Gender trends in match rate to surgical specialties in Canada: A retrospective study from 2003-2022

BACKGROUND

In Canada, there is a recognized underrepresentation of women in the field of surgery. However, the extent to which this trend applies across various surgical specialties is not well delineated. The aim of this study is to identify existing disparities and trends over time to inform the need for future interventions to make the match process more equitable for applicants.

METHODS

Data regarding surgical specialty applicants was extracted from the Canadian Resident Matching Service (CaRMS)'s 2003 to 2022 reports.

RESULTS

A total of 9,488 applicants ranked surgical specialties as their first choice from 2003-2022. Increases in the proportion of women applicants comparing periods 2003-2007 to 2018-2022 were significant for cardiac surgery (22% to 43%, p = 0.03), general surgery (46% to 60%, p<0.001), orthopedic surgery (23% to 35%, p<0.001), urology (23% to 38%, p<0.001), and all aggregated surgical specialties ('all surgery') (45% to 55%, p<0.001). An increase in the proportion of women applicants who matched over the same periods was observed for general surgery (+47% to 60%, p<0.001), orthopedic surgery (24% to 35%, p<0.01), urology (21% to 34%, p<0.001), and all surgery (46% to 54%, p<0.001). From 2003-2022, a lower match rate for women compared to men was observed for otolaryngology (0.60 v 0.69, p = 0.008), urology (0.61 v 0.72, p = 0.003), and all surgery (0.71 v 0.73, p = 0.038), while higher match rates were observed for ophthalmology (0.65 v 0.58, p = 0.04). No statistically significant differences in match rate were observed from 2018-2022.

CONCLUSIONS

While the proportion of women applicants to surgical specialties in Canada has been increasing, women remain underrepresented in several surgical specialties. This underrepresentation cannot be solely attributed to fewer women applying to these specialties, as women experience lower success rates when matching to specific surgical specialties. Further research is essential to identify and address the underlying causes of these disparities.

Development of a standardized Canadian undergraduate medical education ophthalmology curriculum

OBJECTIVE

To create a standardized undergraduate medicine ophthalmology curriculum for Canadian medical schools.

DESIGN

Two-stage modified Delphi technique.

PARTICIPANTS

Undergraduate ophthalmology leads at all the medical schools in Canada and 6 nonophthalmologist physicians with medical education expertise.

METHODS

In stage 1, a preliminary list of curricular objectives was developed using the 2018 Association of University Professors in Ophthalmology's list of curricular objectives as a foundation. Subsequently, an online survey was sent to 24 individuals (18 ophthalmology undergraduate curriculum leads and 6 non-ophthalmology medical educators) at 17 institutions to evaluate the objectives using a 5-point Likert-type scale. In stage 2, the ophthalmology curriculum leads were invited to participate in a virtual meeting during which the list of curricular objectives was discussed and finalized by consensus.

RESULTS

In stage 1, a preliminary list of 76 learning objectives organized into 10 overarching topics was developed. A total of 21 survey responses were received (87.5% response rate), allowing for the creation of a revised list. In stage 2, five participants from four schools met, achieving consensus following one round of feedback. The final undergraduate ophthalmology curriculum contained 10 topics and 75 objectives; it covered common presentations of a variety of acute and chronic eye diseases that were felt to be relevant to a wide medical audience.

CONCLUSIONS

The consensus obtained on a comprehensive list of undergraduate medicine ophthalmology curricular objectives identified in this study is the first of its kind in Canada. These objectives can be used by medical schools across Canada to standardize undergraduate ophthalmology teaching.

Trends in ophthalmology applicants going unmatched in the Canadian Resident Matching Service

Background

Applicants to ophthalmology have high rates of going unmatched during the CaRMS process, but how this compares to other competitive or surgical specialties remains unclear. Our research aims to examine this phenomenon by identifying trends and comparing match data with other specialties, to identify disparities that may inform the need for future interventions to improve the match process for applicants.

Methods

We used a cross-sectional analysis of data provided by CaRMS on the residency match from 2013 to 2022.

Results

We obtained data from 608 ophthalmology, 5,153 surgery, and 3,092 top five (most competitive) specialty first choice applicants from 2013-2022. Ophthalmology applicants were more likely to go unmatched (18.9% [120/608]) than applicants to the top five (11.9% [371/3,092]) and surgical (13.5% [702/5,153]) specialties (p<0.001) and were twice as likely to rank no alternate disciplines (31.8%, p < 0.001) over the study period. In the first iteration, when alternate disciplines were ranked, the match rate to alternate disciplines was highest for ophthalmology applicants (0.41, p < 0.001). The majority (57.8%) of unmatched ophthalmology applicants do not participate in the second iteration.

Conclusion

Compared to other competitive specialties, first choice ophthalmology applicants were more likely to go unmatched, rank no alternate disciplines, and choose not to participate in the second iteration. Ophthalmology applicant behaviours should be further studied to help explain these study findings.

Effect of the COVID-19 pandemic on elective cataract surgery wait times

OBJECTIVE

Lengthy wait times for cataract surgery can negatively affect patients' quality of life and increase the incidence of falls and depression. The COVID-19 pandemic has presented significant challenges to the delivery of elective cataract surgeries. The effects of the COVID-19 pandemic on cataract surgery wait times in the Alberta Health Services' Edmonton zone were studied by examining the wait times before and during the pandemic.

METHODS

This study was conducted based on a retrospective population-based design. Data were compiled from a centralized database related to hospital-based cataract surgery (Royal Alexandra, Fort Saskatchewan, and WestView Health Centre) between April 2019 and March 2022 (i.e., 3 fiscal years).

RESULTS

The average wait time for cataract surgery increased from 14.4 ± 1.4 weeks in 2019-2020 to 18.2 ± 2.7 weeks in 2020-2021 (p = 0.005) and then decreased to 11.5 ± 1.3 in 2021-2022 (p < 0.001). The number of completed surgeries decreased from 13,103 in 2019-200 to 9,308 (p = 0.09) and 10,365 (p = 0.1) during the next 2 years. The annual operating room time for scheduled cases was reduced to 4463 hours (p = 0.42) and 4552 hours (p = 0.15) during the pandemic compared with 5541 hours before the pandemic. However, the average waitlist size decreased from 6629 at the end of 2019-200 to 6122 (p = 0.029) and 4011 (p < 0.001) during the next 2 years.

CONCLUSION

The COVID-19 pandemic resulted in significantly increased average wait times for elective cataract surgery during the first year of the pandemic. Because of a reduction of the waitlist size, the wait times decreased during the second year of the pandemic.

