Internal limiting membrane peeling in rhegmatogenous retinal detachment: A meta-analysis.

PURPOSE: To determine whether pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling for rhegmatogenous retinal detachment (RRD) could get better functional and anatomical outcomes. METHODS: A comprehensive literature search was performed to find relevant studies. A meta-analysis was conducted by comparing the weighted mean differences (WMD) in the mean change of best corrected visual acuity (BCVA) from baseline and calculating the odd ratios (OR) for rates of epiretinal membrane (ERM) formation and recurrence of retinal detachment (RD). RESULTS: Fourteen studies were selected, including 2259 eyes (825 eyes in the ILM peeling group and 1434 eyes in the non-ILM peeling group). There was no significant difference in terms of mean change in BCVA from baseline and the rate of RD recurrence (WMD = 0.02, 95% CI, -0.20 to 0.24, P = 0.86, and OR = 0.55, 95% CI, 0.24 to 1.26, P = 0.16), but ILM peeling was associated with a significantly lower frequency of postoperative ERM formation (OR = 0.13, 95% CI, 0.06 to 0.26, P<0.00001). Similar results were obtained in a sub-analysis based on macula-off RRD. CONCLUSION: ILM peeling results in similar BCVA, with same rate of RD recurrence, but lower rate of postoperative ERM development. ILM peeling could be considered in selected cases with risk factors that are likely to develop an ERM.

Pre-stimulus bioelectrical activity in light-adapted ERG under blue versus white background.

To compare the baseline signal between two conditions used to generate the photopic negative response (PhNR) of the full-field electroretinogram (ERG): red flash on a blue background (RoB) and white flash on a white background (LA3). The secondary purpose is to identify how the level of pre-stimulus signal affects obtaining an unambiguous PhNR component. A retrospective chart review was conducted on four cohorts of patients undergoing routine ERG testing. In each group, LA3 was recorded the same way while RoB was generated differently using various luminances of red and blue light. The background bioelectrical activity 30 ms before the flash was extracted, and the root mean square (RMS) of the signal was calculated and compared between RoB and LA3 using Wilcoxon test. Pre-stimulus noise was significantly higher under RoB stimulation versus LA3 in all four conditions for both right and left eyes (ratio RoB/LA3 RMS 1.70 and 1.57 respectively, p < 0.033). There was also no significant difference between the RMS of either LA3 or RoB across protocols, indicating that the baseline noise across cohorts were comparable. Additionally, pre-stimulus noise was higher in signals where PhNR was not clearly identifiable as an ERG component versus signals with the presence of unambiguous PhNR component under RoB in all four groups for both eyes (p < 0.05), whereas the difference under LA3 was less pronounced. Our study suggests that LA3 produces less background bioelectrical activity, likely due to decreased facial muscle activity. As it seems that the pre-stimulus signal level affects PhNR recordability, LA3 may also produce a better-quality signal compared to RoB. Therefore, until conditions for a comparable bioelectrical activity under RoB are established, we believe that LA3 should be considered at least as a supplementary method to evaluate retinal ganglion cell function by ERG.

Postoperative Outcome of Combined Phacovitrectomy in Eyes with Excessive Myopia (>-30 D).

Background: To report the outcomes of phacoemulsification combined with vitrectomy in eyes with extreme myopia (-30 diopters or more). Case Presentation. Three patients with cataract, vitreous opacities, and extreme myopia of more than -30 diopters underwent a combined surgical procedure of cataract extraction combined with vitrectomy. Postoperative refractive correction of the three cases ranged from -1.0 D to -2.5 D spherical equivalent. There was an obvious hyperopic shift of all cases. All patients noted a significant improvement in uncorrected and best-corrected visual acuity from 0.4 to 0.8 in case 1, from CF/70 cm to 1.0 in case 2, and from 0.12 to 0.5 in the right eye and 0.15 to 0.2 in the left eye in case 3. Vitreous floaters disappeared in all cases. No complications were noted during follow-up. Conclusions: To the best of the authors' knowledge, these represent the first reported clinical cases of combined cataract extraction+vitrectomy surgery in eyes with extreme (>-30 D) myopia. Our results support the notion that phacoemulsification combined with vitrectomy may be a good therapeutic option for cataracts and vitreous floaters in cases with extreme myopia.

