Stabilization of refractive error and associated factors following small incision phacoemulsification cataract surgery.

BACKGROUND: Accumulating evidence suggests that refractive stabilization occurs rapidly following small incision cataract surgery. Nonetheless, many guidelines still suggest waiting four to 6 weeks before prescribing corrective lenses. This study was undertaken to supplement the existing literature regarding refractive stabilization, and evaluate multiple contributing factors that could dissuade clinicians from confidently correcting refractive error in the early post-operative course following routine cataract surgeries. METHODS: Adult patients undergoing phacoemulsification cataract surgery with uncomplicated surgeries and post-surgical courses at the Calgary Ophthalmology Centre (Calgary, Alberta, Canada) were included in this prospective observational case series. Exclusion criteria included known corneal dystrophies, infectious keratitis, complicated surgery or toric/multifocal IOLs. Data was collected at weekly intervals for a total of 6 weeks. Collected data included autorefraction, visual acuity, corneal pachymetry, and effective lens position. RESULTS: One hundred six eyes of 104 patients were included in this study. Post-operative sphere, cylinder and spherical equivalent were not significantly different at any post-operative week compared with week six, and 80-86% of patients were within 0.5D of last follow-up spherical equivalent at any week. The secondary outcomes of central corneal thickness, effective lens position and visual acuity did, however, exhibit significant differences between early post-operative weeks and last follow-up values. CONCLUSIONS: These data suggest that refractive error can be effectively measured and corrected as early as one-week post-operatively in the majority of patients, though other measures of post-operative stability including central corneal thickness, effective lens position and visual acuity can require up to 4 weeks to stabilize. Thus a conservative and pragmatic approach may be to wait until 4 weeks post-operatively prior to obtaining refractive correction following uncomplicated phacoemulsification cataract surgery.

Selective Laser Trabeculoplasty versus Argon Laser Trabeculoplasty in Glaucoma Patients Treated Previously with 360° Selective Laser Trabeculoplasty: A Randomized, Single-Blind, Equivalence Clinical Trial.

PURPOSE: The effectiveness of selective laser trabeculoplasty (SLT) was compared with argon laser trabeculoplasty (ALT) in a randomized clinical trial for patients with medically uncontrolled open-angle glaucoma who have previously received 360° SLT. DESIGN: An active equivalence parallel armed randomized control trial. PARTICIPANTS: Patients with open-angle glaucoma including pigmentary dispersion syndrome and pseudoexfoliation syndrome were enrolled into the study from 7 different sites across Canada. METHODS: One setting of 180° of either SLT or ALT was assigned randomly and applied to each participant. MAIN OUTCOME MEASURES: The change in intraocular pressure (IOP) from baseline to 12 months was compared between the 2 groups. RESULTS: A total of 132 patients were recruited, 2 of which dropped out early in the study, leaving 130 patients who completed the study as per protocol. For those, the study's primary outcome was calculated. The IOP change at 1 year in comparison to baseline for SLT vs. ALT was found to be different by 0.33 mmHg between the 2 groups (3.16 for SLT and 2.83 for ALT) and was not statistically significant (P = 0.71) Further analysis, though, showed that SLT had a significantly lower IOP reduction at early time points: 1 week and 1 month, but this effect was lost by 3 months. Corresponding to this finding was the strong trend for ALT to fail more quickly than SLT. Although repeatable, the first repeat SLT reduced IOP to only about half compared with initial SLT treatment. CONCLUSIONS: The comparison at 12 months following the laser therapy showed that both modalities lowered the IOP with approximately 3 mmHg, yet essentially all of the time-to-failure analyses favored SLT over ALT. The repeat SLT effect was found to be half of the initial treatment.

Efficacy of gonioscopy-assisted transluminal trabeculotomy in advanced-age glaucoma patients.

BACKGROUND: The prevalence and severity of many etiologies of glaucoma increase with age, often requiring surgery later in life. Surgery in the most aged demographic, however, poses multiple unique physiologic and psychosocial challenges with variable outcomes. In this study, we evaluate the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in an advanced-age population (>85 years of age). METHODS: This is a single-centre retrospective cohort study of consecutive patients who underwent GATT at or above 85 years of age. This included patients with GATT of any circumferential extent (90°-360°) with or without concurrent phacoemulsification cataract surgery. The primary outcome measure was proportion of successful surgeries at 1 year by the "complete success" criteria (intraocular pressure [IOP] <17 mm Hg on no medications 3 months after surgery with no additional interventions). Secondary outcomes included proportion of successful surgeries by alternative criteria, cross-sectional analyses of IOPs and medication use, and analyses of postoperative complications and interventions. RESULTS: Forty eyes of 31 patients were included in the study. Mean baseline IOP was 16.75 ± 7.33 mm Hg on 1.60 ± 1.43 classes of medication. At 1 year, the cumulative survival by Kaplan-Meier analysis was 46.6%. There was a statistically significant reduction in IOP at all postoperative time points to a mean of 11.78 ± 3.07 mm Hg at the last follow-up. There were postoperative complications in 18 eyes, with hyphema and corneal edema accounting for the majority. CONCLUSIONS: This study provides evidence that GATT is a safe and effective intervention in advanced-age glaucoma populations.

