Light adaptation enables the vertebrate visual system to operate over a wide range of ambient illumination. Regulation of phototransduction in photoreceptors is considered a major mechanism underlying light adaptation. However, various types of neurons and glial cells exist in the retina, and whether and how all retinal cells interact to adapt to light/dark conditions at the cellular and molecular levels requires systematic investigation. Therefore, we utilized single-cell RNA sequencing to dissect retinal cell-type-specific transcriptomes during light/dark adaptation in mice. The results demonstrated that, in addition to photoreceptors, other retinal cell types also showed dynamic molecular changes and specifically enriched signaling pathways under light/dark adaptation. Importantly, Müller glial cells (MGs) were identified as hub cells for intercellular interactions, displaying complex cell‒cell communication with other retinal cells. Furthermore, light increased the transcription of the deiodinase Dio2 in MGs, which converted thyroxine (T4) to active triiodothyronine (T3). Subsequently, light increased T3 levels and regulated mitochondrial respiration in retinal cells in response to light conditions. As cones specifically express the thyroid hormone receptor Thrb, they responded to the increase in T3 by adjusting light responsiveness. Loss of the expression of Dio2 specifically in MGs decreased the light responsive ability of cones. These results suggest that retinal cells display global transcriptional changes under light/dark adaptation and that MGs coordinate intercellular communication during light/dark adaptation via thyroid hormone signaling.
Animals ; Mice ; Dark Adaptation ; Light ; Retina ; Retinal Cone Photoreceptor Cells/metabolism* ; Adaptation, Ocular ; Neuroglia/physiology* ; Cell Communication ; Thyroid Hormones

PURPOSE: We report a case of fundus albipunctatus discovered in a young patient. CASE SUMMARY: A 7.6-year-old female showed numerous small whitish-yellow flecks in the perimacular area and retinal periphery. Dark adapted 0.01 electroretinography (ERG) and dark adapted 3.0 ERG were profoundly reduced. At 26 months after the first visit, the best-corrected visual acuities were 1.0 right eye and 0.9 left eye. There were no pigmented lesions, atrophic lesions, or vascular abnormalities in the retina. Humphrey and Goldmann visual field tests were performed, but neither of the tests revealed any scotomas or other visual field defect. The number and size of characteristic numerous small whitish-yellow retinal flecks seemed almost unchanged. In spectral domain-optical coherence tomography (SD-OCT), the subretinal hyper-reflective lesions spanned the retinal pigment epithelium and the external limiting membrane. ERG showed improved dark adapted responses (dark adapted 0.01 ERG and dark adapted 3.0 ERG) after prolonged dark adaptation (2.5 hours). No family member showed any abnormal findings. CONCLUSIONS: Fundus albipunctatus is a rare disease in Koreans. We report a case diagnosed using fundus photography, SD-OCT, visual field tests, and ERG after prolonged dark adaptation (2.5 hours).
Child ; Dark Adaptation ; Electroretinography ; Female ; Humans ; Membranes ; Photography ; Rare Diseases ; Retina ; Retinal Pigment Epithelium ; Retinaldehyde ; Scotoma ; Tomography, Optical Coherence ; Visual Acuity ; Visual Field Tests ; Visual Fields

PURPOSE: We present the results of visual evoked potential (VEP), electroretinography (ERG), and electrooculography (EOG) in normal subjects using the Mon-pack 3 system (Metrovision). METHODS: VEP, ERG, and EOG were obtained in 92 normal eyes. The measurements followed the International Society for Clinical Electrophysiology of Vision (ISCEV) standardization protocol. In VEP, the standard electrode was placed on the forehead and the active electrode was attached on the occiput. In ERG, a 20-minute dark adaptation was performed after mydriasis, and an ERG-jet electrode was used. EOG was measured by attaching an electrode to each medial canthal skin. Each latent period and electric potential was measured with average, standard deviation, median, and 95% confidencenterval (95% CI). RESULTS: The mean P100 latency in pattern VEP was 104.36 ms, and P100 latency in flash VEP was 116.71 ms. For the maximal ERG response, the implicit times of a and b waves were 22.65 ms and 44.58 ms, respectively and the amplitude of a and b waves were 274.09 microv and 489.52 microv, respectively. For the ERG cone response, the implicit time of a and b waves were 18.21 ms and 33.40 ms, respectively, and the amplitude of a and b waves were 35.87 microv and 104.42 microv, respectively. The mean ERG oscillitatory potential was 285.53 microv. The average EOG Arden ratio was 2.54. CONCLUSIONS: VEP, ERG, and EOG results from normal subjects using the Mon-pack 3 system can be applied to the diagnosis of retina and optic nerve disease and basic research.
Dark Adaptation ; Diagnosis ; Electrodes ; Electrooculography* ; Electrophysiology ; Electroretinography* ; Evoked Potentials, Visual* ; Forehead ; Mydriasis ; Optic Nerve Diseases ; Retina ; Skin

