Epiretinal Membrane Impairs the Inner Retinal Layer in a Traction Force-Dependent Manner.

Purpose: To investigate the relationship between retinal traction force and impairment of the inner retinal layer in patients with epiretinal membrane (ERM). Design: Nonrandomized, retrospective consecutive case series. Participants: Two hundred nine eyes of 201 patients with idiopathic ERM who underwent vitrectomy for idiopathic ERM were enrolled. Methods: Retinal folds caused by ERM were visualized using en face OCT, and the maximum depth of retinal folds within the parafovea (MDRF) was measured. Focal macular electroretinogram (ERG) was used to measure the amplitude and implicit time of each component for the ERM eyes and the normal fellow eyes. B-scan OCT images were used to measure the thicknesses of the inner nuclear layer (INL) and outer nuclear layer (ONL) + outer plexiform layer (OPL). Expression of α-smooth muscle actin (α-SMA) in surgically removed ERM specimens was quantified by reverse-transcription polymerase chain reaction. Main Outcome Measures: We analyzed the relationship between MDRF and the relative amplitudes of focal macular ERG (affected eye/fellow eye), the relationships between MDRF and the mean INL thickness and ONL+OPL thickness, comparison of INL thickness and ONL+OPL thickness for each area when cases were classified according to MDRF localization in the ETDRS chart, and the relationship between MDRF and the relative expression of α-SMA in the ERM specimens. Results: The MDRF significantly correlated with the relative amplitudes (affected eye/fellow eye) of b-waves and oscillatory potentials (r = -0.657, P = 0.015; r = -0.569, P = 0.042, respectively) and the mean INL thickness and ONL+OPL thickness (r = 0.604, P < 0.001; r = 0.210, P = 0.007, respectively). However, only the INL thickness progression rate was significantly correlated with the MDRF progression rate (r = 0.770, P < 0.001). On case stratification by localization of MDRF based on the ETDRS chart, in regions other than temporal regions, the INL thickness was significantly greater in regions with MDRF than in other regions. The MDRF significantly correlated with α-SMA expression in the ERM specimens (r = 0.555, P = 0.009). Conclusions: The findings suggest that ERM impairs the inner retinal layer in a traction force-dependent manner. Financial Disclosures: The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Comparison of ocular morphological measurement by wide-angle echography and magnetic resonance imaging.

Objectives: To compare the eye axial length (AL), equatorial horizontal diameter (HD), and equatorial vertical diameter (VD) of normal eyes using a novel wide-angle, arc-scanning, ultrasound diagnostic device for wide-angle B-mode echography. Methods: In this cross-sectional study, wide-angle B-mode echography and magnetic resonance imaging (MRI) were conducted on 22 normal eyes; the AL, HD, and VD were measured. Results: The mean ALs were as follows: wide-angle B-mode echography, 25.22±1.47 mm and MRI, 25.24±1.46 mm; a significant correlation was observed between the two measurements (ß=0.995 [0.976, 1.013]; p<0.001; 95% R2=1.00). The mean HDs were as follows: wide-angle B-mode echography, 22.33±0.84 mm and MRI, 22.55±0.90 mm; a significant correlation was observed between the two measurements (ß=0.902 [0.750, 1.179]; p<0.001; 95% R2=0.81). The mean VDs were as follows: wide-angle B-mode echography, 22.77±0.91 mm; and MRI, 22.88±0.92 mm; a significant correlation was observed between the two measurements (ß=0.966 [0.853, 1.097]; p<0.001; 95% R2=0.93). Conclusions: There were no significant differences in the measurements for each parameter by wide-angle B-mode echography and MRI. Therefore, wide-angle B-mode echography permits accurate visualization of ocular morphology.

Modified inverted internal limiting membrane flap technique for macular hole closure.

