Publications

2022

Song S, Lemire C, Seto B, Arroyo J. Nocturnal normobaric hyperoxia treatment in a case of chronic diabetic macular edema. Eur J Ophthalmol. 2022;:11206721221101365.
PURPOSE: To study the long-term anatomic and physiologic effects of nocturnal normobaric hyperoxia (NNBH) in a patient with treatment-resistant diabetic macular edema (DME). METHODS: A 64-year-old diabetic man with bilateral DME requiring regular anti-VEGF treatments in both eyes was started on 5 LPM (40% FiO2) NNBH treatment 6-h per night. Visual acuity, OCT measurements of retinal thickness and volume, as well as the number of injections given in each eye were retrospectively examined one year prior and prospectively after initiation of NNBH, as well as before and after a planned 1-month discontinuation of NNBH. RESULTS: The patient received 12 anti-VEGF injections in the year prior to beginning NNBH treatment (4 OD; 8 OS) and did not require any injections after commencing NNBH treatment. Visual acuity improved and stabilized to 20/20 and macular edema rapidly resolved in both eyes following initiation of NNBH. After a planned 1-month NNBH vacation, DME recurred but quickly resolved once NNBH treatment was restarted. CONCLUSION: This model case demonstrates that a 6-h NNBH regimen can be successful in treating DME and improving vision, without the need for intravitreal injections. NNBH is a more acceptable treatment regimen compared to 24-h continuous oxygen delivery and may provide a less invasive alternate method for treating DME in patients with diabetes. Further study is warranted.
Fonseca M, Nouck-A-Nwal A, Ambrosio L, Altschwager P, Hansen R, Fulton A, Akula J. The relation of the multifocal electroretinographic response to macular layer volume. Doc Ophthalmol. 2022;
PURPOSE: To determine the association of the multifocal electroretinographic (mfERG) response amplitude with the volumes of the inner, postreceptor, and photoreceptor retinal layers in the region stimulated by each mfERG element. METHODS: Sixteen healthy, young adult control subjects were studied. Each of the 103 hexagonal elements of the standard, scaled mfERG were aligned, where possible, with patches of retina imaged using optical coherence tomography. Stimuli falling on the fovea and on the optic nerve head were excluded. Linear mixed-effects modeling was then used to derive estimated coefficients (voltage/volume) for the mfERG response throughout the full 80 ms standard epoch. The resulting predicted response amplitudes originating in each layer were then compared to pharmacologically "dissected" mfERGs obtained from other studies in monkey eyes. RESULTS: Across the duration of the response, the amplitude of the modeled contribution from (1) the inner retina was small-to-modest, (2) the postreceptor retina was larger and contained two prominent peaks, and (3) the photoreceptor response was the largest and most closely paralleled the overall (i.e., intact) response, including late-appearing oscillations. The significance of each layer's contribution was greatest when the absolute amplitude of that layer's response was largest. The contribution of the inner retina was maximally significant in the interval between the prominent troughs and peaks of the intact response. The contributions of the postreceptor and photoreceptor responses were maximally significant at the prominent troughs and peaks of the intact response. CONCLUSIONS: The results of the model were in good overall agreement with previous interpretations of the cellular contributions to the mfERG. There was also fair agreement with pharmacologically dissected monkey mfERG responses. Thus, the estimations of the contributions of the retinal layers to the mfERG so produced appeared plausible.
Zabaleta N, Bhatt U, Hérate C, Maisonnasse P, Sanmiguel J, Diop C, Castore S, Estelien R, Li D, Dereuddre-Bosquet N, Cavarelli M, Gallouët AS, Pascal Q, Naninck T, Kahlaoui N, Lemaitre J, Relouzat F, Ronzitti G, Thibaut HJ, Montomoli E, Wilson J, Le Grand R, Vandenberghe L. Durable immunogenicity, adaptation to emerging variants, and low-dose efficacy of an AAV-based COVID-19 vaccine platform in macaques. Mol Ther. 2022;30(9):2952–2967.