The potential of stem cell therapy to tackle visual impairment

Visual impairment adversely impacts quality of life and affects more than 295 million individuals globally. Currently, there is no cure or tissue regenerative approaches in clinical practice for vision loss caused by corneal disease, glaucoma, cataracts, macular degeneration, diabetic retinopathy, and inherited retinal disease. Stem cells-based therapeutic approaches to diseases causing moderate to severe visual impairment have shown encouraging outcomes in animal models and in vitro studies. The goal of this narrative review is to describe and evaluate the potential of stem cell-based treatment, and their advantages and safety concerns in treating conditions causing vision loss.

A qualitative description of barriers to visual rehabilitation experienced by stroke survivors with visual impairment in Alberta, Canada

BACKGROUND

Post-stroke visual impairment (VI) is a common but under-recognized care challenge. Common manifestations of post-stroke VI include: diplopia, homonymous hemianopia, oscillopsia secondary to nystagmus, and visual inattention or neglect. In acute care settings, post-stroke VI recognition and treatment are often sub-optimal as emphasis is placed on survival. Stroke survivors with VI often face inconsistencies when accessing care out of hospital because variable availability and subsidization of visual rehabilitation. We sought to identify gaps in care experienced by stroke survivors with VI from stroke survivors' and care providers' perspectives.

METHODS

We conducted a qualitative description study across 12 care sites in Alberta, Canada, using semi-structured interviews. Survivor interviews focused on the health system experience. Provider interviews discussed approaches to care, perceived gaps, and current resources. Interviews were audio-recorded and transcribed. Iterative content analysis was completed using NVivo 12. We promoted rigour through an audit trail, open-ended questions, thick description, and collaborative coding.

RESULTS

We completed 50 interviews: 19 survivor interviews and 31 provider interviews. The majority of survivors were male (n = 14) and recruited from community settings (n = 16). Providers varied in profession and location within the care continuum. Two key themes emerged from the provider and survivor interviews pertaining to (a) facets of visual rehabilitation (sub-themes: access, resources, and multidisciplinary professional interaction); and (b) functioning with post-stroke VI (sub-themes: early experiences post-stroke and living with VI in the real world).

CONCLUSIONS

The visual rehabilitation model needs to be optimized to ensure transparent inter-disciplinary communication and efficient referral pathways. Future research will focus on evaluating the effectiveness of post-stroke care from multiple perspectives in Alberta.

Towards preventing exfoliation glaucoma by targeting and removing fibrillar aggregates associated with exfoliation syndrome

Exfoliation syndrome presents as an accumulation of insoluble fibrillar aggregates that commonly correlates with age and causes ocular complications, most notably open-angle glaucoma. Despite advances in understanding the pathogenesis and risk factors associated with exfoliation syndrome, there has been no significant progress in curative pharmacotherapy of this disease. It is thought that the ability to target the fibrillar aggregates associated with exfoliation may offer a new therapeutic approach, facilitating their direct removal from affected tissues. Phage display techniques yielded two peptides (LPSYNLHPHVPP, IPLLNPGSMQLS) that could differentiate between exfoliative and non-affected regions of the human lens capsule. These peptides were conjugated to magnetic particles using click chemistry to investigate their ability in targeting and removing exfoliation materials from the anterior human lens capsule. The behavior of the fibrillar materials upon binding to these magnetic particles was assessed using magnetic pins and rotating magnetic fields of various strengths. Ex vivo studies showed that the magnetic particle-peptide conjugates could generate enough mechanical force to remove large aggregates of exfoliation materials from the lens capsule when exposed to a low-frequency rotating magnetic field (5000 G, 20 Hz). Biocompatibility of targeting peptides with and without conjugated magnetic particles was confirmed using MTT cell toxicity assay, live/dead cell viability assay, and DNA fragmentation studies on primary cultured human trabecular meshwork cells. This is a novel, minimally invasive, therapeutic approach for the treatment of exfoliation glaucoma via the targeting and removal of exfoliation materials that could be applied to all tissues within the anterior segment of the eye.

Quantifying the cost of single-use minims and multidose bottles for eye drops in routine ophthalmic practice: a multicentre study

OBJECTIVE

To compare costs between two different eye drop delivery modalities: multidose bottles and single-use minims.

DESIGN

Retrospective cohort study.

METHODS

Monthly dilating eye drop costs and quantities (tropicamide 1%, phenylephrine 2.5%, cyclopentolate 1%) were studied over a 2-year period between April 2013 and March 2015 at 2 tertiary ophthalmic centres (Royal Alexandra Hospital [RAH, Edmonton] and Rockyview General Hospital [RGH, Calgary]). In April 2014, RAH switched its dilating eye drop practice from predominantly multidose bottles to single-use minims, whereas RGH continued using predominantly multidose bottles. Eye drop volume and total and per-patient eye drop costs were quantified at RAH before switching (pre-intervention) and after (post-intervention) using an interrupted time-series analysis with RGH as a control. A counterfactual analysis was also performed. Significance was obtained using independent t-testing.

RESULTS

After switching to single-use minims, RAH experienced changes in the following: an increase in single-use minims as a proportion of total eye drop utilization (from 5.6% to 89.1%; p = 0.001), an increase in total eye drop cost by $2117 per month (95% confidence interval [CI], $1354-$2880; p < 0.001), an increase in per-patient costs by $984 per 1000 patients per month (95% CI, $674-$1293). Contrastingly, RGH did not experience similar changes. Ultimately, the cost of switching to single-use minims was $22 481 (95% CI, $7830-$31 336) over a 12-month period.

CONCLUSIONS

If safe eye drop practices are enforced via proper protocols, the use of multidose bottles may be a more cost-effective option than single-use minims for routine clinical practice.

Leadership development facilitated by the "sandwich" and related glaucoma fellowship programs

PURPOSE

The purpose of this paper is to evaluate leadership training in the Sandwich Glaucoma Fellowship (SGF), a program in which fellows learn skills in a developed world institution and their home country to become leaders in glaucoma care.

DESIGN/METHODOLOGY/APPROACH

This paper is a retrospective, qualitative and quantitative evaluation. Participants of the SGF between 2007 and 2019 were provided a survey eliciting demographic information, leadership training exposure, development of leadership competencies and feedback for the fellowship program.