PURPOSE: To investigate the efficacy of modified internal limiting membrane (ILM) flap technique combined with vitreous surgery for treating macular holes and examine the outcomes in visual function and anatomic macular hole closure. STUDY DESIGN: Retrospective, observational. METHODS: Between July 1, 2015, and October 1, 2019, the modified inverted ILM flap technique combined with vitreous surgery was used to treat idiopathic macular holes, postoperative progression was then followed for at least 6 months in 96 participants (98 eyes). We modified the method by removing the lower half of the ILM while peeling and inverting the upper half. The mean age of the participants was 65.9 ± 11.9 years (41 men (42.7%) and 55 women (57.3%)). Retrospective evaluations of macular hole diameter, corrected visual acuity, and macular hole closure rates were performed using data from medical records. RESULTS: The mean macular hole diameter was 623.6 ± 207.4 µm. The mean corrected visual acuity (logMAR) was 0.79 ± 0.27 before surgery and 0.46 ± 0.35 at 1, 0.35 ± 0.39 at 3, and 0.31 ± 0.36 at 6 months Post surgery, showing significant differences before and after surgery (p = 2.30 × 10- 2). The macular hole closure rate was 98%. CONCLUSION: The modified inverted ILM flap technique combined with vitreous surgery was an effective method for treating macular holes, resulting in improvement in closure and visual acuity.

Genetic characterization of 1210 Japanese pedigrees with inherited retinal diseases by whole-exome sequencing.

Inherited retinal diseases (IRDs) comprise a phenotypically and genetically heterogeneous group of ocular disorders that cause visual loss via progressive retinal degeneration. Here, we report the genetic characterization of 1210 IRD pedigrees enrolled through the Japan Eye Genetic Consortium and analyzed by whole exome sequencing. The most common phenotype was retinitis pigmentosa (RP, 43%), followed by macular dystrophy/cone- or cone-rod dystrophy (MD/CORD, 13%). In total, 67 causal genes were identified in 37% (448/1210) of the pedigrees. The first and second most frequently mutated genes were EYS and RP1, associated primarily with autosomal recessive (ar) RP, and RP and arMD/CORD, respectively. Examinations of variant frequency in total and by phenotype showed high accountability of a frequent EYS missense variant (c.2528G>A). In addition to the two known EYS founder mutations (c.4957dupA and c.8805C>G) of arRP, we observed a frequent RP1 variant (c.5797C>T) in patients with arMD/CORD.

A Case of Cat Scratch Disease with Neuroretinitis in a 16-Month-Old Boy.

Purpose: We report a case of neuroretinitis associated with cat scratch disease (CSD) in young children. Method: Case report. Results: A 16-month-old boy was admitted for a detailed examination and treatment of a fever of unknown origin. Blood tests revealed no significant findings other than a white blood cell count of 16,100/mm3 and C-reactive protein level of 9.89 mg/dL. Computed tomography revealed no relevant findings to determine the causative disease. Antibiotic therapy with cefotaxime was initiated; however, the fever did not resolve. The patient was referred to our department for further examination to detect the cause of the fever. Fundoscopy revealed neuroretinitis in the right eye. His mother reported a history of breeding cats. Cat scratch disease (CSD) was suspected based on the clinical course and fundus findings. Cefotaxime was discontinued, and azithromycin, rifampicin, and prednisolone were administered, following which the fever disappeared and fundus findings improved. Immunoglobulin G (IgG) and IgM antibodies against Bartonella henselae was positive, leading to a definitive diagnosis of CSD. Conclusion: Infants cannot complain of decreased visual acuity; therefore, these findings may be overlooked unless a fundus examination is performed. As in this case, the early detection of neuroretinitis by an ophthalmologist may help in the diagnosis of CSD. It is extremely difficult to capture a photograph of the fundus of an infant, and recording with a smartphone is relatively simple and useful for monitoring continuous changes. Summary. We describe a case of neuroretinitis associated with cat scratch disease (CSD) that was diagnosed on the basis of fundus findings. The findings suggest the importance of an aggressive ophthalmologic examination when CSD is suspected in young children who are unable to describe their symptoms.

A Case of Fabry Disease with Central Retinal Artery Occlusion.

