Assessment of amblyopic children undergoing occlusion therapy by pattern visual evoked potentials and contrast sensitivity tests.

Background: Amblyopia is a case where one or less commonly, both eyes have impaired visual performance, even with the best optical correction and no visible disease of the visual system. Objectives: To assess contrast sensitivity tests (CST) and pattern visual evoked potentials (PVEP) results in amblyopic children who have already started occlusion therapy for durations ranging from 6 to 12 months. Methods: This cross-sectional study was conducted on 200 eyes of 50 patients with monocular amblyopia and 50 age and sex matched controls. Both patients and controls underwent ophthalmological assessment, PVEP, and CST. Results: There was no statistically significant difference in the results of P100 latencies of qualitative PVEP in amblyopic eyes compared to non-amblyopic eyes and control eyes, while the qualitative CST showed a highly statistically significant difference, being affected in 98% of amblyopic eyes compared to unaffected eyes (4%) and control eyes (4%). The maximum contrast level and minimal contrast level of quantitative CST were significantly lower in amblyopic eyes compared to non-amblyopic and control eyes. The cutoff value of maximal contrast level at mean frequencies of 2.5 ± 0.9 Hz, and a range of (1.1-4.1) for amblyopic eyes is ≤21 dB, while the cutoff value of minimal contrast level at mean frequencies of 13.4 ± 2.6 Hz, and a range of (6.7-18) for amblyopic eyes is ≤12 dB. Conclusion: Detection of amblyopia by CST is a noninvasive and easy procedure, which represents a promising tool to support the diagnosis of amblyopia.

VITAMIN D LEVEL AND ITS LINK WITH VISUAL ACUITY AND CONTRAST SENSITIVITY IN PATIENTS WITH AGE-RELATED MACULAR DEGENERATION.

OBJECTIVE: The aim: Determination of vitamin D level and its connection with visual functions in patients with age-related macular degeneration, dry form. PATIENTS AND METHODS: Materials and methods: We analyzed the data of studies (25(OH)D3 levels (nmol/l), LogMAR visual acuity and Logarithmic contrast sensitivity) of 2 groups of women of postmenopausal age: 1 group (58 people - 58 eyes) - patients with age-related macular degeneration (dry form) - study group; 2 group (29 people - 29 eyes) - people without ophthalmic pathology - control group. RESULTS: Results: In the study group, 37 patients (63,8%) had vitamin D deficiency, 21 people (36,2%) had vitamin D insufficiency. In the control group, these figures were 69% and 31%, respectively. These indicators were defined as low (the normal supply of vitamin D is considered to be 100 nmol/l and more). Visual acuity due to ETDRS chart in the study group was 0,22±0,04 (in patients with vitamin D deficiency) and 0,12±0,03 (in patients with vitamin D insuffi¬ciency), in the control group - 0,13±0,04 and 0,05±0,04 respectively. In the control group, the logarithmic values of contrast sensitivity (log CS) were 1,58±0,04 log CS (in patients with vitamin D deficiency) and 1,62±0,02 log CS (in patients with vitamin D insufficiency). For patients from the study group, these figures were reduced to 0,98±0,1 log CS and 1,10±0,06 log CS respectively. CONCLUSION: Conclusions: Patients with age-related macular degeneration, dry form, have low levels of vitamin D, with a predominance of its deficiency. It has been determined that with age-related macular degeneration, functional losses are observed when perceiving objects of low contrast.

Impact of intravitreal injection therapy on contrast sensitivity in patients with nAMD and DME.