PURPOSE: To report specific spectral domain OCT findings of Oguchi disease diagnosed with fundoscopic examination and electrophysiological study. CASE SUMMARY: A 14-year-old patient visited our clinic with a complaint of night blindness for ten years. Fundoscopic examination showed a golden-yellow fundus reflex. After three hours of dark adaptation, the fundus color returned to normal (Mizuo-Nakamura phenomenon). In full-field ERG, rod b-wave was not detectable. The a-wave amplitude in maximal combined response increased after three hours of dark adaptation, although the b-wave amplitude was similar to the amplitude before dark adaptation, demonstrating a negative waveform. In the spectral domain OCT images of the perifoveal area, no gap between the retinal pigment epithelium and the inner segment/outer segment (IS/OS) junction was detected before prolonged dark adaptation, and a highly reflective band was shown. However, the gap appeared after three hours of dark adaptation, and two highly reflective bands were detected in the OCT images. CONCLUSIONS: The characteristic OCT finding in addition to the specific fundoscopic finding and full-field ERG results may be useful to diagnose Oguchi disease.
Adolescent ; Dark Adaptation ; Electroretinography ; Humans ; Night Blindness ; Reflex ; Retinal Pigment Epithelium ; Tomography, Optical Coherence

PURPOSE: To report the change of pupil sizes according to age and illuminance in the normal Korean population. METHODS: Normal Koreans outpatients who never had a history of ophthalmic disease were examined. The patients consisted of 320 eyes of 160 patients, which were classified into 8 age decades (teenage to 80's) with 40 eyes in each age group. The vertical and horizontal pupil size and area under 4 different illuminances (3,500, 1,200, 500, 5 lux) were measured using the Colvard pupillometer(R) (OASIS Medical, Glendora, CA, USA). RESULTS: The pupil size was significantly decreased as the age increased under each illuminance. The pupil area measured after dark adaptation was 47.30 mm2 in the teenage group, 43.32 mm2 in the 20's group, 41.94 mm2 in the 30's group, 40.98 mm2 in the 40's group, 40.61 mm2 in the 50's group, 38.60 mm2 in the 60's group, 37.78 mm2 in the 70's group and 35.45 mm2 in the 80's group. The decrease in pupil area was statistically significant. CONCLUSIONS: In the normal Korean population, a significant decrease in pupil size and area was observed with aging. The present study results provide good basic data for cataract and presbyopia refractive surgery.
Aging ; Cataract ; Dark Adaptation ; Eye ; Humans ; Outpatients ; Presbyopia ; Pupil ; Refractive Surgical Procedures

PURPOSE: To investigate the effect of dark rearing immediately after birth on the maturation of the visual relay neurons in the lateral geniculate nucleus. METHODS: Fifty neonatal rats were used. Neonates of the control groups were raised under a normal light/dark cycle. Neonates of the experiment groups were dark reared and isolated from light during the entire experimental period, then exposed to the sun light for 1 hour before sacrifice. RESULTS: In the control groups, the neurons in the dorsal lateral geniculate nucleus developed normally at each age tested. In the experiment groups, the cytoplasm of the large neurons in the dorsal lateral geniculate nucleus of 2-week-old rats contained small vesicles, and the cytoplasm of the large neurons of 4-week-old rats was converted into a vacuole-like space. Moreover, c-Fos immunoreactivity of the large neurons in the dorsal lateral geniculate nucleus in the experiment groups was significantly increased compared to that of the control groups. CONCLUSIONS: We suppose that the maturation of the neurons in the lateral geniculate nucleus might be influenced by light stimulation during the critical period. Furthermore, c-Fos could be a marker of the functional activity of the visual relay neurons of the lateral geniculate nucleus in albino rats.
Animals ; Animals, Newborn ; Critical Period (Psychology) ; *Dark Adaptation ; Geniculate Bodies/*metabolism ; Immunohistochemistry ; *Light ; Neurons/*metabolism ; Proto-Oncogene Proteins c-fos/*metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo characterize dark-adapted and light-adapted oscillatory potentials (OPs) in human electroretinogram (EGR) elicited by flashing light stimulation of the same intensity.

METHODSDark- and light-adapted ERGs of normal eyes were studied. The frequency spectra of the extracted dark-adapted OPs and light-adapted OPs were analyzed by a fast Fourier transform. The peak frequency, latency and total power of the OPs were determined.

RESULTSThe averaged peak frequency, latency, and power of the dark-adapted OPs was 125.3∓9.93 Hz, 41.7∓3.56 ms, and 9.25∓5.55 (V·s)(2), as compared with 79.5∓6.79 Hz, 50.8∓5.36 ms, and 3.56∓2.18 (V·s)(2) for light-adapted Ops, respectively, showing significant differences in the parameters between dark- and light-adapted Ops (P<0.001).

