Purpose: Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results. Methods: This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated. Results: A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare. Conclusions Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.

Purpose: Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results. Methods: This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated. Results: A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare. Conclusions Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.

Purpose: Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results. Methods: This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated. Results: A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare. Conclusions Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.

Purpose: Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results. Methods: This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated. Results: A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare. Conclusions Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.

Purpose: Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results. Methods: This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated. Results: A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare. Conclusions Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.

Approximately 80% of pediatric amblyopia cases are caused by refractive errors. Therefore, the early detection of refractive errors and prescription of appropriate glasses are very important to children's visual function and preventing and treating amblyopia. Unlike for adults, glasses must be prescribed carefully for children because their visual function is under development; moreover, they commonly have abundant accommodation, emmetropia, and strabismus. This review aimed to provide guidelines for the prescription of glasses for children.

Background: To report the clinical manifestations of non-arteritic anterior ischemic optic neuropathy (NAION) cases after coronavirus disease 2019 (COVID-19) vaccination in Korea. Methods: This multicenter retrospective study included patients diagnosed with NAION within 42 days of COVID-19 vaccination. We collected data on vaccinations, demographic features, presence of vascular risk factors, ocular findings, and visual outcomes of patients with NAION. Results: The study included 16 eyes of 14 patients (6 men, 8 women) with a mean age of 63.5 ± 9.1 (range, 43–77) years. The most common underlying disease was hypertension, accounting for 28.6% of patients with NAION. Seven patients (50.0%) had no vascular risk factors for NAION. The mean time from vaccination to onset was 13.8 ± 14.2 (range, 1–41) days. All 16 eyes had disc swelling at initial presentation, and 3 of them (18.8%) had peripapillary intraretinal and/or subretinal fluid with severe disc swelling. Peripapillary hemorrhage was found in 50% of the patients, and one (6.3%) patient had peripapillary cotton-wool spots. In eight fellow eyes for which we were able to review the fundus photographs, the horizontal cup/ disc ratio was less than 0.25 in four eyes (50.0%). The mean visual acuity was logMAR 0.6 ± 0.7 at the initial presentation and logMAR 0.7 ± 0.8 at the final visit. Conclusion Only 64% of patients with NAION after COVID-19 vaccination have known vascular and ocular risk factors relevant to ischemic optic neuropathy. This suggests that COVID-19 vaccination may increase the risk of NAION. However, overall clinical features and visual outcomes of the NAION patients after COVID-19 vaccination were similar to those of typical NAION.

Mutations in the RPE65 gene, associated with Leber congenital amaurosis, early-onset severe retinal dystrophy, and retinitis pigmentosa, gained growing attention since gene therapy for patients with RPE65-associated retinal dystrophy is available in clinical practice. RPE65 gene accounts for a very small proportion of patients with inherited retinal degeneration, especially Asian patients. Because RPE65-associated retinal dystrophy shares common clinical characteristics, such as early-onset severe nyctalopia, nystagmus, low vision, and progressive visual field constriction, with retinitis pigmentosa by other genetic mutations, appropriate genetic testing is essential to make a correct diagnosis. Also, fundus abnormalities can be minimal in early childhood, and the phenotype is highly variable depending on the type of mutations in RPE65-associated retinal dystrophy, which makes a diagnostic difficulty. The aim of this paper is to review the epidemiology of RPE65-associated retinal dystrophy, mutation spectrum, genetic diagnosis, clinical characteristics, and voretigene neparvovec, a gene therapy product for the treatment of RPE65-related retinal dystrophy.

Purpose: To investigate the status of low-vision care in Korea and the needs of ophthalmologists, and to define future directions for the diagnosis and treatment of low-vision patients. Methods: Twenty survey questions exploring low-vision knowledge were emailed to members of the Korean Ophthalmological Society, and the responses were analyzed. Results: In total, 158 responses were collected from ophthalmologists working in different institutions, including 62 (45.6%) at university hospitals. Many respondents (91, 57.6%) reported knowing the criteria for low vision, but approximately half (74, 46.9%) reported that they had little or no knowledge of low vision in general. More than half of the respondents (87, 55.1%) had never written a prescription for a visual aid, and only 32 (20.2%) were able to prescribe such aids. The principal reasons for hesitation in the treatment of low-vision patients were lack of knowledge (117, 74.5%) and poor medical reimbursement (41, 26.1%). Many respondents (152, 96.2%) wanted to learn more about low vision, and approximately half (71, 45.5%; 74, 47.4%) felt that the current low-vision care environment in Korea requires improvement. Conclusions Despite the increasing need for low-vision care in South Korea, the number of ophthalmologists who can provide such care (including prescriptions for visual aids) is insufficient. Lack of education and poor medical reimbursement are important problems. Low-vision clinics must promote outreach activities, and institutions should develop programs to educate ophthalmologists.