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 Leber's 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 Tukey's 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

Miller Fisher Syndrome Presenting as Sixth Nerve Palsies and Tonic Pupils Following Campylobacter Jejuni Infection

Guillain-Barré syndrome (GBS) is an acute, acquired, and self-limiting inflammatory polyneuropathy. The Miller Fisher syndrome (MFS) is part of the continuum of GBS, characterized by ophthalmoplegia, ataxia, and areflexia. We present a case of GBS-MFS associated with antecedent Campylobacter Jejuni infection

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

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

Epidemiology of ocular emergencies in a large Canadian eye centre

Objective: The Eye Institute of Alberta Emergency Eye Clinic (EIA EEC) is a tertiary eye care centre that provides emergency eye services to a population of more than 1 million. The purpose of this study was to describe the epidemiology of ocular emergencies at the EIA EEC.Design: Prospective epidemiologic study based on secondary use of patient data.Participants: All patients seen in the EIA EEC on weekdays between July 2020 and June 2021.Methods: Charts were reviewed to obtain patient demographics, referral details, final diagnoses, need for imaging, emergency procedures, or further referrals. SPSS Statistics was used for data analysis.Results: A total of 2586 patients were seen over the study period. Most of the referrals (58%) were from emergency physicians. Optometrists and general physicians contributed 14% and 11% of referrals, respectively. Most referral diagnoses were related to inflammation (32%), and trauma (22%). Of all the cases of inflammation, 41% involved infection of the eye and 8% involved infection of ocular adnexa. In addition, 44% and 7% of cases involved noninfectious inflammation of the eye and adnexa, respectively. Frequently preformed emergency procedures were corneal or conjunctival foreign-body removal (39%) and corneal scraping (14%).Conclusions: Continuing education related to emergency eye care may be most beneficial to emergency physicians, general practitioners, and optometrists. Educational opportunities could focus on most frequently seen diagnostic categories such as inflammation and trauma. Targeted public education aimed at preventing ocular trauma and infection, such as promoting wearing eye protection and practicing contact lens hygiene, may be beneficial

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 \u3c 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 \u3c 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 \u3e 25 mm, traumatic glaucoma, and NTG were found to be significant predictors of steroid response

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 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 \u3c 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