The COVID-19 pandemic continues to have devastating consequences on health and economy, even after the approval of safe and effective vaccines. Waning immunity, the emergence of variants of concern, breakthrough infections, and lack of global vaccine access and acceptance perpetuate the epidemic. Here, we demonstrate that a single injection of an adenoassociated virus (AAV)-based COVID-19 vaccine elicits at least 17-month-long neutralizing antibody responses in non-human primates at levels that were previously shown to protect from viral challenge. To improve the scalability of this durable vaccine candidate, we further optimized the vector design for greater potency at a reduced dose in mice and non-human primates. Finally, we show that the platform can be rapidly adapted to other variants of concern to robustly maintain immunogenicity and protect from challenge. In summary, we demonstrate this class of AAV can provide durable immunogenicity, provide protection at dose that is low and scalable, and be adapted readily to novel emerging vaccine antigens thus may provide a potent tool in the ongoing fight against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2).
Friedman D, Chang D, Jiang Y, Huang S, Kim J, Muñoz B, Aung T, He M, Foster P. Acute Angle-Closure Attacks Are Uncommon in Primary Angle-Closure Suspects after Pharmacologic Mydriasis: The Zhongshan Angle-Closure Prevention Trial. Ophthalmol Glaucoma. 2022;5(6):581–586.
PURPOSE: Angle-closure glaucoma is a major cause of blindness worldwide that carries an excessive risk of severe, bilateral visual impairment. A common concern among clinicians is the precipitation of acute angle-closure (AAC) attacks because of mydriasis. We evaluated the risk of AAC after pharmacologic dilation in Chinese individuals classified as having bilateral primary angle-closure suspects (PACSs). DESIGN: Randomized, interventional, controlled trial. PARTICIPANTS: A total of 889 patients with bilateral PACSs, aged between 50 and 70 years, were identified through community screening in Guangzhou, China, and enrolled in the study. METHODS: In the Zhongshan Angle-Closure Prevention Trial, bilateral PACSs were treated with laser peripheral iridotomy (LPI) in 1 randomly selected eye, with the fellow eye serving as an untreated control. Over 72 months of follow-up, the participants had their pupils pharmacologically dilated 6 times with 5% phenylephrine and 0.5% tropicamide. MAIN OUTCOME MEASURES: Incidence and risk of post-mydriasis AAC in LPI-treated and untreated, control eyes classified as PACSs. RESULTS: One bilateral AAC attack occurred after mydriasis at the 2-week post-LPI visit. No other AAC events occurred in the LPI-treated eyes. In the untreated eyes, 4 additional attacks occurred: 2 occurred after dilation (1 at 54 months and 1 at 72 months of follow-up) and 2 occurred spontaneously. The risk of post-mydriasis AAC in the untreated eyes was 1 attack in 1587 dilations. The risk of spontaneous AAC in the untreated eyes was 0.44 per 1000 eye-years (95% confidence interval, 0.11-1.77 per 1000 eye-years). CONCLUSIONS: The risk of incident AAC attacks in PACSs was extremely low, even in a higher-risk group that underwent repeated pharmacologic pupillary dilation over 6 years of follow-up. Prophylactic LPI reduced this small but real risk. This trial was registered at ISRCTN.com as ISRCTN45213099.
Halawa O, Roldan A, Meshkin R, Zebardast N, Fenwick E, Lamoureux EL, Friedman D. Factors associated with glaucoma-specific quality of life in a US glaucoma clinic in a pilot implementation of an online computerised adaptive test (GlauCAT). Br J Ophthalmol. 2022;
OBJECTIVES: Measure quality of life (QoL) outcomes using a novel computerised adaptive test in a clinical setting, and determine the social and demographic factors associated with specific QoL domains in patients with glaucoma. DESIGN: Cross-sectional study between July 2020 and April 2021. PARTICIPANTS: English-speaking adults presenting to glaucoma clinic. Patients with cognitive impairment on a six-item cognitive impairment screen or with intraocular surgery within 90 days prior to presentation were excluded. RESULTS: Of 206 patients surveyed, mean age was 64.8 years (SD 15.2), 122 (56.7%) were female and 159 (74.7%) were white. On multivariable regression, visual acuity was associated with greater activity limitation (β=-2.8 points, 95% CI -3.8 to -1.8, p<0.001) and worse mobility (β=-2.1 points, 95% CI -3.2 to -0.9, p<0.001), while poorer visual field (VF) mean deviation was associated with lower scores on the emotional well-being domain (β=-2.4 points, 95% CI -4.6 to -0.3, p=0.03). Glaucoma suspects and those with early VF defects had higher QoL scores than those with severe glaucoma in the following domains: activity limitation (88.5±14.6 vs 74.3±21.9, respectively, p<0.001), mobility (91.0±12.5 vs 80.0±25.3, respectively, p=0.005) and concerns domains (82.2±13.9 vs 72.5 5±18.9, respectively, p=0.01). CONCLUSIONS: In a busy glaucoma clinic where QoL was measured with online adaptive tests for glaucoma, we found that several demographic and clinical variables are associated with lower domain scores, suggesting that patients with predisposing demographic and clinical factors are at a higher risk of worse QoL.
