Outcomes and risk factors for Kahook Dual Blade excisional goniotomy with concomitant phacoemulsification: a multicentre Canadian study.

OBJECTIVE: To assess the outcomes and failure risk factors for Kahook Dual Blade (KDB) excisional goniotomy with cataract surgery (phaco-KDB) in eyes with various glaucoma subtypes and severities. METHODS: This multisurgeon consecutive case series included glaucomatous eyes with cataract that underwent phaco-KDB and had a minimum follow-up of 12 months postoperatively. Efficacy was assessed by absolute and qualified surgical success (defined by different criteria) and changes in intraocular pressure (IOP) and antiglaucoma medication (AGM) at the last postoperative follow-up. Safety included best-corrected visual acuity, cup-to-disc ratio, visual field mean deviation, retinal nerve fibre layer thickness, and adverse events. RESULTS: A total of 108 eyes of 89 patients with a median follow-up of 18 months (range, 12-47 months) were included. IOP decreased by 26% from 19.1 ± 5.0 mm Hg to 14.1 ± 3.5 mm Hg (p < 0.001), AGM use decreased by 29% from 2.4 ± 1.3 medications to 1.7 ± 1.3 (p < 0.001), and 25% of eyes became free of AGMs (vs 3% at baseline). Qualified success rates achieved for IOP cutoffs of 18, 15, and 12 mm Hg were 87%, 68%, and 46%, respectively. Higher baseline IOP and postoperative incidence of IOP spikes were associated with a higher risk of surgical failure. Best-corrected visual acuity improved postoperatively (p < 0.001), and visual field mean deviation, cup-to-disc ratio, and retinal nerve fibre layer thickness remained stable. Overall, safety was favourable, and adverse events were transient and not sight threatening. CONCLUSION: This multicentre Canadian study provides real-world data that support the safety and efficacy of phaco-KDB in reducing IOP and AGM use with no evidence of disease progression during the follow-up period.

Investigation of the Peripapillary Choriocapillaris in Normal Tension Glaucoma, Primary Open-angle Glaucoma, and Control Eyes.

PRECIS: The peripapillary choriocapillaris (CC) was observed to be significantly impaired in normal tension glaucoma (NTG) subjects compared with normal controls using optical coherence tomography angiography (OCTA). PURPOSE: The aim was to quantitatively evaluate the peripapillary CC in NTG, primary open-angle glaucoma (POAG), and control eyes using OCTA. MATERIALS AND METHODS: Ninety eyes (30 controls, 30 NTG, and 30 POAG) from 73 patients were imaged using the Zeiss Plex Elite 9000. Five repeat 3×3 mm OCTA scans were acquired both nasally and temporally to the optic disc and subsequently averaged. Four CC flow deficit (FD) measures were calculated using the fuzzy C-means approach: FD density (FDD), mean FD size (MFDS), FD number (FDN), and FD area (FDA). RESULTS: Temporal NTG CC parameters were associated with visual field index and mean deviation (P<0.05). The control group showed a significantly lower nasal FDD (nasal: 3.79±1.26%, temporal: 4.48±1.73%, P=0.03), FDN (nasal: 156.43±38.44, temporal: 178.40±45.68, P=0.02), and FDA (nasal: 0.22±0.08, temporal: 0.26±0.10, P=0.03) when compared with temporal optic disc. The NTG group showed a significantly higher FDD (NTG: 5.04±2.38%, control: 3.79±1.26%, P=0.03), FDN (NTG: 185.90±56.66, control: 156.43±38.44, P=0.04), and FDA (NTG: 0.30±0.14 mm2, control: 0.22±0.08 mm2, P=0.03) nasal to the optic disc compared with controls. CONCLUSIONS: Association between CC parameters and glaucoma severity in NTG, but not POAG subjects, suggests vascular abnormalities may be a potential factor in the multifactorial process of glaucoma damage in NTG patients.

Focal limbal stem cell deficiency associated with soft contact lens wear.