We report a case of Fabry disease diagnosed after recurrent cerebral infarction in a patient with central retinal artery occlusion (CRAO). A 23-year-old man presented with vision loss in his right eye (20/2000), showing CRAO. There was no identified cause for the loss of vision; however, corneal verticillata was detected in both eyes on the recurrence of the cerebral infarction. The α-galactosidase activity in leukocytes was significantly reduced to <0.3 nmol/mg of protein/hour, leading to a definitive diagnosis of Fabry disease. Enzyme replacement therapy was commenced concomitant to rehabilitation. It is necessary to identify Fabry disease as a cause of CRAO in young individuals, and the detection of cornea verticillata, used frequently as an ocular finding, is helpful.

Risk factors for epiretinal membrane surgery after initial pars plana vitrectomy for rhegmatogenous retinal detachment.

OBJECTIVES: The purpose of this study was to examine the incidence of, and risk factors for, epiretinal membrane (ERM) surgery after an initial pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD). METHODS: The records of consecutive patients (3,495 eyes of 3,387 patients) who underwent RRD repair at Fujita Health University Hospital between January 1, 2008, and February 28, 2019, were retrospectively reviewed. A total of 1,736 eyes without an ERM in preoperative optical coherence tomography were included in this study. RESULTS: The incidence of ERM surgery after RRD repair was 2.4%. The mean time from RRD repair to ERM surgery was 19.5±27.2 months. The odds ratios after adjusting for age and sex were as follows: the preoperative visual acuity (logarithm of the minimum angle of resolution, logMAR), 2.17 (p=0.02; 95% confidence interval [CI], 1.11-5.16); axial length, 1.38 (p=0.002; 95% CI, 1.12-1.72); 20-gauge vitreous surgery instruments, 3.82 (p<0.0001; 95% CI, 2.02-7.16); internal limiting membrane (ILM) peeling, 0.28 (p=0.033; 95% CI, 0.05-0.92). ERM surgery improved visual acuity from 0.36 to 0.01 logMAR, even at ≥1.5 years after RRD repair. CONCLUSIONS: Careful follow-up is required in the following cases: long axial length before RRD repair, low visual acuity, use of 20-gauge vitreous surgery instruments, and a lack of ILM peeling.

Asymmetric extent of distortion measured using the Watzke-Allen Test in patients with macular hole.

Visual dysfunction in patients with macular hole is believed to occur because of cone cell displacement, often measured by the Watzke-Allen test (WAT). However, it is unknown if the horizontal and vertical measurements recorded by WAT reflect the true extent of photoreceptor displacement. This study aimed to measure the extent of photoreceptor displacement in patients with macular hole using WAT and compare the displacement value with the hole diameter measured by optical coherence tomography (OCT). This prospective, observational study at a single tertiary referral center included 43 patients with macular hole. WAT thresholds were assessed for their ability to detect macular hole. The slit was presented vertically and horizontally, and the brightness of the monitor screen was 180 cd/m2. Horizontal and vertical WAT thresholds for distortion were measured. Correlations and performance evaluations were assessed by Pearson's correlation analysis and Wilcoxon rank-sum test, respectively, between WAT threshold values and hole diameters. Horizontal and vertical WAT thresholds and diameters were compared using paired t-tests. The mean vertical WAT threshold (1.95° ± 0.87°) was significantly higher than the mean horizontal threshold (1.71° ± 0.73°; P < 0.0001). The mean minimum horizontal hole diameter (303.42 ± 111.16 mm; visual angle, 1.01°) was significantly greater than the mean minimum vertical diameter (264.12 ± 107.88 mm; visual angle, 0.88°; P = 0.0149). The minimum vertical and horizontal macular hole diameters were positively correlated with the vertical and horizontal WAT threshold values (r = 0.514, P < 0.01; r = 0.447, P < 0.01, respectively). The WAT threshold values were greater than the respective minimum macular hole diameters, indicative of cone cells displacement over an area larger than that of the hole. The difference in the extent of vertical and horizontal distortions suggests asymmetric hole formation. Hence, WAT threshold values may help evaluate visual function in patients with macular hole.

