longer follow-up. At the final follow-up, 4 of the eyes were graded as failure and 1 eye was graded as partial success. Grading the sixth eye was not possible because of an adverse event. None of the patients maintained a total anatomical success in the long-term. Only 1 patient maintained a modest improvement in best-corrected visual acuity from hand motion to counting fingers. Four serious adverse events were recorded in 2 patients. CONCLUSIONS Severe AAK remains a challenging condition to manage. Transplantation of allogenic ex vivo cultivated limbal stem cells may provide a temporary improvement in ocular surface stability, but anatomical and functional results are poor in the long-term. The eyes are prone to adverse events, and any surgical treatment should take this into consideration.
PURPOSE To report an observation made while performing Scheimpflug densitometry analysis on the c... more PURPOSE To report an observation made while performing Scheimpflug densitometry analysis on the corneal region affected in keratoconus (KC) that seems to delineate the base of the cone. METHODS Scheimpflug densitometries of 20 healthy subjects and 90 patients with KC were examined. Corneal densitometry was analyzed using both "1-layer" and "2-layer" approaches. The first considers the corneal transparency layer by layer at different depths, whereas the second averages densitometry between 2 corneal layers selected by the examiner. Fixed layers, 120 μm depth, and endothelium were selected. Repeated same-day scans and longitudinal series of scans were also evaluated to see whether the findings evolved over time. RESULTS Eighty-eight of 90 KC cases displayed a bright area on the densitometry map that corresponded to the cone location. The area's characteristics, such as its brightness, contrast, and the presence of a delimiting arc correlated with KC severity and was more noticeable in advanced cases. No similar marks were found in any of the normal subjects. The shape, location, and extent of the mark were consistent over consecutive measures taken on the same day. Changes over time were also seen in eyes with known clinical progression but was also seen in eyes considered clinically stable. CONCLUSIONS The densitometry mark seems to correspond with the zone most affected by KC and could be a supplementary tool for documenting KC stage, alongside conventional parameters. Further studies are required to ascertain whether it could prove useful in KC detection, to determine progression, and to relate it to corneal biomechanical behavior.
PURPOSE To investigate the current patterns of diagnosis and referral in keratoconus. METHODS A r... more PURPOSE To investigate the current patterns of diagnosis and referral in keratoconus. METHODS A retrospective chart review was performed of patients who had recently been diagnosed with keratoconus and attended dedicated clinics at Antwerp University Hospital, Belgium and Maria Middelares General Hospital, Ghent, Belgium between June 2013 and February 2018. Exclusion criteria included longstanding keratoconus diagnosis, reduced cognitive capabilities and prior surgical procedures (corneal crosslinking, penetrating keratoplasty or any type of refractive surgery). RESULTS Three-hundred and ninety-nine patients (722 eyes) were included in this study. The mean age was 24.7 ± 6.5 years and the average maximal keratometry was 51 ± 5.2 D for the better eye and 58.4 ± 9.6 D for the worse eye. Upon diagnosis, 233 eyes (32.2 %) and 51 eyes (7.1 %) had a thinnest pachymetry <450 and <400 μm, respectively. At 6-month follow-up, 58 % of patients had been fitted with specialty contact lenses. During follow-up, 199 eyes (27.6 %) underwent corneal crosslinking. One patient underwent corneal graft surgery of his worse eye due to contact lens intolerance and insufficient visual acuity. CONCLUSION Despite advances in diagnostic tools, keratoconus is often diagnosed at a relatively late stage. Earlier detection of keratoconus would increase the overall clinical benefit of corneal crosslinking. Further research into screening strategies is required to develop cost-effective screening programs.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
PURPOSE To evaluate differences in corneoscleral shape in keratoconus patients with and without s... more PURPOSE To evaluate differences in corneoscleral shape in keratoconus patients with and without specialty lenses compared to controls. METHODS A cross-sectional study was performed comparing three groups of keratoconus eyes: 24 lens-naïve keratoconus eyes (17 patients; group 1), 7 eyes with corneal lens wear (7 patients; group 2) and 7 eyes with scleral lens wear (7 patients; group 3). For comparison, 25 eyes of 25 emmetropic participants and 11 eyes of 11 astigmatic participants were included. Corneoscleral topography measurements taken with the Eye Surface Profiler (ESP, Eaglet Eye BV, Houten, Netherlands) were exported and assessed using custom-made software to demarcate the limbal radius, and to calculate sagittal height and corneoscleral asymmetry. RESULTS In non-lens wearing keratoconus patients, sagittal height was found to be significantly larger than in control eyes, in both the corneal periphery and sclera (paired t-test, pairwise comparisons p < 0.01). The level of peripheral corneal and scleral asymmetry was also significantly higher in non-lens wearing keratoconus eyes compared to controls (t-test, p < 0.01). Both corneal and scleral lens wear resulted in significant changes to the shape of the corneal periphery and sclera. In all 3 groups of keratoconus eyes, asymmetry of the peripheral cornea showed a very strong correlation with scleral asymmetry (R2 = 0.90, 0.86 and 0.85 for groups 1-3, respectively). CONCLUSION The corneal periphery and sclera have a distinctly different shape in keratoconus eyes compared to controls. Specialty lens wear induces significant regional changes to the shape of the anterior eye in keratoconus eyes.
