Samir Nazarali

The Photopic Negative Response: An Objective Measure of Retinal Ganglion Cell Function in Patients With Leber's Hereditary Optic Neuropathy

Purpose The photopic negative response (PhNR) is a slow negative component of a flash photopic full-field ERG that has been shown to be specific for retinal ganglion cell (RGC) activity. Direct evaluation of RGC function is desirable in patients with Lebers hereditary optic neuropathy (LHON) in which the loss of central acuity can make it difficult to monitor patients with standard metrics. The purpose of this study was to evaluate the use of PhNR as an objective noninvasive clinical metric in LHON. Methods Full-field photopic ERG recordings were collected in subjects with the mt.11778G>A/ND4 LHON mutation using a red on blue stimulus. The PhNR was identified using a computer-based automated detection system, and data were manually examined to remove movement artifacts. Results The PhNR amplitude was compared between controls (n = 13), carriers (n = 17), and affected (n = 6). Mean PhNR amplitude decreased significantly across groups (P < 0.0001). Post hoc Tukeys test revealed a significant decrease in PhNR amplitude between carriers and controls (P < 0.05) and between carriers and affected (P < 0.01). Conclusions We are able to demonstrate that the PhNR amplitude is significantly decreased in patients affected by LHON compared to carriers in a well-described pedigree. Surprisingly, there was also a decrease in PhNR in carriers, suggesting potential subclinical RGC dysfunction in some carriers. This is important in patients affected with LHON who typically have a dense central scotoma. The PhNR may be a useful objective outcome measure for future clinical trials.

STOP Glaucoma in Sub Saharan Africa: enhancing awareness, detection, management, and capacity for glaucoma care

ABSTRACT Introduction: Glaucoma in Sub Saharan Africa (SSA) poses a daunting challenge. Communities are often unaware of the serious implications of glaucoma and are faced with limited access to specialists, making early detection and management difficult. For those who have been diagnosed, socioeconomic barriers limit access to treatment. Since 2006, we have been involved in an innovative program we term ‘STOP Glaucoma in SSA’. The four main pillars of this program include building capacity, enhancing awareness, and improving glaucoma detection and management. The aim of this initiative is to train the first generation of highly qualified glaucoma subspecialist leaders and to develop centers of excellence for glaucoma care throughout SSA that are interconnected. Our ultimate aim is to reduce the burden of blindness from glaucoma in SSA. Areas covered: Our review addresses background context, provides learning from the first decade of this program, and offers solutions to help tackle the scourge of glaucoma in SSA. Expert commentary: Research in ocular genetics, primary congenital glaucoma, ophthalmic nanomedicine, and cost effective therapies will continue to improve our understanding of glaucoma as well as access to quality care for glaucoma in SSA.

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 1st 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.

Ophthalmology at the University of Alberta: Over 8 Decades of People-driven Contributions

The Department of Ophthalmology and Visual Sciences at the University of Alberta has a long history of dedication to outstanding patient-centered eye care for a population of over 3 million, many of whom reside in geographically remote areas. It was established as the Department of Ophthalmology and Rhino-Oto-Laryngology in 1937. By 1946, Dr. Mark Marshall had become director of graduate medical education at the University of Alberta and established the “Marshall Plan”, which led to the development of several residency programs, including ophthalmology, at the University of Alberta. Some ophthalmology residents made extraordinary contributions while still in training while many others obtained valuable training elsewhere, and then returned to serve the Department.

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.

Case of Ab Interno Trabeculectomy in Juvenile Open-angle Glaucoma with 5-year Follow-up

Juvenile open-angle glaucoma (JOAG) is a subset of primary open-angle glaucoma (POAG) affecting those between 3 and 40 years of age and often with a more progressive course compared to POAG. Transmission is typically autosomal dominant with mutations identified in the myocilin (MYOC) and CYP1B1 genes. Approximately 83% of JOAG patients require surgical intervention, with success rates after trabeculectomy between 50% and 87% over 3 years of follow-up. Filtering surgery outcomes have been inferior in JOAG versus POAG because of exaggerated healing in younger eyes. JOAG patients undergoing trabeculectomy are also prone to hypotony maculopathy, and the use of antimetabolites places these patients at a long-term risk for bleb-associated postoperative complications. Trabectome is a minimally invasive glaucoma surgery (MIGS) that uses an ab interno approach to trabeculectomy (AIT). The procedure is performed using a disposable hand piece providing irrigation, aspiration, and electrocautery. Through a temporal corneal incision, the hand piece is inserted into the anterior chamber, facilitating ablation of the inner wall of Schlemm’s canal and trabecular meshwork to enhance outflow of aqueous humor without disturbing the conjunctiva. This procedure has been shown to result in fewer complications compared to ab externo trabeculectomy. However, as for all ab interno procedures, AIT carries a risk of collateral damage to structures adjacent to Schlemm’s canal. We report the long-term follow-up of a patient with JOAG who underwent AIT.