Comparison of analgesia and akinesia between sub-Tenon's capsule anesthesia and trans-Tenon's capsule retrobulbar anesthesia in vitrectomy.

OBJECTIVES: We compared the effects of sub-Tenon's capsule anesthesia (STA) and trans-Tenon's capsule retrobulbar anesthesia (TTRBA) in 68 patients with epiretinal membrane. METHODS: Either STA or TTRBA was induced with 3 mL of lidocaine (2%) before vitrectomy combined with phacoemulsification and aspiration (phacovitrectomy). Akinesia was evaluated by range of eye movement (ROEM) in upward, downward, nasal, and temporal directions at 4, 10, and 30 minutes after injection. Analgesia was evaluated with a visual analogue pain score, which ranged from 0 to 10. RESULTS: The mean cumulative ROEMs were 1.44±1.02 corneal diameters (CDs) at 4 minutes, 0.55±0.76 CDs at 10 minutes, and 0.26±0.33 CDs at 30 minutes in patients who received STA; these values were 0.39±0.35 CDs at 4 minutes, 0.22±0.30 CDs at 10 minutes, and 0.13±0.29 CDs at 30 minutes in patients who received TTRBA. At both 4 and 10 minutes, the cumulative ROEMs in all directions, as well as the temporal ROEMs, were significantly larger in patients who received STA than in patients who received TTRBA. Pain scores did not significantly differ between groups at any time point. CONCLUSIONS: STA and TTRBA produced identical degrees of analgesia, but akinesia was slower in patients who received STA. TTRBA might be preferable for patients undergoing brief vitrectomy.

The effect of age on full-field electroretinograms recorded with skin electrodes.

OBJECTIVES: The aim of this study was to determine whether age correlates with amplitude and latency, when full-field electroretinography (ERG) is performed using skin electrodes. The ability of pulse reference power line noise reduction (PURE) to dampen the noise associated with the use of skin electrodes, was also investigated. METHODS: ERG was performed on 77 eyes in 77 healthy subjects (mean age: 55.6±19.0 years; age range: 9 to 86 years). Subjects with -5D or higher myopia, Emery-Little grade III or higher cataracts, retinal disease, uveitis, glaucoma, ≤5 mm mydriasis, or a history of intraocular surgery other than cataract surgery, were excluded. The active, reference, and ground electrodes were placed on the lower eyelid, outer canthus, and earlobe, respectively. Responses were averaged 10 times for dark-adapted (DA) ERGs, and 32 to 64 times for light-adapted (LA) ERGs. Noise was removed using the PURE method. RESULTS: The DA ERGs without PURE were so noisy that the amplitude or latency could not be determined, whereas those with PURE were comparatively quieter. ERG with PURE demonstrated a significant negative correlation between age and amplitude and a significant positive correlation between age and latency. CONCLUSIONS: We could record the measurable ERG waveforms with skin electrodes by using the PURE method, especially in fewer averaged conditions. It is suggested that skin electrode with PURE is suitable to examine the pathological ERGs, and other types of electrodes. It is recommended that the aging effect should be taken into consideration when pathological ERGs are evaluated.

Unilaterally extinguished electroretinograms in an eye with normal visual acuity and visual field.

PURPOSE: This study reports a case of unilateral retinopathy with extinguished full-field ERGs (ffERGs), wherein the visual acuity was 16/16 and the visual field was spared. METHODS: Observational case report. RESULTS: A 39-year-old female had developed nyctalopia in her left eye. Two years later, she visited an ophthalmologist who noted a bilaterally reduced pigmentation of the fundus. Her best-corrected visual acuity was 16/16 in both the eyes. Goldmann perimetry demonstrated that her visual field was bilaterally fully spared. ffERGs measurement was performed in accordance with the ISCEV standard protocol and indicated that her right eye was normal. However, all ERG responses were severely attenuated in her left eye. Multifocal ERG responses were found to be normal in the right eye and extinguished in the left eye except for residual responses that were exclusively located at the center. During the 7 years of the follow-up period, the visual field in the left eye, which was once normal, became shaded, and the development of a ring scotoma was identified. The visual field in the right eye is still full. CONCLUSIONS: The pathogenesis of this patient's condition still remains unknown, while unilateral retinitis pigmentosa, unilateral pigmentary retinopathy, acute zonal occult outer retinopathy, and autoimmune retinopathy can all be considered as possible explanations. The uniqueness of this case study is that the extinguished ERG responses are predictive of the functional alteration in the affected eye, when the initial visual acuity and the visual field were normal.

