To examine the risk of myocardial infarction and stroke with single and repeated doses of intravi... more To examine the risk of myocardial infarction and stroke with single and repeated doses of intravitreal bevacizumab in wet age-related macular degeneration (AMD). Nested case-control study and retrospective cohort study. setting: Two patient cohorts from British Columbia, Canada. Patients with wet AMD. For the cohort study, patients who received the first intravitreal bevacizumab; for the nested case-control study, repeated injections of intravitreal bevacizumab. Myocardial infarction for the retrospective cohort study; myocardial infarction and stroke for the nested case-control study. In the cohort analysis, there were 2564 AMD subjects not on a vascular endothelial growth factor (VEGF) inhibitor and 5644 subjects receiving intravitreal bevacizumab. The rate of myocardial infarction (MI) among bevacizumab users was 11/1000 person-years, compared to 14.9/1000 person-years in nonusers. The adjusted rate ratio (RR) for MI was 0.70 (95% confidence interval [CI]: 0.50-1.00) and 0.74 (0.46-1.20) for the propensity score-adjusted analysis. In the nested case-control analysis there were 7452 new users of VEGF inhibitors, within which there were 313 cases of MI with 3130 matched controls. The adjusted RR for MI among those receiving 3 or more injections compared to those receiving fewer than 3 was 0.71 (95% CI: 0.41-1.22). Also in the nested case-control analysis, the adjusted RR for stroke was 0.81 (95% CI: 0.39-1.65) for those receiving ≥4 injections vs those receiving fewer than 4 injections. Single or repeated doses of intravitreal bevacizumab were not shown to increase the risk of myocardial infarction or stroke in patients with wet AMD.
To examine the risk of age related macular degeneration (AMD) with oral bisphosphonates. Three st... more To examine the risk of age related macular degeneration (AMD) with oral bisphosphonates. Three study designs were used. 1) disproportionality analysis;2) case-control study; 3) Self-controlled case series (SCCS). Setting: 1) Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) Database;2) Two patient cohorts from British Columbia, Canada. 1) All reports of AMD to the FDA with oral bisphosphoantes;2) Patients with wet AMD in British Columbia (2009-2013) and one million controls (2000-2007). Oral bisphosphonates. 1) Reports of AMD to the FDA;2) First diagnosis of wet AMD verified by a retina specialist in British Columbia. In the disproportionality analysis there were 133 cases of AMD reported with alendronate, 20 with ibandronate, and 14 with risedronate. The reported odds ratios (RORs) for alendronate, ibandronate and risedronate were 3.82 (2.94-4.96), 2.40 (1.49-3.86) and 2.87 (1.58-5.19) respectively. In the case-control analysis there were 6,367 cases and 637...
To correlate clinical and optical coherence tomographic features with histopathological and immun... more To correlate clinical and optical coherence tomographic features with histopathological and immunohistochemical findings in an eye undergoing surgical excision of lamellar hole-associated epiretinal proliferation (LHEP). An eye with a lamellar macular hole and LHEP without a tractional epiretinal membrane component was identified with spectral-domain optical coherence tomographic imaging and underwent pars plana vitrectomy with LHEP and internal limiting membrane peeling and gas tamponade. The surgically excised LHEP specimen was analyzed with histopathological and immunohistochemical staining using flat-mount preparation techniques. Postsurgical outcomes including visual acuity and optical coherence tomographic imaging were reviewed. With spectral-domain optical coherence tomography, the lamellar macular hole was found to be closed with no residual LHEP after the surgery. Visual acuity improved from 20/200 preoperatively to 20/40 at 6 months after the surgery. Histopathological and...
