A comparison of robotic and manual surgery for internal limiting membrane peeling.

PURPOSE: To compare the Preceyes Surgical Robotic System (Eindhoven, Netherlands) to manual internal limiting membrane (ILM) peeling using the Eyesi surgical simulator (VRmagic, Mannheim, Germany) as the operative platform. METHODS: A comparative study was carried out with surgeons initially performing ILM peeling manually and then with the robot. Twenty-three vitreoretinal surgeons agreed to participate and all consented to the use of their surgical data from the Eyesi surgical simulator. Surgeons were given a 5-min demonstration of the devices and were allowed to practice for 10 min before attempting the membrane peel. Initially, the peel was performed manually and afterwards, this was repeated using the robot-controlled forceps. Surgical simulator outcome measures were compared between approaches. RESULTS: The average time required for the procedure was 5 min for the manual approach and 9 min with the robot (paired t test, p = 0.002). Intraocular instrument movement was reduced by half with the robot. On average 344 mm was required to complete the ILM peeling with the robot compared with 600 mm using the manual approach (paired t test, p = 0.002). There were fewer macular retinal hemorrhages with the robot: 53 with manual surgery, 32 with the robot (Mann-Whitney U test, p = 0.035). Retinal injuries were eliminated with the robot. CONCLUSIONS: Intraocular robotic surgery is still in its infancy and validation work is needed to understand the potential benefits and limitations of emerging technologies. Safety enhancements over current techniques may be possible and could lead to the broader adoption of robotic intraocular surgery in the future.

LAMELLAR HOLE-ASSOCIATED EPIRETINAL PROLIFERATION: A Clinicopathologic Correlation.

PURPOSE: 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). METHODS: 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. RESULTS: 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 immunohistochemical analyses of the LHEP specimen revealed retinal glial cells that reacted positively with anti-glial fibrillary acidic protein and anti-glutamine synthetase, a Müller cell-specific antibody. CONCLUSION: Lamellar macular hole with LHEP may demonstrate closure after pars plana vitrectomy with LHEP and internal limiting membrane peeling and gas tamponade. There was considerable improvement in visual acuity. It is possible that LHEP originates from middle retinal layers of the lamellar hole defect because it contains retinal glial cells, specifically Müller cells.

ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY FOR PROLIFERATIVE DIABETIC RETINOPATHY: A Systematic Review and Meta-Analysis.

PURPOSE: To systematically review and perform meta-analysis on the available randomized controlled trial data for anti-vascular endothelial growth factor (anti-VEGF) agents in the management of proliferative diabetic retinopathy and its complications. METHODS: The authors identified randomized controlled trials using anti-VEGF agents, either as stand-alone therapy or combined with other interventions, in the management of proliferative diabetic retinopathy. The primary outcome measures were change in best-corrected visual acuity and (in the context of vitrectomy) duration of surgery and postoperative vitreous hemorrhage. Secondary outcomes were change in central retinal thickness and (in the context of vitrectomy) intraoperative variables suggestive of complex surgery (retinal breaks, intraoperative bleeding, and endodiathermy applications). The quality of evidence for all outcomes was appraised using the GRADE criteria. RESULTS: Twenty-two studies involving 1,397 subjects met the criteria for inclusion in this study. One study compared intravitreal ranibizumab with saline, one compared intravitreal pegaptanib to pan-retinal photocoagulation (PRP), one compared intravitreal bevacizumab to PRP, 3 compared combined intravitreal ranibizumab/PRP to PRP, 5 compared combined intravitreal bevacizumab/PRP to PRP alone, and 11 compared combined intravitreal bevacizumab/PPV to PPV alone. When used in conjunction with PRP, there is a high-quality evidence to suggest that intravitreal ranibizumab is associated with superior visual acuity and central retinal thickness outcomes at 3 months to 4 months. In the context of PPV, there is moderate quality evidence to suggest that preoperative intravitreal bevacizumab results in a significant reduction in the duration of surgery, fewer retinal breaks, less intraoperative bleeding, and fewer endodiathermy applications. Although there is evidence to suggest occurrence of early postoperative vitreous hemorrhage is reduced, the quality of evidence in support of this finding is low. CONCLUSION: The use of anti-VEGF agents before PRP results in superior functional and structural outcomes at 3 months to 4 months. The use of anti-VEGF agents before PPV results in decreased duration of surgery, fewer breaks, and less intra-operative bleeding. Although there is evidence for a decreased incidence of early postoperative vitreous hemorrhage, the quality of evidence is low. The available data therefore support the use of anti-VEGF agents as adjuncts to PRP and PPV in patients with complicated proliferative diabetic retinopathy primarily as a means of facilitating, and potentially minimizing the iatrogenic damage resulting from, these procedures.

