Prevalence and clinical implications of subretinal fluid in retinal diseases: a real-world cohort study.

BACKGROUND/AIMS: To characterise the baseline prevalence of subretinal fluid (SRF) and its effects on anatomical and visual acuity (VA) outcomes in diabetic macular oedema (DME) and retinal vein occlusion (RVO) following anti-vascular endothelial growth factor (VEGF). METHODS: This is a retrospective cohort study of 122 DME and 54 RVO patients who were initiated on anti-VEGF therapy with real-world variable dosing. The DME and RVO cohorts were subclassified based on the presence of SRF at presentation. Snellen VA was measured and converted to logarithm of the minimum angle of resolution (LogMAR). Changes in VA and central subfield thickness (CST) were assessed up to 24 months. RESULTS: SRF was present in 22% and 41% in DME and RVO patients, respectively. In the DME subcohort, eyes with SRF showed an improvement of 0.166 logMAR (1.7 Snellen chart lines) at 12 months and 0.251 logMAR (2.6 Snellen chart lines) at 24 months, which were significantly greater compared with those of the non-SRF group. A significantly greater reduction in CST was noted in the SRF eyes compared with the non-SRF eyes at 3 months and 1 month in the DME and RVO subcohorts, respectively. CONCLUSION: Baseline SRF is a good marker for a greater reduction in CST in both DME and RVO, but an improvement in VA associated with SRF may be only noted in DME.

Effects of Sleep Deprivation, Non-Dominant Hand Employment, Caffeine and Alcohol Intake During Surgical Performance: Lessons Learned From the Retina Eyesi Virtual Reality Surgical Simulator.

Purpose: Determine whether real-life surgical experience correlates with scores on a retina virtual simulator and the effects of various challenges on surgical performance. Methods: The study was performed using the Eyesi Surgical Simulator, a virtual reality retina surgical simulator. Residents, fellows, and retina staff were assessed on surgical simulations to determine surgical skills. Participants were assigned baseline scores on speed, efficiency of movement, and ability to avoid retinal damage. After receiving their baseline scores, participants were challenged to use their non-dominant hand or to use the simulator after sleep deprivation or the intake of caffeine or alcohol. Results: At baseline, junior residents had an average score of 943; senior residents, 1045; retina fellows, 1153; and surgical retina staff, 1161. A 12.5% overall improvement in scores was achieved when comparing baseline 1 to baseline 2; a major improvement was recorded in residents (14.5%) compared with fellows and retina staff (9.97%). A statistically significant difference was observed between residents and fellows (P = 0.027), as well as between residents and retina staff (P = 0.04). A significant decrease in performance (15.7%) was observed when the non-dominant hand was used (P = 0.043). Performance after sleep deprivation and alcohol intake decreased, but not with a statistically significant difference (P = 0.6 and P = 0.5, respectively). A trend toward increasing performance was observed after caffeine intake (6.1%; P = 0.06). Conclusions: The retina virtual simulator is a novel teaching tool for retinal surgery. A significant association was observed between real surgical experience and the retina surgery virtual simulator results based on surgical experience. Translational Relevance: An association between real surgical experience and retina surgery virtual simulator results was demonstrated. A complete training program with a cut-off threshold score should be validated for retina training programs.

Optimizing Color Performance of the Ngenuity 3-Dimensional Visualization System.

