R. Buhrmann

The definition and classification of glaucoma in prevalence surveys

This review describes a scheme for diagnosis of glaucoma in population based prevalence surveys. Cases are diagnosed on the grounds of both structural and functional evidence of glaucomatous optic neuropathy. The scheme also makes provision for diagnosing glaucoma in eyes with severe visual loss where formal field testing is impractical, and for blind eyes in which the optic disc cannot be seen because of media opacities.

Evidence-based clinical guidelines for immigrants and refugees

(see Appendix 2, available at [www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.090313/-/DC1][1] for summary of recommendations and clinical considerations) There are more than 200 million international migrants worldwide,[1][2] and this movement of people has implications for individual and

Selective laser trabeculoplasty versus argon laser trabeculoplasty: results from a 1-year randomised clinical trial

Aims: To compare selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT), in terms of intraocular pressure (IOP) lowering, in patients with open-angle glaucoma. Methods: 176 eyes of 152 patients were enrolled in this study, 89 in the SLT and 87 in the ALT groups. Patients were randomised to receive either SLT or ALT treatment to 180° of the trabecular meshwork. Patients were followed up to 12 months after treatment. The main outcome measured was IOP lowering at 12 months after treatment, compared between the SLT and ALT groups. Results: No significant difference (p = 0.846) was found in mean decrease in IOP between the SLT (5.86 mm Hg) and ALT (6.04 mm Hg) groups at 1 year or at any other time points, nor were there any significant differences in the rate of early or late complications between the two groups. Conclusions: SLT is equivalent to ALT in terms of IOP lowering at 1 year, and is a safe and effective procedure for patients with open-angle glaucoma.

The consequences of waiting for cataract surgery: a systematic review

Background: Cataract surgery is the most common operative procedure performed in Canada, and how patients are affected by wait times for this surgery has important clinical, public health and health policy considerations. We conducted a systematic review to understand the relation between wait time for cataract surgery and patient outcomes and the variables that modify this relation. Methods: We performed an electronic search of 11 databases and the proceedings of 4 conferences. The search was restricted to studies published after the transition to phacoemulsification (1990). We assessed the quality of the included studies using the Jadad Scale for randomized controlled trials and the Newcastle–Ottawa Scale for cohort and case–control studies. The data were found to be inappropriate for meta-analysis, thus we performed a qualitative synthesis. Results: We found a total of 27 studies that met our inclusion criteria. When these studies were reviewed, a dichotomy was observed for the wait time–outcome relation: outcomes associated with wait times of ≤ 6 weeks were better than outcomes associated with wait times of ≥ 6 months. Patients who waited more than 6 months to receive cataract surgery experienced more vision loss, a reduced quality of life and had an increased rate of falls compared with patients who had wait times of less than 6 weeks. The outcomes associated with wait times between 6 weeks and 6 months remain unclear. Interpretation: Patients who wait more than 6 months for cataract surgery may experience negative outcomes during the wait period, including vision loss, a reduced quality of life and an increased rate of falls.

Baseline IOP predicts selective laser trabeculoplasty success at 1 year post-treatment: results from a randomised clinical trial

Background/aims: The efficacy and safety of selective laser trabeculoplasty (SLT) has been found to be equivalent to argon laser trabeculoplasty (ALT). Since SLT produces significantly less disturbance to the trabecular meshwork and is theoretically more repeatable than ALT, it has potential to replace ALT as the standard procedure to treat medically uncontrolled open angle glaucoma. This study’s objective is to determine factors that predict successful SLT at 1 year post-treatment. Methods: As part of a randomised clinical trial comparing the efficacy and safety of SLT to ALT, data on 72 SLT patients were collected, and successful SLT defined as having an SLT induced intraocular pressure (IOP) reduction of ⩾20% at 1 year post-treatment follow up. Results: 43 out of the 72 patients who had completed their 1 year follow up visit had an IOP reduction of ⩾20% from baseline. No glaucoma risk factors studied predicted successful SLT. The amount of trabecular meshwork pigmentation was not a significant predictor. However, it was discovered that baseline IOP strongly predicted SLT success (odds ratio = 1.16; p = 0.0001). Conclusion: SLT success was significantly predicted by baseline IOP but not by age, sex, other glaucoma risk factors, type of open angle glaucoma, or by degree of trabecular meshwork pigmentation.

Long term effects on the lowering of intraocular pressure: selective laser or argon laser trabeculoplasty?