FINDINGS

Seven of nine alumni responded. The fellowship strongly impacted leadership competencies including integrity (8.8, 95% CI 7.8-9.8), work ethic (8.64, 95% CI 7.7-9.6) and empathy (8.6, 95% CI 7.7-9.5). A total of 85% of alumni indicated positive changes in their professional status and described an increasing role in mentorship of colleagues or residents as a result of new skills. Lack of formal leadership training was noted by three respondents. Informal mentorship equipped fellows practicing in regions of Sub Saharan Africa with competencies to rise in their own leadership and mentoring roles related to enhancing glaucoma management. Suggested higher-order learning objectives and a formal curriculum can be included to optimize leadership training catered to the individual fellow experience.

ORIGINALITY/VALUE

Leadership is necessary in health care and specifically in the context of low- and middle-income countries to bring about sustainable developments. The SGF contains a unique "Sandwich" design, focusing on the acquisition of medical and leadership skills. This evaluation outlines successes and challenges of this, and similar fellowship programs. Other programs can use a similar model to promote the development of skills in partnership with the fellows' home country to strengthen health-care leaders.

Incidence of steroid response in microinvasive glaucoma surgery with trabecular microbypass stent and ab interno trabeculectomy

OBJECTIVE

To determine the incidence and risk factors for steroid response in patients undergoing combined phacoemulsification cataract extraction (PCE) and microinvasive glaucoma surgery with either trabecular microbypass stent implantation (iStent) or ab interno trabeculectomy (Trabectome).

DESIGN

Retrospective, noncomparative, single-institutional observational chart review.

PARTICIPANTS

Consecutive patients with open-angle glaucoma who underwent PCE with iStent or Trabectome with 3 months of follow-up.

METHODS

Data were collected from patient charts, including pre- and postoperative intraocular pressure (IOP) following application of topical corticosteroid on postoperative visits for at least 3 months. A steroid response was defined as an IOP rise of greater than 5 mm Hg beginning at least 3 days after surgery with no other obvious explanation and with IOP < 20 mm Hg following rapid tapering or withdrawal of the steroid.

RESULTS

A total of 118 eyes from 89 patients, average age of 71.4 ±12.1 years, were included. Overall, a steroid response was seen in 12.7% of eyes (n = 15), and no difference was noted between Trabectome (11.8%) and iStent (13.6%, p = 0.782) eyes. Axial length (AL; p = 0.01), younger age (p = 0.009), traumatic glaucoma (p = 0.004), and normal-tension glaucoma (NTG; p = 0.0048) were significant predictors of steroid response in a multivariate analysis. In eyes with AL ≥ 25 mm, the steroid response rate was 40%, in contrast to eyes with AL < 25 mm, where it was 10.2%.

CONCLUSION

A steroid response develops in approximately 1 in 8 patients undergoing PCE with Trabectome or iStent. Young age, AL > 25 mm, traumatic glaucoma, and NTG were found to be significant predictors of steroid response.

Detecting Glaucoma in Rural Kenya: Results From a Teleglaucoma Pilot Project in Nyamira, Kenya

PRECIS

A teleglaucoma (TG) case-finding model was used in Kenya. Of the patients, 3.46% had definite glaucoma and 4.12% were glaucoma suspects. Most cases were of moderate to advanced stage and referred for further assessment.

PURPOSE

The aim was to evaluate glaucoma prevalence in a high-risk population using a TG model.

METHODS

Patients aged 35 or over were referred to the TG program from the outpatient diabetic and hypertensive clinics at Nyamira District Hospital (NDH) and from community awareness programs. Comprehensive ophthalmic examination included structured history, visual acuity, intraocular pressure, central corneal thickness, stereoptic nerve, and macular images. A glaucoma specialist provided diagnosis and management recommendation through virtual consultation. Glaucoma diagnosis and staging were based on at least 1 eye meeting the optic nerve criteria as specified by the Canadian glaucoma guidelines.

RESULTS

In all, 1206 participants were seen and 19 of these could not complete the examination. Of 1187 patients, 56% were women and the mean age was 56.60±12.36 years. Of the patients, 11.8% had images that were ungradable in at least 1 eye. The prevalence of glaucoma and glaucoma suspects was 3.46% (n=42) and 4.12% (n=50), respectively. The proportion of patients with early, moderate, advanced, and absolute glaucoma was 2.4%, 33.3%, 52.4%, and 2.4%, respectively. Other diagnoses (pathology in at least 1 eye) included cataract in 13.2%, diabetic retinopathy in 1.48%, and optic atrophy in 1.98%. Of the patients, 28.2% were referred to the Innovation Eye Centre, Kisii, for further assessment.

CONCLUSION

A structured TG program detected glaucoma in 3.46% of a rural Kenyan population. Timely patient referral was also initiated.

The Muranga Teleophthalmology Study: A Comparison of Virtual (Teleretina) Assessment with in-person Clinical Examination to Diagnose Diabetic Retinopathy and Age-related Macular Degeneration in Kenya

PURPOSE:

This study compares a web-based teleophthalmology assessment with a clinical slit lamp examination to screen for diabetic retinopathy (DR) and age-related macular degeneration (AMD) among diabetic patients in a rural East African district.

METHODS:

Six hundred and twelve eyes from 306 diabetic patients underwent both a clinical slit lamp examination and a teleretina (TR) assessment by an experienced ophthalmologist. Both assessments were compared for any DR and AMD using the early treatment diabetic retinopathy study and age-related eye disease study grading scales, respectively.

RESULTS:

Of the 612 TR assessment photos, 74 (12%) were deemed ungradable due to media opacities, poor patient cooperation, or unsatisfactory photographs. The ability to detect DR and AMD showed a fair agreement (kappa statistic 0.27 and 0.23, respectively) between the TR and clinical slit lamp examination. Relative to a clinical slit lamp evaluation, a positive TR diagnosis carried a 75.0% positive predictive value when diagnosing DR and a 27.3% positive predictive value when diagnosing AMD. A negative TR diagnosis carried a 97.2% negative predictive value for the diagnosis of DR and a 98.1% negative predictive value for the diagnosis of AMD.

CONCLUSION:

When comparing TR assessments to clinical slit lamp examinations to diagnose DR and AMD, there was a fair agreement. Although further validation is needed, the TR approach provides a promising method to diagnose DR and AMD, two major causes of ocular impairment worldwide.

Amsler grid test for detection of advanced glaucoma in Ethiopia

Objective

This study was done to determine the validity of amsler grid test black on white (BOW), as well as white on black (WOB) for identifying central visual field (VF) defects in patients with advanced glaucoma.

Design

Prospective study.

Participants

We prospectively included 100 consecutive eyes of 88 adult patients with advanced glaucoma and 100 eyes of 100 normal individuals. We used a lottery method to choose the side of the eye for the control groups.