OBJECTIVE: The aim of this study is to summarize the clinical characteristics of patients with contact lens-associated focal limbal stem cell deficiency (FLSCD) from a tertiary corneal referral centre. DESIGN: Retrospective, observational case series in a tertiary care centre. METHODS: Patients with contact lens-associated FLCSD were identified in our database. Clinical data were retrieved by chart review. A questionnaire asking for contact lens brand, type, cleaning solution, and duration of contact lens wear was sent to the patients with telephone follow-up. Clinical features and recovery time were identified. RESULTS: Twenty-seven eyes of 17 patients were identified with superior corneal whorl-like patches of opaque epithelium, sometimes accompanied by neovascularization. Of the patients, 17/17 used soft contact lenses, with a mean wearing duration of 11.4 hours per day. Patients had been wearing lenses for an average of 18.1 years. Silicone hydrogel lenses were noted in 12/17 cases. LSCD was superior in all 27 eyes, and all of them improved with contact lens wear cessation, preservative-free topical steroids, and preservative-free artificial tears. Visual acuity improved from 20/28 to 20/22 (p < 0.001). CONCLUSIONS: Contact lens-associated FLSCD typically presents in the superior cornea with whorl-like epithelial opacities advancing from the limbus. Conservative medical treatment is available and shows a high success rate after a slow recovery.

Quantitative Optical Coherence Tomography Angiography of Radial Peripapillary Capillaries in Glaucoma, Glaucoma Suspect, and Normal Eyes.

PURPOSE: To evaluate the quantitative characteristics of the radial peripapillary capillary (RPC) network in glaucoma, glaucoma suspect, and normal eyes using speckle variance optical coherence tomography angiography (OCT-A). To determine correlations between RPC density, nerve fiber layer (NFL) thickness, and visual field indices. DESIGN: Cross-sectional study. METHODS: OCT-A images of RPCs were acquired at a single institution using a custom-built 1060 nm system from 3 groups: unilateral glaucoma (10 eyes from 5 subjects), glaucoma suspects (6 eyes from 3 subjects), and normal control eyes (16 eyes from 9 normal subjects). Peripapillary NFL thickness measurements were determined using spectral-domain optical coherence tomography. Glaucoma and glaucoma suspects also underwent automated 30-2 Humphrey visual field analysis. Manual tracing techniques were used to quantify RPC density in the OCT-A images. Data were analyzed using a linear mixed model with 1 fixed-effect covariate. Correlations between main outcome measures (RPC density, NFL thickness, and visual field index) were determined. RESULTS: Mean age was not significantly different between the 3 groups (P = .25). The density of RPCs was significantly lower in glaucomatous eyes compared with matched-peripapillary regions in the fellow eye, glaucoma suspect group, and normal group (all P < .001). RPC density was strongly correlated with NFL thickness (P < .001) and visual field index (P < .001). CONCLUSIONS: Significant reductions in RPC density were correlated with sites of NFL decrease and visual field loss in glaucoma. Speckle variance OCT-A allows visualization and quantification of RPCs and may therefore be a useful tool for indirectly quantifying and monitoring retinal ganglion cell axonal injury in glaucoma.

The corneal ulcer one-touch study: a simplified microbiological specimen collection method.

