Canadian legal cases in ophthalmology: a closer look at 40 years' worth of data.

OBJECTIVE: To assess the characteristics of malpractice lawsuits against Canadian ophthalmologists and the predisposing factors leading to claims. DESIGN: Retrospective case series. METHODS: A systematic search of the 2 largest Canadian online legal databases, LexisNexis Canada and Westlaw Canada, was performed to collect cases against ophthalmologists in Canadian courts from 1977 to 2021. RESULTS: This study comprised 68 legal cases, including 52 lawsuits, 14 cases appealed once, and 2 cases appealed twice. Most cases concerned surgical procedures (46.2%), followed by misdiagnoses or lack thereof (32.7%) and nonsurgical procedures (21.2%). Half the cases (n = 26) were immediately dismissed by the judge in favour of the ophthalmologist, though among the remaining half that proceeded to trial the majority (88.5%) were won by the patients. All appeals by patients were dismissed by the judge. The median monetary value of damages awarded was $308,202. CONCLUSIONS: This study is the first to report on ophthalmology-involved medical litigation cases in Canada. Most cases were ruled in favour of the ophthalmologist, but most of those that were not immediately dismissed by the judge were ruled in favour of the plaintiff. Notably, a plurality of these cases argued for a lack of informed consent, and every case in which a lack was successfully pleaded was ruled in favour of the plaintiff, highlighting the importance of appropriate informed consent. The findings of this study give Canadian ophthalmologists insight into areas of practice that commonly lead to litigation and can aid in improving clinical practice and risk management.

EXTENSIVE ORBITAL AND PARAPHARYNGEAL EMPHYSEMA REQUIRING URGENT CANTHOTOMY AND CANTHOLYSIS AFTER PARS PLANA VITRECTOMY.

PURPOSE: The authors report the emergent management of a case of orbital and parapharyngeal emphysema causing orbital compartment syndrome and signs of peripheral neuropathy days after pars plana vitrectomy. METHODS: Case report. RESULTS: A 20-year-old woman underwent 3-port 23-gauge pars plana vitrectomy in the right eye for total retinal detachment under general anesthesia. All sclerotomies were secured with 7-0 polyglactin 910 (Vicryl; Ethicon) sutures before instillation of 15% C3F8 gas. On the third postoperative day, the patient presented with a 3-mm proptosis, near-total ophthalmoplegia, jaw protrusion, head deviation, tongue protrusion, and facial twitching. Computed tomography showed extensive subcutaneous gas in the right orbit and bilateral parapharyngeal spaces, and a tethered right optic nerve with globe tenting. A decision was made to perform urgent lateral canthotomy and cantholysis. Three hours after canthotomy and cantholysis, her neurologic signs had resolved except for intermittent tongue protrusion, which resolved thereafter. At postoperative Week 7, the patient's vision was 20/70 and her intraocular pressure was 13 mmHg. CONCLUSION: To the authors' knowledge, this is the only report of a modern small-gauge vitrectomy procedure being complicated by orbital compartment syndrome and extensive emphysema causing peripheral neuropathy, and successfully treated with urgent canthotomy and cantholysis.

Imaging Biomarkers and Their Impact on Therapeutic Decision-Making in the Management of Neovascular Age-Related Macular Degeneration.

These recommendations, produced by a group of Canadian retina experts, have been developed to assist both retina specialists and general ophthalmologists in the management of vision-threatening neovascular age-related macular degeneration (nAMD). The recommendations are based on published evidence as well as collective experience and expertise in routine clinical practice. We provide an update on practice principles for optimal patient care, focusing on identified imaging biomarkers, in particular retinal fluid, as well as current and emerging therapeutic approaches. Algorithms for delivering high-quality care and improving long-term patient outcomes are provided, with an emphasis on timely and appropriate treatment to preserve and maintain vision. In the context of nAMD, increasing macular fluid or leakage on fluorescein angiography (FA) may indicate disease activity regardless of its location. Early elimination of intraretinal fluid (IRF) is of particular relevance as it is a prognostic indicator of worse visual outcomes. Robust referral pathways for second opinion and peer-to-peer consultations must be in place for cases not responding to intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy.