Methods

All participants had reliable Humphrey 10–2 Swedish Interactive Threshold Algorithm (SITA) standard VF. Both the BOW and WOB amsler grid tests were done for each group. Sensitivity, specificity, and positive and negative predictive values of the amsler grid scotoma area were calculated with the 10–2 VF as the reference standard.

Results

The mean ± standard deviation (SD) of age and the 10–2 VF mean deviation (MD) of advanced glaucoma eyes were 59.8 ± 11.8 (range 34–84) years and -19.94 ± 9.8(range -34.98–-0.52) respectively. Among 108 eyes with normal 10–2 VF test, 103 had a normal BOW amsler grid test and 5 had an abnormal BOW test. Among 92 eyes with an abnormal 10–2 VF test, 74 had an abnormal and 18 had normal BOW amsler grid test. Sensitivity, specificity, and positive and negative predictive values of the BOW amsler grid test were 80.4%, 95.4%, 93% and 85.1% respectively whereas that of the WOB amsler grid test were 71.7%, 95.4%, 93% and 72.8% respectively.

Conclusion

The sensitivity and specificity of both BOW and WOB amsler grid tests were high in detecting VF defects in advanced glaucoma.

Recent advances in risk factors associated with ocular exfoliation syndrome

Exfoliation syndrome is generally considered a progressive age-related systemic disorder of the extracellular matrix, which is clinically characterized through the observation of flaky white aggregates on ocular tissues. Exfoliation syndrome is directly linked to exfoliative glaucoma in elderly patients, where it is known as the most common identifiable cause of open-angle glaucoma. Despite the identification of various risk factors associated with exfoliation syndrome, the exact pathogenesis of this syndrome has not been fully elucidated. There is a growing number of genome-wide association studies in different populations around the world to identify genetic factors underlying exfoliation syndrome. Besides variants in LOXL1 and CACNA1A genes, new loci have been recently identified which are believed to be associated with exfoliation syndrome. Among different genetic factors, functional variants might help to better understand mechanisms underlying this systemic disorder. Besides genetic factors, epigenetic regulation of different gene expression patterns has been thought to play a role in its pathogenesis. Other factors have been also considered to be involved in the development of exfoliation syndrome at cellular organelles level where mitochondrial impairment and autophagy dysfunction have been suggested in relation to exfoliation syndrome. This review addresses the most recent findings on genetic factors as well as cellular and molecular mechanisms involved in both the development and progression of exfoliation syndrome.

Optimizing preoperative requirements for outpatient cataract surgery at the Royal Alexandra Hospital

OBJECTIVE

To evaluate preoperative testing for cataract surgery, implement stakeholder-driven change, and increase the number of patients who arrived for surgery with complete preoperative requirements, for the purpose of delivering safe, high-quality, and cost-effective care for patients.

DESIGN

Quality improvement.

PARTICIPANTS

Cataract surgery patients, health care staff in Ophthalmology Day Surgery, an Ophthalmology improvement team, the Clinical Section Heads of Ophthalmology and Anaesthesia, Quality Consultants, and members of the Quality Council participated in this study.

METHODS

A lean quality improvement approach was used to define and build understanding of the problem. Between July and November 2016, a chart-based reporting system captured all patients who arrived for cataract surgery with expired or incomplete preoperative requirements. A cost analysis was completed, and evidence was reviewed to ensure alignment with best practice preoperative recommendations.

RESULTS

On average, 25% (619/2451 over a 17-week period) of patients per day arrived at the Ophthalmology Day Surgery for cataract surgery with incomplete and/or expired physical history forms and ECGs. An improvement team worked to implement a radical improvement idea and relied on an existing questionnaire to ensure patient safety preoperatively.

CONCLUSIONS

Based on the literature, best practice guidelines, and a cost analysis, it was decided that patients undergoing routine cataract surgery in Edmonton Zone Hospitals under regional anaesthesia would no longer require physician history and physicals and ECGs. Elimination of the preoperative requirements for all but select high-risk patients meant that 100% of patients who arrived for cataract surgery would not have outstanding presurgery requirements.

Association of pseudoexfoliation syndrome with cardiovascular and cerebrovascular disease: a systematic review and meta-analysis

OBJECTIVE

Pseudoexfoliation syndrome (PEX) is a systemic disease, but evidence of its association with cardiovascular disease (CVD) and cerebrovascular disease (CVA) is controversial. A quantitative systematic review will provide an accurate summary of the current body of the literature.

DESIGN

Meta-analysis.

PARTICIPANTS

Not applicable.

METHODS

A comprehensive literature search of published and unpublished English-language studies was performed. Summary statistics were calculated using inverse variance weighting and are presented in forest plots. Sources of variance were evaluated statistically.

RESULTS

After screening 4547 studies, 47 articles were reviewed, and 25 eligible studies were selected that reported patients from around the world. Twenty studies enrolling 9583 individuals with PEX evaluated CVD, providing a summary odds ratio (OR) of 1.61 (95% CI 1.37-1.90). Eleven studies, enrolling 1308 PEX patients, evaluated CVA and generated a summary OR of 1.76 (1.40-2.22). For any vascular event (AVE) using all 25 studies, there were 9716 PEX patients and 363,312 control patients, yielding a summary OR of 1.64 (95% CI 1.39-1.92). Analysis for publication bias with the Egger's test was not significant for studies reporting CVD and AVE (p = 0.92 and 0.64, respectively) but was significant for CVA (p = 0.03). Asymmetry of Begg's funnel plot was noted for the CVA and AVE analyses. Multiple sensitivity analyses were performed, including assessment of study quality; the OR for all 3 outcomes varied minimally and remained significant in all analyses.

CONCLUSION

There is strong evidence that PEX is significantly associated with both CVD and CVA.

Review of economic evaluations of teleophthalmology as a screening strategy for chronic eye disease in adults

BACKGROUND/AIMS

Teleophthalmology is well positioned to play a key role in screening of major chronic eye diseases. Economic evaluation of cost-effectiveness of teleophthalmology, however, is lacking. This study provides a systematic review of economic studies of teleophthalmology screening for diabetic retinopathy (DR), glaucoma and macular degeneration.

METHODS

Structured search of electronic databases and full article review yielded 20 cost-related articles. Sixteen articles fulfilled the inclusion criteria and were retained for a narrative review: 12 on DR, 2 on glaucoma and 2 on chronic eye disease.