Fenofibrate Ameliorates Retinal Pigment Epithelium Injury Induced by Excessive Fat Through Upregulation of PI3K/AKT Signaling.

Purpose: This study aimed to determine the effect and its mechanism of fenofibrate on retinal pigment epithelium (RPE) injury induced by excessive fat in vitro and in vivo. Methods: ARPE-19 cells were co-incubated with palmitic acid (PA) and fenofibric acid (the active form of fenofibrate after metabolism in vivo) and mice fed with high-fat diet (HFD) were supplemented with fenofibrate. The following methods were used: Western blot and immunofluorescent staining to determine expressions of reactive oxygen species (ROS)-associated factors and proinflammatory cytokines; electroretinogram (ERG) c-wave to evaluate RPE function; TUNEL staining to detect the apoptotic cell in RPE tissue. Additionally, ARPE19 cells were treated with PI3K/AKT inhibitor or agonist to investigate the mechanism of fenofibric acid inhibiting PA-induced RPE damage. Results: We found that the application of PA inhibited RPE cell viability in a dose-dependent manner, and increased the levels of NAPDH oxidase 4 (NOX4), 3-nitrotyrosin (3-NT), intracellular adhesion molecule-1(ICAM1), tumor necrosis factor alpha (TNFα) and vascular endothelial growth factor (VEGF) at 400µM. The application of fenofibric acid resulted in the inhibition of NOX4, 3-NT, TNFα, ICAM1 and VEGF expression in ARPE-19 cells treated with PA. Moreover, wortmannin, as a selective inhibitor of PI3K/AKT pathway, abolished the effects of fenofibrate on the oxidative stress and inflammation in ARPE-19 cells. In addition, 740Y-P, a selective agonist of PI3K/AKT pathway, enhanced the protective action of fenofibrate. Meanwhile, in vivo dosing of fenofibrate ameliorated the downregulated amplitudes of ERG c-wave in HFD-fed mice and suppressed the HFD-induced oxidative injury and inflammatory response in RPE tissues. Conclusion: Our results suggested that fenofibrate ameliorated RPE cell damage induced by excessive fat in vitro and in vivo, in part, through activation of the PI3K/AKT signaling pathway.

Hydrogen peroxide-induced oxidative damage and protective role of peroxiredoxin 6 protein via EGFR/ERK signaling pathway in RPE cells.

Introduction: Damage to retinal pigment epithelium (RPE) cells caused by oxidative stress is closely related to the pathogenesis of several blinding retinal diseases, such as age-related macular degeneration (AMD), retinitis pigmentosa, and other inherited retinal degenerative conditions. However, the mechanisms of this process are poorly understood. Hence, the goal of this study was to investigate hydrogen peroxide (H2O2)-induced oxidative damage and protective role of peroxiredoxin 6 (PRDX6) protein via EGFR/ERK signaling pathway in RPE cells. Methods: Cells from a human RPE cell line (ARPE-19 cells) were treated with H2O2, and then cell viability was assessed using the methyl thiazolyl tetrazolium assay. Cell death and reactive oxygen species (ROS) were detected by flow cytometry. The levels of PRDX6, epidermal growth factor receptor (EGFR), P38 mitogen-activated protein kinase (P38MAPK), c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) were detected by Western blot assay. PRDX6 and EGFR were also detected via immunofluorescence staining. Results: Our results show that H2O2 inhibited cell viability, induced cell death, and increased ROS levels in ARPE-19 cells. It was also found that H2O2 decreased the levels of PRDX6, EGFR, and phosphorylated ERK but increased the levels of phosphorylated P38MAPK and JNK. PRDX6 overexpression was found to attenuate H2O2-induced inhibition of cell viability and increased cell death and ROS production in ARPE-19 cells. PRDX6 overexpression also increased the expression of EGFR and alleviated the H2O2-induced decrease in EGFR and phosphorylated ERK. Moreover, inhibition of epidermal growth factor-induced EGFR and ERK signaling in oxidative stress was partially blocked by PRDX6 overexpression. Discussion: Our findings indicate that PRDX6 overexpression protects RPE cells from oxidative stress damage caused by decreasing ROS production and partially blocking the inhibition of the EGFR/ERK signaling pathway induced by oxidative stress. Therefore, PRDX6 shows promise as a therapeutic target for the prevention of RPE cell damage caused by oxidative stress associated with retinal diseases.