One-year outcomes of Aflibercept for refractory diabetic macular edema in Bevacizumab nonresponders.

Purpose: A sub-population of patients with diabetic macular edema (DME) responds less effectively to off-label use of Bevacizumab. Approval of Aflibercept for DME has offered Bevacizumab nonresponders an alternative therapeutic option. Herein, we investigate the anatomical and functional changes associated with Aflibercept treatment in Bevacizumab nonresponders with chronic DME in a Canadian setting. Methods: A retrospective study of eyes with persistent DME that were switched to Aflibercept due to nonresponse following ≥6 consecutive monthly Bevacizumab injections was performed. Anatomical and functional changes and the predictors of response were assessed using patients' characteristics prior to receiving their first (baseline) and seventh consecutive Aflibercept injections (follow-up). Results: Twenty-four eyes were included, with a mean age of 63.9 ± 10.7 years, an average of 16.8 ± 8.5 Bevacizumab injections prior to switching to Aflibercept, and mean follow-up duration of 11.8 ± 1.7 months following switching to Aflibercept. Best-corrected visual acuity (BCVA) improved significantly from 0.49 ± 0.13 to 0.41 ± 0.11 logMAR (P < 0.001) and central subfield thickness (CST) decreased by 119.4 µm from 409.4 ± 85.8 µm to 290.0 ± 64.5 µm (P < 0.001), with 50% of eyes showing complete anatomical response. Worse BCVA and higher CST at baseline predicted greater vision improvements (P = 0.001 and P = 0.035, respectively) while a larger decrease in CST was associated with greater baseline CST (P = 0.001) and better glycemic control (P = 0.039). Conclusion: Our data from a real-world clinical setting highlight the efficacy of Aflibercept as an alternative therapeutic option for DME recalcitrant to Bevacizumab, with potential additional benefit to those with worse vision, greater CST, and better glycemic control at baseline.

EPSTEIN-BARR VIRUS ACUTE RETINAL NECROSIS IN AN IMMUNOCOMPETENT HOST.

PURPOSE: To describe a case of Epstein-Barr virus (EBV)-associated acute retinal necrosis (ARN) in an immunocompetent patient and to summarize the clinical features of published molecularly confirmed EBV-ARN cases. METHODS: Case report and literature review. RESULTS: An 83-year-old immunocompetent woman with unilateral ARN presented with visual acuity of light perception. Oral valacyclovir was started. One week later, vitrectomy was conducted for worsening inflammation. Intraoperatively, a severe confluent necrotizing retinitis and occlusive vasculitis involving all four quadrants of posterior and peripheral retina were noted. Vitreous polymerase chain reaction was exclusively positive for EBV. Other autoimmune, infective, and hematological work-up was negative. The retinitis resolved 3 months later, but with significant macular and generalized retinal atrophy, visual acuity remained light perception. From the literature, there are four EBV-ARN cases (six eyes) diagnosed based on polymerase chain reaction or fluorescence in-situ hybridization of vitreous or retinal samples. All patients were immunocompromised or on immunosuppressive treatment. Presenting visual acuity was light perception or worse in 3/6 eyes. Three patients received systemic acyclovir-based therapy. Vitrectomy was performed in 4/6 eyes between 4 and 8 weeks from disease onset. All cases had involvement of the posterior and peripheral retina. Retinal detachment occurred in 2/6 eyes, and final visual acuity was no light perception in 3/6 eyes. CONCLUSION: This case expands the clinical spectrum of EBV-ARN to include infection in immunocompetent hosts. Epstein-Barr virus-ARN seems to be characterized by a global peripheral and posterior fulminant retinitis, with adverse visual acuity outcomes despite systemic acyclovir-based therapy. The benefits of adjunctive intravitreal foscarnet, systemic steroids, and early vitrectomy may warrant further investigation.

Prognostic factors of postoperative intraretinal cystoid spaces after primary pars plana vitrectomy for vitreomacular traction.

