A Single-Center Case Series of Acute Retinal Necrosis at Teikyo University: Clinical Characteristics and Treatment Outcomes.

Aim To evaluate the clinical characteristics, treatment course, and prognosis of patients with acute retinal necrosis (ARN), which can rapidly progress and cause severe vision loss. Design Single-center retrospective case series. Subjects and methods Six patients and seven eyes diagnosed with ARN at Teikyo University Hospital were included in this study. The clinical presentation and treatment prognosis were investigated based on data obtained from medical records. Results The mean age of the patients at the initial diagnosis was 63.6 years. Although the mean Logarithm of the Minimum Angle of Resolution (LogMAR) visual acuity tended to decrease from 0.77 at the first visit to 1.29 at the last visit, the difference was not statistically significant. Intraocular manifestations observed during the study period included ocular hypertension (14.3%), anterior uveitis (100.0%), retinal hemorrhage (71.4%), vitreous opacity (100.0%), retinal exudative vasculitis (85.7%), optic nerve atrophy (85.7%), retinal vascular occlusion (85.7%), choroidal atrophy (85.7%), macular edema (100.0%), subretinal fluid in the macula (71.4%), and retinal detachment (85.7%). Treatment modalities included oral and intravitreal antivirals (85.7%), antiplatelet medications (85.7%), steroid eye drops (85.7%), subcapsular (57.1%) and vitreous (42.9%) steroid injections, oral steroids (71.4%), and surgical intervention (85.7%). Vitrectomy led to retinal recovery in all five eyes that underwent the procedure. Conclusions The visual prognosis of patients with ARN is poor, particularly in those with preexisting visual impairment. Early detection coupled with antiviral therapy and prompt surgical intervention have been identified as potential factors that influence visual outcomes. Given the severity of ARN, collecting data from multiple centers could aid in devising future diagnostic and therapeutic strategies.

Electroretinographic Assessments of Macular Function after Brilliant Blue G Staining for Inner Limiting Membrane Peeling.

Purpose: The purpose of this study was to determine the effect of brilliant blue G (BBG) staining of the inner limiting membrane (ILM) on macular function. Method: Fourteen eyes of 14 patients consisting of 9 men and 5 women who underwent vitreous surgery with ILM peeling were studied. The mean age of the patients was 68.8 ± 9.14 years. Three eyes had a macular hole and eleven eyes had an epiretinal membrane. The ILM was made more visible by spraying 0.25% BBG into the vitreous cavity. The macular function was assessed by recording intraoperative focal macular electroretinograms (iFMERGs) before and after the intravitreal spraying of the BBG dye. The iFMERGs were recorded three times after core vitrectomy. The first recording was performed before the BBG injection (Phase 1, baseline), the second recording was performed after the spraying of the BBG and washing out the excess BBG (Phase 2), and the third recording was performed after the ILM peeling (Phase 3). All recordings were performed after 5 min of light-adaptation and stabilization of the intraocular conditions. The iFMERGs were recorded twice at each phase. The implicit times and amplitudes of the a- and b-wave, the PhNR, and the d-wave were measured. Wilcoxon signed-rank test were used to determine the significance of differences of the findings at Phase 2 vs. Phase 1 and Phase 3 vs. Phase 1. A p value < 0.05 was taken to be statistically significant. Results: The average implicit times of the a-wave, b-wave, PhNR, and d-wave were not significantly different in Phase 1, 2, and 3. The average a-wave, b-wave, PhNR, and d-wave amplitudes at Phase 1 did not differ significantly from that at Phase 2 and at Phase 3. Conclusions: The results indicated that the intravitreal injection of BBG does not alter the physiology of the macula, and we conclude that BBG is safe. We also conclude that iFMERGs can be used to monitor the macular function safely during intraocular surgery.

Intraocular Temperature Distribution in Eyes Undergoing Different Types of Surgical Procedures during Vitreous Surgery.