To evaluate the effect of intravitreal bevacizumab on visual acuity (VA) and central retinal thic... more To evaluate the effect of intravitreal bevacizumab on visual acuity (VA) and central retinal thickness (CRT) in patients with macular edema (ME) secondary to branch retinal vein occlusion (BRVO). Retrospective review. The study included 42 patients with ME secondary to BRVO who received intravitreal injections of bevacizumab in 2 referral-based retinal practices in Vancouver, B.C., between November 2005 and July 2006. We performed a retrospective review of consecutive patients with ME secondary to BRVO. All of the patients in this study had nonischemic BRVOs. Patients were all treated with at least 1 bevacizumab injection and were seen at 6- to 8-week intervals for VA testing. Most of the patients also underwent optical coherence tomography (OCT) 2 months and 6 months after treatment. VA and OCT measurements at each follow-up time point were compared with the baseline values. A total of 42 eyes from 42 patients with ME secondary to BRVO were reviewed. The mean VA improved from 20/280 at baseline to 20/180 at first follow-up session (p < 0.04; average follow-up = 42 days) and remained at a similar level, 20/170, through the eighth follow-up session (p < 0.04; average follow-up = 356). The CRT was reduced from a mean of 451 microm (388-512 microm) at baseline to 358 microm (298-418 microm) at 2 months (p < 0.02) and to 400 microm (335-465 microm) at 6 months postinjection (p < 0.068). We found a significant improvement in VA and CRT in patients with ME secondary to BRVO after intravitreal bevacizumab injection(s). No complications or serious side effects were observed. Intravitreal bevacizumab appears to have an emerging role as either a primary or an adjuvant treatment modality in the setting of ME secondary to BRVO.
The purpose of this study was to evaluate the real-world use, efficacy, and safety of one or more... more The purpose of this study was to evaluate the real-world use, efficacy, and safety of one or more dexamethasone intravitreal implant(s) 0.7 mg (DEX implant) in patients with macular edema (ME). This was a retrospective cohort study of patients with ME secondary to retinal disease treated at ten Canadian retina practices, including one uveitis center. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), intraocular pressure (IOP), glaucoma and cataract surgery, and safety data were collected from the medical charts of patients with ≥3 months of follow-up after the initial DEX implant. One hundred and one patient charts yielded data on 120 study eyes, including diagnoses of diabetic ME (DME) (n=34), retinal vein occlusion (RVO, n=30; branch in 19 and central in 11), and uveitis (n=23). Patients had a mean age of 60.9 years, and 73.3% of the study eyes had ME for a duration of ≥12 months prior to DEX implant injection(s). Baseline mean (± standard error) BCVA was 0.63±0.03 logMAR (20/86 Snellen equivalents) and mean CRT was 474.4±18.2 μm. The mean number of DEX implant injections was 1.7±0.1 in all study eyes; 44.2% of eyes had repeat DEX implant injections (reinjection interval 2.3-4.9 months). The greatest mean peak changes in BCVA lines of vision occurred in study eyes with uveitis (3.3±0.6, P<0.0001), followed by RVO (1.3±0.5, P<0.01) and DME (0.7±0.5, P>0.05). Significant decreases in CRT were observed: -255.6±43.6 μm for uveitis, -190.9±23.5 μm for DME, and -160.7±39.6 μm for RVO (P<0.0001 for all cohorts). IOP increases of ≥10 mmHg occurred in 20.6%, 24.1%, and 22.7% of DME, RVO, and uveitis study eyes, respectively. IOP-lowering medication was initiated in 29.4%, 16.7%, and 8.7% of DME, RVO, and uveitis study eyes, respectively. Glaucoma surgery was performed in 1.7% of all study eyes and cataract surgery in 29.8% of all phakic study eyes receiving DEX implant(s). DEX implant(s) alone or combined with other treatments and/or procedures resulted in functional and anatomic improvements in long-standing ME associated with retinal disease.