Purpose: To evaluate the effect of surgeon-controlled parameters on the color performance of the Ngenuity 3-dimensional (3D) visualization system. Design: A calibrated reference target was placed inside a model eye to assess the Ngenuity 3D camera under different settings. The Ngenuity 3D display was assessed with a commercial colorimeter. Methods: Manufacturer-recommended methodology for white balancing was compared against all common deviations in technique. Following white balance, images of a calibrated reference target were extracted and tested using Imatest Master software to calculate quantitative color differences (delta E and delta C). The Ngenuity monitor was assessed using a SpyderX Elite commercial colorimeter to assess for image burn-in by quantifying color uniformity and maximum luminescence. Main Outcome Measures: Delta E and delta C were calculated for all variables. Color uniformity and luminance were assessed in candelas per square meter (nits). Results: Color performance using the manufacturer-recommended specifications yielded a delta E of 12.81 ± 1.67. Changing the white balance target to a videography grey card (P = 0.07) and 4 × 4 gauze (P = 0.37) provided similar performance, whereas using white computer paper or the operator's palm significantly increased the delta E from 12.81 ± 1.67 to 15.28 ± 1.22 (P = 0.01) and 17.71 ± 2.03 (P < 0.01), respectively. Changes to card position, magnification, stability, or ambient lighting did not significantly impact white balance results, whereas having the card in crisp focus did decrease color accuracy (15.78 ± 1.63; P = 0.03). Minor improvement in performance occurred when the laser filter was off for white balance and image acquisition (9.28 ± 0.25; P < 0.01), but deterioration occurred if the laser filter was placed after balancing (16.59 ± 1.17; P < 0.01). Both light sources of 23-gauge light pipe at 34% intensity and 25-gauge chandelier at 50% intensity gave similar color accuracy (P = 0.37). When comparing different Ngenuity machines, color uniformity and maximum luminescence decreased with increased device use. Conclusions: Overall, the Ngenuity 3D has robust color performance. A few limitations of both the camera and monitor were identified, and surgeons should be aware of these pitfalls as well as solutions examined herein to mitigate their effects during surgery.

Optimizing Visual Performance With Digitally Assisted Vitreoretinal Surgery.

BACKGROUND AND OBJECTIVE: Evaluate depth of field (DOF) and lateral resolution (LR) on digitally assisted vitreoretinal surgery (DAVS) with different camera aperture values and TV viewing distances to determine maximal optical performance. PATIENTS AND METHODS: Five retinal surgeons objectively evaluated DOF and LR at low (10×), medium (15×), and high (20×) magnification on a conventional microscope (CM) and DAVS. DAVS was evaluated at different camera apertures (30%, 50%, and 75%) and TV viewing distances (1.2 meters [m], 1.5 m, and 2.0 m). A comparison between CM and optimized DAVS values was carried out. RESULTS: On DAVS, DOF significantly increased as camera aperture size was reduced (75% to 50%, P = .022; 75% to 30%, P ≤ .001; and 50% to 30%, P = .001) and as microscope magnification was reduced (high to medium, P = .009; high to low, P ≤ .001; and medium to low, P = .002). LR significantly increased as microscope magnification was increased (low to medium, P = .010; low to high, P ≤ .001; and medium to high, P = .015) and as TV display distance decreased (2.0 m to 1.5 m, P = .019; 2.0 m to 1.2 m, P = .009; and 1.5 m to1.2 m, P = .185). When comparing optimized DAVS against CM, DOF was significantly larger on DAVS (P = .019). LR on DAVS outperformed the CM, but statistical significant was not reached (P = .185). CONCLUSIONS: The authors' study is the first to evaluate different aperture, magnification, and TV distance settings, and when optimized, DAVS can significantly outperform a CM with respect to DOF and LR. Optimized visual performance for DAVS is obtained with a 30% camera aperture and a TV viewing distance no further than 1.5 m. Maximal microscope magnification to exploit LR during macular surgery and low-to-medium magnification to increase DOF for overall vitrectomy surgery is recommended. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:S15-S21.].

ECTOPIC INNER FOVEAL LAYER CLASSIFICATION SCHEME PREDICTS VISUAL OUTCOMES AFTER EPIRETINAL MEMBRANE SURGERY.