An overview of scaffolds for corneal endothelial tissue engineering, their properties and materia... more An overview of scaffolds for corneal endothelial tissue engineering, their properties and materials starting from the Descemet's membrane and evaluating the scaffolds from a materials scientist perspective.
Eye & Contact Lens: Science & Clinical Practice, 2020
OBJECTIVES To report the clinical outcome of hybrid contact lens fitting in keratoconus. METHODS ... more OBJECTIVES To report the clinical outcome of hybrid contact lens fitting in keratoconus. METHODS A retrospective chart review was performed of keratoconus patients who had been fitted with hybrid contact lenses in one or both eyes. Patients with a history of previous intraocular surgery (except for corneal crosslinking) and relevant concurrent ocular disease limiting visual outcome were excluded. The outcome data at 6-month follow-up included hybrid lens-corrected visual acuity, wearing time, and lens discontinuation. RESULTS Fifty-four keratoconus patients (102 eyes) were included. Mean visual acuity with habitual correction before hybrid lens fitting was 0.63±0.29 (decimal Snellen). Eyes were fitted with Eyebrid lenses (LCS Laboratories, Caen, France) and SynergEyes lenses (SynergEyes Inc., Carlsbad, CA). Refits were necessary in 13 eyes, because of poor fitting (76.9%) or suboptimal refraction (23.1%). Visual acuity had significantly improved with hybrid lenses (0.93±0.14; P<0.0001). In 37 eyes (37.8%), hybrid lens wear was discontinued within 6 months after lens fitting. Reported issues were discomfort in 27 eyes (73%), handling difficulties in 14 eyes (37.8%) and poor vision in 1 eye (2.7%). Success rate of lens fitting was significantly correlated to cone morphology (P=0.01). CONCLUSIONS New generation hybrid lenses are an appropriate, safe therapeutic option for keratoconus patients. Excellent visual outcomes are achieved in successful fittings, yet a dropout rate of 37.8%-mainly occurring in sagging, more peripheral, cones - still limit their clinical success.
Eye & Contact Lens: Science & Clinical Practice, 2020
OBJECTIVES To report the clinical outcome of hybrid contact lens fitting in keratoconus. METHODS ... more OBJECTIVES To report the clinical outcome of hybrid contact lens fitting in keratoconus. METHODS A retrospective chart review was performed of keratoconus patients who had been fitted with hybrid contact lenses in one or both eyes. Patients with a history of previous intraocular surgery (except for corneal crosslinking) and relevant concurrent ocular disease limiting visual outcome were excluded. The outcome data at 6-month follow-up included hybrid lens-corrected visual acuity, wearing time, and lens discontinuation. RESULTS Fifty-four keratoconus patients (102 eyes) were included. Mean visual acuity with habitual correction before hybrid lens fitting was 0.63±0.29 (decimal Snellen). Eyes were fitted with Eyebrid lenses (LCS Laboratories, Caen, France) and SynergEyes lenses (SynergEyes Inc., Carlsbad, CA). Refits were necessary in 13 eyes, because of poor fitting (76.9%) or suboptimal refraction (23.1%). Visual acuity had significantly improved with hybrid lenses (0.93±0.14; P<0.0001). In 37 eyes (37.8%), hybrid lens wear was discontinued within 6 months after lens fitting. Reported issues were discomfort in 27 eyes (73%), handling difficulties in 14 eyes (37.8%) and poor vision in 1 eye (2.7%). Success rate of lens fitting was significantly correlated to cone morphology (P=0.01). CONCLUSIONS New generation hybrid lenses are an appropriate, safe therapeutic option for keratoconus patients. Excellent visual outcomes are achieved in successful fittings, yet a dropout rate of 37.8%-mainly occurring in sagging, more peripheral, cones - still limit their clinical success.