RetINal Toxicity And HydroxyChloroquine Therapy (INTACT): protocol for a prospective population-based cohort study.

PURPOSE: Hydroxychloroquine (HCQ) is an important medication for patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and other rheumatic diseases. Although it is well-tolerated and cost-effective, the risk of HCQ retinal toxicity is of increasing concern. The aim of this study is to re-examine the HCQ retinal toxicity incidence rate, risk factors and clinical course after discontinuation. METHODS: We designed a prospective population-based cohort study in adult patients with SLE or RA, currently receiving HCQ for five or more years, who are residents of British Columbia (BC), Canada. Based on administrative data, we identified 5508 eligible participants (1346 SLE and 4162 RA). They will participate in annual or biannual retinal screening over 5 years in alignment with the recently revised American Academy of Ophthalmology guidelines. To standardise procedures for retinal screening, imaging, diagnostic criteria, severity staging and data transfer, a consensus meeting was convened in December 2019 with participation of BC retinal specialists and the research team. Agreement was attained on: use of spectral domain-optical coherence tomography as the primary objective screening modality; classification of images into categories of normal, equivocal or abnormal; and transferring the equivocal and abnormal images plus corresponding subjective test results via cloud-based server from each clinic to a reading centre. Confirmation of HCQ retinal toxicity diagnoses and severity staging will be performed by three independent and masked reviewers. The incidence of HCQ retinal toxicity will be calculated, accounting for the competing risk of death. Hazard ratios for each risk factor will be calculated for the risk of HCQ retinopathy, after adjusting for confounders. We will also estimate the risk of HCQ retinal toxicity progression over 5 years. ETHICS AND DISSEMINATION: This study has received approval from the University of British Columbia Clinical Research Ethics Board (H20-00736) and the Vancouver Coastal Health Research Institute.

Evaluating Signs of Microangiopathy Secondary to Diabetes in Different Areas of the Retina with Swept Source OCTA.

Purpose: The purpose of this study was to compare perfusion parameters of the parafovea with scans outside the parafovea to find an area most susceptible to changes secondary to diabetic retinopathy (DR). Methods: Patients with different DR severity levels as well as controls were included in this cross-sectional clinical trial. Seven standardized 3 × 3 mm areas were recorded with Swept Source Optical Coherence Tomography Angiography: one centered on the fovea, three were temporal to the fovea, and three nasally to the optic disc. The capillary perfusion density (PD) of the superficial capillary complex (SCC) and deep capillary complex (DCC) as well as the fractal dimension (FD) were generated. Statistical analyses were done with R software. Results: One hundred ninety-two eyes (33 controls, 51 no-DR, 41 mild DR, 37 moderate/severe DR, and 30 proliferative DR), of which 105 patients with diabetes and 25 healthy controls were included (59 ± 15 years; 62 women). Mean PD of the DCC was significantly less in patients without DR (parafovea = 0.48 ± 0.03; temporal = 0.48 ± 0.02; and nasal = 0.48 ± 0.03) compared to controls (parafovea = 0.49 ± 0.02; temporal = 0.50 ± 0.02; and nasal = 0.50 ± 0.03). With increasing DR severity, PD and FD of the SCC and DCC further decreased. Conclusions: Capillary perfusion of the retina is affected early by diabetes. PD of the DCC was significantly reduced in patients with diabetes who did not have any clinical signs of DR. The capillary network outside the parafovea was more susceptible to capillary perfusion deficits compared to the capillaries close to the fovea. Trial Registration: clinicaltrial.gov, NCT03765112, https://clinicaltrials.gov/ct2/show/NCT03765112?term=NCT03765112&rank=1.