Canadian journal of ophthalmology. Journal canadien d'ophtalmologie, 2002
Variability is introduced in three-dimensional (3-D) ultrasound assessments of intraocular tumour... more Variability is introduced in three-dimensional (3-D) ultrasound assessments of intraocular tumours when multiple observers examine the same tumour or when multiple scans and measurements of the same tumour are carried out. We evaluated the magnitude and sources of variation associated with 3-D ultrasound measurements of choroidal tumour volume. Three examiners performed 3-D ultrasonography of five choroidal tumours. Each examiner performed three scans of each tumour and then measured each scan three times to determine the volume. We determined the variation attributable to differences between examiners, scans and measurements by evaluating the contribution of each to the overall variation in tumour volume. A similar process was performed for tumour height for comparison purposes. The reliability of tumour volume measurements was found to be very high. The amount of overall variation, as defined by the coefficient of variation, was similar for tumour volume and tumour height and rang...
To compare the sensitivity and specificity of the Optomap Panoramic200 wide-field confocal scanni... more To compare the sensitivity and specificity of the Optomap Panoramic200 wide-field confocal scanning laser imaging system for detecting peripheral retinal lesions. Optomap images were obtained in patients with known retinal pathology. Two masked retinal specialists evaluated Optomap images to identify lesions requiring referral to a retinal specialist. Their performance was compared to gold standard examination with scleral indentation performed by a retinal specialist. Sensitivity was calculated overall and again for lesions that were found on clinical examination to require treatment. These sensitivities were calculated separately for lesions posterior and anterior to the equator. Specificity was calculated from fellow eyes that were found to have no pathology on clinical examination. For retinal lesions posterior to the equator, sensitivity was 74% (95% confidence interval [95% CI] 61%-87%) overall for all lesions and 76% (95% CI 59%-93%) for lesions requiring treatment. For anterior lesions, sensitivity was 45% (95% CI 28%-62%) overall and 36% (95% CI 14%-58%) for treatable lesions. Specificity was 85% (95% CI 63%-100%). The Optomap showed high specificity and moderate sensitivity for lesions posterior to the equator and low sensitivity for lesions anterior to the equator.
To assess the contribution of vitreous cytologic evaluation to the diagnosis of clinically undiag... more To assess the contribution of vitreous cytologic evaluation to the diagnosis of clinically undiagnosed vitritis.
ObjectiveTo differentiate polypoidal choroidal vasculopathy (PCV) from central serous chorioretin... more ObjectiveTo differentiate polypoidal choroidal vasculopathy (PCV) from central serous chorioretinopathy (CSC).
To determine the relationship between the height of macular detachment and visual recovery after ... more To determine the relationship between the height of macular detachment and visual recovery after treatment of macula-off retinal detachments (RDs) of < or = 7 days' duration. Prospective comparative case series. Fifty-two eyes of 52 consecutive patients who presented to one institution with macula-off RDs of < or = 7 days' duration were prospectively enrolled in the study. Gender, age, lens status, duration of macular detachment, and presenting visual acuity (VA) were recorded for all patients. Each patient underwent a 3-dimensional B-scan ultrasound examination at the time of presentation. The height of macular detachment was calculated using the mean measured distance between the retinal pigment epithelium and the outer neurosensory retina 3, 4, and 5 mm temporal to the center of the optic nerve head. All patients underwent primarily successful reattachment surgery within 7 days of macular detachment. Final vision was recorded with a minimum of 6 months' follow-up. Postoperative VA evaluated as a continuous variable. For the 52 subjects, a direct correlation between lower height of macular detachment and better final postoperative vision (dependent variable) was observed with linear regression (slope, 0.114; 95% confidence interval, 0.022-0.206; P = 0.016). Multivariate linear regression analysis with a backward stepwise approach did not demonstrate any significant association between postoperative vision and predictor variables (gender, age, lens status, duration of macular detachment, macular height, and preoperative vision), except for macular height. Lower height of macular detachment correlates with better visual recovery after treatment of macula-off RDs of < or = 7 days' duration.