The influence of mild cataract on ISCEV standard electroretinogram recorded from mydriatic eyes.

PURPOSE: To investigate the effect of mild cataract and its surgery on the ISCEV standard electroretinogram (ERG) by comparing pre- and postoperative ERGs elicited from fully dilated eyes. METHODS: Twenty-two patients participated. Each eye had cataract of grade 2 according to Emery-Little classification. None had complications during and after phacoemulsification and intraocular lens implantation. According to the ISCEV standard, pre- and 1-week postoperative full-field ERGs, dark adapted (DA) 0.01, DA 3, DA 3 oscillatory potentials (OPs), DA 10, and light adapted (LA) 3, and LA 3 flicker, were elicited from fully dilated eyes using skin electrodes. Photopic negative response (PhNR) 1 amplitude was measured from the baseline to the trough before the i-wave in the LA 3 ERG waveform. Statistical analysis was performed using SigmaPlot version 11.0 (Systat Software, Inc., San Jose, CA, USA). Pre- and postoperative data were compared using a paired t-test. Non-normally distributed data were evaluated using the Wilcoxon signed rank test. RESULTS: The pre- and 1-week postoperative amplitudes in each component were as follows: DA 0.01: 48.4 ± 19.5 µV and 57.1 ± 20.0 µV (p = 0.002), a-wave of DA3: 51.5 ± 14.8 µV and 58.3 ± 17.3 µV (p = 0.003), b-wave of DA3: 88.3 ± 27.5 µV and 101.5 ± 29.7 µV (p = 0.003), DA 3 ΣOPs (sum of DA 3 OP1, OP2, and OP3 amplitude): 30.7 ± 16.3 µV and 37.1 ± 21.9 µV (p < 0.001), a-wave of DA 10: 65.5 ± 18.8 µV and 74.2 ± 19.5 µV (p < 0.001), b-wave of DA 10: 95.5 ± 29.6 µV and 111.1 ± 29.9 µV (p < 0.001), a-wave of LA 3: 7.2 ± 2.6 µV and 8.2 ± 2.2 µV (p = 0.025), b-wave of LA 3: 30.6 ± 12.9 µV and 35.3 ± 12.7 µV (p = 0.003), PhNR1: 5.8 ± 2.5 µV and 5.5 ± 2.6 µV (p = 0.562), and LA 3 flicker: 25.4 ± 8.9 µV and 27.8 ± 8.6 µV (p = 0.039), respectively. The implicit time of all the components did not reveal significant differences before and after surgery. CONCLUSIONS: Cataractous lens removal and intraocular lens implantation may influence ISCEV standard ERGs, even if the cataract is relatively mild.

Comparison of microscopic illumination between a three-dimensional heads-up system and eyepiece in cataract surgery.

INTRODUCTION: The ability to reduce illumination levels is generally accepted as one of the main benefits of a three-dimensional heads-up system (3D system: Ngenuity®; Alcon, CA, USA). Some studies have focused on illumination reduction in vitreoretinal procedures; however, information regarding illumination reduction in cataract surgery has not been published. PURPOSE: This study aimed to compare the illumination of the operational field with a 3D system and a standard microscope eyepiece during cataract surgery. SUBJECT AND METHODS: We retrospectively evaluated 91 eyes of 84 consecutive patients who were undergoing cataract surgery at our hospital. We used the 3D system and the eyepiece on alternative days. We determined the minimum light intensity required for safe surgery using the foot switch of the microscope (OMS800; Topcon, Tokyo, Japan). Illuminance on the ocular surface and the minimum illuminance required for the operation were calculated from the minimum light intensity. RESULTS: The 3D system was used in 45 eyes (3D group), and the eyepiece was used in 46 eyes (eyepiece group). The values of minimum illuminance in the 3D group were significantly lower than those in the eyepiece group (3D: 5500 ± 2000 lux, eyepiece: 11,900 ± 1800 lux; p < 0.001*). In addition, the illuminance of the operational field was reduced by 60.4% on average using the 3D system. CONCLUSION: With real-time digital processing and automated brightness control, the 3D system reduced ocular surface illumination by 50% or more. Hence, the 3D system may contribute to reducing the risk of retinal phototoxicity and patient photophobia.