Human amnionic progenitor cell secretome mitigates the consequence of traumatic optic neuropathy in a mouse model.

Traumatic optic neuropathy (TON) is a condition in which acute injury to the optic nerve from direct or indirect trauma results in vision loss. The most common cause of TON is indirect injury to the optic nerve caused by concussive forces that are transmitted to the optic nerve. TON occurs in up to 5% of closed-head trauma patients and there is currently no known effective treatment. One potential treatment option for TON is ST266, a cell-free biological solution containing the secretome of amnion-derived multipotent progenitor (AMP) cells. We investigated the efficacy of intranasal ST266 in a mouse model of TON induced by blunt head trauma. Injured mice treated with a 10-day regimen of ST266 showed an improvement in spatial memory and learning, a significant preservation of retinal ganglion cells, and a decrease in neuropathological markers in the optic nerve, optic tract, and dorsal lateral geniculate nucleus. ST266 treatment effectively downregulated the NLRP3 inflammasome-mediated neuroinflammation pathway after blunt trauma. Overall, treatment with ST266 was shown to improve functional and pathological outcomes in a mouse model of TON, warranting future exploration of ST266 as a cell-free therapeutic candidate for testing in all optic neuropathies.

Effect of spatial averaging on the amplitude ring ratio in multifocal electroretinography.

PURPOSE: The purpose of this study was to evaluate the effect of spatial averaging on the multifocal electroretinography (mfERG) amplitude ring ratios used in screening for hydroxychloroquine (HCQ) toxicity. METHODS: This was a retrospective review of the records of patients screened for HCQ retinopathy at the USF Eye Institute (University of South Florida) during the period of 2015-2020. Patients were tested binocularly with Diagnosys mfERG system (Diagnosys LLC, Lowell, MA). Only the records of patients referred internally were used. The effects of the lowest level (level 1, or 8%) of spatial averaging on the P1 amplitude ring ratios used for screening of HCQ maculopathy: R1/R2, R2/R5, R5/R3 and R5/R4, were evaluated. RESULTS: The records of 40 patients (4 males, 36 females) aged 54.4 ± 14.1 years were selected for analysis. The use of spatial averaging had a significant effect on P1 amplitudes, and on the ring ratios and this effect was correlated with the magnitude of the amplitudes and the ratios. Spatial averaging diminished P1 amplitude significantly in ring 1 (p < 0.0001) and increased it slightly in ring 4 (p < 0.05), while it had no effect on the amplitude of the other three rings. Although as a group spatial averaging had a moderate effect on the R1/R2 ratio (~ -15%), on an individual basis the range was wide, from -36 to 43%. The effect on the other ring ratios was similar: The average group effect was ~ -5%, ~ -3.4% and ~ -4% for R2/R5, R5/R3 and R5/R4 ratios, but individual effects ranged from 0.18% to -27.3%, 0.9% to -14.2% and 0.9% to -26.2%, respectively. CONCLUSIONS: For all ring ratios used in this analysis, spatial averaging has a substantial effect on the ring ratio, which could affect the interpretation of the results. Therefore, use of spatial averaging should be avoided when analyzing mfERG results for HCQ screening.