Corneal blindness is the fourth leading cause of visual impairment. Of specific interest is blind... more Corneal blindness is the fourth leading cause of visual impairment. Of specific interest is blindness due to a dysfunctional corneal endothelium which can only be treated by transplanting healthy tissue from a deceased donor. Unfortunately, corneal supply does not meet the demand with only one donor for every 70 patients. Therefore, there is a huge interest in tissue engineering of grafts consisting of an ultra-thin scaffold seeded with cultured endothelial cells. The present research describes the fabrication of such artificial Descemet membranes based on the combination of a biodegradable amorphous polyester (poly (d,l-lactic acid)) and crosslinkable gelatins. Four different crosslinkable gelatin derivatives are compared in terms of processing, membrane quality, and function, as well as biological performance in the presence of corneal endothelial cells. The membranes are fabricated through multi-step spincoating, including a sacrificial layer to allow for straightforward membrane detachment after production. As a consequence, ultrathin (<1 µm), highly transparent (>90%), semi-permeable membranes could be obtained with high biological potential. The membranes supported the characteristic morphology and correct phenotype of corneal endothelial cells while exhibiting similar proliferation rates as the positive control. As a consequence, the proposed membranes prove to be a promising synthetic alternative to donor tissue.
Corneal blindness is the fourth leading cause of visual impairment. Of specific interest is blind... more Corneal blindness is the fourth leading cause of visual impairment. Of specific interest is blindness due to a dysfunctional corneal endothelium which can only be treated by transplanting healthy tissue from a deceased donor. Unfortunately, corneal supply does not meet the demand with only one donor for every 70 patients. Therefore, there is a huge interest in tissue engineering of grafts consisting of an ultra-thin scaffold seeded with cultured endothelial cells. The present research describes the fabrication of such artificial Descemet membranes based on the combination of a biodegradable amorphous polyester (poly (d,l-lactic acid)) and crosslinkable gelatins. Four different crosslinkable gelatin derivatives are compared in terms of processing, membrane quality, and function, as well as biological performance in the presence of corneal endothelial cells. The membranes are fabricated through multi-step spincoating, including a sacrificial layer to allow for straightforward membrane detachment after production. As a consequence, ultrathin (<1 µm), highly transparent (>90%), semi-permeable membranes could be obtained with high biological potential. The membranes supported the characteristic morphology and correct phenotype of corneal endothelial cells while exhibiting similar proliferation rates as the positive control. As a consequence, the proposed membranes prove to be a promising synthetic alternative to donor tissue.
PURPOSE To develop an objective severity scoring system for keratoconus for the use in clinical p... more PURPOSE To develop an objective severity scoring system for keratoconus for the use in clinical practice. METHODS Corneal elevation and minimum thickness data of 812 subjects were retrospectively collected and divided into two groups: one control group with normal topography in both eyes (304 eyes), and one keratoconus group (508 eyes). Keratoconus cases ranged from suspect to moderate and had at least 1 examination in 1 of 2 recruiting centres. The elevation data were fitted to Zernike polynomial functions up to 8th order. An adapted machine learning algorithm was then applied to derive a platform-independent severity scoring and identification system for keratoconus. RESULTS The resulting logistic index for keratoconus (Logik) provided consistent and progressing scoring that reflected keratoconus severity. Moreover, the system provided an accurate classification of suspect keratoconus versus normal (sensitivity of 85.2%, specificity of 70.0%) when compared with Belin/Ambrosio Display Deviation (BAD_D) (sensitivity of 75.0%, specificity of 74.4%) and the Pentacam Topographical Keratoconus Classification (TKC) (sensitivity of 9.3%, specificity of 97.0%). Logik also showed better accuracy for grading keratoconus stages with an average accuracy of 99.9% versus (98.2%, 94.7%) with BAD_D and TKC respectively. CONCLUSION Logik is a reliable index to identify suspect keratoconus and to score the severity of the disease. It shows an agreement with existing approaches while achieving better performance.
PURPOSE To assess the efficacy and safety of human leukocyte antigen-matched allogeneic cultivate... more PURPOSE To assess the efficacy and safety of human leukocyte antigen-matched allogeneic cultivated limbal epithelial stem cell grafts in the treatment of aniridia-associated keratopathy (AAK). METHODS Six eyes of 6 patients with severe AAK received an allogeneic stem cell graft between January 2010 and March 2017. Anatomical and functional results were assessed at 6 months, 1 year, 2 years, and the final follow-up visit available. Safety analysis was performed by considering all perioperative and postoperative adverse events and additional surgeries required during the follow-up period. RESULTS The mean follow-up was 53.6 months (range 24-104 months). In most patients (80%), there was an early improvement of the keratopathy postoperatively, which slowly regressed during longer follow-up. At the final follow-up, 4 of the eyes were graded as failure and 1 eye was graded as partial success. Grading the sixth eye was not possible because of an adverse event. None of the patients maintained a total anatomical success in the long-term. Only 1 patient maintained a modest improvement in best-corrected visual acuity from hand motion to counting fingers. Four serious adverse events were recorded in 2 patients. CONCLUSIONS Severe AAK remains a challenging condition to manage. Transplantation of allogenic ex vivo cultivated limbal stem cells may provide a temporary improvement in ocular surface stability, but anatomical and functional results are poor in the long-term. The eyes are prone to adverse events, and any surgical treatment should take this into consideration.