Correctable visual impairment and its impact on quality of life in a marginalized Canadian neighbourhood.

OBJECTIVE: To study the impact of visual impairment due to either underlying ocular pathology or easily correctable refractive error on vision-related functioning and quality of life (QOL) in Vancouver's downtown eastside (VDES). DESIGN: Cross-sectional study. PARTICIPANTS: Two hundred consecutive patients seeking general medical care at the Vancouver Native Health Society (VNHS) medical clinic were included. METHODS: An ocular examination was performed and a standardized history and QOL information were obtained for each participant. Effective visual impairment was classified based on patients' current refractive means. Pathological visual impairment was classified based on patients' best-corrected visual acuity (VA). Vision-related functioning was quantified using the Daily Tasks Dependent on Vision (DTDV) questionnaire. Health-related QOL was assessed using the 12-Item Short Form Health Survey (SF-12). RESULTS: Two hundred patients participated; they suffered, on average, 6.2 comorbid conditions. Sixty-two patients (31%) were effectively visually impaired and, of these, 14 patients (7%) were effectively blind. Ten patients (5%) had pathological eye disease to explain their visual impairment. The remaining 52 visually impaired patients (26%) had VA that normalized with correction. Difficulty with the tasks described in the DTDV questions was significantly correlated with effective visual impairment. Patients with effective visual impairment had lower Physical Composite Scores on the SF-12 in multivariate analyses. CONCLUSIONS: We have demonstrated a very high rate of visual impairment in a low socioeconomic population that is associated with decreased vision-dependent functioning and decreased overall physical health status. Public health efforts need to be directed toward improving easily correctable refractive error.

Ocular adverse events with immune checkpoint inhibitors.

PURPOSE: To quantify the risk of ocular adverse events with immune checkpoint inhibitors (ICIs) as reported to the Food and Drug Administration (FDA). METHODS: Disproportionality analysis using data from U.S. FDA's Adverse Events Reporting System (FAERS) database 2003 to 2018. Data from pharmaceutical manufacturers, healthcare providers, consumers in the U.S., and post-marketing clinical trial reports from U.S. and non-U.S. studies. All cases of uveitis, dry eye syndrome, ocular myasthenia and eye inflammation with use of the following ICIs: atezolizumab, avelumab, cemiplimab, durvalumab, ipilimumab, nivolumab and pembrolizumab. Reported odds ratios (RORs) and corresponding 95% confidence intervals (CIs) were computed for all drugs as a group or as individual agents. RESULTS: We identified 113 ocular adverse events for all ICIs of interest including uveitis, dry eye, ocular myasthenia and eye inflammation. Nivolumab had the highest number of adverse events (N = 68) associated with use of the ICI. Nivolumab had the highest association with ocular myasthenia [ROR = 22.82, 95% CI (7.18-72.50)] followed by pembrolizumab [ROR = 20.17, 95% CI (2.80-145.20)]. Among all ICIs approved in North America, atezolizumab had the highest association with eye inflammation [ROR = 18.89, 95% CI (6.07-58.81)] and ipilmumab had the highest association with uveitis [ROR = 10.54, 95% CI (7.30-15.22)]. CONCLUSION: The results of this disproportionality analysis suggest use of ICIs is associated with an increase risk for ocular adverse reactions. Future epidemiologic studies are needed to better quantify these adverse events.

Contribution of vitreous cytology to final clinical diagnosis fifteen-year review of vitreous cytology specimens from one institution.