PURPOSE: To study the anatomical and surgical prognostic factors related to developing postoperative intraretinal cystoid spaces (ICS) six months after 25-gauge pars plana vitrectomy (PPV) for vitreomacular traction (VMT). METHODS: The study is a retrospective case series of patients presenting with VMT treated primarily with PPV. All patients underwent 25-gauge PPV by the same retina surgeon. Intra-operative parameters were all recorded. Postoperative visual acuity (VA), foveal thickness, and ICS were collected over six months of follow-up. ICS were defined as hyporeflective cysts divided by hyperreflective septa on optical coherence tomography (OCT). Patients with ICS persistence 3 months postoperatively received topical treatment extension. The primary outcome measure was odds of preoperative ICS in patients with postoperative ICS compared to controls. Secondary outcome measures were odds of presence of an attached hyaloid to the optic disc, presence of pseudophakia, the use of intra-operative air, and the use of more than one intra-operative indocyanine green (ICG) injections in patients with postoperative ICS compared to controls. RESULTS: Two hundred and eighty treatment-naïve patients with preoperative diagnosis of epiretinal membrane (ERM) were reviewed. Thirty patients with VMT, confirmed both preoperatively on OCT and intra-operatively, were included. Postoperatively, 40% (n = 12) presented with ICS at 6 months. Among these, 83% (n = 10) had ICS prior to PPV. Patients presenting with preoperative ICS were significantly more at risk of having persistent ICS postoperatively (P < 0.05). The following factors did not statistically affect ICS occurrence: optic disc hyaloid attachment status, phakia/pseudophakia, intra-operative air vs. sulfur hexafluoride (SF6), and the number of intra-operative ICG injections. CONCLUSIONS: Our data demonstrate a predictive relationship between the occurrence/persistence of ICS post-PPV for VMT and the initial foveal status. Specifically, having preoperative ICS is a major risk factor for its persistence postoperatively. Our data highlight the pathophysiological importance of the vitreous phase and its effect on visual prognosis.

Impact of surgical case order on epiretinal membrane peeling surgery.

OBJECTIVE: To determine whether surgical warm-up affects epiretinal membrane (ERM) peeling complication rates and surgical case times. SETTING: Jewish General Hospital, Montreal, QC, Canada. DESIGN: Retrospective case-control study. METHODS: We assessed consecutive patients who underwent pars plana vitrectomy for ERM peel (macular pucker) by one surgeon at the Jewish General Hospital from January 2006 until March 2016. Cases evaluated were sequential ERM peels performed as the first 2 surgeries of the day. The first case of the day was considered the "warm-up" and the second case was the "post-warm-up." Baseline demographics, pre-operative characteristics, perioperative and postoperative best-corrected visual acuity (BCVA) at 2 months and 6 months, as well as postoperative complications are described. Results were analyzed using the χ2 test, t test, and Fischer's exact test. Regression models were used to identify any predictors of postoperative BCVA. RESULTS: The study reviewed 108 patients. The warm-up group was compared with the post-warm-up group, and there was no significant difference between the mean pre-operative BCVA and the post-operative BCVA at 2 and 6 months. ERM peeling surgery complication rates were not statistically different between the warm-up cases and the post-warm-up cases. There was a tendency for performing complex surgeries that needed phaco procedures in post-warm-up cases (13% vs 2%, p = 0.03). Analysis of simple ERM peeling procedures (with no concomitant phaco procedures) showed no statistically significant tendencies for any of the groups to go beyond the 60 minutes allocated for the surgery (25.4% vs 20.0%, p = 0.27). CONCLUSION: Warming-up does not influence the rate of postoperative complications or the postoperative BCVA in patients undergoing ERM peels. The strongest predictor of post-operative BCVA was pre-operative BCVA.

Disorganization of Retinal Inner Layers and Ellipsoid Zone Disruption Predict Visual Outcomes in Central Retinal Vein Occlusion.

