Evaluation of clinical validity of the Rabin cone contrast test in normal phakic or pseudophakic eyes and severely dichromatic eyes

Fujikawa, Masato; Muraki, Sanae; Niwa, Yuichi; Ohji, Masahito

doi:10.1111/aos.13495

Cited by 13 publications

(11 citation statements)

References 10 publications

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“…As previously reported, Cone contrast test (CCT) scores of 75 or greater were defined as normal (Rabin et al, 2011). Also, the CCT can be used after cataract surgery in elderly patients (Fujikawa et al, 2018).…”

Section: Methodsmentioning

confidence: 99%

Investigating Multimodal Diagnostic Eye Biomarkers of Cognitive Impairment by Measuring Vascular and Neurogenic Changes in the Retina

et al. 2018

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Previous studies have demonstrated that cognitive impairment (CI) is not limited to the brain but also affects the retina. In this pilot study, we investigated the correlation between the retinal vascular complexity and neurodegenerative changes in patients with CI using a low-cost multimodal approach. Quantification of the retinal structure and function were conducted for every subject (n = 69) using advanced retinal imaging, full-field electroretinogram (ERG) and visual performance exams. The retinal vascular parameters were calculated using the Singapore Institute Vessel Assessment software. The Montreal Cognitive Assessment was used to measure CI. Pearson product moment correlation was performed between variables. Of the 69 participants, 32 had CI (46%). We found significantly altered microvascular network in individuals with CI (larger venular-asymmetry factor: 0.7 ± 0.2) compared with controls (0.6 ± 0.2). The vascular fractal dimension was lower in individuals with CI (capacity, information and correlation dimensions: D0, D1, and D2 (mean ± SD): 1.57 ± 0.06; 1.56 ± 0.06; 1.55 ± 0.06; age 81 ± 6years) vs. controls (1.61 ± 0.03; 1.59 ± 0.03; 1.58 ± 0.03; age: 80 ± 7 years). Also, drusen-like regions in the peripheral retina along with pigment dispersion were noted in subjects with mild CI. Functional loss in color vision as well as smaller ERG amplitudes and larger peak times were observed in the subjects with CI. Pearson product moment correlation showed significant associations between the vascular parameters (artery-vein ratio, total length-diameter ratio, D0, D1, D2 and the implicit time (IT) of the flicker response but these associations were not significant in the partial correlations. This study illustrates that there are multimodal retinal markers that may be sensitive to CI decline, and adds to the evidence that there is a statistical trend pointing to the correlation between retinal neuronal dysfunction and microvasculature changes suggesting that retinal geometric vascular and functional parameters might be associated with physiological changes in the retina due to CI. We suspect our analysis of combined structural-functional parameters, instead of individual biomarkers, may provide a useful clinical marker of CI that could also provide increased sensitivity and specificity for the differential diagnosis of CI. However, because of our study sample was small, the full extent of clinical applicability of our approach is provocative and still to be determined.

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Section: Methodsmentioning

confidence: 99%

Investigating Multimodal Diagnostic Eye Biomarkers of Cognitive Impairment by Measuring Vascular and Neurogenic Changes in the Retina

et al. 2018

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“…The original cone contrast test by Rabin 40 (RCCT) presented a randomized series of colored letters visible to a single cone type in five 41 steps of decreasing contrast to determine an interpolated contrast threshold 16,20 . Using RCCT, 42 Fujikawa et al found a gradual decline in CCT scores with age in phakic subjects that increased 43 back to normal values in pseudophakic subjects 10 . 44 CCT testing differentiates itself from prior testing modalities because it rapidly yields continuous 46 quantitative data for all 3 cone classes.…”

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confidence: 99%

Quantifying Color Vision Changes Associated with Cataracts Using Cone Contrast Thresholds