PURPOSE: To assess the contribution of vitreous cytologic evaluation to the diagnosis of clinically undiagnosed vitritis. DESIGN: Retrospective chart review and database study. PARTICIPANTS: Two hundred seventy-eight eyes of 255 patients who had diagnostic vitrectomies. METHODS: We performed a retrospective review of all patients who had vitreous cytology specimens between October 1990 and October 2005 at Vancouver General Hospital. We reviewed the patient charts to obtain the results of microbial and other laboratory testing and to determine the follow-up course. MAIN OUTCOME MEASURES: Categories of vitreous cytology specimen results and final clinical diagnosis in patients who had diagnostic vitrectomy specimens. RESULTS: We reviewed vitreous cytology results from diagnostic vitrectomies in 278 eyes of 255 patients. One patient had 3 diagnostic vitrectomies, 21 patients had 2 procedures, and 233 patients had a single procedure. We categorized the results of vitreous cytologic examination into 6 major categories: acute inflammation consistent with endophthalmitis (n = 33), primary intraocular lymphoma (PIOL; n = 14), granulomatous inflammation (n = 41), mixed chronic nonspecific inflammation (n = 76), hypocellular specimens (n = 50), and miscellaneous specimens (n = 64). We determined that cytologic diagnosis aided or confirmed a clinical diagnosis, or ruled out PIOL, in 126/228 (55.3%) specimens where patients were not lost to follow-up. CONCLUSIONS: Cytologic analysis of vitreous specimens in clinically undiagnosed vitritis is a useful procedure, particularly in the diagnosis of endophthalmitis and PIOL. It is also helpful in confirming granulomatous, nonspecific, and miscellaneous clinical diagnoses and in ruling out PIOL. In this series, it helped to suggest or confirm a diagnosis in the majority of our specimens.

One-year effectiveness study of intravitreous bevacizumab in neovascular age-related macular degeneration: a population-based retrospective cohort study.

OBJECTIVE: To assess effectiveness of intravitreous bevacizumab in a cohort of patients with neovascular age-related macular degeneration (nAMD) in British Columbia, Canada. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients with new-onset AMD who completed 1 year of bevacizumab treatment. METHODS: A cohort of 4507 patients with nAMD (5174 eyes) aged 50 years and older treated on an as-needed basis with bevacizumab was followed from June 1, 2010, to May 31, 2014, and then evaluated after completing a follow-up treatment at 1 year. Descriptive statistics were used to characterize eyes treated with bevacizumab. Multivariable regression models were used to quantify visual acuity (VA) changes over time, adjusting for baseline prognostic variables. RESULTS: On average, patients received 8.6 injections (SD 2.4) per eye during the year of treatment. There was an average gain of 5.2 letters over the 1-year study period. Among eyes treated with bevacizumab, improvement in VA was greater for eyes with poorer baseline VA and for eyes receiving more injections. The odds ratio for VA at 1 year was 9.35 (95% CI 6.00-14.6) for eyes with VA 20/50-20/80 versus 20/20-20/40 and increased to 74.5 (95% CI 47.7-116.4) for eyes 20/400 or worse versus 20/20-20/40. CONCLUSION: Intravitreous bevacizumab is effective in treating nAMD, especially for eyes with poor baseline VA. Gains in VA were greatest by month 3 and were generally maintained thereafter.

One-Year Effectiveness Study of Intravitreous Ranibizumab in Wet (Neovascular) Age-Related Macular Degeneration: A Meta-Analysis.

PURPOSE: The clinical efficacy of ranibizumab has been examined by a large number of prospective and retrospective studies to date. This meta-analysis was conducted to summarize the current body of evidence on visual acuity (VA) changes with use of ranibizumab in the treatment of wet (neovascular) age-related macular degeneration (wAMD). METHODS: A literature review of multiple electronic databases (EMBASE, MEDLINE, MedMEME) was conducted to find randomized controlled trials (RCTs) and observational studies that reported changes in VA while patients with wAMD were on ranibizumab. Study factors analyzed were baseline patient characteristics, study type, sample size, and 12-month change in VA. Data were pooled in a meta-analysis with VA change as the main outcome. Data were then stratified by study design and a meta-regression was conducted to assess 12-month VA change against baseline VA and age. RESULTS: A total of 42 studies were included for analysis. An overall increase of 5.58 letters (95% confidence interval [CI]: 4.42-6.75; p heterogeneity, < 0.001) was shown with use of ranibizumab compared to baseline. Improvements in VA were larger for RCTs, at 7.71 letters (95% CI: 6.66-8.76; p heterogeneity, 0.013), compared to observational studies, at 4.85 letters (95% CI: 3.32-6.38; p heterogeneity, < 0.001). The meta-regression showed a significant decrease in effect size between baseline VA and 12-month VA change. CONCLUSION: This meta-analysis suggests visual improvements at 12 months of 0.5-mg ranibizumab use in patients with wAMD. A higher gain in VA was observed when pooling results from RCTs compared to those in observational studies.