Vitreous temperature has been reported to vary during intraocular surgery. We measured the temperature at three intraocular sites, just posterior to the crystalline lens (BL), mid-vitreous (MV), and just anterior to the optic disc (OD), and investigated temperature changes before and after different types of surgical procedures in 78 eyes. The mean temperature at the beginning was 30.1 ± 1.70 °C in the anterior chamber, 32.4 ± 1.41 °C at the BL, 33.8 ± 0.95 °C at the MV, and 34.7 ± 0.95 °C at the OD. It was lowest at the BL, and highest at the OD. The mean temperature after cataract surgery was slightly lower especially at an anterior location. Thus, the temperature gradient became slightly flatter. The mean temperature after core vitrectomy was even lower at all sites and a gradient of the temperature was not present. The mean temperature after membrane peeling was significantly higher than that after core vitrectomy, and there was no gradient. The mean temperature after fluid/air exchange was lower at the BL and higher at the MV and at the OD. Thus, a gradient of higher temperatures at the OD appeared. The intraocular temperature distribution is different depending on the surgical procedure which can then change the temperature gradient. The temperature changes at the different intraocular sites and the gradients should be further investigated because they may affect the physiology of the retina and the recovery process.

Intraocular Temperature at Different Sites in Eye Measured at the Beginning of Vitreous Surgery.

The temperature of the vitreous has been reported to vary during cataract and vitreous surgery. We measured intraocular temperature at four intraocular sites; the anterior chamber (AC), just behind the crystalline lens, mid-vitreous, and just anterior to the optic disc (OD) at the beginning of vitrectomy with a thermoprobe in 48 eyes. The temperatures were compared in three groups; eyes that underwent vitrectomy for the first time (Group V, n = 30), eyes that had previous vitrectomy and the vitreous cavity had been filled with balanced salt solution (BSS; Group A, n = 12), and eyes that had previous vitrectomy and the vitreous cavity was filled with silicone oil (Group S, n = 6). There was a gradient in the temperature in all groups, i.e., it was lowest in the AC, and it increased at points closer to the retina. The intraocular temperature was significantly correlated with the type of fluid in the vitreous cavity. The mean intraocular temperatures were not significantly different in Groups V and A, but they were significantly higher in Group S. Clinicians should be aware of the differences in the temperature at the different intraocular sites because the temperatures may affect the physiology of the retina and the recovery process.

Effect of Paracentesis on Retinal Function Associated With Changes in Intraocular Pressure Caused by Intravitreal Injections.

Purpose: Intravitreal injections of antivascular endothelial growth factor agents are widely performed, and subsequent intraocular pressure increase may cause retinal nerve fiber damage. This study aimed to determine the effects of paracentesis before intravitreal injection of an antivascular endothelial growth factor on electroretinograms. Methods: This was a retrospective observational study in a university hospital. Twenty-five eyes of 25 patients who underwent intravitreal injections of antivascular endothelial growth factor agents were selected for evaluation. Intraocular pressures and electroretinograms were recorded before surgery (baseline), after anterior chamber paracentesis, and after intravitreal injection. The amplitudes and latencies of the a- and b-waves, photopic negative response, and oscillatory potential were measured. Changes in each component of the electroretinograms, intraocular pressure, and relationships between these two factors were investigated. The preoperative and postoperative ocular perfusion pressure was calculated based on blood pressure. Results: The amplitudes of the b-waves were significantly smaller after intravitreal injection than at baseline (P = 0.02), while no significant change was found in the other components during surgery. There were no significant changes in the latencies of any component during surgery. The intraocular pressure was significantly lower (P < 0.001) after anterior chamber paracentesis (6.8 ± 4.3 mm Hg) compared to baseline (24.1 ± 8.1 mm Hg) or after intravitreal injection (17.1 ± 9.6 mm Hg; P < 0.001). Conclusions: Performing anterior chamber paracentesis before an intravitreal injection can prevent the intraocular pressure elevation and thus minimize the electrophysiological retinal dysfunction. Translational Relevance: Anterior chamber paracentesis before an intravitreal injection mitigates the adverse effects on retinal function.