Electroretinographic Findings in Melanoma-Associated Retinopathy Treated by Intravitreal Dexamethasone Implant.

A 63-year-old male with a history of bladder cancer in remission presented with progressive vision loss during a period of 2 years. Slit-lamp and funduscopic examination were unremarkable. Electroretinogram (ERG) revealed an unrecordable scotopic response and a moderately decreased photopic response. Computed tomography of the chest, abdomen, and pelvis showed a new duodenal mass. Subsequent biopsy disclosed malignant melanoma, and a diagnosis of melanoma-associated retinopathy (MAR) was made. The patient was then treated with a dexamethasone intravitreal implant 0.7 mg in his left eye. Two months after the implant, the patient reported a mild symptomatic improvement in his left eye, and ERG testing performed after the implant insertion revealed partial improvement in several scotopic and photopic ERG parameters. Repeat spectral-domain optical coherence tomography disclosed an improvement in retinal thickening. To the best of the authors' knowledge, this is the first report illustrating potential subjective visual improvement, improvement in retinal thickening, and ERG changes following treatment by intravitreal dexamethasone implant for MAR. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:454-456.].

Volumetric histological characterization of optic nerve degeneration using tissue clearing: literature review and practical study.

Tissue clearing technologies can greatly improve the depth and accuracy with which the three-dimensional structure of tissues, especially those of th*-e nervous system, can be visualized. A review of the present literature suggests that the growing diversity and sophistication of various approaches have contributed to the expansion of this method to a greater variety of tissue types, experimental conditions, and imaging modalities. In the proof-of-concept study presented in this paper, a simplified and modified version of the tissue clearing method CUBIC (clear, unobstructed brain imaging cocktails and computational analysis) was used in conjunction with fluorescent staining and immunohistochemistry to illustrate the three-dimensional structure and molecular characteristics of inflammatory and degenerative activity in the mouse optic nerve. Based on the studies summarized in this mini-review, and our impression from using the mCUBIC method, it appears that tissue clearing could be a viable approach revealing three-dimensional histological features of myelin-rich tissues under normal conditions and after injury.

Relationship between stimulus size and different components of the electroretinogram (ERG) elicited by flashed stimuli.

PURPOSE: To investigate how light stimulus conditions of varying spatial sizes affect components of the flash and long-flash electroretinogram (ERG) in normal subjects. METHOD: Three stimulus conditions were generated by a Ganzfeld stimulator: a white flash on white background (WoW), a red flash on a blue background (RoB) and an L+M-cone isolating on-off (long flash) stimulus (Cone Iso). ERGs were recorded from six subjects (5 M, 1 F) with DTL electrodes to full-field (FF), 70°, 60°, 50°, 40°, 30° and 20° diameter circular stimuli. Amplitudes and peak times for a-, b-, d- and i-wave, and PhNR were examined. PhNR amplitudes were estimated in two different ways: from baseline (fB) and from preceding b-wave peak (fP). RESULTS: With decreasing stimulus size, amplitudes for all ERG waveform components attenuated and peak times increased, although the effect varied across different components. An exponential fit described the relationship between amplitudes and size of stimulated retinal area well for most components and conditions (R2= 0.75-0.99), except for PhNR(fB) (R2= - 0.16-0.88). For peak times, an exponential decay function also fitted the data well (R2= 0.81-0.97), except in a few cases where the exponential constant was too small and a linear regression function was applied instead (a-wave Cone Iso, b- and i-wave WoW). The exponential constants for RoB amplitudes (b-wave, PhNR(fB), PhNR(fP)) were larger compared to their counterparts under WoW (p < 0.05), while there was no difference between the constants for a-wave amplitudes and peak times and for PhNR peak times. The exponential constants of amplitudes vs. area under WoW and Cone Iso were remarkably similar, while under RoB PhNR(fB) showed larger constants compared to either a- or b-wave (p < 0.05). CONCLUSION: ERG components change in a predictable way with stimulus size and spectral characteristics of the stimulus under these conditions. This predictability could allow a modified version of these sets of stimuli to be tested for clinical applicability.