Use of lipid-lowering agents for the prevention of age-related macular degeneration: a meta-analysis of observational studies.

PURPOSE: To examine the effect of lipid-lowering agents in the development of age-related macular degeneration (AMD) through the techniques of meta-analysis. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Association of Repeated Intravitreous Bevacizumab Injections With Risk for Glaucoma Surgery.

Importance: Intravitreous injections of anti-vascular endothelial growth factor (VEGF) agents are associated with a sustained increase in intraocular pressure. This sustained elevated intraocular pressure could lead to higher rates of glaucoma surgery to lower this pressure. Objective: To determine the risk of glaucoma surgery following repeated intravitreous bevacizumab injections. Design, Setting, Participants: This nested, case-control study acquired and analyzed data from large, population-based, linked health databases supported by the British Columbia Ministry of Health in Canada. Study participants included all patients with ophthalmic issues in British Columbia, such as those of the Provincial Retinal Diseases Treatment Program, who had received intravitreous bevacizumab injections for exudative age-related macular degeneration between January 1, 2009, and December 31, 2013. Cases were identified using glaucoma surgical codes for trabeculectomy, complicated trabeculectomy, glaucoma drainage device, and cycloablative procedure. For each case, 10 controls were identified and matched for age, preexisting glaucoma, calendar time, and follow-up time. The number of intravitreous bevacizumab injections received per year-3 or fewer, 4 to 6, or 7 or more-was determined for both cases and controls. Data analysis was performed from February 23, 2016, to November 14, 2016. Main Outcomes and Measures: Risk of glaucoma surgery compared with the number of intravitreous bevacizumab injections per year in cases and controls. Rate ratios were adjusted for covariates (diabetes mellitus, myocardial infarction, stroke, and verteporfin use). Results: Seventy-four cases of glaucoma surgery and 740 controls were identified, with a mean (SD) age of 81.3 (8.4) years for cases and 81.4 (7.9) for controls. The case group had more males than the control group (38 [51.4%] vs 272 [36.8%]). The adjusted rate ratio of glaucoma surgery among those who received 7 or more injections per year was 2.48 (95% CI, 1.25-4.93). There was a 10.3% higher number of 7 or more injections among cases compared with controls. The adjusted rate ratio for those who received 4 to 6 injections per year compared with those who received 3 or fewer was 1.65% (95% CI, 0.84-3.23). Conclusions and Relevance: Findings from this large, pharmacoepidemiologic study suggest that 7 or more intravitreous injections of bevacizumab annually is associated with a higher risk of glaucoma surgery and that 4 to 6 injections per year show a nonstatistically significant rate ratio in the same direction.

Risk factors for posterior vitreous detachment: a case-control study.