Guindolet D, Woodward A, Gabison E, Argüeso P. Glycogene Expression Profile of Human Limbal Epithelial Cells with Distinct Clonogenic Potential. Cells. 2022;11(9).
Glycans function as valuable markers of stem cells but also regulate the ability of these cells to self-renew and differentiate. Approximately 2% of the human genome encodes for proteins that are involved in the biosynthesis and recognition of glycans. In the present study, we evaluated the expression of a small subset of glycogenes in human limbal epithelial cells with distinct clonogenic potential. Individual clones were classified as abortive or clonogenic, based on the fraction of the terminal colonies produced; clones leading exclusively to terminal colonies were referred to as abortive while those with half or fewer terminal colonies were referred to as clonogenic. An analysis of glycogene expression in clonogenic cultures revealed a high content of transcripts regulating the galactose and mannose metabolic pathways. Abortive clones were characterized by increased levels of GCNT4 and FUCA2, genes that are responsible for the branching of mucin-type O-glycans and the hydrolysis of fucose residues on N-glycans, respectively. The expansion of primary cultures of human limbal epithelial cells for 10 days resulted in stratification and a concomitant increase in MUC16, GCNT4 and FUCA2 expression. These data indicate that the clonogenic potential of human limbal epithelial cells is associated with specific glycosylation pathways. Mucin-type O-glycan branching and increased fucose metabolism are linked to limbal epithelial cell differentiation.
Halawa OA, Sekimitsu S, Boland M, Zebardast N. Sex-Based Differences in Medicare Reimbursements among Ophthalmologists Persist across Time. Ophthalmology. 2022;129(9):1056–1063.
PURPOSE: To evaluate differences in Medicare reimbursements between male and female ophthalmologists between 2013 and 2019. DESIGN: Retrospective cohort study. PARTICIPANTS: Ophthalmologists receiving Medicare reimbursements between 2013 and 2019. METHODS: The Centers for Medicare and Medicaid Services Physician and Other Supplier Public Use File was used to determine total reimbursements and number of services submitted by ophthalmologists between 2013 and 2019. Reimbursements were standardized to account for geographic differences in Medicare reimbursement per service. Data from the American Community Survey (ACS) were used to determine socioeconomic characteristics (unemployment, poverty, income, and education) by zip code for the location of each physician's practice. A multivariate linear regression model was used to evaluate differences in annual reimbursements by sex, accounting for calendar year, years of experience, total number of services, ACS zip code data, and proportion of procedural services. MAIN OUTCOME MEASURES: Annual Medicare reimbursement and use of billing codes (e.g., outpatient office visits and eye examinations, diagnostic testing, laser treatment, and surgery). RESULTS: Among 20 281 ophthalmologists who received Medicare reimbursements between 2013 and 2019, 15 451 (76%) were men. The most common billing codes submitted were for outpatient visits and eye examinations (13.8 million charges/year), diagnostic imaging of the retina (5.6 million charges/year), intravitreal injections (2.9 million charges/year), and removal of cataract with insertion of lens (2.4 million charges/year). Compared with men, female ophthalmologists received less in median annual reimbursements (median, $94 734.21 [interquartile range (IQR), $30 944.52-$195 701.70] for women vs. $194 176.90 [IQR, $76 380.76-$355 790.80] for men; P < 0.001) and billed for fewer annual median services (median, 1228 [IQR, 454-2433] vs. 2259 [IQR, 996-4075, respectively]; P < 0.001). After adjustment for covariates, female ophthalmologists billed for 1015 fewer services (95% confidence interval [CI], 1001-1029; P < 0.001) and received $20 209.12 less in reimbursements than men (95% CI, -$21 717.57 to -$18 700.66; P < 0.001). CONCLUSIONS: Female ophthalmologists billed for fewer services and received less in reimbursement from Medicare than men over time and across all categories of billing codes. Disparities persisted after controlling for physician and practice characteristics.
