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.

Purpose: We present a case of central anticholinergic syndrome following the administration of atropine eye drops.Case summary: A 60-year-old male presented with decreased visual acuity in his left eye and was diagnosed with intraocular lens dislocation. Preoperatively, Isopto atropine® eye drops (1 drop at 15-minutes intervals) were used for pupil dilation. Within an hour of the first instillation, the patient exhibited drowsiness, disorientation, agitation, and urinary retention. Laboratory tests and computed tomography of the brain were unremarkable. Considering the recent administration of atropine eye drops, a diagnosis of central anticholinergic syndrome was made. The surgery was postponed and the patient recovered fully after 3 hours of observation. He remained asymptomatic during an additional day of hospitalization. Conclusions A small dose of atropine eye drops even at a therapeutic dose can induce central anticholinergic syndrome. Therefore, ophthalmologists should be aware of this rare and severe complication.

Purpose: We present a case of central anticholinergic syndrome following the administration of atropine eye drops.Case summary: A 60-year-old male presented with decreased visual acuity in his left eye and was diagnosed with intraocular lens dislocation. Preoperatively, Isopto atropine® eye drops (1 drop at 15-minutes intervals) were used for pupil dilation. Within an hour of the first instillation, the patient exhibited drowsiness, disorientation, agitation, and urinary retention. Laboratory tests and computed tomography of the brain were unremarkable. Considering the recent administration of atropine eye drops, a diagnosis of central anticholinergic syndrome was made. The surgery was postponed and the patient recovered fully after 3 hours of observation. He remained asymptomatic during an additional day of hospitalization. Conclusions A small dose of atropine eye drops even at a therapeutic dose can induce central anticholinergic syndrome. Therefore, ophthalmologists should be aware of this rare and severe complication.

Purpose: This study used anterior segment swept-source optical coherence tomography (AS SS-OCT) to explore the effect of temporal decentration within the orthokeratologic lens treatment zone on corneal aberrations. Methods: After lens placement, AS SS-OCT was used to evaluate anterior, posterior, and total corneal astigmatism and the magnitudes of the individual 1st- to 4th-order aberrations of the anterior and entire corneal fields. Also, the 4th-to 7th-order root mean square (RMS), and the low- and high-ordered RMSs of both the anterior and entire corneal areas were recorded. We compared subjects lacking (the no decentration [ND] group) to those exhibiting (the temporal decentration [TD] group) temporal decentration. Results: In all, 61 eyes of 32 patients (44 eyes in the ND group and 17 in the TD group) were included. In the TD group, the average temporal decentration was 0.74 ± 0.15 mm. The baseline axial length, spherical equivalent, anterior mean corneal power, and anterior corneal astigmatism did no difference between the two groups. However, the TD group exhibited more anterior and total corneal horizontal tilts, and horizontal coma, than the ND group. That group also had less with-the-rule (WTR)/against-therule (ATR) astigmatism, elevated anterior and total corneal 5th-order RMS values, and greater low- and high-ordered RMS levels. However, despite these differences, the extent of myopia correction did not significantly differ between the groups. Conclusions Although myopia reduction was not significantly compromised by temporal decentration of an orthokeratologic lens, the anterior and total corneal low- and high-ordered RMS values increased. In terms of individual aberrations, the low-ordered horizontal tilt and the high-ordered horizontal coma increased.

Purpose: We present a case of central anticholinergic syndrome following the administration of atropine eye drops.Case summary: A 60-year-old male presented with decreased visual acuity in his left eye and was diagnosed with intraocular lens dislocation. Preoperatively, Isopto atropine® eye drops (1 drop at 15-minutes intervals) were used for pupil dilation. Within an hour of the first instillation, the patient exhibited drowsiness, disorientation, agitation, and urinary retention. Laboratory tests and computed tomography of the brain were unremarkable. Considering the recent administration of atropine eye drops, a diagnosis of central anticholinergic syndrome was made. The surgery was postponed and the patient recovered fully after 3 hours of observation. He remained asymptomatic during an additional day of hospitalization. Conclusions A small dose of atropine eye drops even at a therapeutic dose can induce central anticholinergic syndrome. Therefore, ophthalmologists should be aware of this rare and severe complication.