OBJECTIVE Selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT) are used to lower intraocular pressure (IOP) in patients with open-angle glaucoma (OAG). We report long-term follow-up data comparing SLT to ALT. DESIGN Follow-up of prospective randomized clinical trial. PARTICIPANTS Patients with glaucoma from the practices of three ophthalmologists at the University of Ottawa. METHODS We randomized 176 eyes of 152 patients with uncontrolled IOP on maximal tolerated medical therapy (MTMT, with or without previous ALT) to undergo either SLT or ALT. Data were available for 142 eyes at 3 years, 134 eyes at 4 years, and 120 eyes at 5 years. The primary outcome was change in IOP from pretreatment baseline. RESULTS Comparison of baseline parameters was similar in the two groups. Lowering of IOP were similar at 3 years (SLT -6.7 ± 7.1 vs ALT -6.1 ± 5.1); at 4 years (SLT 7.0 ± 7.7 vs ALT -6.3 ± 5.0); and at 5 years (SLT -7.4 ± 7.3 vs ALT -6.7 ± 6.6). There was no statistically significant change in IOP in either of the two groups. Medication changes were equivalent in each group. A number of interventions were required in both groups, cumulatively, over the 5-year follow-up period (49 SLT and 33 ALT). Survival analysis indicated that the time to 50% failure in each group was approximately 2 years. CONCLUSIONS The IOP-lowering effect of SLT and ALT was similar over 5 years in this group of patients with open-angle glaucoma on MTMT.

An inventory of information on blindness and visual impairment in Canada.

BACKGROUND Several health databases contain information on blindness and visual impairment in Canada. Such databases may permit studies of the outcomes, predictors, economic costs and meta-analysis of ocular health problems and visual disability. In this paper we summarize the existing public health information on blindness and visual impairment in Canada. METHODS A systematic search was performed to find the information in three areas: health administrative databases, health surveys and registries. Both literature searching and Internet searching were performed. The institutions were notified by email or telephone that information pertaining to vision and blindness was desired. When necessary, we visited the institution to obtain the information. RESULTS Health administrative databases contain information on a wide cross-section of diagnoses but are usually limited in detail and seldom provide longitudinal information. Health surveys have a limited amount of systematic information on vision-related questions and rely exclusively on self-reporting. Registries exist on a wide range of visual topics. The Canadian National Institute for the Blind (CNIB) has the most comprehensive registry. INTERPRETATION This is the first attempt at summarizing all the public health information on blindness and visual impairment in Canada. The present population-based ocular information has numerous shortcomings. More comprehensive validation of large registries, such as that of the CNIB, is needed to provide the foundation for a longitudinal ocular surveillance system. Such a system could guide research on risk factors and the effect of treatment, economic analyses, and public policy for ocular research and service allocation.

Delayed spontaneous hyphemas after Ab interno trabeculectomy surgery for glaucoma.

BACKGROUND The ab interno trabeculectomy, also commonly known as the Trabectome system, is a novel surgical approach to lowering intraocular pressure (IOP) in primary open-angle glaucoma. It is a microelectrosurgical device that removes a strip of trabecular meshwork and inner wall of the Schlemm canal to improve aqueous outflow.1,2 One of the main known complications is hyphema secondary to intraoperative blood reflux, but this typically clears within days postoperatively.1 We report 5 cases from multiple centers of delayed hyphemas that occurred several months after uncomplicated ab interno trabeculectomy procedures.

Interaction Between Visual Acuity and Peripheral Vascular Disease with Balance: Vision, Vascular Disease, and Balance

To determine whether visual acuity is related to balance in older adults with peripheral vascular disease (PVD) or diabetes mellitus.

Eye care utilization and its determinants in Canada

OBJECTIVE To provide the frequency and potential determinants of eye care utilization over the last 12 months among Canadians between the ages of 45 and 85 years old. DESIGN Cross-sectional population-based study. PARTICIPANTS 30,097 people in the Comprehensive Cohort of the Canadian Longitudinal Study on Aging. METHODS Inclusion criteria included being between the ages of 45 and 85 years old, community-dwelling and living near one of the 11 data collection sites across 7 Canadian provinces. Eye care utilization was defined as the self-report of a visit to an optometrist or ophthalmologist in the past 12 months. RESULTS In the last year, 57% of 28 728 adults visited an eye care provider although there was heterogeneity between provinces. The highest eye care utilization was found in Ontario at 62%, whereas the lowest was in Newfoundland and Labrador at 50%. Of concern, 25.3% of people with diabetes above the age of 60 years had not seen an eye care provider in the last year. Our novel finding was that current smokers were less likely to use eye care compared to never smokers (odds ratio [OR] = 0.76, 95% confidence interval [CI] 0.67-0.87). Confirming previous research, men compared to women (OR = 0.67, 95% CI 0.62-0.71), people with less than a bachelors degree compared to more than a bachelors degree (OR = 0.87, 95% CI 0.79-0.95), and people making less income (linear trend p < 0.05) were less likely to use eye care. CONCLUSIONS Disparities exist in eye care utilization in Canada. Efforts should be made to reduce these disparities to reduce avoidable vision loss.