PURPOSE: The study aims to evaluate changes in contrast sensitivity (CS) during therapy with intravitreal vascular endothelial growth factor (VEGF) inhibitors in patients with neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME). METHODS: Prospective, uncontrolled, multicenter study on patients with neovascular AMD or DME who underwent intravitreal injection therapy with Ranibizumab, Aflibercept, or Bevacizumab was conducted. Best corrected visual acuity (BCVA) and CS measured by Mars Letter Contrast Sensitivity Test (MLCS) and Freiburg Visual Acuity and Contrast Test (FrACT) in logCS were evaluated before 3 consecutive VEGF inhibitor injections, which followed the pro renata regimen in treatment-naïve and pretreated eyes with a maximum of 9 injections. Correlation of MLCS and FrACT was calculated by the Spearman's rank correlation coefficient. RESULTS: Eighty eyes of 74 patients (mean age 72.7; SD ± 9.96) were included. BCVA improved significantly from 0.44 (SD ± 0.21) logMAR to 0.38 (SD ± 0.23) logMAR by 0.06 (SD ± 0.14) logMAR values (p < 0.001). CS measured by MLCS increased significantly from 1.27 (SD ± 0.25) logCS to 1.39 (SD ± 0.22) logCS (p < 0.001). CS measured by FrACT also improved significantly from 1.22 (SD ± 0.32) logCS to 1.30 (SD ± 0.29) logCS (p = 0.035). A positive correlation between MLCS and FrACT was found (r = 0.389; p < 0.001). Despite statistical significance, results for BCVA, MLCS, and FrACT failed clinical significance. Overall best test results were achieved with MLCS. CONCLUSIONS: Intravitreal injection therapy with VEGF inhibitors led to an improvement of BCVA and CS measured by MLCS and FrACT. MLCS was superior and more sensitive compared to FrACT and even BCVA to evaluate CS in elderly patients with macular pathology.

Change in contrast sensitivity and OCT parameters in idiopathic intracranial hypertension.

Background: Deterioration in peripheral contrast sensitivity (CS) can be an indicator to detect progressive deterioration of visual function in patients with idiopathic intracranial hypertension (IIH). Objectives: The aim of this study was to evaluate the changes in central and peripheral CS and optical coherence tomography (OCT) parameters and in patients with IIH. Design and Methods: In this pilot observational study, data of 20 eyes of 10 'treatment-naïve' IIH patients were analyzed. Detailed ocular examination was performed including CS assessment using both Pelli-Robson (PR) test and Spaeth-Richman Contrast Sensitivity Test (SPARCS) along with the OCT for macular and optic nerve head (ONH) parameters. A comparative analysis was done for CS and OCT parameters from baseline to a follow-up visit > 12 months (range: 18-24 months). Results: The study population had a female preponderance (80%, n = 8), and mean age at diagnosis was 31.9 ± 10.3 years. Mean follow-up period was 21.2 months (range: 15-24 months). At presentation, 6/6 visual acuity was noted in 75% eyes (n = 15) while all eyes had 6/6 vision at the last follow-up. Average PR score increased from 1.96 ± 0.36 to 2.30 at the last visit (Wilcoxon test: V = 0.0, p ⩽ 0.001) while average SPARCS score (total) increased from 71.85 ± 9.10 to 77.55 ± 6.20 (Paired t-test: t = -2.3, p = 0.035). Change in SPARCS score was significant in average total score (p = 0.035), and quadrant-wise score in superonasal (p = 0.014), inferonasal (p = 0.001), and inferotemporal (p = 0.021) quadrants. Same trend in SPARCS scores was observed when eyes with and without recurrence were analyzed. Statistically significant difference in retinal nerve fiber layer (RNFL) thickness (p = 0.007) and macular thickness (MT) in nasal quadrant (p = 0.006) was seen between the eyes with recurrence and without recurrence. Conclusion: Peripheral CS showed significant difference in all eyes over time. It showed significant change in eyes with recurrence, even in the presence of intact visual acuity and preserved central CS. Changes in RNFL thickness and nasal MT could differentiate eyes which developed recurrence from normal eyes.