Cytomegalovirus as a cause of recurrent corneal endotheliitis in the Canadian population.

OBJECTIVE: To report the clinical manifestations, response to antiviral treatment, and long-term visual outcomes of cytomegalovirus endotheliitis in a Canadian population. DESIGN: Retrospective case series. PARTICIPANTS: A total of 9 eyes of 7 patients referred to a cornea subspecialty clinic in a major Canadian centre with corneal endotheliitis. METHODS: A retrospective review of all patients presenting with corneal endotheliitis to 1 corneal surgeon was completed. Patients underwent anterior chamber biopsy with positive cytomegalovirus polymerase chain reaction. All patients received systemic valganciclovir for a minimum of 3 months. Primary outcomes included visual acuity, intraocular pressure control, medication dependence, and corneal status. RESULTS: The average follow-up was 76.4 ± 11.8 months. Two patients had bilateral disease. Corneal manifestations included linear, disciform, and circinate patterns of endotheliitis. Best-corrected visual acuity improved from a mean of 0.48 ± 0.19 logMAR at presentation to 0.24 ± 0.11 logMAR at last follow-up. Intraocular pressure decreased from a peak of 35 ± 3.1 mm Hg to 14.2 ± 4.3 mm Hg. Antiglaucoma medications were reduced from 2.6 ± 0.45 to 0.89 ± 0.29 agents. Two eyes required endothelial transplantation. Valganciclovir therapy was well tolerated by all patients; at the time of last follow-up, all patients were stable on low-dose valganciclovir at an average dose of 1395 mg per week. CONCLUSIONS: Cytomegalovirus is an uncommon but clinically significant cause of corneal endotheliitis that must be considered in the differential diagnosis of corneal endotheliitis, even in the immunocompetent population. Our results support prior findings that this entity responds robustly to oral valganciclovir and demonstrate for the first time the efficacy of chronic low-dose antiviral maintenance therapy.

Ab Interno Canaloplasty in Open-angle Glaucoma Patients Combined With In Vivo Trypan Blue Aqueous Venography.

PURPOSE: To demonstrate canalogram patterns observed when trypan blue tracer is combined with oculoviscoelastic device during ab interno canaloplasty, and discuss surgical results and potential implications for diagnosis, prognosis, and treatment. METHODS: This is a retrospective small case series study. RESULTS: The authors performed this procedure on 5 patients with informed consent with 4 to 18 months of follow-up. All procedures have been complication free. The average preoperative intraocular pressure was 16.4 mm Hg with an average number of topical glaucoma medications being equal to 3.6. Postoperatively, the average intraocular pressure for the group was reduced to 13 mm Hg with a concurrent drop in the average number of topical medications used equaling 1.8. CONCLUSIONS: Currently, there are limited practical options to evaluate the patency of the aqueous outflow system in our patients. The primary purpose of this paper is to describe canalogram patterns observed during ab interno canaloplasty with trypan blue. This technique may allow us to further our understanding of the aqueous outflow system and its role in the underlying pathophysiology of glaucoma. Further research is required to evaluate the prognostic and diagnostic significance of this technique.

Management of Ocular Surface Disease in Glaucoma: A Survey of Canadian Glaucoma Specialists.

