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Ophthalmologic Side Effects
Published in Ayse Serap Karadag, Berna Aksoy, Lawrence Charles Parish, Retinoids in Dermatology, 2019
Some patients may experience decreased dark adaptation and night blindness during retinoid treatment, but this is reversible. Isotretinoin can cause reversible abnormalities in the function of rod cells in rats that can be documented with electroretinography (27). Administration of high dose isotretinoin to rats (40 mg/kg) slows recovery of rod signaling after bleaching by slowing down the regeneration of rhodopsin (a complex protein sensitive to light that contains another vitamin A derivative, 11-cis retinal, as cofactor) in the visual cycle; however, rod functions become normal after dark adaptation, when enough time is allowed for the delayed recovery of rhodopsin and no histological damage occurs at the retinal tissue (28). Decreased color vision may occur during isotretinoin treatment but this is also reversible (4). The incidence of this adverse effect is very low and could not be repeated in some studies (27,29). Both isotretinoin and acitretin treatments are also associated with a reduction in contrast sensitivity (5,30). There is no detailed study on the influence of acitretin, bexarotene, and alitretinoin on dark adaptation; however, package inserts of acitretin and alitretinoin also list night blindness among the adverse events (22,25).
Draw a dark adaptation curve and identify the component parts and their significance
Published in Nathaniel Knox Cartwright, Petros Carvounis, Short Answer Questions for the MRCOphth Part 1, 2018
Nathaniel Knox Cartwright, Petros Carvounis
Dark adaptation is the process by which the eye recovers its sensitivity to dim stimuli following exposure to bright light. To measure dark adaptation subjects are fully light adapted and then the change in absolute visual threshold is measured over time in the dark.
Visual changes with aging
Published in Pablo Artal, Handbook of Visual Optics, 2017
Dark adaptation represents the ability of the visual system to adjust sensitivity when ambient light levels change from bright light (photopic) to low light (scotopic) conditions. Measurement of dark adaptation is therefore an important clinical tool for the assessment of change in visual sensitivity over time in the dark and is commonly used to assess retinal photoreceptor function. A variety of techniques are available to measure dark adaptation, but the most common approach is to assess sensitivity over time following an initial photobleach exposure, using an achromatic stimulus, either at the fovea or around 5°–12° from the fovea (Jackson et al. 1999, Dimitrov et al. 2008, Owsley et al. 2014).
Ocular side effects of systemic isotretinoin – a systematic review and summary of case reports
Published in Journal of Dermatological Treatment, 2023
Olivia Lamberg, Arianna Strome, Foster Jones, Julia Mleczek, Adrienne Jarocki, Jonathon P. Troost, Yolanda Helfrich
While isotretinoin is a very effective treatment option for patients with recalcitrant acne vulgaris, its clinical use is associated with a variety of adverse events ranging in severity and implications. It is well recognized that the most serious potential adverse event of isotretinoin use is teratogenicity. Yet, there are many other more common side effects, including mucocutaneous effects such as cheilitis and xerosis, and neurologic effects such as headaches (3). There are also several reported ophthalmologic side effects that also range in severity. These include less severe effects such as ocular surface alterations, dry eye diseases, ocular irritation, visual field defects, and abnormalities in dark adaptation. More serious and extremely rare adverse effects include retinal toxicity, corneal opacities, and optic neuritis, which may lead to permanent ocular damage if unrecognized (4,5). These ocular adverse events have been reported within days to years of isotretinoin therapy initiation (6). In some reported cases, these ocular side effects are suspected to be dose dependent and become tolerable with a change in dosing and symptomatic management (2).
Static and dynamic pupillary features in graves’ ophthalmopathy
Published in Clinical and Experimental Optometry, 2023
Kubra Serbest Ceylanoglu, Emine Malkoc Sen, Mehmet Ali Sekeroglu
In darkness, dynamic pupillometry measurements were taken for a duration of 90 seconds after 5 minutes of dark adaptation. Resting pupil diameter for each eye was calculated as the average pupil diameter over a period of 5 seconds before the onset of the stimulus. Latency was defined as the elapsed time between the onset of light and the onset of constriction. The amplitude of pupil contraction (in mm) was the difference between the pupil size at maximum contraction and baseline. Participants were examined with white light flashes (stimulation ON time = 200 ms; stimulation OFF time = 3300 ms, total brightness 100 cd/m2; total intensity 20 lux). Full-field (ganzfeld) light stimulation was used. Then this procedure was repeated two more times so that each participant received a total of 75 repetitions of the light stimulus responses. Images were acquired from both eyes and processed in real time (30 images/sec). Interpolation algorithm software sampled the data at 1 kHz, allowing more accurate measurement of response time. Luminance was measured using a Minolta (Konica Minolta Sensing Americas, Inc.) LS100 luminance metre. Since stimulus onset time is slower than pupillary reflexes, waveforms contaminated by blinks were discarded.
Comparing Rod-Mediated Dark Adaptation in Older Adults before and after Cataract Surgery
Published in Current Eye Research, 2023
Tarushi Tanaya, Thomas A. Swain, Mark E. Clark, Jason C. Swanner, Virginia R. Lolley, Michael A. Callahan, Gerald McGwin, Cynthia Owsley
A parsimonious explanation for our data may be that age-related cataract is serving as a filter to reduce the photo-bleach magnitude, and then after cataract removal and IOL insertion, the bleach is increased, thus generating a longer RIT (meaning slower dark adaptation). As mentioned, this effect is modest in moderate cataracts, but with greater opacity in more severe cataract, this has a more marked impact on the slowing of dark adaptation. An optical consequence of age-related cataract is to reduce shorter wavelength light particularly in the region of 400–500 nm, but transmission is also reduced as high as 600 nm in some eyes as noted by Artigas et al.25 However, we simply do know the individual spectral characteristics of the cataracts in our sample. Another potential explanation for our results may be that cataract generates forward light scatter, which may have reduced the localized intensity of the bleach.