To examine the effect of lipid-lowering agents in the development of age-related macular degenera... more To examine the effect of lipid-lowering agents in the development of age-related macular degeneration (AMD) through the techniques of meta-analysis. Case-control and cohort studies presenting relative risks and 95% confidence intervals were identified through a literature review. Inclusion was limited to studies where both the exposure of interest (lipid-lowering agents) and outcome (AMD) were explicitly defined. Pooled estimates were computed using the random effects model. To quantify heterogeneity we calculated the proportion of total variance of between study variance using the Ri statistic. The Q statistic for heterogeneity was also calculated. Eight studies were identified. The pooled relative risk (RR) for all studies was 0.74 (95% CI, 0.55-1.00). When only those studies examining the use of statins were pooled (n=7), the RR was 0.70 (95% CI, 0.48-1.03). Using the Ri statistic, the heterogeneity between studies was found to be 0.85 for all studies and 0.89 for studies examining statins. Lipid-lowering agents, including statins, do not appear to lower the risk of developing AMD, although clinically significant effects cannot be excluded. The use of these agents in the prevention of AMD cannot be recommended until well designed prospective studies with long follow up have demonstrated a benefit.
To evaluate the quality of digital retinal images taken by three photographers with different lev... more To evaluate the quality of digital retinal images taken by three photographers with different levels of photographic training, using a non-mydriatic fundus camera. This study compares 45-degree digital retinal images taken with a non-mydriatic fundus camera by three different photographers with different levels of photographic training: (I) A professional ophthalmic photographer with 20 years of experience; (2) a non-professional photographer with 2 days of photographic training and experience with 50 patients; (3) a non-professional photographer with 1 hour of photographic training and experience with 10 patients. The quality of the photographs was evaluated by the consensus of two retina specialists. Sixty-four (64) eyes of 33 subjects were imaged by the three photographers for a total of 192 images. Thirty-four eyes were photographed in the non-dilated state. The trained ophthalmic photographer and the two non-professional photographers did not have statistically significant differences in image quality based on the image evaluations. (Chi-square P-value: 0.57). This finding was consistent for eyes in both the non-dilated and dilated state. Fundus image quality for images taken with a non-mydriatic camera were not significantly different among three photographers with different levels of training.
This study evaluates a single, 45-degree fundus image from a non-mydriatic camera for the triage ... more This study evaluates a single, 45-degree fundus image from a non-mydriatic camera for the triage of subjects at risk for diabetic retinopathy. A complete retinal assessment by a retina specialist was the main comparator for the camera. Inter-observer agreements were calculated for the reading of digital images with different grades of retinopathy. Two hundred eyes of 100 consecutive subjects were evaluated as part of the James Bay diabetic retinopathy screening project; 62% of subjects had no retinopathy, 12% had microaneurysms only, 24% had non-proliferative retinopathy, 5% had clinically significant macular edema (CSME), and 2% had proliferative disease (PDR). The Kappa statistic for two independent observers was 0.85 (p < 0.001) for the identification of retinopathy from the digital images. The sensitivity of the digital camera for the evaluation of any retinopathy was 84.4%, for CSME and/or PDR it was over 90%. The use of a single digital retinal image for the evaluation of diabetic retinopathy was performed with a high degree of inter-observer concordance and a high degree of sensitivity.
To determine the risk of uveitis associated with the use of oral fluoroquinolones. Nested case-co... more To determine the risk of uveitis associated with the use of oral fluoroquinolones. Nested case-control study of all patients who visited an ophthalmologist in British Columbia, Canada, between 2000 and 2007, as captured in the British Columbia Health Linked Database. A total 3383 incident cases of uveitis and 33,830 corresponding controls were identified. Among patients who had used oral fluoroquinolones within the past 30 days, the adjusted relative risk of uveitis was 3.53 (95% CI, 2.84-4.39). However, the relative risk of uveitis among patients taking oral macrolides and beta-lactams was also significantly elevated. Our data do not provide convincing evidence of an association between fluoroquinolones and uveitis, as this study found an association between several classes of antibiotics and uveitis. It is possible that the systemic processes for which these antibiotics are being prescribed are in fact the inciting factors for the uveitis.