PRéCIS:: Ocular surface disease (OSD) in glaucoma is an area for improvement in the management of patients with glaucoma. This study explores the knowledge of glaucoma subspecialists toward OSD in glaucoma, then provides a suggested treatment algorithm. PURPOSE: To assess the attitudes, knowledge, and level of comfort of Canadian glaucoma specialists with respect to the assessment and management of OSD among patients with glaucoma. METHODS: Ophthalmologist members of the Canadian Glaucoma Society with fellowship training in glaucoma were contacted to participate in this cross-sectional survey study. Responses were recorded to statements regarding attitudes toward OSD in glaucoma, and assessment and management modalities. These were recorded primarily in the form of a Likert scale rated 1 to 7 from "strongly disagree" to "strongly agree." Descriptive statistics were generated, and mean and SD for responses on Likert scales. RESULTS: Thirty-six responses were included. All respondents agreed that comprehensive management of OSD could improve quality of life, 97% agreed it could lead to better glaucoma outcomes, whereas only 22% agreed it is presently being adequately managed in glaucoma practices. Respondents were asked to list all treatment modalities they felt knowledgeable about, ranging from 100% for optimizing topical glaucoma therapies to 31% for serum tears. Nearly all respondents (92%) agreed that a suggested algorithm for the treatment of OSD in glaucoma could improve their approach to management. CONCLUSION: OSD is a common comorbidity of glaucoma. Although respondents overwhelmingly agreed that comprehensive management of OSD may lead to improved quality of life and glaucoma-related outcomes, only a small percentage felt it was presently adequately managed. Increasing knowledge related to the assessment and management of OSD in glaucoma may in the future improve patient care.

Cadaver corneoscleral model for angle surgery training.

PURPOSE: To assess a new training model (Tackdriver) for new-generation microinvasive glaucoma surgeries (MIGS). SETTING: Resident training centers in Canada. DESIGN: Evaluation of technology. METHODS: Human cadaver corneoscleral rims recovered after Descemet-stripping endothelial keratoplasty or not suitable for transplantation were acquired from an eye bank. The tissue was fixated with a single tack through the center of the cornea, which was inverted in a concave fashion. A water-based medical lubricant was used for placement of a goniolens after visualization of the anterior chamber and the trabecular meshwork. Microbypass stent (iStent) insertion and gonioscopy-assisted transluminal trabeculotomy (GATT) were practiced on this model. The model was qualitatively assessed for ease of preparation, accuracy of surgical simulation, and the number and variety of MIGS procedures that can be performed. RESULTS: Efficient high-volume training was performed for microbypass stent insertion using first-generation and second-generation microbypass stents. The GATT procedure was also performed as a final step in a titratable fashion in 90-, 180-, or 270-degree segments or a complete 360-degree treatment. The model simulated bimanual angle surgery with good fidelity. CONCLUSIONS: The training model allowed for high-volume bimanual MIGS training for techniques such as microbypass stent insertion and removal as well as GATT. Preparation was relatively simple, efficient, and cost-effective compared with other models. Inverting the specimen allowed the trainee to practice MIGS techniques independent of the tissue's corneal clarity. Other MIGS techniques and angle training procedures can be adopted to this model.

Evaluation of a modified protocol for selective laser trabeculoplasty.

PURPOSE: To compare the intraocular pressure (IOP) response to a modified protocol for selective laser trabeculoplasty (SLT) to standard protocols for SLT and argon laser trabeculoplasty (ALT). MATERIALS AND METHODS: A retrospective study of 318 eyes of 284 patients diagnosed with either primary open angle, pigmentary or pseudoexfoliation glaucoma who underwent laser trabeculoplasty from September 1997 to September 2005. One hundred and two patients, who underwent a modified SLT protocol with 100 overlapping laser spots over 180 degrees of trabecular meshwork were compared with 89 patients who received SLT with 100 nonoverlapping spots over 360 degrees and another 127 patients who received ALT with 50 spots over 180 degrees. IOPs were measured at baseline and postoperatively at 1 hour, 6 weeks, 4 months, and 14 months. Regression models, based on the observed data, were used to predict the fall in IOP in the 3 groups, controlling for differences in baseline pressure. RESULTS: The IOP response to overlapping SLT was significantly worse than to nonoverlapping SLT or ALT, both of which had similar responses. Baseline IOP was the only preoperative factor that predicted response to ALT (P<0.0001) and nonoverlapping SLT (P=0.0019) at all follow-up times. There were no statistically significant predictive factors for IOP reduction in the overlapping SLT group. CONCLUSIONS: Overlapping application of SLT results in a poorer IOP response compared with ALT and nonoverlapping SLT.

Evaluation of occupational ocular trauma: are we doing enough to promote eye safety in the workplace?