Deiner M, Kaur G, McLeod S, Schallhorn J, Chodosh J, Hwang D, Lietman T, Porco T. A Google Trends Approach to Identify Distinct Diurnal and Day-of-Week Web-Based Search Patterns Related to Conjunctivitis and Other Common Eye Conditions: Infodemiology Study. J Med Internet Res. 2022;24(7):e27310.
BACKGROUND: Studies suggest diurnal patterns of occurrence of some eye conditions. Leveraging new information sources such as web-based search data to learn more about such patterns could improve the understanding of patients' eye-related conditions and well-being, better inform timing of clinical and remote eye care, and improve precision when targeting web-based public health campaigns toward underserved populations. OBJECTIVE: To investigate our hypothesis that the public is likely to consistently search about different ophthalmologic conditions at different hours of the day or days of week, we conducted an observational study using search data for terms related to ophthalmologic conditions such as conjunctivitis. We assessed whether search volumes reflected diurnal or day-of-week patterns and if those patterns were distinct from each other. METHODS: We designed a study to analyze and compare hourly search data for eye-related and control search terms, using time series regression models with trend and periodicity terms to remove outliers and then estimate diurnal effects. We planned a Google Trends setting, extracting data from 10 US states for the entire year of 2018. The exposure was internet search, and the participants were populations who searched through Google's search engine using our chosen study terms. Our main outcome measures included cyclical hourly and day-of-week web-based search patterns. For statistical analyses, we considered P<.001 to be statistically significant. RESULTS: Distinct diurnal (P<.001 for all search terms) and day-of-week search patterns for eye-related terms were observed but with differing peak time periods and cyclic strengths. Some diurnal patterns represented those reported from prior clinical studies. Of the eye-related terms, "pink eye" showed the largest diurnal amplitude-to-mean ratios. Stronger signal was restricted to and peaked in mornings, and amplitude was higher on weekdays. By contrast, "dry eyes" had a higher amplitude diurnal pattern on weekends, with stronger signal occurring over a broader evening-to-morning period and peaking in early morning. CONCLUSIONS: The frequency of web-based searches for various eye conditions can show cyclic patterns according to time of the day or week. Further studies to understand the reasons for these variations may help supplement the current clinical understanding of ophthalmologic symptom presentation and improve the timeliness of patient messaging and care interventions.
Wang Z, Wiggs J, Aung T, Khawaja A, Khor CC. The genetic basis for adult onset glaucoma: Recent advances and future directions. Prog Retin Eye Res. 2022;90:101066.
Glaucoma, a diverse group of eye disorders that results in the degeneration of retinal ganglion cells, is the world's leading cause of irreversible blindness. Apart from age and ancestry, the major risk factor for glaucoma is increased intraocular pressure (IOP). In primary open-angle glaucoma (POAG), the anterior chamber angle is open but there is resistance to aqueous outflow. In primary angle-closure glaucoma (PACG), crowding of the anterior chamber angle due to anatomical alterations impede aqueous drainage through the angle. In exfoliation syndrome and exfoliation glaucoma, deposition of white flaky material throughout the anterior chamber directly interfere with aqueous outflow. Observational studies have established that there is a strong hereditable component for glaucoma onset and progression. Indeed, a succession of genome wide association studies (GWAS) that were centered upon single nucleotide polymorphisms (SNP) have yielded more than a hundred genetic markers associated with glaucoma risk. However, a shortcoming of GWAS studies is the difficulty in identifying the actual effector genes responsible for disease pathogenesis. Building on the foundation laid by GWAS studies, research groups have recently begun to perform whole exome-sequencing to evaluate the contribution of protein-changing, coding sequence genetic variants to glaucoma risk. The adoption of this technology in both large population-based studies as well as family studies are revealing the presence of novel, protein-changing genetic variants that could enrich our understanding of the pathogenesis of glaucoma. This review will cover recent advances in the genetics of primary open-angle glaucoma, primary angle-closure glaucoma and exfoliation glaucoma, which collectively make up the vast majority of all glaucoma cases in the world today. We will discuss how recent advances in research methodology have uncovered new risk genes, and how follow up biological investigations could be undertaken in order to define how the risk encoded by a genetic sequence variant comes into play in patients. We will also hypothesise how data arising from characterising these genetic variants could be utilized to predict glaucoma risk and the manner in which new therapeutic strategies might be informed.