A New Two-Step Anesthesia for 23- or 25-Gauge Vitrectomy Surgery: A Prospective, Randomized Clinical Trial.

OBJECTIVE: To investigate the safety and efficacy of topical anesthesia combined with subconjunctival anesthesia (termed two-step anesthesia) for 23- or 25-gauge pars plana vitrectomy or other posterior segment surgery. METHODS: Patients (n = 90) requiring 23-/25-gauge vitrectomy or other posterior segment surgery were randomized into 3 groups. Group 1 received peribulbar anesthesia, group 2 received retrobulbar anesthesia and group 3 received two-step anesthesia. A 5-point visual analog pain scale (VAPS) was used to measure self-report of patient pain. Complications were recorded for subsequent analysis. RESULTS: VAPS scores for overall intraoperative pain ranged from 0 to 3 (1.07 ± 1.07) in group 1, from 0 to 2 (0.69 ± 0.93) in group 2 and from 0 to 3 (1.06 ± 0.98) in group 3. Assessment of surgeon discomfort score ranged from 0 to 2 (0.31 ± 0.66) in group 1, from 0 to 3 (0.38 ± 0.82) in group 2 and from 0 to 2 (0.47 ± 0.62) in group 3. Both scores reveal no significant difference among the 3 groups. While there were no complications noted in group 1, there was an ocular perforation in group 2. Additionally, there were no complications in group 3 related to the anesthetic technique. CONCLUSIONS: Results suggest that two-step anesthesia is a safe and effective anesthetic approach for selected patients undergoing 23- or 25-gauge pars plana vitrectomy or other posterior segment surgeries. It may offer a viable alternative to peribulbar anesthesia and retrobulbar anesthesia for carefully selected 23- or 25-gauge cannular-access ocular surgeries.

Carbon Dots Fabrication: Ocular Imaging and Therapeutic Potential.

Vision loss is a major complication in common ocular infections and diseases such as bacterial keratitis, age-related macular degeneration (AMD) and diabetic retinopathy (DR). The prevalence of such ophthalmic diseases represents an urgent need to develop safe, effective, and long-term treatments. Current therapies are riddled with drawbacks and limitations which calls for the exploration of alternative drug delivery mechanisms. Toxicity of the inorganic metals and metal oxides used for drug delivery raise safety concerns that are alleviated with the alternate use of, a natural and organic polymer which is both biocompatible and environmentally friendly. Carbon dots (CDs) represent a great potential in novel biomedical applications due to their tunable fluorescence, biocompatibility, and ability to be conjugated with diverse therapeutic materials. There is a growing interest on the exploitation of these properties for drug delivery with enhanced bio-imaging. However, there are limited reports of CD applications for ophthalmic indications. In this review, we focus on the CD potential and the development of translational therapies for ophthalmic diseases. The current review presents better understanding of fabrication of CDs and how it may be useful in delivering anti-bacterial agents, anti-VEGF molecules as well as imaging for ophthalmic applications.

Natural protection of ocular surface from viral infections - A hypothesis.