PURPOSE: To assess the associations and predictive value of spectral-domain (SD) OCT inner and outer retinal structural parameters and visual acuity (VA) outcomes in macular edema (ME) secondary to central retinal vein occlusion (CRVO). DESIGN: Retrospective, longitudinal cohort study. PARTICIPANTS: Eighty-four patients with ME secondary to CRVO receiving pro re nata anti-vascular endothelial growth factor (VEGF) therapy at 3 tertiary-level retina referral centers. METHODS: In all participants, VA, demographic and clinical parameters, and SD OCT images from baseline, 3 months, and 12 months were reviewed. Spectral-domain OCT-based morphologic features in the 1500-µm foveal zone were analyzed by masked graders for disorganization of the retinal inner layers (DRIL), ellipsoid zone (EZ) and external limiting membrane disruption, cone outer segment tip (COST) visibility, cysts, subretinal and intraretinal fluid, and epiretinal membranes. MAIN OUTCOME MEASURES: Spectral-domain OCT-based retinal structural parameters and VA outcomes. RESULTS: In multivariate analyses adjusting for baseline VA, worsening VA over 1 year was associated with 1-year increases in DRIL (point estimate, 0.06 per 100 µm; P < 0.001) and EZ disruption (0.07 per 100 µm; P = 0.023), but decreased COST visibility (-0.09 per 100 µm; P = 0.018). A 3-month increase in DRIL (0.05 per 100 µm; P = 0.003) and EZ disruption (0.10 per 100 µm; P < 0.001) were the only factors predicting VA worsening over 1 year, after controlling for baseline VA. A multivariate model including 3-month evolution in DRIL, EZ disruption, and VA accounted for 86.3% of variability in 1-year VA change. Absolute differences between predicted and actual 1-year VA were within 2 lines in 80.9%. When DRIL increased by 250 µm or more over 3 months, no eyes showed VA improvement of 1 line or more in 1 year. When EZ disruption decreased by 250 µm or more over 3 months, no eyes worsened by 1 line or more over 1 year. CONCLUSIONS: Early recovery over 3 months in both DRIL and EZ parameters are key drivers of 1-year VA outcomes. Predictive models incorporating 3-month changes in DRIL and EZ disruption support their usefulness as potential robust determinants of future VA.

Ocriplasmin versus vitrectomy for the treatment of macular holes.

OBJECTIVE: To compare the anatomical and visual outcomes of patients with bilateral macular holes (MH) who have been treated with pars plana vitrectomy in one eye and intravitreal ocriplasmin in the fellow eye. DESIGN: Multicentre, retrospective case series. PARTICIPANTS: Twenty-two eyes of 11 patients with bilateral MH treated with vitrectomy in one eye and ocriplasmin in the other were included. Patients were followed-up by 5 vitreoretinal surgeons from 3 retinal practices in Canada. METHODS: All charts were reviewed for data collection, and optical coherence tomography (OCT) scans pre- and posttreatment were evaluated. RESULTS: MH closed primarily in 36.4% (n = 4) of the ocriplasmin-treated eyes and in 90.9% (n = 10) of the vitrectomy-treated eyes (p = 0.031). The 4 successfully treated ocriplasmin MH were preceded by a vitreomacular traction (VMT) release. Three additional ocriplasmin-treated eyes achieved a VMT release without MH closure. All persistent MH (100%) closed with subsequent vitrectomy, with no significant difference in final best-corrected visual acuity (BCVA) between those who achieved MH closure with primary or secondary interventions (p = 0.073). Final BCVA improved from logMAR 0.85 ± 0.34 to 0.37 ± 0.22 (p = 0.005) in the vitrectomy eyes and from 0.56 ± 0.28 to 0.28 ± 0.16 (p = 0.009) in the ocriplasmin eyes, with no significant difference in final BCVA between treatments (p = 0.306). Postoperative ellipsoid zone disruption persisted more frequently in vitrectomy-treated eyes. CONCLUSION: Both procedures were associated with improved visual outcomes, but eyes initially treated with vitrectomy had a higher primary MH closure rate. On OCT, patients had more outer structural changes in vitrectomy eyes than in ocriplasmin eyes.

Treatment of cystic cavities in X-linked juvenile retinoschisis: The first sequential cross-over treatment regimen with dorzolamide.