Sensibilidad al contraste en edad pediátrica / Contrast sensitivity in pediatric ages

La sensibilidad al contraste es considerada como la capacidad de discriminar diferencias de iluminación entre áreas adyacentes, cuyo umbral se estima como la menor cantidad de contraste que se necesita para lograr esta distinción. La medida de la agudeza visual cuantifica la visión en alto contraste; sin embargo, los objetos que nos encontramos en la vida real no son solo de alto contraste, sino que presentan diferentes niveles de contraste y tamaño, lo cual puede ser determinado con el estudio de la sensibilidad al contraste, ya sea a través de cartillas de bajo contraste o de las pruebas que evalúan las frecuencias espaciales, que serán utilizadas según la edad del paciente pediátrico. Con este trabajo se pretende mostrar los diferentes criterios relacionados con la sensibilidad al contraste en edades pediátricas, para lo cual se realizó una búsqueda en diferentes publicaciones y textos de la especialidad. Existe controversia relacionada con la edad pediátrica en la cual se alcanza la sensibilidad al contraste al nivel del adulto, así como los valores normativos en la infancia con las diferentes pruebas empleadas. La valoración de la sensibilidad al contraste constituye una herramienta más para evaluar la función visual conjuntamente con la determinación de la agudeza visual y la visión de colores. Se necesitan más estudios sobre este tema para unificar criterios con el fin de perfeccionar la atención a la población pediátrica(AU)

Contrast sensitivity is the ability to distinguish differences in luminance between adjacent areas. Its threshold is estimated as the smallest amount of contrast needed to achieve such a distinction. Visual acuity measurement quantifies high contrast vision. However, the objects around us are not only characterized by high contrast: they display different levels of contrast and size, which may be determined through the study of contrast sensitivity, either with low contrast charts or spatial frequency tests, to be used according to the pediatric patient's age. The purpose of the study was to present various criteria about contrast sensitivity in pediatric ages. To achieve this end, a search was conducted in different publications and texts from the specialty. A debate is currently in progress about the pediatric age in which adult contrast sensitivity is achieved and the standard values to be verified with the different tests applied in childhood. Contrast sensitivity assessment is one more tool to evaluate visual function and determine visual acuity and color vision. Further studies are required about the subject aimed at unifying criteria so as to improve the care of the pediatric population(AU)

Contrast sensitivity assessment for early detection of hydroxychloroquine toxicity.

INTRODUCTION: Hydroxychloroquine (HCQ), is known to cause visual dysfunction during its prolonged course of administration. Optical Coherence Tomography (OCT) and field tests are the commonly used screening tests. Not much is known about the role of contrast sensitivity (CS) as method for early detection of HCQ toxicity. This pilot study was designed to study the change in central and peripheral contrast sensitivity for detecting early signs of HCQ toxicity. DESIGN: Prospective study conducted at Government Medical College & Hospital, Chandigarh, India. PARTICIPANTS: Twenty eyes of 10 treatment naïve, autoimmune patients. METHODS: All patients underwent functional tests, contrast sensitivity tests: Pelli Robson and Spaeth Richman Contrast Sensitivity (SPARCS). Average and quadrant wise SPARCS score; Pelli Robson score and structural parameters viz., macular OCT parameters were compared at baseline, 3- and 6-month post treatment with HCQ. MAIN OUTCOME MEASURES: Change in CS using SPARCS and Pelli Robson were recorded at each visit and compared with the baseline. Structural and functional parameters were correlated. RESULTS: The average SPARCS scores at baseline, 3-month post HCQ and at 6-month post HCQ were 82.37 ± 8.40, 73.17 ± 9.63 and 70.37 ± 10.08, respectively. Quadrant wise change from first visit to third visit was statistically significant only in superotemporal (p = 0.002), inferotemporal (p = 0.02) and central (p = 0.01) quadrants. There was no correlation between SPARCS and Pelli Robson (S = 0.1454, p = 0.466). Similarly, there was no significant correlation between the structural and functional parameters. CONCLUSIONS: HCQ affect the CS by virtue of its action on bipolar and ganglion cells. Decrease in central and peripheral CS as measured by SPARCS can be a sign of early visual dysfunction, hence must be considered as an early indicator of HCQ toxicity.

Assessing glaucoma deterioration using Spaeth/Richman contrast sensitivity test.