Visualization of the posterior surface of the lens nucleus with triamcinolone acetonide in phacoemulsification.

PURPOSE: We report a novel technique for visualizing the posterior surface of the lens nucleus during phacoemulsification. SURGICAL TECHNIQUE: Hydro-dissection was performed using a solution of 20 mg triamcinolone acetonide powder without preservatives mixed with 3 ml BSS-plus, and triamcinolone acetonide was clearly identifiable underneath the posterior surface of the lens nucleus. Using a phaco-tip, the nucleus was shaved to the level of the triamcinolone acetonide and could be easily divided. The remnant triamcinolone acetonide was aspirated as much as possible from the lens cortex with an infusion/aspiration tip. SUBJECTS AND EVALUATION TECHNIQUE: Twenty-eight eyes in 28 patients with cataracts were enrolled in this study. Triamcinolone acetonide-assisted phacoemulsification was performed in 13 eyes in 13 patients (triamcinolone acetonide-phacoemulsification group), and normal phacoemulsification was performed in 15 eyes in 15 patients (phacoemulsification group). Intraocular pressure was measured in all patients pre-operatively, 1 day after, and 1 week after surgery. Corneal endothelial cell density was measured pre-operatively and 1 month after surgery. The time of surgical phacoemulsification (surgical phaco time) was measured from the video of the surgery. RESULTS: Surgery was successively performed in all eyes. Pre-operative and post-operative intraocular pressures and cell densities did not significantly differ between the two groups. Surgical phaco time was shorter in the triamcinolone acetonide-phacoemulsification group than in the phacoemulsification group (157.1 ± 51.7 s vs 225.3 ± 45.1 s; p = 0.006). CONCLUSION: The triamcinolone acetonide-assisted phacoemulsification procedure is safe and useful for visualizing the posterior surface of the lens nucleus and facilitates removal of the lens nucleus by phacoemulsification.

Ocular Injury Caused by the Sprayed Venom of the Asian Giant Hornet (Vespa mandarinia).

This report presents the details of a case of sight-threatening injury in the right eye of a 77-year-old man which was caused by the venom of the Asian giant hornet (Vespa mandarinia). The patient was not stung, rather the venom was sprayed into his eye. Although the injured eye was washed as a first aid treatment, persistent corneal defect, corneal endothelial decompensation, iris atrophy, pupil dilation, and mature cataract were observed and a hand movement visual acuity was recorded 8 weeks after the injury. Since a slight a-wave was detected in his electroretinogram (ERG) result after the corneal epithelial defect had healed, we performed cataract surgery and Descemet stripping automated endothelial keratoplasty (DSAEK). After the DSAEK, the cornea of the right eye became clearer; however, the visual acuity of his right eye did not improve. Fundus examination revealed branch retinal artery occlusion but no optic disc atrophy. ERG showed that the a-wave amplitude of the injured eye recorded after the surgery was almost half of that of the fellow eye. The iris atrophy and mature cataract show that the sprayed Vespa venom of the Asian giant hornet can permeate into the intraocular area even without stinging. Whether the venom directly affects retinal function is unclear, but the decreased a-wave of the injured eye shows that the venom caused damage of retinal function in some way. Irrigation of the anterior chamber as well as eye washing is needed as a first aid treatment in similar cases.

Measurement of the volume of the vitrectomized space during vitrectomy in myopic patients with retinal detachment.