To examine the risk of myocardial infarction and stroke with single and repeated doses of intravi... more To examine the risk of myocardial infarction and stroke with single and repeated doses of intravitreal bevacizumab in wet age-related macular degeneration (AMD). Nested case-control study and retrospective cohort study. setting: Two patient cohorts from British Columbia, Canada. Patients with wet AMD. For the cohort study, patients who received the first intravitreal bevacizumab; for the nested case-control study, repeated injections of intravitreal bevacizumab. Myocardial infarction for the retrospective cohort study; myocardial infarction and stroke for the nested case-control study. In the cohort analysis, there were 2564 AMD subjects not on a vascular endothelial growth factor (VEGF) inhibitor and 5644 subjects receiving intravitreal bevacizumab. The rate of myocardial infarction (MI) among bevacizumab users was 11/1000 person-years, compared to 14.9/1000 person-years in nonusers. The adjusted rate ratio (RR) for MI was 0.70 (95% confidence interval [CI]: 0.50-1.00) and 0.74 (0.46-1.20) for the propensity score-adjusted analysis. In the nested case-control analysis there were 7452 new users of VEGF inhibitors, within which there were 313 cases of MI with 3130 matched controls. The adjusted RR for MI among those receiving 3 or more injections compared to those receiving fewer than 3 was 0.71 (95% CI: 0.41-1.22). Also in the nested case-control analysis, the adjusted RR for stroke was 0.81 (95% CI: 0.39-1.65) for those receiving ≥4 injections vs those receiving fewer than 4 injections. Single or repeated doses of intravitreal bevacizumab were not shown to increase the risk of myocardial infarction or stroke in patients with wet AMD.
To examine the risk of age related macular degeneration (AMD) with oral bisphosphonates. Three st... more To examine the risk of age related macular degeneration (AMD) with oral bisphosphonates. Three study designs were used. 1) disproportionality analysis;2) case-control study; 3) Self-controlled case series (SCCS). Setting: 1) Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) Database;2) Two patient cohorts from British Columbia, Canada. 1) All reports of AMD to the FDA with oral bisphosphoantes;2) Patients with wet AMD in British Columbia (2009-2013) and one million controls (2000-2007). Oral bisphosphonates. 1) Reports of AMD to the FDA;2) First diagnosis of wet AMD verified by a retina specialist in British Columbia. In the disproportionality analysis there were 133 cases of AMD reported with alendronate, 20 with ibandronate, and 14 with risedronate. The reported odds ratios (RORs) for alendronate, ibandronate and risedronate were 3.82 (2.94-4.96), 2.40 (1.49-3.86) and 2.87 (1.58-5.19) respectively. In the case-control analysis there were 6,367 cases and 637...
To correlate clinical and optical coherence tomographic features with histopathological and immun... more To correlate clinical and optical coherence tomographic features with histopathological and immunohistochemical findings in an eye undergoing surgical excision of lamellar hole-associated epiretinal proliferation (LHEP). An eye with a lamellar macular hole and LHEP without a tractional epiretinal membrane component was identified with spectral-domain optical coherence tomographic imaging and underwent pars plana vitrectomy with LHEP and internal limiting membrane peeling and gas tamponade. The surgically excised LHEP specimen was analyzed with histopathological and immunohistochemical staining using flat-mount preparation techniques. Postsurgical outcomes including visual acuity and optical coherence tomographic imaging were reviewed. With spectral-domain optical coherence tomography, the lamellar macular hole was found to be closed with no residual LHEP after the surgery. Visual acuity improved from 20/200 preoperatively to 20/40 at 6 months after the surgery. Histopathological and...