RESULTS

Teleophthalmology for DR yielded the most cost savings when compared with traditional clinic examination. The study settings varied among urban, rural and remote settings, community, hospital and health mobile units. The most important determinant of cost-effectiveness of teleophthalmology was the prevalence of DR among patients screened, indicating an increase of cost savings with the increase of screening rates. The required patient pool size to be screened varied from 110 to 3500 patients. Other factors potentially influencing cost-effectiveness of teleophthalmology were older patient age, regular screening and full utilisation of the equipment. Teleophthalmology for glaucoma was more cost-effective compared with in-person examination. Similarly, increasing number of glaucoma patients targeted for screening yielded more cost savings.

CONCLUSIONS

This economic review provides supportive evidence of cost-effectiveness of teleophthalmology for DR and glaucoma screening potentially increasing screening accessibility especially for rural and remote populations. Special selection of the targeted screening population will optimise the cost-effectiveness of teleophthalmology.

Prospective randomized controlled trial of phaco-trabectome versus phaco-trabeculectomy in patients with open angle glaucoma

OBJECTIVE

To compare the efficacy and safety of ab interno trabeculectomy with the Trabectome combined with cataract surgery (phaco-AIT) versus Trabeculectomy with mitomycin C combined with cataract surgery (phaco-Trab) in open-angle glaucoma.

METHODS

A prospective randomized controlled trial with a single surgeon and surgical center was undertaken. Patients were recruited from July 2009 to October 2014. Primary outcomes were mean intraocular pressure (IOP) at 6 months and surgical complications. Secondary outcomes were mean IOP at 12 months, achievement of target IOP, number of glaucoma medications, and rate of secondary surgery.

RESULTS

The trial was ended early before achieving our intended sample size due to difficulties in recruitment and lack of clinical equipoise over time. Nineteen patients were enrolled, 10 phaco-AIT and 9 phaco-Trab. Baseline IOP was 20.0 ± 5.3 in phaco-AIT and 23.1 ± 6.4 mm Hg in phaco-Trab (p = 0.22). IOP decreased to 17.5 ± 3.8 and 16.0 ± 6.0 mm Hg at 6 months (p = 0.54), and 16.8 ± 2.7 and 17.1 ± 5.0 mm Hg at 1 year (p = 0.57), respectively. Mean number of glaucoma medications at baseline was 1.8 ± 1.3 in phaco-AIT and 1.4 ± 1.1 in phaco-Trab (p = 0.59). Mean number of glaucoma medications decreased to 0.78 ± 1.39 and 0.38 ± 0.74 at 6 months (p = 0.68), and 0.44 ± 0.88 and 0.75 ± 0.89 at 1 year (p = 0.41), respectively. Mild and moderate complications were seen in both treatment groups, but severe complications were seen only in phaco-Trab. One secondary glaucoma procedure was required in the phaco-AIT group.

CONCLUSIONS

Phaco-AIT achieved similar IOP lowering at 6 and 12 months compared with phaco-Trab with a similar number of glaucoma medications required at 1 year, and no serious complications were identified in the Phaco-AIT group.

What have we learned about exfoliation syndrome since its discovery by John Lindberg 100 years ago?

Exfoliation syndrome (XFS) is a systemic disease with significant ocular manifestations, including glaucoma and cataract. The disease impacts close to 70 million people globally and is now recognised as the most common identifiable cause of open-angle glaucoma. Since the discovery of XFS 100 years ago by Dr John G. Lindberg, there has been considerable advancement in understanding its pathogenesis and resulting clinical implications. The purpose of this paper is to summarise information regarding the epidemiology, pathophysiology, ocular manifestations and systemic associations of XFS with the objective of sharing clinical pearls to assist in early detection and enhanced management of patients.

Cataract and Glaucoma Surgery: Endoscopic Cyclophotocoagulation versus Trabeculectomy

PURPOSE:

To compare the efficacy and safety of endoscopic cyclophotocoagulation (ECP) versus trabeculectomy with mitomycin C (trab) in combination with cataract surgery.

MATERIALS AND METHODS:

We evaluated the 6-month results of patients undergoing phacoemulsification (phaco) with either ECP or trab. The primary outcome was mean intraocular pressure (IOP) at 6 months; secondary outcomes were change in glaucoma medications, visual acuity, intraocular inflammation, and postoperative complications. Complete success was a target IOP of <21 mmHg and >6 mmHg without glaucoma medications. Qualified success was target IOP achieved through glaucoma medications.

RESULTS:

We evaluated 53 eyes of 53 patients; 24 (45.3%) eyes were treated with ECP-phaco and 29 (54.7%) with trab-phaco. At 6 months, there was no significant difference in mean IOP of the two groups (ECP-phaco 14.2 ± 3.6 mmHg; trab-phaco 13.0 ± 2.5 mmHg; P = 0.240). Six (25.0%) ECP-phaco eyes and 20 (69.0%) trab-phaco eyes achieved complete success (P = 0.002). Qualified success was achieved in 18 (75.0%) ECP-phaco eyes and 9 (31.0%) trab-phaco eyes (P = 0.002). The mean reduction of medication from baseline was significant (ECP-phaco 1.2 ± 1.1; trab-phaco 2.1 ± 1.5; P = 0.020). ECP-phaco resulted in more IOP spikes on the 1^st postoperative day (P = 0.040) and more anterior cellular reaction at 1 week and 1 month compared to trab-phaco (P < 0.05). The rate of postoperative complications was not significantly different between groups.

CONCLUSION:

At 6 months, ECP-phaco demonstrated similar improvements in IOP and visual acuity compared to trab-phaco. However, ECP-phaco patients had higher incidences of immediate postoperative IOP spikes and anterior chamber inflammation as well as requiring additional medications postoperatively.

Improving patient identification in an ophthalmology clinic using name alerts

OBJECTIVE

To develop a standardized process for reviewing daily patient lists and identifying potential risks of misidentification. Our goal was to develop a proactive approach to identify and eliminate risks of patient misidentification.

METHODS

Assessment of current patient identification practices took place over a period of 4 weeks. Using a process map, a patient survey was developed to determine the encounter points when patient identification was confirmed. This information was used to develop a standardized protocol for review of daily appointment lists.

RESULTS

Review of daily appointment lists was completed to identify potential similar/same name risks. A standardized manual process of chart review, flagging, and tracking was developed.

CONCLUSIONS

The name alert process resulted in a simple manual process for identifying which patients have a higher name risk and allowed care providers to take preventative action to decrease potential risk of incorrect diagnostic testing, procedure, or medication administration.