PURPOSE: We present a novel technique for measuring volume of space replaced by air during fluid-air exchange in vitrectomy (vitrectomized space) for intravitreal gas injection. To confirm the feasibility of this technique, we assessed postoperative intraocular pressure (IOP) and the duration of injected gas. Using this technique, we found remarkable differences in volume between high myopic eyes with retinal detachment caused by peripheral break (PB-RD group) and those with macular hole retinal detachment (MH-RD group). We studied the relationships between the volume and biometric values, axial length (AL) and corneal curvature radius (CCR) in both PB-RD and MH-RD group. STUDY DESIGN: Retrospective study. METHODS: During fluid-air exchange, the aspirated fluid accumulates in the measuring cup between the infusion needle and vitrectomy instrument. Vitrectomized space volume is obtained by subtracting the volume of the tube between the infusion needle and the 3-way stopcock from the aspirated fluid volume. We performed phaco-vitrectomies by measuring the vitrectomized space volume and then injected pure SF6 at 15% of the volume into the vitreous cavity in 156 myopic eyes (AL > 26 mm) with RD consisting of 144 eyes in PB-RD group and 12 in MH-group. RESULTS: The IOP (mean ± SD) was 13.5 ± 3.4 mmHg preoperatively, 23.4 ± 10.4 mmHg on day 1, 18.2 ± 7.4 mmHg on day 2, and 16.1 ± 4.5 on day 7. The gas disappeared in 16.1 ± 1.9 days. Axial length was longer in the MH-RD group but the volume of vitrectomized space was larger in the PB-RD group. AL and volume were significantly correlated in both groups (P < 0.01), but the fitting lines differed. The CCR and volume significantly correlated in the PB-RD group (P < 0.01) but not in the MH-RD group. CONCLUSION: Our novel technique for measuring the volume of vitrectomized space can achieve target gas concentration in the vitreous cavity. The difference in the shape of eyeballs may explain discrepancies in relationship between volume and the biometric factors.

Cone ERG Changes During Light Adaptation in Two All-Cone Mutant Mice: Implications for Rod-Cone Pathway Interactions.

Purpose: The b-wave of the cone ERG increases in amplitude and speed during the first few minutes of adaptation to a rod-suppressing background light. Earlier studies implicate rod pathway input to the cone pathway in these changes. Methods: The timing and amplitude of the cone b-wave and isolated oscillatory potentials (OP) during the first 10 minutes of light adaptation in wild-type (WT) mice and two mutant lines without functional rods was examined: rhodopsin knockout (Rho-/-), lacking rod outer segments, and NRL knockout (Nrl-/-), in which rods are replaced by S-cones. Expression of the immediate-early gene c-fos, which is increased in the inner retina by light-induced activity, was evaluated by immunohistochemistry in dark- and light-adapted retinas. Results: WT b-wave and OP amplitudes increased, and implicit times decreased during light adaptation. Subtracting OP did not alter b-wave changes. Rho-/- b-wave and OP amplitudes did not increase during adaptation. B-wave timing and amplitude and the timing of the major OP at 1 minute of adaptation were equivalent to WT at 10 minutes. The light-adapted ERG b-wave in Nrl-/- mice, which originates in both the rod and cone pathways, changed in absolute amplitude and timing similar to WT. C-fos expression was present in the inner retinas of dark-adapted Rho-/- but not WT or Nrl-/- mice. Conclusions: Activity in the distal rod pathway produces changes in the cone ERG during light adaptation. Rods in Rho-/- mice constitutively activate this rod-cone pathway interaction. The rod pathway S-cones in Nrl-/- mice may maintain the WT interaction.

Adherence to face-down and non-supine positioning after macular hole surgery.