PURPOSE: To identify possible risk factors for the development of posterior vitreous detachment (PVD). DESIGN: Retrospective case-control study. METHODS: A total of 138 cases with PVD and 114 age-matched controls were accrued from two different sites. Demographic, medical, ocular, and lifestyle data were obtained through chart review, questionnaires, and clinical examination. A 108-item semiquantitative food frequency questionnaire was also used to estimate macro- and micronutrient intake. Univariate and multivariate regression analyses were employed to identify variables significantly associated with the main outcome measure of PVD. Subgroup analysis of gender-specific variables was performed. RESULTS: Among all patients, multivariate regression analysis demonstrated female gender (odds ratio [OR] = 2.01, P = .016), myopic refraction (OR = 4.32, P < .0005), and higher intake of vitamin B6 (OR = 2.61, P = .001) to be associated with PVD after controlling for age. In the subgroup analysis of women, menopause (OR = 18.2, P < .0005), myopic refraction (OR = 3.42, P = .01), and higher intake of vitamin B6 (OR = 3.92, P = .005) were associated with PVD. Specifically, there was a significant association between vitamin B6 and PVD amongst premenopausal women but not amongst postmenopausal women. CONCLUSIONS: An association between PVD and menopause has not been documented previously. We suspect that high estrogen levels seen in premenopausal women may be protective against PVD and that hormonal changes associated with menopause may lead to changes in the vitreous, predisposing to PVD. Higher levels of intake of vitamin B6 were also associated with the development of PVD in premenopausal women possibly through an anti-estrogen effect. These findings should be investigated further with prospective studies.

Risk of Myocardial Infarction and Stroke With Single or Repeated Doses of Intravitreal Bevacizumab in Age-Related Macular Degeneration.

PURPOSE: To examine the risk of myocardial infarction and stroke with single and repeated doses of intravitreal bevacizumab in wet age-related macular degeneration (AMD). DESIGN: Nested case-control study and retrospective cohort study. METHODS: setting: Two patient cohorts from British Columbia, Canada. STUDY POPULATION: Patients with wet AMD. INTERVENTION: For the cohort study, patients who received the first intravitreal bevacizumab; for the nested case-control study, repeated injections of intravitreal bevacizumab. MAIN OUTCOME MEASURES: Myocardial infarction for the retrospective cohort study; myocardial infarction and stroke for the nested case-control study. RESULTS: 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. CONCLUSION: Single or repeated doses of intravitreal bevacizumab were not shown to increase the risk of myocardial infarction or stroke in patients with wet AMD.

Comparison of photodynamic therapy and transpupillary thermotherapy for subfoveal choroidal neovascularization due to age-related macular degeneration.

BACKGROUND: The purpose of this study was to compare photodynamic therapy (PDT) against subthreshold transpupillary thermotherapy (TTT) with a diode laser for subfoveal choroidal neovascularization secondary to age-related macular degeneration (AMD). METHODS: Patients with subfoveal choroidal neovascularization secondary to AMD were offered PDT as an initial intervention. If they declined PDT, then TTT was offered. RESULTS: We evaluated and followed 115 consecutive patients for an average of 1 year. The primary outcome measure was visual acuity, but the interventions were also compared on the basis of lesion size and angiographically determined lesion activity. Baseline comparisons between the 2 treatment groups showed significant differences in pretreatment visual acuity, lesion size, and lesion composition. Univariate analysis of outcomes demonstrated equivalence between the treatment groups in final lesion size, angiographic activity, and visual acuity. Multivariate analysis also demonstrated equivalence between the treatment groups in final visual acuity while controlling for age, pretreatment visual acuity, and lesion category. Predominantly classic lesions were associated with poorer visual outcomes. INTERPRETATION: The PDT and TTT groups were equivalent in terms of all outcome parameters evaluated.

Socioeconomic status and clinical features of patients undergoing photodynamic therapy or transpupillary thermotherapy for subfoveal choroidal neovascularization due to age-related macular degeneration.

BACKGROUND: The purpose of this study was to compare baseline clinical and socioeconomic features of patients undergoing self-funded photodynamic therapy (PDT) or government-funded subthreshold transpupillary thermotherapy (TTT) with a diode laser for subfoveal choroidal neovascularization secondary to age-related macular degeneration (AMD). METHODS: Between July 2000 and August 2001, 115 patients with subfoveal choroidal neovascularization secondary to AMD were offered PDT as an initial intervention. If individuals believed that they could not afford or did not want PDT, then TTT was offered. In masked fashion, leakage pattern and lesion size were determined retrospectively from pretreatment angiograms. Baseline visual acuity was determined with autorefraction and subsequent Snellen testing. The mean income of each treatment group was estimated from the average sex-specific income for each subject's postal code, based on the 1996 Canadian census data. The average education level for each subject's postal code was also determined. RESULTS: The patients who were not willing to pay for PDT had significantly worse macular disease before treatment (larger lesions and poorer visual acuity) and a significantly lower mean income than the patients who were willing to pay for PDT. INTERPRETATION: The severity of exudative choroidal neovascularization appears to be associated with lower socioeconomic status.