PURPOSE: To report the first sequential cross-over treatment with the longest ophthalmic follow-up in a case of X-linked juvenile retinoschisis (XLRS) successfully treated with topical dorzolamide. OBSERVATIONS: A healthy 34 year-old man presented with one month history of decreased visual acuity in his left eye. Funduscopy was significant for a blunted and cystoid-like foveal reflex in both eyes. The macular OCT showed cystic foveal changes OU. The patient was diagnosed with XLRS and was observed. On two subsequent follow-ups, a significant decrease in the patient's visual acuity warranted the use of topical dorzolamide for treating the cystic foveal changes, which completely resolved two months post-treatment initiation. CONCLUSION AND IMPORTANCE: Previous reports showed the benefit of dorzolamide in treating foveal cystic cavities in XLRS. To our knowledge, this is the first case of XLRS demonstrating the benefits of topical dorzolamide based on a sequential cross-over treatment regimen. It may also represent a case with the longest ophthalmic follow-up providing, in consequence, long-term understanding of the natural history and complications of this rare disease After ruling out major causes of cystoid macular edema, XLRS patients presenting with worsening of their visual acuities due to larger cystic macular changes may benefit from an alternating ON/OFF regimen of topical dorzolamide, which offers a significant treatment advantage outweighing its well-known side effects. Our study consolidates the importance of "medication vacation" by showing its efficacy in providing anatomical and visual functional improvements in patients with chronic cystic macular changes.

Long-term outcomes of sutureless 25-G+ pars-plana vitrectomy for the management of diabetic tractional retinal detachment.

PURPOSE: To evaluate the short- and long-term surgical and clinical outcomes in eyes with diabetic tractional retinal detachment (TRD) undergoing 25-G+ pars-plana vitrectomy (PPV). METHODS: A total of 238 patients were reviewed for inclusion in this study. A retrospective cohort study of 109 eyes of 73 patients operated on for diabetic TRD were included. All eyes received intraocular tamponade of air, sulfur hexafluoride, octofluropropane or silicone oil. All patients were followed up for a minimum period of one year. RESULTS: The mean age of all patients at surgery was 53.9 years ± 9.2, while the mean duration of diabetes was 18.7 ± 10.4 years. The mean length of follow-up was 923 ± 87 days after surgery (range, 432-1792 days). Thirty-two cases (29.3 %) had an associated rhegmatogenous component. Mean BCVA improved from logarithm minimum angle of resolution (logMAR) 1.17 (20/300) to 0.812 (20/130) (p < 0.05). All eyes underwent intraoperative laser photocoagulation. Primary, single-surgery anatomic reattachment was achieved in 99 eyes (91 %). Final anatomic attachment was achieved in 107 eyes (98 %). There was no statistically significant difference in primary or secondary re-attachment rate in terms of type of tamponade agent used. There were five cases of post-operative hypotony (≤5 mmHg) on postoperative day 1, while 11 eyes had IOP ≥ 30 mmHg. There were no cases of endophthalmitis in our cohort. CONCLUSIONS: 25G+ PPV provides for safe and effective repair of diabetic TRDs. Patients experienced positive functional and anatomic outcomes, with no significant intraoperative complications and minimal postoperative sequelae.

Pericyte Status in Routinely Discarded Vitrectomy Samples May Be an Early Marker of Diabetic Retinopathy.

BACKGROUND: Diabetic retinopathy (DR) is the leading cause of blindness among the working-age population. The earliest morphological manifestation of the disease is pericyte loss, as shown by animal models. AIMS: The purpose of this study was to evaluate the presence of pericytes in vitreous samples (VS) from diabetic and nondiabetic patients. METHODS: VS from 125 patients with and without diabetes were analyzed. Thirty-three of the VS contained blood vessels and were therefore included in further analysis. Pericyte status was evaluated using α-smooth muscle actin and quantified using the following scoring system: total loss (3), >50% loss (2), <50% loss (1), and no loss (0). RESULTS: Of the 33 VS, 29 samples were from patients with diabetes and 4 from nondiabetic patients. Six diabetic cases had a score of 1, 8 diabetic cases had a score of 2, and 15 cases had a score of 3. A positive correlation between glycemia levels and pericyte loss was observed (p = 0.0016; Spearman's r = 0.61). Moreover, all nondiabetic cases had a score of 0 (sensitivity and specificity = 100%). CONCLUSION: Pericyte loss in VS might be a sensitive and specific marker of DR that correlates with glycemia levels. Furthermore, VS, which are currently discarded, may contain valuable information for diabetic management.