PURPOSE To report an observation made while performing Scheimpflug densitometry analysis on the c... more PURPOSE To report an observation made while performing Scheimpflug densitometry analysis on the corneal region affected in keratoconus (KC) that seems to delineate the base of the cone. METHODS Scheimpflug densitometries of 20 healthy subjects and 90 patients with KC were examined. Corneal densitometry was analyzed using both "1-layer" and "2-layer" approaches. The first considers the corneal transparency layer by layer at different depths, whereas the second averages densitometry between 2 corneal layers selected by the examiner. Fixed layers, 120 μm depth, and endothelium were selected. Repeated same-day scans and longitudinal series of scans were also evaluated to see whether the findings evolved over time. RESULTS Eighty-eight of 90 KC cases displayed a bright area on the densitometry map that corresponded to the cone location. The area's characteristics, such as its brightness, contrast, and the presence of a delimiting arc correlated with KC severity and was more noticeable in advanced cases. No similar marks were found in any of the normal subjects. The shape, location, and extent of the mark were consistent over consecutive measures taken on the same day. Changes over time were also seen in eyes with known clinical progression but was also seen in eyes considered clinically stable. CONCLUSIONS The densitometry mark seems to correspond with the zone most affected by KC and could be a supplementary tool for documenting KC stage, alongside conventional parameters. Further studies are required to ascertain whether it could prove useful in KC detection, to determine progression, and to relate it to corneal biomechanical behavior.
PURPOSE To investigate the current patterns of diagnosis and referral in keratoconus. METHODS A r... more PURPOSE To investigate the current patterns of diagnosis and referral in keratoconus. METHODS A retrospective chart review was performed of patients who had recently been diagnosed with keratoconus and attended dedicated clinics at Antwerp University Hospital, Belgium and Maria Middelares General Hospital, Ghent, Belgium between June 2013 and February 2018. Exclusion criteria included longstanding keratoconus diagnosis, reduced cognitive capabilities and prior surgical procedures (corneal crosslinking, penetrating keratoplasty or any type of refractive surgery). RESULTS Three-hundred and ninety-nine patients (722 eyes) were included in this study. The mean age was 24.7 ± 6.5 years and the average maximal keratometry was 51 ± 5.2 D for the better eye and 58.4 ± 9.6 D for the worse eye. Upon diagnosis, 233 eyes (32.2 %) and 51 eyes (7.1 %) had a thinnest pachymetry <450 and <400 μm, respectively. At 6-month follow-up, 58 % of patients had been fitted with specialty contact lenses. During follow-up, 199 eyes (27.6 %) underwent corneal crosslinking. One patient underwent corneal graft surgery of his worse eye due to contact lens intolerance and insufficient visual acuity. CONCLUSION Despite advances in diagnostic tools, keratoconus is often diagnosed at a relatively late stage. Earlier detection of keratoconus would increase the overall clinical benefit of corneal crosslinking. Further research into screening strategies is required to develop cost-effective screening programs.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
PURPOSE To evaluate differences in corneoscleral shape in keratoconus patients with and without s... more PURPOSE To evaluate differences in corneoscleral shape in keratoconus patients with and without specialty lenses compared to controls. METHODS A cross-sectional study was performed comparing three groups of keratoconus eyes: 24 lens-naïve keratoconus eyes (17 patients; group 1), 7 eyes with corneal lens wear (7 patients; group 2) and 7 eyes with scleral lens wear (7 patients; group 3). For comparison, 25 eyes of 25 emmetropic participants and 11 eyes of 11 astigmatic participants were included. Corneoscleral topography measurements taken with the Eye Surface Profiler (ESP, Eaglet Eye BV, Houten, Netherlands) were exported and assessed using custom-made software to demarcate the limbal radius, and to calculate sagittal height and corneoscleral asymmetry. RESULTS In non-lens wearing keratoconus patients, sagittal height was found to be significantly larger than in control eyes, in both the corneal periphery and sclera (paired t-test, pairwise comparisons p < 0.01). The level of peripheral corneal and scleral asymmetry was also significantly higher in non-lens wearing keratoconus eyes compared to controls (t-test, p < 0.01). Both corneal and scleral lens wear resulted in significant changes to the shape of the corneal periphery and sclera. In all 3 groups of keratoconus eyes, asymmetry of the peripheral cornea showed a very strong correlation with scleral asymmetry (R2 = 0.90, 0.86 and 0.85 for groups 1-3, respectively). CONCLUSION The corneal periphery and sclera have a distinctly different shape in keratoconus eyes compared to controls. Specialty lens wear induces significant regional changes to the shape of the anterior eye in keratoconus eyes.
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