BACKGROUND: This study aimed to investigate patient adherence to face-down positioning (FDP) and non-supine positioning (NSP) following vitrectomy with gas tamponade for treating macular holes (MHs). METHODS: Nursing records of 92 patients who underwent vitrectomy with gas tamponade for small-diameter (diameter < 400 µm) MHs during April 2016-June 2017 were examined. Forty-seven and 45 patients were instructed to maintain FDP and NSP (FDP and NSP groups), respectively. Patient adherence was evaluated seven times a day for 3 days, and the adherence rate was calculated. RESULTS: The mean adherence rate was significantly higher in the NSP group (99.3% ± 2.7%) than in the FDP group (93.7% ± 13.3%; P < 0.001, Mann-Whitney U test). Forty-one patients (91.1%) in the NSP group had an adherence rate of 100%, which was significantly higher than that in the 24 patients in the FDP group (51.1%; P < 0.001, chi-squared test). No statistically significant difference was observed between the patients in the two groups regarding sex, age, MH diameter, and pre- and postoperative visual acuities. MH closure was achieved in all patients. CONCLUSIONS: Almost half of the patients in the FDP group did not obtain 100% adherence rate, suggesting that patient adherence was largely compromised. Patient adherence was better in the NSP group as patient compliance to NSP was better, however, 8.9% of patients were found in face-up positioning at least once. Incompleteness of patient adherence was common, although to differing degrees.

Comparison of visual acuity, metamorphopsia, and aniseikonia in patients with an idiopathic epiretinal membrane.

PURPOSE: The clinical course of reduced visual acuity, metamorphopsia, and aniseikonia are dissimilar in patients with an epiretinal membrane (ERM). We measured and compared the best-corrected visual acuity (BCVA), metamorphopsia, and aniseikonia of patients with ERM. METHODS: We measured metamorphopsia and aniseikonia horizontally as well as vertically with the M-CHART (MH and MV) and New Aniseikonia Test (NATH and NATV) in 61 patients with unilateral idiopathic ERM. We compared the BCVA with the other values. Comparisons between the MH and the NATV and between the MV and the NATH were performed, because the MH assesses vertical metamorphopsia, and the MV, horizontal metamorphopsia. RESULTS: BCVA was not significantly correlated with the other values (MH vs BCVA: P = .69; MV vs BCVA: P = .114; NATH vs BCVA: P = .656; NATV vs BCVA: P = .935). The MH and NATV magnitudes were significantly correlated, but the correlation coefficient was small (P = .007, r = 0.343); no significant correlation was found between the MV and NATH magnitudes (P = .065). We found patients with aniseikonia, but no metamorphopsia (n = 6), and more patients with metamorphopsia, but no aniseikonia (n = 11). Only 23 patients had coincident directions of metamorphopsia and aniseikonia. CONCLUSIONS: The magnitudes of metamorphopsia and aniseikonia were not closely correlated and their directions did not coincide in most patients. Neither the M-CHARTS nor the NAT measurements correlated with the BCVA. Quantitative testing of metamorphopsia and aniseikonia in addition to that for BCVA is necessary to assess visual function in patients with ERM.

Adherence to the face-down positioning after vitrectomy and gas tamponade: a time series analysis.

OBJECTIVE: To determine the adherence to the face-down positioning (FDP) in 296 patients who had undergone vitrectomy and gas tamponade. RESULTS: We studied 119 female and 177 male patients who had undergone primary vitrectomy and gas tamponade for a macular hole (MH) or for rhegmatogenous retinal detachments (RRDs). Adherence was assessed and recorded four times per day for 3 days postsurgery. The mean ± standard deviation adherence rate was 88.3 ± 11.7 (range 50.0-100.0). Female patients (90.8 ± 10.0) had significantly better adherence than male patients (86.7 ± 13.3; P < 0.02, U test). The adherence was significantly better after MH surgery (90.8 ± 11.7) than after RRD surgery (87.5 ± 12.5; P < 0.02). There were diurnal variations in adherence, being highest in the evening and significantly lower at midnight, and we evidenced a decline in adherence over time, with it being significantly low on the last follow-up day. Adherence to the FDP varied considerably among patients. Adherence was higher in female than in male patients, and higher in patients with MH than in those with RRD. We found patients age had no effect on adherence. Adherence also varied with time, being worst at midnight and declining over time.