OBJECTIVE: The aim of this study was to document the use of eye personal protective equipment (PPE) by patients who had sustained an eye injury in the workplace and to evaluate the characteristics and outcomes of these patients. DESIGN: Case-control study. PARTICIPANTS: All adult patients who had sustained an eye injury in the workplace and presented to the urgent ophthalmology clinic of a tertiary care hospital from October 1, 2013, to November 30, 2014, were eligible for inclusion. METHODS: Medical records were reviewed to obtain occupational eye injury data, including etiology, type, and severity of injury as per the Ocular Trauma Score. Use of eye PPE at the time of injury was recorded. Outcome data, including disposition, duration of follow-up, and return to baseline best-corrected visual acuity, were also recorded. RESULTS: One hundred sixty-nine patients were included in this study. The median age of the cohort was 31 years (range, 17-68 years), and 92.9% were male. Chemical exposure (31.4%), grinding (17.9%), and injuries sustained by a sharp-object, metal, or nail (13.1%) were overall the most common etiologies of injury. Eye PPE was not worn by 66.9% of the cohort, with 33.1% of the cohort sustaining an occupational eye injury despite the use of eye PPE. CONCLUSIONS: Use of eye PPE among workers who sustain an eye injury in the workplace remains low; yet, its use does not preclude a significant proportion of such workers from injury. Increasingly advocating for both the use and appropriate selection of eye PPE in the workplace is an important public health initiative that should therefore be encouraged.

Morning dosing of once-daily glaucoma medication is more convenient and may lead to greater adherence than evening dosing.

PURPOSE: To determine if adherence and convenience of once-daily glaucoma medication is greater in the morning or the evening. DESIGN: Prospective, randomized crossover treatment trial. PATIENTS AND METHODS: Thirty patients newly diagnosed with glaucoma or ocular hypertension requiring intraocular pressure (IOP) reduction were started on travoprost eye drops and randomized to either morning or evening administration for 1 month. They were then crossed over to the opposite dosing schedule for the following month. Adherence was monitored using an automated dosing aid. MAIN OUTCOME MEASURES: Adherence was compared between morning versus evening dosing and first versus second month dosing. Demographic characteristics were obtained, treatment effect was measured, and patients completed a post-study questionnaire regarding the convenience of the 2 dosing regimens. RESULTS: Patient adherence overall was good (89.3%). There was no statistically significant difference (P=0.07) in adherence between morning dosing (90.9%) and evening dosing (87.3%). Adherence in the first month (91.7%) was superior to the second month (86.5%). There was no significant difference in IOP response between morning and evening dosing. Patients found morning dosing more convenient than evening dosing. CONCLUSIONS: Early adherence to treatment with a prostaglandin analogue is good, but patients prefer morning administration to evening administration. This may lead to greater adherence with morning administration, particularly among men. Adherence decreases from the first to second month after initiation of treatment. IOP response to this treatment is not significantly affected by morning versus evening administration.

Comparison of data analysis tools for detection of glaucoma with the Heidelberg Retina Tomograph.

PURPOSE: To evaluate the performance of three linear discriminant functions (LDFs) and the Moorfields Regression Analysis (MRA) in classifying optic disc topography images obtained with the Heidelberg Retina Tomograph (HRT) from patients with open-angle glaucoma and normal controls. Furthermore, to investigate whether the classification of glaucomatous eyes is related to the severity of visual field loss or to optic disc size. DESIGN: Prospective comparative observational case series. PARTICIPANTS: One eye of 104 patients with a diagnosis of open-angle glaucoma (mean age, 63.2; range, 30-88 years) and 48 normal controls (mean age, 52.4; range, 33-75 years). TESTING: Subjects were examined with the HRT. MAIN OUTCOME MEASURES: Diagnostic performance was calculated for the LDFs published by Mikelberg et al (LDF1), Burk (LDF2), and Bathija et al (LDF3) and for the MRA. RESULTS: Large differences in sensitivity and specificity were found among the different analyses when using the originally suggested cutoff criteria. When specificity was equalized to 90%, the sensitivities were more similar (LDF1, 55%; LDF2, 61%; and LDF3, 67%). At 95% specificity, the sensitivities decreased further (LDF1, 39%; LDF2, 55%; LDF3, 44%). When treating the "borderline" outcomes as test positives, MRA sensitivity and specificity were 78% and 81%, respectively. When treating the "borderline" outcomes as test negatives, the MRA gave a sensitivity of 58%, with a specificity of 96%. In glaucoma patients, the correlation between the severity of visual field damage, as measured by the mean deviation index, and the outcome of the classification systems was low to moderate (Spearman's r between 0.26 and 0.39). When the entire sample was stratified into equal thirds on the basis of optic disc size, large discs (area > 2.10 mm(2)) tended to be classified with a higher sensitivity but lower specificity than small discs (area < 1.73 mm(2)) with all methods except LDF3. Using a multiple regression model controlling for mean deviation, LDF1, and LDF2, but not LDF3, were significantly influenced by disc size. CONCLUSIONS: The 4 methods of analysis had similar sensitivities once their specificities were equalized. In this sample, the LDFs and MRA generally did not discriminate between glaucoma patients and controls as well as reported in the original respective studies that described the methods.