Peptides for targeting βB2-crystallin fibrils

Crystallins are a major family of proteins located within the lens of the eye. Cataracts are thought to be due to the formation of insoluble fibrillar aggregates, which are largely composed of proteins from the crystallin family. Today the only cataract treatment that exists is surgery and this can be difficult to access for individuals in the developing world. Development of novel pharmacotherapeutic approaches for the treatment of cataract rests on the specific targeting of these structures. βB2-crystallin, a member of β-crystallin family, is a large component of the crystallin proteins within the lens, and as such was used to form model fibrils in vitro. Peptides were identified, using phage display techniques, that bound to these fibrils with high affinity. Fibrillation of recombinantly expressed human βB2-crystallin was performed in 10% (v/v) trifluoroethanol (TFE) solution (pH 2.0) at various temperatures, and its amyloid-like structure was confirmed using Thioflavin-T (ThT) assay, transmission electron microscopy (TEM), and X-ray fiber diffraction (XRFD) analysis. Affinity of identified phage-displayed peptides were analyzed using enzyme-linked immunosorbent assay (ELISA). Specific binding of a cyclic peptide (CKQFKDTTC) showed the highest affinity, which was confirmed using a competitive inhibition assay.

Compressed 3D and 2D digital images versus standard 3D slide film for the evaluation of glaucomatous optic nerve features

SYNOPSIS

Clinicians can feel confident compressed three-dimensional digital (3DD) and two-dimensional digital (2DD) imaging evaluating important features of glaucomatous disc damage is comparable to the previous gold standard of stereoscopic slide film photography, supporting the use of digital imaging for teleglaucoma applications.

BACKGROUND/AIMS

To compare the sensitivity and specificity of 3DD and 2DD photography with stereo slide film in detecting glaucomatous optic nerve head features.

METHODS

This prospective, multireader validation study imaged and compressed glaucomatous, suspicious or normal optic nerves using a ratio of 16:1 into 3DD and 2DD (1024×1280 pixels) and compared both to stereo slide film. The primary outcome was vertical cup-to-disc ratio (VCDR) and secondary outcomes, including disc haemorrhage and notching, were also evaluated. Each format was graded randomly by four glaucoma specialists. A protocol was implemented for harmonising data including consensus-based interpretation as needed.

RESULTS

There were 192 eyes imaged with each format. The mean VCDR for slide, 3DD and 2DD was 0.59±0.20, 0.60±0.18 and 0.62±0.17, respectively. The agreement of VCDR for 3DD versus film was κ=0.781 and for 2DD versus film was κ=0.69. Sensitivity (95.2%), specificity (95.2%) and area under the curve (AUC; 0.953) of 3DD imaging to detect notching were better (p=0.03) than for 2DD (90.5%; 88.6%; AUC=0.895). Similarly, sensitivity (77.8%), specificity (98.9%) and AUC (0.883) of 3DD to detect disc haemorrhage were better (p=0.049) than for 2DD (44.4%; 99.5%; AUC=0.72). There was no difference between 3DD and 2DD imaging in detecting disc tilt (p=0.7), peripapillary atrophy (p=0.16), grey crescent (p=0.1) or pallor (p=0.43), although 3D detected sloping better (p=0.013).

CONCLUSIONS

Both 3DD and 2DD imaging demonstrates excellent reproducibility in comparison to stereo slide film with experts evaluating VCDR, notching and disc haemorrhage. 3DD in this study was slightly more accurate than 2DD for evaluating disc haemorrhage, notching and sloping.

Tele-Ophthalmology for Age-Related Macular Degeneration and Diabetic Retinopathy Screening: A Systematic Review and Meta-Analysis

BACKGROUND

To synthesize high-quality evidence to compare traditional in-person screening and tele-ophthalmology screening.

METHODS

Only randomized controlled trials (RCTs) were included in this systematic review and meta-analysis. The intervention of interest was any type of tele-ophthalmology, including screening of diseases using remote devices. Studies involved patients receiving care from any trained provider via tele-ophthalmology, compared with those receiving equivalent face-to-face care. A search was executed on the following databases: Medline, EMBASE, EBM Reviews, Global Health, EBSCO-CINAHL, SCOPUS, ProQuest Dissertations and Theses Global, OCLC Papers First, and Web of Science Core Collection. Six outcomes of care for age-related macular degeneration (AMD), diabetic retinopathy (DR), or glaucoma were measured and analyzed.

RESULTS

Two hundred thirty-seven records were assessed at the full-text level; six RCTs fulfilled inclusion criteria and were included in this review. Four studies involved participants with diabetes mellitus, and two studies examined choroidal neovascularization in AMD. Only data of detection of disease and participation in the screening program were used for the meta-analysis. Tele-ophthalmology had a 14% higher odds to detect disease than traditional examination; however, the result was not statistically significant (n = 2,012, odds ratio: 1.14, 95% confidence interval (CI): 0.52-2.53, p = 0.74). Meta-analysis results show that odds of having DR screening in the tele-ophthalmology group was 13.15 (95% CI: 8.01-21.61; p < 0.001) compared to the traditional screening program.

CONCLUSIONS

The current evidence suggests that tele-ophthalmology for DR and age-related macular degeneration is as effective as in-person examination and potentially increases patient participation in screening.

UV-B induced fibrillization of crystallin protein mixtures

Environmental factors, mainly oxidative stress and exposure to sunlight, induce the oxidation, cross-linking, cleavage, and deamination of crystallin proteins, resulting in their aggregation and, ultimately, cataract formation. Various denaturants have been used to initiate the aggregation of crystallin proteins in vitro. All of these regimens, however, are obviously far from replicating conditions that exist in vivo that lead to cataract formation. In fact, it is our supposition that only UV-B radiation may mimic the observed in vivo cause of crystallin alteration leading to cataract formation. This means of inducing cataract formation may provide the most appropriate in vitro platform for in-depth study of the fundamental cataractous fibril properties and allow for testing of possible treatment strategies. Herein, we showed that cataractous fibrils can be formed using UV-B radiation from α:β:γ crystallin protein mixtures. Characterization of the properties of formed aggregates confirmed the development of amyloid-like fibrils, which are in cross-β-pattern and possibly in anti-parallel β-sheet arrangement. Furthermore, we were also able to confirm that the presence of the molecular chaperone, α-crystallin, was able to inhibit fibril formation, as observed for ‘naturally’ occurring fibrils. Finally, the time-dependent fibrillation profile was found to be similar to the gradual formation of age-related nuclear cataracts. This data provided evidence for the initiation of fibril formation from physiologically relevant crystallin mixtures using UV-B radiation, and that the formed fibrils had several traits similar to that expected from cataracts developing in vivo.

Phaco-trabectome versus phaco-iStent in patients with open-angle glaucoma

OBJECTIVE

To investigate efficacy and safety of phaco-trabectome (PT) versus phaco-iStent (Pi) for intraocular pressure (IOP) control in open-angle glaucoma (OAG).