PURPOSE: To determine if a new, single-sample device (ESwab; Copan Diagnostics, Inc) can simplify the traditional multi-sample approach to specimen collection in infectious keratitis. DESIGN: Prospective, diagnostic test evaluation. METHODS: In this institutional study, patients with suspected infectious keratitis meeting traditional criteria for diagnostic corneal specimen collection and culture were randomized to the order of first specimen collection method: ESwab or a sample directly plated for growth on chocolate agar. This was followed by standard samples for blood agar, Gram stain, Sabouraud agar, thioglycolate broth, and brain heart infusion broth in all cases. The specimens collected using the 2 approaches were analyzed separately by the laboratory in a masked fashion. The main outcome measure was positive growth on cultured media. RESULTS: Eighty-one eyes from 80 consecutive patients were sampled. Culture positivity rate for the multi-sample method and ESwab was 70% and 69%, respectively, with a 75% agreement rate. ESwab sensitivity was 84% (95% confidence interval [CI]: 72%-93%), with a specificity of 67% (95% CI: 45%-84%). Positive and negative predictive values of the ESwab were 86% (95% CI: 74%-94%) and 64% (95% CI: 43%-82%), respectively. There was no difference in positive culture reports with respect to the order of specimen collection technique used. CONCLUSIONS: The single-sample ESwab method is a more accessible and less cumbersome approach to corneal culturing for ophthalmologists, particularly those in the community setting who do not have access to the full set of traditional culture materials. Culture results using this single-sample approach were comparable to the multi-sample method.

High-density silicone oil Densiron-68 as an intraocular tamponade for primary inferior retinal detachments.

PURPOSE: To evaluate the effectiveness and safety of the heavy silicone oil Densiron-68 as an internal retinal tamponade after vitrectomy in patients with primary inferior rhegmatogenous retinal detachment. METHODS: A retrospective consecutive case series involving inferior rhegmatogenous retinal detachment in 42 patients recruited between 2007 and 2010 was completed. All patients underwent primary vitrectomy followed by injection of Densiron-68. Each patient was then examined at 1 week, 1 month, 3 months, and 6 months after its removal. Included patients had a rhegmatogenous retinal detachment with at least 1 retinal break between 4 and 8 clock hours and completed 6 months of follow-up after removal of Densiron-68. Assessments for reattachment of the retina, visual acuity, and any complications from the surgery were recorded. RESULTS: Thirty-nine of 42 patients completed all follow-up visits. Anatomical success was achieved in 85% (33 of 39) of cases with one procedure, increasing to 95% (37 of 39) with additional surgery. The mean visual acuity improved from mean logarithm of the minimum angle of resolution of 1.29 ± 0.61 preoperatively to 0.87 ± 0.67 postoperatively. The most common complications were cataracts (83%, 10 of 12), posterior capsular opacification (22%, 6 of 27), and ocular hypertension (15%, 6 of 39). CONCLUSION: High anatomical success rates can be achieved with primary vitrectomy for inferior rhegmatogenous retinal detachment with the use of Densiron-68.

Motivations and future trends: a survey of Canadian ophthalmology residents.

BACKGROUND: There has been little investigation into the attitudes and aspirations of current ophthalmology residents. The object of this study was to investigate the factors influencing career choice and to identify the future plans of Canadian ophthalmology residents. METHODS: All ophthalmology residents in English Canadian ophthalmology residency training programs were invited to complete an anonymous survey in June 2006. Data were categorized by demographic variables and basic statistics; chi2 comparative analyses were performed. RESULTS: Of 128 residents surveyed, 49 (38%) responded to the survey. Having the ability to combine medicine and surgery was the most common factor influencing the decision to pursue ophthalmology (98% of respondents), with intellectual stimulation (76%) and mentorship (50%) also emerging as important factors. The majority of residents (62%) plan on pursuing fellowship training, with medical retina, anterior segment/cataract, and cornea being the most popular choices (36%, 34%, and 32%, respectively). Most residents expressed plans of pursuing fellowships abroad, and only 22% planned on training within Canada. Fourteen percent indicated an interest in performing laser refractive surgery, female residents being significantly less likely than males to express such an interest (0% vs. 21%; p < 0.02). Most residents (71%) expressed the wish to practice in an urban or suburban setting, with only 6% intending to work in a rural community. INTERPRETATION: The appeal of the dual medical and surgical nature of ophthalmology is the most common motivating factor for pursuing an ophthalmology residency. The trends identified, including the high level of interest in subspecialty training and the desire to work in an urban setting, have important implications for the future of ophthalmology in Canada.