CONCLUSIONSCompared with dark-adapted OPs, light-adapted Ops is characterized by a lower peak frequency and a lower power with a prolonged latency.

Adaptation, Ocular ; physiology ; Adult ; Dark Adaptation ; physiology ; Electroretinography ; methods ; Female ; Humans ; Male ; Oscillometry ; Retina ; physiology ; Young Adult

BACKGROUNDPrimary angle-closure glaucoma (PACG) is a major cause of visual morbidity in East Asia. Dark-room provocative test (DRPT) has been used to determine which narrow angles have the risk to develop angle closure. However, the accuracy of DRPT might be altered because that after emerging from the dark room, the configuration of the angle is affected by the light of the slit-lamp and the appositionally closed angle reopens. The aim of this study was to examine the pupillary diameter in different light conditions and use it as a parameter to assess the accuracy of dark-room provocative test.

METHODSPatients with suspected primary angle-closure glaucoma undergoing DRPT were recruited. The anterior chamber angle was examined by anterior segment optical coherence tomography under the following conditions: (1) in standard room illumination; (2) after short-term dark-adaptation and (3) after DRPT. Mean values of pupil size and numbers of appositionally closed angle under different conditions were compared.

RESULTSA total of 47 eyes of 47 patients were analyzed. The pupil size after DRPT was smaller than that after short-term dark-adaptation (P < 0.001) and smaller than that in standard room illumination (P = 0.026). The numbers of appositionally closed angles after short-term dark-adaptation were significantly larger than those after DRPT (P < 0.001). There was no significant difference between the numbers of appositionally closed angles in standard room illumination and after DRPT (P = 0.157).

CONCLUSIONSConstriction of pupil size immediately after prolonged dark room provocative test may lead to change in the angle configuration, which may lead to false negative results. We suggest a modified protocol of recording intraocular pressure immediately after DRPT and performing gonioscopy following short-term dark adaptation to improve the accuracy of angle closure assessment.

Adult ; Aged ; Dark Adaptation ; Diagnostic Techniques, Ophthalmological ; Female ; Glaucoma, Angle-Closure ; diagnosis ; diagnostic imaging ; Humans ; Male ; Middle Aged ; Sensitivity and Specificity ; Ultrasonography

PURPOSE: To analyze the effect of the daily use of brimonidine tartrate 0.15% on the dark-adapted pupil diameter in dark brown irides. METHODS: Twenty-five healthy volunteers administered brimonidine tartrate 0.15% to their right eyes once daily for 3 weeks. Infrared digital photographs of the pupil were taken before administration and 1 hour and 4 hours after administration after dark adaptation (at <0.1 lux ambient illumination for 5 minutes). The diameters of both pupils were measured on the first day, on administration days 7 and 21, and on washout day 7. RESULTS: Four hours after the first administration, pupils showed a decrease of 0.95+/-0.74 mm, 1.03+/-0.94 mm, 0.61+/-0.85 mm on the first day, administration day 7, and administration day 21, respectively (p<0.01), compared with baseline data. The anti-mydriatic effect of brimonidine was sustained for 3 weeks, but the proportions of the eyes showing a reduction in pupil diameter by 0.5 mm or more were 84%, 76%, 68%, and 52% at 4 hours on the first day, administration days 7 and 21, and washout day 7, respectively. CONCLUSIONS: The anti-mydriatic effect of the daily use of brimonidine 0.15% on dark brown irides in a scotopic condition is maintained during the instillation period but has a tendency to fade over time. This point should be considered when using this compound as a miotic agent.
Dark Adaptation ; Eye ; Lighting ; Pupil ; Quinoxalines ; Brimonidine Tartrate

The optimal dark adaptation time of electroretinograms (ERG's) performed on conscious dogs were determined using a commercially available ERG unit with a contact lens electrode and a built-in light source (LED-electrode). The ERG recordings were performed on nine healthy Miniature Schnauzer dogs. The bilateral ERG's at seven different dark adaptation times at an intensity of 2.5 cd.s/m2 was performed. Signal averaging (4 flashes of light stimuli) was adopted to reduce electrophysiologic noise. As the dark adaptation time increased, a significant increase in the mean a-wave amplitudes was observed in comparison to base-line levels up to 10 min (p > 0.05). Thereafter, no significant differences in amplitude occured over the dark adaptation time. Moreover, at this time the mean amplitude was 60.30 +/- 18.47 microV. However, no significant changes were observed for the implicit times of the a-wave. The implicit times and amplitude of the b-wave increased significantly up to 20 min of dark adaptation (p > 0.05). Beyond this time, the mean b-wave amplitudes was 132.92 +/- 17.79 microV. The results of the present study demonstrate that, the optimal dark adaptation time when performing ERG's, should be at least 20 min in conscious Miniature Schnauzer dogs.
Animals ; Dark Adaptation/*physiology ; Dogs/*physiology ; Electroretinography/*veterinary ; Male ; Retina/*physiology ; Time Factors