PURPOSE: To evaluate the ectopic inner foveal layer (EIFL) staging scheme as a visual prognostic factor for patients undergoing epiretinal membrane (ERM) surgery. METHODS: Retrospective study of 88 pseudophakic patients with diagnosis of idiopathic ERM who underwent ERM surgery with a minimum follow-up of 12 months. Preoperative and postoperative EIFL staging was correlated with the final best-corrected visual acuity (BCVA). As a secondary outcome, evaluation of the proportion of patients achieving final best-corrected visual acuity ≥20/40 in each stage was assessed. RESULTS: Based on the EIFL staging scheme, of 88 pseudophakic eyes analyzed, 24 (27.4%) were diagnosed as Stage 2 ERM, 45 (51.1%) as Stage 3 ERM, and 19 (21.5%) as Stage 4 ERM preoperatively. At the final follow-up visit, 70.8% of eyes with Stage 2 showed an improvement in EIFL staging scheme, while 68% of eyes in Stage 3 and 4 remained the same. The final best-corrected visual acuity significantly improved with all EIFL stages (P = <0.05). However, earlier stages were associated with better visual outcomes both preoperatively and postoperatively (Stage 2 > Stage 3 > Stage 4 P < 0.001). Final best-corrected visual acuity ≥20/40 was reached in 91.7% of eyes with Stage 2, 42.3% with Stage 3, and 5.2% with Stage 4. CONCLUSION: The EIFL staging scheme is an easy, fast, and reproducible method to evaluate visual prognosis with ERM surgery. Surgery on Stage 2 ERM results in significantly better visual outcomes and a greater chance of reversibility in anatomical changes.

Same-Day Bilateral Intravitreal Anti-Vascular Endothelial Growth Factor Injections: Experience of a Large Canadian Retina Center.

OBJECTIVE: To evaluate the outcomes and complications of bilateral same-day intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections. METHODS: This is a single-center, retrospective study that included 524 eyes of 262 patients who received concomitant bilateral intravitreal anti-VEGF injections in 2016 at St. Michael's Hospital, Toronto. If any of the patients were receiving simultaneous bilateral injections on a regular basis prior to 2016, data pertaining to previous injections were also reviewed. Everyone received bevacizumab, ranibizumab, or aflibercept in an office setting. RESULTS: A total of 9,798 intravitreal anti-VEGF injections (4,899 bilateral injection sessions) were performed in 524 eyes of 262 patients. The average number of bilateral injection sessions per patient was 18.7 ± 14.1. Ranibizumab was the most commonly used anti-VEGF drug (83.8%). The incidence of endophthalmitis was 0.01%, and there were 2 episodes of acute intraocular inflammation among the 9,798 injections (0.02%). All 3 cases occurred after treatment with ranibizumab. There were 2 deaths (0.76%) due to nonvascular causes but no vascular related systemic adverse events were reported. CONCLUSIONS: Same-day bilateral intravitreal anti-VEGF injections present a low rate of complications and are well tolerated by patients. This safe practice may reduce the burden on the health-care system and on the patients.

Age-related macular degeneration: is polypoidal choroidal vasculopathy recognized and treated?

OBJECTIVE: To assess how polypoidal choroidal vasculopathy (PCV) is recognized and treated, and to assess whether treatment outcomes are different between Chinese and Caucasian Canadian patients with age-related macular degeneration (AMD). DESIGN: Retrospective chart review. PARTICIPANTS: 154 eyes from 135 Chinese patients and 2291 eyes from 1792 Caucasian patients who were newly diagnosed with either AMD or PCV and had more than 1 year of follow-up were included. METHODS: All newly diagnosed AMD patients presenting to the Retina Service of 3 Toronto University Hospitals, between March 25, 2008, to September 30, 2014, were reviewed. RESULTS: 10/154 eyes (6.5%) in Chinese Canadians and 16/2291 eyes (0.7%) in Caucasian Canadians were diagnosed as having PCV. Indocyanine green angiography (ICGA) was used to diagnose PCV in 20% of Chinese Canadians and 8.8% of Caucasian Canadians. Clinical practices with a larger percentage of Chinese patients were more likely to diagnose PCV in both Chinese (p = 0.004) and Caucasian patients (p = 0.03), were more likely to use photodynamic therapy (PDT) (p < 0.01), and had significantly greater central retinal thickness decrease (p < 0.001). CONCLUSION: Our study has shown that PCV is under-recognized in a Canadian population, and ICGA is underutilized. In clinical practices with a greater portion of Chinese patients, PCV is more often recognized and PDT is used more liberally.

Optical coherence tomography-based positioning regimen for macular hole surgery.