Magnification Effect of Foveal Avascular Zone Measurement Using Optical Coherence Tomography Angiography.

PURPOSE: The aim of this study was to evaluate the foveal avascular zone (FAZ) of healthy subjects and examine the magnification effect. METHODS: A total of 33 healthy volunteers were enrolled and all subjects were eligible for analysis. Optical coherence tomography angiography (OCTA) examination scanned 3 × 3 mm of the macular area. The FAZ area was measured on the superficial OCTA en face image with and without correction by axial length. The relationship between changes in the FAZ area after correction with the axial length was examined. RESULTS: The mean age was 21.9 ± 0.6 years. The mean axial length was 24.87 ± 1.17 mm and mean spherical equivalent (SE) value was -3.64 ± 2.83 diopters (D). The FAZ area was 0.26 ± 0.10 mm2 before the axial length correction and 0.27 ± 0.10 mm2 after the correction. In the eyes that had an axial length longer than or equal to 26 mm or SE less than or equal to -6 D, the FAZ area after correction was significantly larger than that before correction (p < 0.01). The change of FAZ area after correction with axial length was significantly correlated with the axial length (R 2 = 0.88, p < 0.01) or SE value (R 2 = 0.55, p < 0.01). CONCLUSION: FAZ areas were comparable to previous reports. In high myopic cases, the magnification effect needs to be considered when evaluating the FAZ area.

Retinal function determined by flicker ERGs before and soon after intravitreal injection of anti-VEGF agents.

BACKGROUND: To evaluate the retinal function before and soon after an intravitreal injection of an anti-vascular endothelial growth factor (anti-VEGF) agents. METHODS: Seventy-nine eyes of 79 patients that were treated by an intravitreal injection of an anti-VEGF agent for age-related macular degeneration (AMD), diabetic macular edema (DME), or retinal vein occlusion (RVO) with macular edema (ME) were studied. The RETeval® system was used to record 28 Hz flicker electroretinograms (ERGs) from the injected and non-injected eyes before (Phase 1, P1), within 2 h after the injection (P2), and 2 to 24 h after the injection (P3). Patients were grouped by disease or by the injected agent and compared. The significance of the changes in the implicit times and amplitudes was determined by t tests. RESULTS: The amplitudes were not significantly different at the three phases. The implicit time of the injected eye was 31.2 ± 3.2 msec at P1, and it was not significantly different at P2 (31.7 ± 3.1 msec) but it was significantly longer at P3 (32.2 ± 3.3 msec, P < 0.01, ANOVA for both). The implicit time in the non-injected fellow eye was 30.5 ± 3.3 msec at P1, and it was significantly longer at P2 (31.1 ± 3.2 msec) and phase 3 (31.3 ± 3.4 msec, P < 0.01, ANOVA for both). CONCLUSIONS: The results indicate that an intravitreal anti-VEGF injection will increase the implicit times not only in the injected eye but also in the non-injected eye soon after the intravitreal injection.

Intraoperative electrophysiological evaluations of macular function during peripheral scleral indentation.

Scleral indentation is widely used to examine the peripheral fundus, however it can increase the intraocular pressure (IOP) to high levels which can then affect retinal function. We evaluated the effects of scleral indentation on the macular function electrophysiologically. Intraoperative focal macular electroretinograms (iFMERGs) were recorded with and without controlling the IOP in 7 eyes. Without IOP control, the IOP increased from 21.7 ± 4.9 to 92.7 ± 20.2 mmHg significantly (P = 0.020) and the amplitudes of the b-wave (from 6.29 ± 1.160 to 3.71 ± 1.98 uV, P = 0.007), on-photopic negative response (from 2.29 ± 0.99 to 0.72 ± 0.47 uV, on-PhNR, P = 0.005), and d-wave (from 2.57 ± 0.41 to 1.64 ± 0.69 uV, P = 0.007) decreased significantly soon after beginning the indentation. All values returned to the baseline levels after releasing the indentation. In the eyes with IOP controlled, the IOP and the amplitude of all components did not change significantly during and after the indentation except the on-PhNR amplitude which was significantly reduced during the indentation. The changes in the iFMERGs and macular function caused by scleral indentation were transient and reversible. The changes can be minimized by controlling the IOP.