DESIGN

Retrospective comparative case series.

PARTICIPANTS

A total of 70 eyes of 55 patients with OAG underwent either PT surgery by a single surgeon or Pi (insertion of 2 stents) by another surgeon in Canada between January 2010 and December 2012.

METHODS

The medical records of consecutive adult patients who underwent either PT or Pi surgery were reviewed. All patients who satisfied both the inclusion and exclusion criteria were included in the outcomes analyses. IOP reduction, reduction in glaucoma medication, safety profile, and best-corrected visual acuity were evaluated.

RESULTS

Thirty-six eyes of 30 patients had PT and 34 eyes of 25 patients had Pi. Baseline IOP was higher in the PT group (20.92 ± 5.07 mm Hg) than in the Pi group (17.47 ± 4.87 mm Hg; p = 0.026). At 12 months there was no significant difference between groups in relative reduction of mean IOP (PT -5.09 ± 5.73, 24% relative reduction vs. Pi -3.84 ± 3.80, 22% relative reduction; p = 0.331) or glaucoma medication use (PT -0.49 ± 1.17 vs. Pi -0.26 ± 0.73; p = 0.168) from baseline. However, Pi had significantly fewer individual complications (PT 20 vs. Pi 5; p < 0.0001) throughout the postoperative period.

CONCLUSION

At 12 months of follow-up, both techniques significantly lowered IOP, but fewer complications were observed in the Pi group.

Summary of Glaucoma Diagnostic Testing Accuracy: An Evidence-Based Meta-Analysis

Background

New glaucoma diagnostic technologies are penetrating clinical care and are changing rapidly. Having a systematic review of these technologies will help clinicians and decision makers and help identify gaps that need to be addressed. This systematic review studied five glaucoma technologies compared to the gold standard of white on white perimetry for glaucoma detection.

Methods

OVID^® interface: MEDLINE^® (In-Process & Other Non-Indexed Citations), EMBASE^®, BIOSIS Previews^®, CINAHL^®, PubMed, and the Cochrane Library were searched. A gray literature search was also performed. A technical expert panel, information specialists, systematic review method experts and biostatisticians were used. A PRISMA flow diagram was created and a random effect meta-analysis was performed.

Results

A total of 2,474 articles were screened. The greatest accuracy was found with frequency doubling technology (FDT) (diagnostic odds ratio (DOR): 57.7) followed by blue on yellow perimetry (DOR: 46.7), optical coherence tomography (OCT) (DOR: 41.8), GDx (DOR: 32.4) and Heidelberg retina tomography (HRT) (DOR: 17.8). Of greatest concern is that tests for heterogeneity were all above 50%, indicating that cutoffs used in these newer technologies were all very varied and not uniform across studies.

Conclusions

Glaucoma content experts need to establish uniform cutoffs for these newer technologies, so that studies that compare these technologies can be interpreted more uniformly. Nevertheless, synthesized data at this time demonstrate that amongst the newest technologies, OCT has the highest glaucoma diagnostic accuracy followed by GDx and then HRT.

Optic nerve gray crescent can confound neuroretinal rim interpretation: review of the literature

The optic nerve gray crescent can be of clinical significance if unrecognized during assessment for glaucoma. It has a characteristic appearance of a slate gray area of pigmentation within the disc margins and commonly appears along the inferotemporal or temporal neuroretinal rim areas. This type of disc rim pigmentation can create the impression of neuroretinal rim thinning, and thus lead to the misdiagnosis of glaucoma or "glaucoma suspect" with attendant implications for overtreatment or unnecessary close monitoring of such patients. The gray crescent is more common in African Americans than whites (prevalence rate 27% vs 7%) and is bilateral in at least 58% of cases. It has been reported in association with Kjer optic atrophy type 1. Suggested causes of the gray crescent include an accumulation of melanocytes, or retinal pigment epithelium cells partially located in the optic nerve head region if Bruch's membrane extends internal to the peripapillary scleral ring. Other causes of pigmentation that may resemble gray crescent are conus pigmentosus and variations of peripapillary atrophy. When a gray crescent is present, clinicians should endeavour to identify the true anatomical disc margins via the scleral lip and, if necessary, evaluate the patient further with imaging and visual field studies.

Efficacy of SLO-Microperimetry and Humphrey for evaluating macular sensitivity changes in advanced glaucoma

OBJECTIVE

To compare the efficacy of scanning laser ophthalmoscope microperimetry (SLO-MP) and Humphrey visual fields in detecting macular sensitivity changes in advanced glaucoma.

DESIGN

Prospective cohort study.

PARTICIPANTS

25 patients with advanced primary open angle glaucoma and 2 consecutive abnormal Humphrey 10-2 SITA Standard visual field tests.

METHODS

Thirty-six eyes of 25 patients with 2 consecutive abnormal Humphrey 10-2 SITA Standard (H10) visual fields were retested with a modified 10-2 SLO-MP within 3 months of the last reliable H10. A standardized grid was used to mark the macula. Primary outcome was change in mean macular sensitivity (dB; H10 and SLO-MP) in relation to mean macular retinal nerve fibre layer (RNFL) thickness (µm) by SLO- optical coherence tomography (SLO-OCT). Secondary outcome was comparison of reliability indices for both tests. Linear regression was used for analysis.

RESULTS

Mean macular sensitivity was significantly lower in SLO-MP (9.33 ± 3.37 dB) than H10 (18.83 ± 6.46 dB; p < 0.0001). Mean macular RNFL thickness correlated significantly with retinal sensitivity by both SLO-MP (r = 0.39, p < 0.02) and H10 (r = 0.37, p < 0.03). Fixation losses were better controlled in SLO-MP (0.38 ± 1.1) than H10 (4.28 ± 7.9; p = 0.008). False-positive responses were similar (SLO-MP: 2.25 ± 4.53, H10: 1.78 ± 3.33; p = 0.80). A statistically significant difference was noted in the false-negative responses (SLO-MP: 26.87 ± 25.24, H10: 5.33 ± 9.70; p < 0.0001).

CONCLUSIONS

Macular sensitivity determined by both H10 and SLO-MP correlates significantly with mean macular RNFL thickness measured by SLO-OCT. Precise localization of the macula in SLO-MP results in lower fixation losses. Detection of denser field defects by SLO-MP results in higher false-negative responses. A larger sample size is needed to further study the value of this diagnostic tool.