To evaluate the effect of intravitreal bevacizumab on visual acuity (VA) and central retinal thic... more To evaluate the effect of intravitreal bevacizumab on visual acuity (VA) and central retinal thickness (CRT) in patients with macular edema (ME) secondary to branch retinal vein occlusion (BRVO). Retrospective review. The study included 42 patients with ME secondary to BRVO who received intravitreal injections of bevacizumab in 2 referral-based retinal practices in Vancouver, B.C., between November 2005 and July 2006. We performed a retrospective review of consecutive patients with ME secondary to BRVO. All of the patients in this study had nonischemic BRVOs. Patients were all treated with at least 1 bevacizumab injection and were seen at 6- to 8-week intervals for VA testing. Most of the patients also underwent optical coherence tomography (OCT) 2 months and 6 months after treatment. VA and OCT measurements at each follow-up time point were compared with the baseline values. A total of 42 eyes from 42 patients with ME secondary to BRVO were reviewed. The mean VA improved from 20/280 at baseline to 20/180 at first follow-up session (p < 0.04; average follow-up = 42 days) and remained at a similar level, 20/170, through the eighth follow-up session (p < 0.04; average follow-up = 356). The CRT was reduced from a mean of 451 microm (388-512 microm) at baseline to 358 microm (298-418 microm) at 2 months (p < 0.02) and to 400 microm (335-465 microm) at 6 months postinjection (p < 0.068). We found a significant improvement in VA and CRT in patients with ME secondary to BRVO after intravitreal bevacizumab injection(s). No complications or serious side effects were observed. Intravitreal bevacizumab appears to have an emerging role as either a primary or an adjuvant treatment modality in the setting of ME secondary to BRVO.
The purpose of this study was to evaluate the real-world use, efficacy, and safety of one or more... more The purpose of this study was to evaluate the real-world use, efficacy, and safety of one or more dexamethasone intravitreal implant(s) 0.7 mg (DEX implant) in patients with macular edema (ME). This was a retrospective cohort study of patients with ME secondary to retinal disease treated at ten Canadian retina practices, including one uveitis center. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), intraocular pressure (IOP), glaucoma and cataract surgery, and safety data were collected from the medical charts of patients with ≥3 months of follow-up after the initial DEX implant. One hundred and one patient charts yielded data on 120 study eyes, including diagnoses of diabetic ME (DME) (n=34), retinal vein occlusion (RVO, n=30; branch in 19 and central in 11), and uveitis (n=23). Patients had a mean age of 60.9 years, and 73.3% of the study eyes had ME for a duration of ≥12 months prior to DEX implant injection(s). Baseline mean (± standard error) BCVA was 0.63±0.03 logMAR (20/86 Snellen equivalents) and mean CRT was 474.4±18.2 μm. The mean number of DEX implant injections was 1.7±0.1 in all study eyes; 44.2% of eyes had repeat DEX implant injections (reinjection interval 2.3-4.9 months). The greatest mean peak changes in BCVA lines of vision occurred in study eyes with uveitis (3.3±0.6, P<0.0001), followed by RVO (1.3±0.5, P<0.01) and DME (0.7±0.5, P>0.05). Significant decreases in CRT were observed: -255.6±43.6 μm for uveitis, -190.9±23.5 μm for DME, and -160.7±39.6 μm for RVO (P<0.0001 for all cohorts). IOP increases of ≥10 mmHg occurred in 20.6%, 24.1%, and 22.7% of DME, RVO, and uveitis study eyes, respectively. IOP-lowering medication was initiated in 29.4%, 16.7%, and 8.7% of DME, RVO, and uveitis study eyes, respectively. Glaucoma surgery was performed in 1.7% of all study eyes and cataract surgery in 29.8% of all phakic study eyes receiving DEX implant(s). DEX implant(s) alone or combined with other treatments and/or procedures resulted in functional and anatomic improvements in long-standing ME associated with retinal disease.