A pandemic outbreak of a viral respiratory infection (COVID-19) caused by a coronavirus (SARS-CoV-2) prompted a multitude of research focused on various aspects of this disease. One of the interesting aspects of the clinical manifestation of the infection is an accompanying ocular surface viral infection, viral conjunctivitis. Although occasional reports of viral conjunctivitis caused by this and the related SARS-CoV virus (causing the SARS outbreak in the early 2000s) are available, the prevalence of this complication among infected people appears low (~1%). This is surprising, considering the recent discovery of the presence of viral receptors (ACE2 and TMPRSS2) in ocular surface tissue. The discrepancy between the theoretically expected high rate of concurrence of viral ocular surface inflammation and the observed relatively low occurrence can be explained by several factors. In this work, we discuss the significance of natural protective factors related to anatomical and physiological properties of the eyes and preventing the deposition of large number of virus-loaded particles on the ocular surface. Specifically, we advance the hypothesis that the standing potential of the eye plays an important role in repelling aerosol particles (microdroplets) from the surface of the eye and discuss factors associated with this hypothesis, possible ways to test it and its implications in terms of prevention of ocular infections.

Inverted ILM flap technique versus conventional ILM peeling for idiopathic large macular holes: A meta-analysis of randomized controlled trials.

PURPOSE: To compare the anatomical and visual outcomes of inverted internal limiting membrane (ILM) flap technique with the conventional ILM peeling for idiopathic large macular holes (MHs). METHODS: A meta-analysis of randomized control trials (RCTs) using online databases including NCBI PubMed, ClinicalTrials.gov, and ISI Web of Science was performed. Anatomic success and type 1 closure rates, the mean postoperative best-corrected visual acuity (BCVA) and the mean change of BCVA from baseline were analyzed. RESULTS: Out of 251 articles, four described clinical trials matching the inclusion criteria and were selected. They included 276 eyes (135 eyes in the inverted ILM flap group and 141 eyes in the ILM peeling group). All the studies used gas tamponade, with two studies having a follow-up duration of 3 months, while one study had a follow-up of 6 months and one study- 12 months. The meta-analysis demonstrated that anatomic success and type 1 closure rates (presence of neurosensory retina in MH) were better in the inverted ILM flap technique (odds ratio (OR) = 4.89; 95% confidence interval (CI), 2.09-11.47; P = 0.0003 and OR = 5.23; 95% CI, 2.83-9.66; P<0.00001). Similarly, the inverted flap technique was superior in terms of postoperative logMAR BCVA and mean change of logMAR BCVA from baseline (weighted mean difference (WMD) = 0.17, 95% CI, 0.11 to 0.24, P<0.00001 and WMD = 0.08, 95% CI, 0.01 to 0.16, P = 0.03). CONCLUSION: Inverted ILM flap treatment resulted in better closure rates and visual acuity when compared to the standard ILM peeling for large MHs.

The effect of human gene therapy for RPE65-associated Leber's congenital amaurosis on visual function: a systematic review and meta-analysis.

BACKGROUND: RPE65-associated LCA (RPE65-LCA) is an inherited retinal degeneration caused by the mutations of RPE65 gene and gene therapy has been developed to be a promising treatment. This study aims to evaluate the association between changes in visual function and application of gene therapy in patients with RPE65-LCA. METHODS: Several databases (PubMed, Cochrane Library, and Web of Science) were searched for results of studies describing efficacy of gene therapy in patients with RPE65-LCA. Six studies, which included one randomized and five prospective non-randomized clinical trials, 164 eyes met our search criteria and were assessed. RESULTS: The BCVA significantly improved in treated eyes at 1 yr post treatment by - 0.10 logMAR (95% CI, - 0.17 - -0.04; p = 0·002), while there was no significant difference at 2-3 years post treatment (WMD: 0.01; 95% CI, - 0.00 - 0.02; p = 0·15). FST sensitivity to blue flashes also improved by 1.60 log (95% CI, 0.66-2.55; p = 0.0009), but no significant difference to red flashes (WMD: 0.86; 95% CI, - 0·29-2.01; p = 0.14) at 1 yr. There was no significant difference in central retinal thickness at 1 yr, but central retina in treated eyes appeared thinner at 2-3 years post treatment by 19.21 µm (95% CI, - 34.22 - -4.20; p = 0.01). CONCLUSIONS: Human gene therapy is a pioneering treatment option for RPE65-LCA. Although its efficacy appears to be limited to less than 2 yrs after treatment, it carries the potential for further improvement and prolongation of efficacy.