Risk factors for diabetic retinopathy in the Cree of James Bay.

BACKGROUND: The purpose of this project was to evaluate risk factors for diabetic retinopathy in the Cree population of James Bay, Ontario. METHODS: A retrospective cohort design was employed. The cohort was made up of all known individuals who had previously been diagnosed with diabetes in the communities of Moose Factory and Moosonee, Ontario. Hypertension, body-mass index, serum lipid levels, renal function status, and hemoglobin A1C were the main exposures of interest. Values for these variables were determined from a retrospective chart review and were sought for each individual for a five-year interval beginning one year following the diagnosis of diabetes. Relative risks for the association of these variables with diabetic retinopathy were determined through both univariate and multivariate Poisson regression. The main outcome of interest in this study was the presence or absence of any diabetic retinopathy in either eye, as determined by a retinal specialist. RESULTS: Significant univariate risks for the development of retinopathy included duration of diabetes, body-mass index, hemoglobin A1C, fasting blood glucose, insulin treatment, and serum cholesterol levels. In multivariate analyses, predictors of diabetic retinopathy included body-mass index, insulin treatment, and serum cholesterol levels. An increase in body-mass index reduced the risk of diabetic retinopathy (Relative Risk [RR] 0.64 per five kg/m( 2), 95% Confidence Interval [CI] 0.04 to 1.00). Insulin therapy was associated with an increased risk of retinopathy when compared to individuals on dietary therapy alone (Relative Risk [RR] 4.71, 95% Confidence Interval [CI] 1.16 to 19.16). For individuals with serum cholesterol levels above the average for the cohort, 5.2 mmol/L, the risk of retinopathy was increased (Relative Risk [RR] 2.38, 95% Confidence Interval [CI] 0.98 to 5.79). INTERPRETATION: Elevated serum cholesterol, lower body-mass index and insulin treatment were all associated with an increased risk of diabetic retinopathy in the Cree of James Bay, Ontario.

Factors associated with missed eye examinations in a cohort with diabetes.

BACKGROUND: The diabetes screening program in Moosonee and Moose Factory, Ontario was evaluated to explore which factors may be associated with individuals who had/had not attended screening examinations for diabetic retinopathy. METHODS: Exposure data were collected from patient charts for basic demographic and medical history data. The main outcome of interest was the absence of a retinal examination in the two years preceding data collection. RESULTS: There were 248 subjects identified with diabetes who had complete data for the variables of interest. On univariate analysis, younger age and shorter duration of diabetes were significantly associated with not having an eye examination. On multivariate analysis, younger age, residence in Moosonee, and shorter duration of diabetes remained in the final model. INTERPRETATION: Screening programs for diabetic retinopathy in the James Bay Cree should consider targeting younger individuals with diabetes of less than 5 years duration since this sub-group is not as likely to attend eye examinations.

Infantile Refsum disease in a young adult: case presentation and brief review.

PURPOSE: To review and describe findings, pathophysiology, and management of infantile Refsum disease in a young adult, and to compare with those of classic Refsum Disease. METHODS: Retrospective chart and digital photography review. RESULTS: A 25-year-old woman with a diagnosis of infantile Refsum disease presented with progressively decreasing vision. Findings included a noncorpuscular pigmentary degeneration of both fundi, optic nerve head drusen, attenuated retinal vasculature, cataract, myopia, and esotropia. She was treated with a low phytanic acid diet, resulting in improved metabolic values on laboratory testing. CONCLUSION: Infantile Refsum disease has clinical features and a pathophysiology distinct from classic Refsum disease, despite occasionally presenting for examination later in life. Ophthalmic and systemic distinctions between the two are important to consider for the ophthalmologist, who may be involved in the initial diagnosis of the patient.