Canadian journal of ophthalmology. Journal canadien d'ophtalmologie, 2002
Variability is introduced in three-dimensional (3-D) ultrasound assessments of intraocular tumour... more Variability is introduced in three-dimensional (3-D) ultrasound assessments of intraocular tumours when multiple observers examine the same tumour or when multiple scans and measurements of the same tumour are carried out. We evaluated the magnitude and sources of variation associated with 3-D ultrasound measurements of choroidal tumour volume. Three examiners performed 3-D ultrasonography of five choroidal tumours. Each examiner performed three scans of each tumour and then measured each scan three times to determine the volume. We determined the variation attributable to differences between examiners, scans and measurements by evaluating the contribution of each to the overall variation in tumour volume. A similar process was performed for tumour height for comparison purposes. The reliability of tumour volume measurements was found to be very high. The amount of overall variation, as defined by the coefficient of variation, was similar for tumour volume and tumour height and rang...
To compare the sensitivity and specificity of the Optomap Panoramic200 wide-field confocal scanni... more To compare the sensitivity and specificity of the Optomap Panoramic200 wide-field confocal scanning laser imaging system for detecting peripheral retinal lesions. Optomap images were obtained in patients with known retinal pathology. Two masked retinal specialists evaluated Optomap images to identify lesions requiring referral to a retinal specialist. Their performance was compared to gold standard examination with scleral indentation performed by a retinal specialist. Sensitivity was calculated overall and again for lesions that were found on clinical examination to require treatment. These sensitivities were calculated separately for lesions posterior and anterior to the equator. Specificity was calculated from fellow eyes that were found to have no pathology on clinical examination. For retinal lesions posterior to the equator, sensitivity was 74% (95% confidence interval [95% CI] 61%-87%) overall for all lesions and 76% (95% CI 59%-93%) for lesions requiring treatment. For anterior lesions, sensitivity was 45% (95% CI 28%-62%) overall and 36% (95% CI 14%-58%) for treatable lesions. Specificity was 85% (95% CI 63%-100%). The Optomap showed high specificity and moderate sensitivity for lesions posterior to the equator and low sensitivity for lesions anterior to the equator.
To assess the contribution of vitreous cytologic evaluation to the diagnosis of clinically undiag... more To assess the contribution of vitreous cytologic evaluation to the diagnosis of clinically undiagnosed vitritis.
ObjectiveTo differentiate polypoidal choroidal vasculopathy (PCV) from central serous chorioretin... more ObjectiveTo differentiate polypoidal choroidal vasculopathy (PCV) from central serous chorioretinopathy (CSC).
To determine the relationship between the height of macular detachment and visual recovery after ... more To determine the relationship between the height of macular detachment and visual recovery after treatment of macula-off retinal detachments (RDs) of < or = 7 days' duration. Prospective comparative case series. Fifty-two eyes of 52 consecutive patients who presented to one institution with macula-off RDs of < or = 7 days' duration were prospectively enrolled in the study. Gender, age, lens status, duration of macular detachment, and presenting visual acuity (VA) were recorded for all patients. Each patient underwent a 3-dimensional B-scan ultrasound examination at the time of presentation. The height of macular detachment was calculated using the mean measured distance between the retinal pigment epithelium and the outer neurosensory retina 3, 4, and 5 mm temporal to the center of the optic nerve head. All patients underwent primarily successful reattachment surgery within 7 days of macular detachment. Final vision was recorded with a minimum of 6 months' follow-up. Postoperative VA evaluated as a continuous variable. For the 52 subjects, a direct correlation between lower height of macular detachment and better final postoperative vision (dependent variable) was observed with linear regression (slope, 0.114; 95% confidence interval, 0.022-0.206; P = 0.016). Multivariate linear regression analysis with a backward stepwise approach did not demonstrate any significant association between postoperative vision and predictor variables (gender, age, lens status, duration of macular detachment, macular height, and preoperative vision), except for macular height. Lower height of macular detachment correlates with better visual recovery after treatment of macula-off RDs of < or = 7 days' duration.