ISCEV extended protocol for derivation and analysis of the strong flash rod-isolated ERG a-wave.

The International Society for the Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum set of tests, but encourages the use of additional protocols for clinical ERG testing. This extended protocol describes recording methods and derivations that will allow analysis of rod-driven components of the dark-adapted (DA) strong flash ERG a-wave, more closely related to rod phototransduction than ISCEV standard DA ERGs. The method involves recording ERGs to a flash strength equivalent to 30 cd s m2 under conditions of dark adaptation and additionally to the same stimulus following light adaptation (LA) and in the presence of a standard photopic background luminance of 30 cd m-2. The isolated rod-driven ERG a-wave is derived by subtracting the LA response from the DA ERG. The method is likely to be of value in the characterization of retinal disorders which affect rod quantal catch, diseases that affect the dynamics of any component of the activation phase of rod phototransduction, or those affecting total numbers of rod photoreceptors.

The photopic negative response of the Light-adapted 3.0 ERG in clinical settings.

PURPOSE: To analyze the effects of different methods of measurement on the photopic negative response (PhNR), recorded as part of a standard ISCEV Photopic 3.0 ERG responses from patients with a variety of clinical diagnoses. METHODS: ERGs were recorded from both eyes of 97 patients (187 eyes) as part of a standard clinical assessment. The average age was 56.4 ± 15.7 years, the gender balance was 35 M, 62F, and only recordable responses of acceptable quality were included. PhNR was measured at an identifiable trough before (PhNR1) and after the i-wave (PhNR2), and the amplitudes and peak times were compared with a-, b- and i-wave corresponding parameters. PhNR components were measured: from baseline and from b-wave peak. Correlation between PhNR troughs and with ERG parameters were tested for right eyes. The possibility to predict and substitute PhNR2 amplitude from PhNR1 amplitude was also tested. RESULTS: PhNR1 was recordable in 97.3% of eyes and PhNR2 in 85.6%. An identifiable PhNR2 peak was found to occur before 65 ms at ~ 50% of the records, while in ~ 38% of the cases was within 65-75 ms in ~ 12%-after 75 ms. The correlation between the PhNR1 and PhNR2 peaks was quite strong (with coefficients 0.81-0.98, depending on method of measurement, and slopes close to 1). The average difference between predicted and measured PhNR2 was reasonably small in absolute (< 2 µV) and relative (< 2%) terms. The correlations between PhNR amplitudes and other ERG component amplitudes showed different ranges of correlation coefficients depending on the method of measurement: for the a-wave amplitudes the range of coefficients was 0.48-0.73, while for the b-wave amplitudes it was 0.30-0.95 and 0.39-0.65 for i-wave. CONCLUSION: The strong correlation between the two PhNR troughs could allow using PhNR1 when PhNR2 is poorly defined due to artifacts. Different methods of PhNR measurement lead to different correlations with other ERG parameters, and this needs to be considered when analyzing and comparing PhNR data between studies.

Intraocular Deposition of Copper and ERG Findings in a Patient With Progressive Vision Loss From Hypercupremia.

A 46-year-old woman who presented for progressive glare was found to have dense deposition of copper within Descemet's membrane and lens capsule in both eyes (OU). Systemic workup revealed elevated serum copper secondary to multiple myeloma. Following bilateral Descemet stripping automated endothelial keratoplasty and cataract extraction, a green discoloration of the vitreous was noted. The patient was followed for 3 years with serial exams and electroretinograms. Electroretinograms showed declining photopic response amplitude OU, indicative of progressive retinal toxicity from copper. Although retinal toxicity and vitreous copper deposition are common in chalcosis, this appears to be the first case of hypercupremia associated with these findings. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e324-e326.].