Advanced glaucoma: management pearls

A significant proportion of glaucoma patients present late, particularly in the developing world, and unfortunately, in an advanced stage of the disease. They are at imminent danger of losing remaining vision, and may also be afflicted with various socioeconomic and health challenges. The encounter with such a patient is typically characterized by anxiety/fear and sometimes hopelessness from the patient's perspective. The physician may also feel that they are in a difficult position managing the patient's disease. When dealing with such cases, we suggest a holistic, individualized approach taking into account the ‘biopsychosociospiritual’ (BPSS) profile of each patient. The BPSS model takes into account relevant ocular as well as systemic biology (factors such as the mechanism of glaucoma, level of intraocular pressure [IOP], rate of progression, life expectancy, general health), psychological considerations (e.g., fear, depression), socio-economic factors and spiritual/cultural values and beliefs before being able to decide with the patient and their care partner(s) what treatment goals should be and how they can best be approached. Treatment for advanced glaucoma can be highly effective, and patients and their care partners should be informed that aggressive IOP lowering to the low teens or even single digits offers the best chance of protecting remaining vision. This can be achieved safely and effectively in most cases with trabeculectomy (including an antimetabolite), and in some cases with medical and/or laser therapy. Vision rehabilitation and psychosocial support should also be considered in order to optimize remaining vision, replace fear with hope as appropriate, and thus improve the overall quality of life.

The Muranga Teleophthalmology Study: Comparison of Virtual (Teleglaucoma) with in-Person Clinical Assessment to Diagnose Glaucoma

PURPOSE

While the effectiveness of teleophthalmology is generally accepted, its ability to diagnose glaucomatous eye disease remains relatively unknown. This study aimed to compare a web-based teleophthalmology assessment with clinical slit lamp examination to screen for glaucoma among diabetics in a rural African district.

MATERIALS AND METHODS

Three hundred and nine diabetic patients underwent both the clinical slit lamp examination by a comprehensive ophthalmologist and teleglaucoma (TG) assessment by a glaucoma subspecialist. Both assessments were compared for any focal glaucoma damage; for TG, the quality of photographs was assessed, and vertical cup-to-disk ratio (VCDR) was calculated in a semi-automated manner. In patients with VCDR > 0.7, the diagnostic precision of the Frequency Doubling Technology (FDT) C-20 screening program was assessed.

RESULTS

Of 309 TG assessment photos, 74 (24%) were deemed unreadable due to media opacities, patient cooperation, and unsatisfactory photographic technique. While the identification of individual optic nerve factors showed either fair or moderate agreement, the ability to diagnose glaucoma based on the overall assessment showed moderate agreement (Kappa [κ] statistic 0.55% and 95% confidence interval [CI]: 0.48-0.62). The use of FDT to detect glaucoma in the presence of disc damage (VCDR > 0.7) showed substantial agreement (κ statistic of 0.84 and 95% CI 0.79-0.90). A positive TG diagnosis of glaucoma carried a 77.5% positive predictive value, and a negative TG diagnosis carried an 82.2% negative predicative value relative to the clinical slit lamp examination.

CONCLUSION

There was moderate agreement between the ability to diagnose glaucoma using TG relative to clinical slit lamp examination. Poor quality photographs can severely limit the ability of TG assessment to diagnose optic nerve damage and glaucoma. Although further work and validation is needed, the TG approach provides a novel, and promising method to diagnose glaucoma, a major cause of ocular morbidity throughout the world.

Improving diabetic retinopathy screening in Africa: patient satisfaction with teleophthalmology versus ophthalmologist-based screening

Purpose:

To assess patient preference for diabetic retinopathy (DR) screening with teleophthalmology or face-to-face ophthalmologist evaluation in Nairobi, Kenya.

Materials and Methods:

Fifty seven diabetic patients from a one-stop multidisciplinary diabetic clinic (consisting of a diabetologist, nurse educator, foot specialist, nutritionist, ophthalmologist, and neurologist) in Nairobi, Kenya were included if they had undergone both a teleophthalmology (stereoscopic digital retinal photographs graded by an ophthalmologist remotely) and a traditional clinical screening exam (face to face examination). A structured questionnaire with a 5-point Likert scale was developed in both English and Swahili. The questionnaire was administered over the telephone. Ten questions were used to compare patient experience and preferences between teleophthalmology and a traditional clinical examination for DR. A mean score >3.25 on the Likert scale was considered favourable.

Results:

Successfully telephone contact was possible for 26 (58% male, 42% females) of the 57 patients. The mean ages of the male and female patients were 52.4 and 46.5 years respectively. Patients were satisfied with their teleophthalmology examination (mean 4.15 ± 0.97). Patients preferred the teleophthalmology option for future screenings (mean 3.42 ± 1.52). This preference was driven primarily by convenience, reduced examination time, and being able to visualize their own retina.

Conclusion:

In this study, diabetic patients preferred a teleophthalmology based screening over a traditional ophthalmologist-based screening. The use of teleophthalmology in Africa warrants further study and has the potential to become the screening model of choice. Cost effectiveness in comparison to an ophthalmologist-based screening also requires evaluation.

Phenotypic features of Chinese family members with primary angle closure

OBJECTIVE

To describe ocular phenotypic features in Chinese families with primary angle closure (PAC).

DESIGN

Prospective cohort study.

PARTICIPANTS

428 individuals of 103 eligible families.

METHODS

Probands identified in clinic and their relatives were examined. Measurements included intraocular pressure, anterior chamber depth, lens thickness, axial length, and gonioscopic features related to the anterior chamber angle. Electroretinogram (ERG) testing for dark and light adaptation on both eyes of each individual examined was also obtained.

RESULTS

There were 144 PAC affected patients (33.7%), 60 suspects (14%), and 224 unaffected individuals (52.3%). There were more than 2 affected members in 51 families (49.5%). Compared with unaffected individuals, affected individuals were more likely to be female, have shallower peripheral and central anterior chamber depths, narrower angles, thicker lenses, and shorter axial lengths (p<0.001). Affected patients and suspects had similar axial lengths (p>0.05). Compared with unaffected individuals, affected and suspect individuals showed ERG adaptation abnormalities (p<0.05). Of 45 unaffected individuals with mean axial length ≤ 22.00 mm (10.51%), 20 individuals (4.67%) showed ERG adaptation abnormalities similar to affected patients and suspects (p> 0.05).

CONCLUSIONS

Patients with PAC were significantly more likely to be female, have shorter axial length, and have thicker lenses compared with unaffected individuals. PAC suspects showed similar axial lengths to affected individuals. ERG abnormalities mainly occurred in affected patients and suspects, but also occurred in unaffected individuals with short axial length.