To examine the effect of lipid-lowering agents in the development of age-related macular degenera... more To examine the effect of lipid-lowering agents in the development of age-related macular degeneration (AMD) through the techniques of meta-analysis. Case-control and cohort studies presenting relative risks and 95% confidence intervals were identified through a literature review. Inclusion was limited to studies where both the exposure of interest (lipid-lowering agents) and outcome (AMD) were explicitly defined. Pooled estimates were computed using the random effects model. To quantify heterogeneity we calculated the proportion of total variance of between study variance using the Ri statistic. The Q statistic for heterogeneity was also calculated. Eight studies were identified. The pooled relative risk (RR) for all studies was 0.74 (95% CI, 0.55-1.00). When only those studies examining the use of statins were pooled (n=7), the RR was 0.70 (95% CI, 0.48-1.03). Using the Ri statistic, the heterogeneity between studies was found to be 0.85 for all studies and 0.89 for studies examining statins. Lipid-lowering agents, including statins, do not appear to lower the risk of developing AMD, although clinically significant effects cannot be excluded. The use of these agents in the prevention of AMD cannot be recommended until well designed prospective studies with long follow up have demonstrated a benefit.
To evaluate the quality of digital retinal images taken by three photographers with different lev... more To evaluate the quality of digital retinal images taken by three photographers with different levels of photographic training, using a non-mydriatic fundus camera. This study compares 45-degree digital retinal images taken with a non-mydriatic fundus camera by three different photographers with different levels of photographic training: (I) A professional ophthalmic photographer with 20 years of experience; (2) a non-professional photographer with 2 days of photographic training and experience with 50 patients; (3) a non-professional photographer with 1 hour of photographic training and experience with 10 patients. The quality of the photographs was evaluated by the consensus of two retina specialists. Sixty-four (64) eyes of 33 subjects were imaged by the three photographers for a total of 192 images. Thirty-four eyes were photographed in the non-dilated state. The trained ophthalmic photographer and the two non-professional photographers did not have statistically significant differences in image quality based on the image evaluations. (Chi-square P-value: 0.57). This finding was consistent for eyes in both the non-dilated and dilated state. Fundus image quality for images taken with a non-mydriatic camera were not significantly different among three photographers with different levels of training.
This study evaluates a single, 45-degree fundus image from a non-mydriatic camera for the triage ... more This study evaluates a single, 45-degree fundus image from a non-mydriatic camera for the triage of subjects at risk for diabetic retinopathy. A complete retinal assessment by a retina specialist was the main comparator for the camera. Inter-observer agreements were calculated for the reading of digital images with different grades of retinopathy. Two hundred eyes of 100 consecutive subjects were evaluated as part of the James Bay diabetic retinopathy screening project; 62% of subjects had no retinopathy, 12% had microaneurysms only, 24% had non-proliferative retinopathy, 5% had clinically significant macular edema (CSME), and 2% had proliferative disease (PDR). The Kappa statistic for two independent observers was 0.85 (p < 0.001) for the identification of retinopathy from the digital images. The sensitivity of the digital camera for the evaluation of any retinopathy was 84.4%, for CSME and/or PDR it was over 90%. The use of a single digital retinal image for the evaluation of diabetic retinopathy was performed with a high degree of inter-observer concordance and a high degree of sensitivity.
To determine the risk of uveitis associated with the use of oral fluoroquinolones. Nested case-co... more To determine the risk of uveitis associated with the use of oral fluoroquinolones. Nested case-control study of all patients who visited an ophthalmologist in British Columbia, Canada, between 2000 and 2007, as captured in the British Columbia Health Linked Database. A total 3383 incident cases of uveitis and 33,830 corresponding controls were identified. Among patients who had used oral fluoroquinolones within the past 30 days, the adjusted relative risk of uveitis was 3.53 (95% CI, 2.84-4.39). However, the relative risk of uveitis among patients taking oral macrolides and beta-lactams was also significantly elevated. Our data do not provide convincing evidence of an association between fluoroquinolones and uveitis, as this study found an association between several classes of antibiotics and uveitis. It is possible that the systemic processes for which these antibiotics are being prescribed are in fact the inciting factors for the uveitis.
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Papers by David Maberley