Electroretinographic evaluations of retinal function before, just after, and after intravitreal injections.

Intravitreal injections (IVI) have become a part of daily practice for a growing number of procedures. We evaluated the retinal function by recording intraoperative photopic electroretinograms (ERGs) before an injection (T1), just after the injection (T2), and after the aspiration of the anterior chamber fluid (T3) of 19 eyes of 19 patients (mean age 70.6 years; men = 11) who received an IVI of an anti-vascular endothelial growth factor. The mean amplitudes of the b-wave, photopic negative responses (PhNR), and oscillatory potentials (OPs) 1 and 2 at T2 were significantly smaller than that at T1, but no significant difference was observed between T3 and T1. The mean implicit times of the a-wave and OP1, 2, and 3 at T2 and the a-wave and the OP2 at T3 were significantly longer than that at T1. The mean intraocular pressure (IOP) at T2 (49.32 mm Hg) was significantly higher and the IOP at T3 (8.74 mm Hg) was significantly lower than that at T1 (21.05 mm Hg). The retinal function was reduced and the IOP elevated just after the IVI. The response of each ERG component was different suggesting a different sensitivity of each type of retinal neuron to IVI.

Intraoperative Electroretinograms before and after Core Vitrectomy.

PURPOSE: To evaluate retinal function by intraoperative electroretinograms (ERGs) before and after core vitrectomy. DESIGN: Retrospective consecutive case series. METHOD: Full-field photopic ERGs were recorded prior to the beginning and just after core vitrectomy using a sterilized contact lens electrode in 20 eyes that underwent non-complicated vitreous surgery. A light-emitted diode was embedded into the contact lens, and a stimulus of 150 ms on and 350 ms off at 2 Hz was delivered. The amplitudes and latencies of the a-, b-, and d-waves, photopic negative response (PhNR), and oscillatory potentials (OPs) were analyzed. The intraocular temperature at the mid-vitreous was measured at the beginning and just after the surgery with a thermoprobe. RESULTS: The intraocular temperature was 33.2 ± 1.3°C before and 29.4 ± 1.7°C after the vitrectomy. The amplitudes of the PhNR and OPs were significantly smaller after surgery, and the latencies of all components were prolonged after the surgery. These changes were not significantly correlated with the changes of the temperature. CONCLUSION: Retinal function is reduced just after core vitrectomy in conjunction with significant temperature reduction. The differences in the degree of alterations of each ERG component suggests different sensitivity of each type of retinal neuron.

Assessment of Macular Function during Vitrectomy: New Approach Using Intraoperative Focal Macular Electroretinograms.

PURPOSE: To describe a new technique to record focal macular electroretinograms (FMERGs) during vitrectomy to assess macular function. METHODS: Intraoperative FMERGs (iFMERGs) were recorded in ten patients (10 eyes) who undergo vitrectomy. iFMERGs were elicited by focal macular stimulation. The stimulus light was directed to the macular area through a 25 gauge (25G) glass fiber optic bundle. Background light was delivered through a dual chandelier-type light fiber probe. Focal macular responses elicited with combinations of stimulus and background luminances were analyzed. RESULTS: A stimulus luminance that was approximately 1.75 log units brighter than the background light was able to elicit focal macular responses that were not contaminated by stray light responses. Thus, a stimulus luminance of 160 cd/m2 delivered on a background of 3 cd/m2 elicited iFMEGs from only the stimulated area. This combination of stimulus and background luminances did not elicit a response when the stimulus was projected onto the optic nerve head. The iFMERGs elicited by a 10° stimulus with a duration of 100 ms and an interstimulus interval of 150 ms consisted of an a-, b-, and d-waves, the oscillatory potentials, and the photopic negative response (PhNR). CONCLUSIONS: Focal ERGs with all components can be recorded from the macula and other retinal areas during vitreous surgery. This new technique will allow surgeons to assess the function of focal areas of the retina intraoperatively.