Mehta

Diep

Nguyen

et al. 2020

Preprint

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Color Vision Changes Associated with Cataracts 2 Abstract Purpose: The cone contrast threshold (CCT) test quantified color vision changes in subjects of all ages and those undergoing cataract surgery. Methods: Twenty-four healthy volunteers from two cohort studies performed CCT using best corrected visual acuity, filters, mydriasis, and pinhole correction. Retrospective cross-sectional study of patients seen in eye clinics evaluated the relationship between age and color vision, and age and lens status in 355 eyes. Lastly, 25 subjects performed CCT before and after cataract surgery. Results: CCT scores were most reliable in the non-mydriatic condition without pinhole correction. Progressively dense brown filters produced small but significant reductions in S-cone sensitivity. Linear regression analysis of phakic subjects showed a decline for all cone classes with age. Rate of decline was greater for S-cones (slope (95% CI) = -1.09 (-1.23, 0.94)) than Mcones (slope (95% CI) = -0.80 (-0.95, -0.66)) and L-cones (slope (95% CI) = -0.66 (-0.81, -0.52)). CCT scores increased for S-cones but reduced for L-and M-cones in pseudophakic subjects compared to phakic patients. CCT scores after cataract surgery increased for S-cones, M-cones, and L-cones by 33.0 (p<0.001), 24.9 (p=0.001), and 22.0 (p=0.008). Conclusions: CCT assessment allows for clinically practical quantitation of color and contrast vision improvement after cataract surgery and aging patients who note poor vision despite good visual acuity. Translational Relevance: CCT testing, historically used in research, is now a clinically practical tool to evaluate age and cataract related changes in color and contrast vision and routinely quantify vision beyond black and white visual acuity testing.

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“…3), indicating a near independence from opacities, like cataracts, which attenuate light in the visible spectrum. Results obtained from CCT were highly variable and dependent on media filters, highlighting that it may not be a reliable assessment of macular health in patients with media opacity as was previously noted (13).…”

Section: Discussionmentioning

confidence: 84%

“…IR light is absorbed less by ocular media and therefore penetrates deeper into the eye than visible spectrum light. Traditional visual function tests suffer diminished reliability in patients with lenticular senescence and media opacities (6,13,14). Ruminski Conversely, 2PM is scotopic and the effect of brown filters was only significant for 2PM-Vis and not for 2PM-IR.…”

Section: Discussionmentioning

confidence: 99%

“…Cataractous lenses decrease the sensitivity threshold of all three cone classes due to increased scatter and decreased transmittance of visible light (8)(9)(10)(11), with the greatest impact on short-wavelength cones especially after the age of 60 (11,12). Because of this effect, Fujikawa et al established that CCT can be used reliably up to the seventh decade of life and after cataract surgery in elderly patients (13). Cataractous lenses and posterior capsular opacification (14) also diminish retinal sensitivity measurements obtained using microperimetry.…”

Section: Introductionmentioning

confidence: 99%

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Two-Photon Microperimetry: A media opacity-independent retinal function assay

Wei

Mehta

Palczewska

et al. 2020

Preprint

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Humans perceive light in the visible portion of electromagnetic radiation. However, visible light is scattered and attenuated by optical media opacities. Because all conventional visual function tests rely on visible light, test results are reduced in patients with optical media opacities like corneal scars, cataracts, and vitreous hemorrhages. Infrared (IR) light has greater penetrance through tissue than visible light. Two-photon IR visual stimulation, a recently pioneered technology, should enable testing of retinal visual function and produce results that are less susceptible to media opacities. The effects of simulated media opacities on visual performance in young healthy volunteers and the change in visual function in healthy phakic patients of two age ranges (20-40 and 60-80-year-old) were studied using conventional testing and 2-photon infrared visual stimulation. All subjects completed visual function testing using cone contrast threshold (CCT) testing, conventional microperimetry, visible light microperimetry from a novel device (2PM-Vis), and infrared 2-photon microperimetry (2PM-IR). Retinal sensitivity measured by 2PM-IR demonstrated lower variability than all other devices relying on visible spectrum stimuli. Retinal sensitivity decreased proportionally with the transmittance of light through each filter. CCT scores and retinal sensitivity decreased with age in all testing modalities. Visible spectrum testing modalities demonstrated larger test result differences between young and old patient cohorts; this difference was inversely proportional to the wavelength of the visual function test. 2PM-IR mitigates media opacities which may mask small differences in retinal sensitivity when tested with conventional visual function testing devices.One Sentence SummaryTwo photon infrared visual function testing produces results that are less susceptible to media opacities than conventional tests.

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Evaluation of clinical validity of the Rabin cone contrast test in normal phakic or pseudophakic eyes and severely dichromatic eyes

Cited by 13 publications

References 10 publications

Investigating Multimodal Diagnostic Eye Biomarkers of Cognitive Impairment by Measuring Vascular and Neurogenic Changes in the Retina

Investigating Multimodal Diagnostic Eye Biomarkers of Cognitive Impairment by Measuring Vascular and Neurogenic Changes in the Retina

Quantifying Color Vision Changes Associated with Cataracts Using Cone Contrast Thresholds

Two-Photon Microperimetry: A media opacity-independent retinal function assay

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