PURPOSE: To assess changes in the central and peripheral contrast sensitivity in severe primary open-angle glaucoma (POAG) patients using a computer-based Spaeth/Richman contrast sensitivity test (SPARCS) over a period of 24 months. METHODS: Our pilot, observational study included 15 patients (30 eyes) with severe POAG. Visual acuity, intraocular pressure, number of anti-glaucoma drugs, visual fields, and SPARCS score were recorded at first visit and at 12 and 24 months. RESULTS: We observed changes in mean deviation (MD) from -19.37 ± 5.04 to -20.63 ± 4.07, mean pattern standard deviation (PSD) from 11.49 ± 2.61 to 11.35 ± 2.01, and mean SPARCS score from 54.97 ± 15.66 to 53.50 ± 16.42. We found no statistically significant difference between visual field parameters and SPARCS scores associated with the number or type of prescribed anti-glaucoma drugs. Spearman's correlation coefficient of SPARCS at baseline (SPARCS1) versus MD at baseline (MD1) was 0.274 (p = 0.142) and SPARCS1 versus PSD at baseline (PSD1) was -0.163 (p = 0.389). The correlation coefficient between SPARCS at 12 months (SPARCS2) versus MD (MD2) at the same time point was computed to be 0.391 (p = 0.03), whereas SPARCS2 versus PSD at 12 months was -0.212 (p = 0.262). Similarly, we found the coefficient to be 0.336 (p = 0.069) for SPARCS3 (SPARCS at 24 months) versus MD3 (MD at 24 months) and -0.242 (p = 0.197) for SPARCS3 versus PSD3 (PSD at 24 months). Correlation coefficients between SPARCS1/2, SPARCS1/3, MD1/2, MD1/3 PSD1/2, and PSD1/3 were 0.856, 0.865, 0.748, 0.722, 0.497, and 0.562, respectively (p < 0.001). MD changed by 9.46% ± 12.73%, PSD by 0.64% ± 14.03%, and average SPARCS by 3.31% ± 12.73% over 24 months. CONCLUSION: The data from our study indicate the utilitarian application of SPARCS, an inexpensive and readily available tool for monitoring functional deterioration in cases with advanced glaucomatous damage, especially in resource-poor settings. Furthermore, it is a useful and reliable alternative to the imaging modalities where retinal nerve fiber layer measurement can be erroneous in advanced cases secondary to the floor effect.

Contrast Sensitivity and Color Vision Comparison Between Clear and Yellow-Tinted Intraocular Lens in Diabetic Retinopathy

PURPOSE: To compare contrast sensitivity and color vision after implantation of a clear intraocular lens (IOL) and a yellow-tinted IOL in diabetic retinopathy patients. METHODS: In the 50 eyes of 25 diabetic patients with non-proliferative diabetic retinopathy, clear IOLs were implanted in 25 eyes, and yellow-tinted IOLs were implanted in 25 fellow eyes. Three months after the surgery, contrast sensitivity function was measured with a vision contrast test system, and color discrimination was tested using the Farnsworth Munsell 100-hue test. RESULTS: Eyes implanted with yellow-tinted IOLs had significant differences in contrast sensitivity values compared to those of fellow eyes implanted with clear IOLs in both the moderate diabetic retinopathy group (6.0 cycles per degree) and the severe diabetic retinopathy group (throughout all spatial frequencies except 12.0 cycles per degree). The yellow-tinted IOL did not modify chromatic discrimination compared with that of the clear IOL. In the blue-yellow axis error score, however, there were significant differences between the clear IOL and the yellow-tinted IOL. CONCLUSIONS: With progressing diabetic retinopathy, the yellow-tinted IOL provided better contrast sensitivity than the clear IOL. The yellow-tinted IOL improved color vision in the blue-yellow chromatic axis without causing chromatic discrimination defects.