Recovery of photoreceptor inner and outer segment layer thickness after reattachment of rhegmatogenous retinal detachment.

AIMS: To evaluate the recovery of retinal function and the thicknesses of the photoreceptor inner (IS) and outer segment (OS) layers after a reattachment of a rhegmatogenous retinal detachment (RRD). METHODS: 49 eyes of 49 patients (mean age, 57.4±10.3 years) with successfully reattached RRD were retrospectively studied. Spectral-domain optical coherence tomography was used to obtain images of the foveal area, and the thicknesses of the IS and OS were measured before and 1, 3, 6 and 12 months after surgery. The thicknesses of the corresponding structures of the healthy fellow eye served as control. RESULTS: The thickness of the IS layer was 20.4±5.0 µm and that of the OS layer was 34.4±9.7 at 1 month after surgery, which was significantly thinner than the IS (28.9±2.9) and OS (55.4±5.2) layers of the fellow eyes. The thicknesses gradually increased and were not significantly different from that in the fellow eye at 12 months (IS, 28.4±4.4 µm and OS, 50.7±6.6 µm). The IS and OS thicknesses at 1 month after surgery in eyes that had a decimal visual acuity of 1.0 at 6 months were significantly thicker than those in eyes that had a visual acuity of <1.0. CONCLUSIONS: The increase in the thicknesses of the IS and OS layers of the photoreceptors during the recovery phase of eyes with RRD indicates that the recovery process was slow and gradual. Quantitative analysis of the IS and OS thicknesses may be useful to follow the disease process.

Pars plana vitrectomy combined with focal endolaser photocoagulation for idiopathic macular telangiectasia.

Background. To report the outcome of pars plana vitrectomy (PPV) combined with intraoperative endolaser focal photocoagulation (PC) on eyes with idiopathic macular telangiectasis (MacTel) type 1. Methods. This was a retrospective study of two female patients with MacTel type 1 who were resistant to focal photocoagulation, sub-Tenon triamcinolone injection, and/or antiangiogenic drugs. The best-corrected visual acuity (BCVA) was determined, and fluorescein angiography (FA) and spectral domain optical coherence tomography (SD-OCT) were performed before and after surgery for up to 19 months. Results. After surgery, the BCVA gradually improved from 20/100 to 20/20 at 19 months in Case 1 and from 20/50 to 20/13 at 13 months in Case 2. Fluorescein angiography (FA) showed leakage at the late phase, and OCT showed that the cystoid macular edema was resolved and the fovea was considerably thinner postoperatively. Conclusion. Patients with MacTel type 1 who are refractory to the other types of treatments can benefit from PPV combined with intraoperative endolaser focal PC with functional and morphological improvements.

Effect of intraocular lens diameter implanted in enucleated porcine eye on intraocular pressure induced by scleral depression.

The effect of the diameter of an intraocular lens (IOL) implanted in enucleated porcine eyes on the intraocular pressure induced by scleral depression was investigated. Two IOLs of 6 mm and 7 mm optic diameter were implanted. The intraocular pressure (IOP) was monitored during scleral depression by a transducer placed in the midvitreous through a sclerotomy at 6 o'clock. The area under the curve (AUC) of the IOP changes from the beginning of the indentation to the point when the peripheral retinal surface was observed through the IOL optics was measured. The AUC was significantly larger in eyes with a 6 mm IOL than in eyes with a 7 mm IOL (p < 0.05). The IOP elevation at the endpoint was higher in eyes with the 6 mm IOL than in eyes with the 7 mm IOL. We conclude that the AUC may represent the degree of stress induced by scleral depression. The higher AUC value with the X-60 may be because of the longer distance from the peripheral retina to the edge of the IOL optics.