Usefulness of Discarded Vitreous Samples from Routine Vitrectomy.

Purpose. To describe the histopathological features of vitreous samples obtained after vitrectomy surgery from diabetic and nondiabetic patients. Methods. Vitreous specimens from 137 patients who underwent vitrectomy for different clinical conditions were analysed. All samples were centrifuged and each resulting pellet was fixed and processed as part of routine paraffin section histopathology. The histopathological features were categorized in a semiquantitative fashion. The samples from diabetic and nondiabetic patients were compared. Results. The 125 included patients (58 diabetic, 60% males) were aged 64.2 ± 13.9 years. The presence of hemorrhage, inflammatory cells, and histiocytes was significantly higher in the diabetic group (P < 0.001, P = 0.028, and P = 0.016, resp.), showing more vessels (P < 0.001) and ghost vessels (P = 0.049). The presence of inflammatory cells was the feature with the highest sensitivity for detecting diabetes mellitus (98%) and also the highest negative predictive value (89%). In the multivariate analysis, three variables emerged as independent significant predictors of diabetes in vitrectomy samples: hemorrhage, endothelial-lined vessels, and age (P < 0.001, P < 0.001, and P = 0.019, resp.). Conclusions. Different histopathological features can be found in vitreous samples from diabetic patients. Analysis of vitrectomy samples may serve as a tool for diabetes management.

Spatial judgments in patients with retinitis pigmentosa.

Previous investigations into cortical plasticity in the presence of ocular disease have focused on central retinal damage. Perceptually, patients often report distortions of visual space which can be partially explained by perceptual filling-in. The mechanisms involved could also apply to peripheral field loss. Spatial interval discrimination was tested in 28 retinitis pigmentosa (RP) patients and a control group. When stimuli were presented to both hemispheres, bias did not differ whereas threshold was poorer in RP patients. When presenting the task to only one hemifield, bias was related to field asymmetry, but only in the left visual field, r(2)=.59. Brain laterality may be an important factor when examining changes in cortical function in response to peripheral system damage.

Beyond visual acuity: functional outcome and patient satisfaction following treatment for age-related macular degeneration.

OBJECTIVE: The success of current medical treatments for choroidal neovascular membranes secondary to age-related macular degeneration (AMD) has often been determined anatomically by change in lesion size and cessation of leakage. Measuring the functional success of treatments has most often revolved around visual acuity and has seldom encompassed patients' satisfaction with treatment. Using additional objective and subjective measures to assess the outcome of treatments may provide greater insight into the visual functions that are lost, maintained, or improved during the course of treatment. STUDY DESIGN: Cross-sectional study. PARTICIPANTS: Forty-six patients diagnosed with exudative AMD. Participants had received at least 1 photodynamic therapy (PDT) treatment at the time of testing (mean 3.0, SD 1.9). METHODS: Objective tests of visual function (Snellen, Early Treatment Diabetic Retinopathy Study, Minnesota Low-Vision Reading Test, Contrast Sensitivity, Face Acuity) and a subjective questionnaire, the Visual Function-14 (VF-14) were administered to all patients. Treating ophthalmologists completed a 3-item questionnaire. RESULTS: No objective measures of visual function correlated with patient satisfaction or with the ophthalmologists' evaluation of treatment success. The VF-14 was not related to the ophthalmologists' evaluation of treatment outcome. Similarly, patient satisfaction was unrelated to the ophthalmologists' assessment of treatment success. A correlation was found between the VF-14 and patient satisfaction, r = 0.50, p < 0.05. CONCLUSIONS: Objective measures of visual function do not necessarily reflect the viewpoint of patients regarding PDT treatment outcome. Patients and doctors differ in their interpretation of treatment success and patients' overall satisfaction might best be reflected through a visual function questionnaire.