Comparison of Visual Function Among Aspheric Intraocular Lenses

PURPOSE:To compare the visual function among 3 aspheric intraocular lenses (IOLs) after cataract surgery. METHODS: A prospective analysis among 70 eyes of 68 patients who had undergone phacoemulsification and implantation of aspheric IOLs (Acrysof IQ, 30 eyes; Tecnis ZA9003, 20 eyes; Akreos Adapt-AO, 20 eyes) was performed. The best corrected visual acuity (BCVA), refraction, coma, trefoil, spherical aberration, root-mean-square (RMS), contrast sensitivity test, satisfaction and glare was evaluated during the follow-up period of 3 months. RESULTS: There were no significant differences in BCVA, satisfaction, glare, coma, trefoil, RMS and contrast sensitivity test among the 3 aspheric IOLs. Spherical aberration in Akreos Adapt-AO (0.04+/-0.05 microm) was higher compared with Acrysof IQ (0.03+/-0.04 microm) and Tecnis ZA9003 (0.11+/-0.03 microm)(p<0.01). The predictability of postoperative spherical equivalent in the Akreos Adapt-AO group (-0.57+/-0.22D) represented a statistically significant myopic refractive error compared with the Acrysof IQ (0.01+/-0.77D) and the Tecnis ZA9003 (-0.20+/-0.71D) groups (p=0.04). CONCLUSIONS: There were no significant differences in visual function except spherical aberration, which was highest in the Akreos Adapt-AO group.

Reproducibility of Morphoscopic Contrast Sensitivity Obtained with the Visual Capacity Analyzer in Glaucoma Patients

PURPOSE: To determine the reproducibility of morphoscopic contrast sensitivity test values in the patients with primary open angle glaucoma using the Visual Capacity Analyzer (ACV) designed for assessing full visual performance including contrast sensitivity. METHODS: Morphoscopic contrast sensitivity was measured in each five glaucomatous eyes. The measurement was repeated 5 times under two different luminance level of screen (maximum and 3 cd/m2). RESULTS: Under maximum luminance background, the coefficients of variation (CV) and the reliability coefficients (RC) for the spatial frequencies examined in this study ranged from 2.1% to 29.3%, from 92.1% to 100.0%, respectively. Under 3cd/m2 luminance level of screen, the CV ranged from 2.7% to 32.0%, and the RC ranged from 90.7% to 99.9%. CONCLUSIONS: The results indicates that for the spatial frequencies examined, the morphoscopic contrast sensitivity test using ACV shows good reproducibility in glaucomatous patients.

Clinical Results of AMO ARRAY Multifocal Intraocular Lens

Various kinds of multifocal intraocular lenses(IOLs) have been developed for the improvement of near and far visual acuity after cataract operation. This prospective study was performed to compare a function of AMO ARRAY multifocal IOL(Array group) with conventional monofocal IOL(Mono group). Each type of IOL was implanted into 25 eyes and uncorrected visual acuity(UCVA) and best corrected visual acuity(BCVA) at near, intermediate and far distance were evaluated before and 2 months after operation in both groups. Contrast sensitivity, photophobia and glare were also evaluated as subjective symptoms in both groups. Mean UCVA at distant and near distance before operation was 0.23+/-0.15 and 0.25+/-0.20 in mono group, and 0.13+/-0.11 and 0.14+/-0.11 in Array group. Mean UCVA/BCVA at distant and near distance 2 month after operation was improved to 0.79+/-0.28/0.87+/-0.27 and 0.34+/-0.15/0.82+/-0.26 in mono group and 0.83+/-0.19/0.86+/-0.19 and 0.50+/-0.15/0.79+/-0.15 in Array group. The difference of UCVA at near distance was statistically significant(P<0.05), while that of BCVA at near and far distance was not statistically significant between two groups(P<0.05). Array group had less contrast sensitivity at all spatial frequencies(1.5, 3, 6, 12, 18 cycles/degree) and more glare than the mono group after operation. AMO ARRAY multifocal IOL induces a good result of visual rehabilitation in both near and far distance, but it may cause more glare and less contrast sensitivity than the monofocal IOL.