PURPOSE: To evaluate an optical coherence tomography (OCT)-based positioning regimen for patients undergoing macular hole surgery. METHOD: We reviewed the medical records of all patients in our practice who underwent macular hole repair, instituting a modified OCT-based positioning regimen from November 1, 2011 through July 31, 2013. The regimen consisted of prone positioning at the conclusion of surgery with daily OCT imaging until the hole was confirmed closed at which point positioning was halted. Clinical data that were collected and recorded included visual acuities, stage of hole, size of hole, chronicity, preoperative and postoperative OCT imaging, and length of follow-up. RESULTS: We identified 33 patients (35 eyes) with a mean baseline visual acuity of 20/220, a mean hole size of 465 µm. The mean final (postoperative) visual acuity was 20/135 with a mean follow-up of 7.7 months. Six patients (17%) in our study were diagnosed with myopic degeneration. Thirteen patients (37%) were found to have chronic (≥12 months) holes, and 19 (54%) were found to have large holes (>400 µm). Overall, 28 eyes (80%) had persistent closure of macular holes with an OCT-based positioning regimen. In the absence of high risk factors, such as myopic degeneration, chronic or large holes, the closure rate was 92%. In the presence of 2 or 3 of these risk factors, the closure rate was 85% and 74%, respectively. CONCLUSION: The presence of 2 or 3 high risk factors, such as myopic degeneration, chronic holes (≥12 months), or large holes (>400 µm) can compromise outcomes resulting in reopening after apparent early closure. Based on the presence of these risk factors, a modified postoperative positioning regimen can be used to obtain complete and persistent closure.

The evolution of endoillumination.

Advances in endoillumination over the last decade have been numerous and were necessary to allow transition to smaller-gauge vitrectomy systems. Advances in light sources and their associated filters have resulted in safer, more powerful light sources that provide enough output to drive small fibers for 27-gauge surgery, chandeliers, and lighted instrumentation. Filtered light can also be used to enhance tissue visualization. This chapter will review the history and advances in light sources.

Use of telemedicine in screening for diabetic retinopathy.

BACKGROUND: A diabetic retinopathy screening program was introduced in September 2000 at a university-affiliated hospital in Montreal to meet the demands of an overburdened health care system. In this article we describe our initial experience with this program. METHODS: A Canon CR6-45NM nonmydriatic 45 degrees camera was installed in the outpatient endocrinology clinic of the hospital. All patients who visited the clinic between September 2000 and January 2001 agreed to participate in the program. For each patient, a short questionnaire (age, sex, type of diabetes mellitus, time since diagnosis, prior retinal laser therapy and presence of end-organ involvement) was filled in. Subsequently at least two photographs were obtained of each eye. The photographs were sent via the hospital intranet to a retinal specialist within the hospital. The specialist reviewed the images unchanged and sent a report (grading of the level of diabetic retinopathy, presence or absence of macular hard exudates, quality of the images obtained and follow-up recommendations) via the hospital intranet to the endocrinology service. If the images were judged to be of poor quality and could not be read by the retina specialist, the patient was asked to see his or her regular ophthalmologist. RESULTS: Images of 830 eyes of 415 patients (211 men and 204 women with a mean age of 57.5 years) were obtained. Most (83.6%) had type 2 diabetes. The average duration of disease was 13.3 years. Macular hard exudates were observed in 50 eyes (6.0%). Nonproliferative diabetic retinopathy was noted in 117 eyes (14.1%) and proliferative diabetic retinopathy in 15 eyes (1.8%). Unexpected findings included epiretinal membranes (in three eyes), macular holes (in two), bilateral cotton-wool spots (in one patient) and central retinal vein occlusion (in one eye). Overall, 10% of the patients were referred to a retina specialist based on the screening photographs. The main difficulty encountered with the screening program was image inconsistency. Overall, 35% of the images graded were felt to be of poor quality, the most common reason being poor exposure (84.4%). The quality of the images improved significantly over the study period (p < 0.01). Images obtained from patients aged 65 years or more were consistently poorer than those obtained from patients less than 65 years of age (p < 0.001). INTERPRETATION: Despite the imperfections of such a system, our experience was favourable, allowing us to screen large numbers of patients in a cost-effective, reliable manner.