Changes In Contrast Sensitivity Research Articles

Foveal neural adaptation to optically induced contrast reduction.

Contrast processing is suggested to interact with eye growth and myopia development. A novel contrast-reducing myopia control lens design decreases image contrast and was shown to slow myopia progression. Limited insights exist regarding neural visual processing following adaptation to image contrast reduction. This study investigated foveal neural contrast sensitivity in 29 young adults following a 30-minute adaptation to scattering using a Bangerter occlusion foil 0.8, +0.5-diopter defocus, and a clear lens control condition. Neural contrast sensitivity at its peak sensitivity of 6 cycles per degree was assessed before and after adaptation to the lens conditions, employing a unique interferometric system. Pre-adaptation measurements were averaged from six replicates and post-adaptation measurements by the first and last three of six replicates. The change in neural contrast sensitivity was largest for scattering across the first and last three post-adaptation measurements (+0.05±0.01logCS and +0.04±0.01logCS, respectively) compared with control and defocus (all +0.03±0.01logCS). For scattering, the observed increase of neural contrast sensitivity within the first three measurements differed significantly from the pre-adaptation baseline (p = 0.04) and was significantly higher compared with the control condition (p = 0.04). The sensitivity increases in the control and defocus conditions were not significant (all p > 0.05). As the adaptation effect diminished, no significant differences were found from baseline or between the conditions in the last three measurements (all p > 0.05). When post-adaptation neural contrast sensitivities were clustered into 25-second sequences, a significant effect was observed between the conditions, with only a significant relevant effect between control and scattering at 25 seconds (p = 0.04) and no further significant effects (all p > 0.05). The alteration in neural contrast sensitivity at peak sensitivity was most pronounced following adaptation to the scattering condition compared with defocus and control, suggesting that induced scattering might be considered for myopia control.

XOLARIS: A 24-Month, Prospective, Natural History Study of 201 Participants with Retinitis Pigmentosa GTPase Regulator-Associated X-Linked Retinitis Pigmentosa

ObjectiveTo improve the understanding of the natural disease progression of retinitis pigmentosa GTPase regulator (RPGR)-associated X-linked retinitis pigmentosa (XLRP). DesignA multicenter, prospective, observational natural history study over 24 months. ParticipantsMale participants aged ≥7 years with a pathogenic variant in the RPGR gene, a best-corrected visual acuity (BCVA) score of ≥34 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, and a mean 68-loci retinal sensitivity (assessed by microperimetry) of 0.1–20 decibels (dB). MethodsParticipants were divided into subgroups based on their BCVA score at baseline: 34–73 (lower BCVA) or ≥74 (higher BCVA) ETDRS letters. There were 7 visits over 24 months. Main Outcome MeasuresChange from baseline in BCVA, retinal sensitivity, low luminance visual acuity (LLVA), fixation stability, contrast sensitivity, visual field, anatomical measures, 25-item Visual Function Questionnaire (VFQ-25), intraocular pressure, and adverse events (AEs). ResultsOverall, 201 participants were included. The mean (standard deviation [SD]) age was 30.3 (11.9) years in the lower BCVA subgroup (n=170) and 27.7 (10.1) years in the higher BCVA subgroup (n=31). The study eye baseline mean (SD) BCVA scores were 59.4 (10.30) and 77.3 (3.95) in the lower and higher BCVA subgroups, respectively; the lower BCVA subgroup had lower retinal sensitivity in the study eye at baseline than the higher BCVA subgroup. Over 24 months, there were small observed changes in BCVA, retinal sensitivity, LLVA, fixation, contrast sensitivity, and fundus photography findings. There were observed mean (SD) changes at 24 months in the lower and higher BCVA subgroups of −1.01 (4.67) and 0.03 (5.83) dB-steradians in the volume of full-field hill of vision, −330.6 (869.51) and −122.7 (22.01) μm in distance from foveal center to the nearest border of preserved fundus autofluorescence, −104.3 (277.80) and −207.1 (171.01) μm in central ellipsoid width, and −2.8 (9.7) and −0.6 (7.6) in VFQ-25 composite score, respectively. There was 1 death from completed suicide. There were no ocular serious AEs, and most AEs were mild/moderate. ConclusionsThis study provides evidence of the slow natural progression of XLRP over 24 months in both subgroups and provides important functional, anatomical, and safety data.

Rehabilitation of amblyopia using a digital platform for visual training combined with patching in children: a prospective study

PurposeTo assess the possible benefits of the use of perceptual learning and dichoptic therapy combined with patching in children with amblyopia over the use of only patching.MethodsQuasi-experimental multicentric study including 52 amblyopic children. Patients who improved their visual acuity (VA) by combining spectacles and patching were included in patching group (PG: 20 subjects), whereas those that did not improved with patching performed visual training (perceptual learning + dichoptic therapy) combined with patching, being assigned to the visual treatment group (VT: 32 subjects). Changes in VA, contrast sensitivity (CS), and stereopsis were monitored during a 6-month follow-up in each group.ResultsSignificant improvements in VA were found in both groups at 1 month (p < 0.01). The total improvement of VA was 0.18 ± 0.16 and 0.31 ± 0.35 logMAR in PG and VT groups, respectively (p = 0.317). The Wilcoxon effect size was slightly higher in VT (0.48 vs. 0.54) at 6 months. An enhancement in CS was observed in the amblyopic eye of the VT group for all spatial frequencies at 1 month (p < 0.001). Likewise, the binocular function score also increased significantly in VT group (p = 0.002). A prediction equation of VA improvement at 1 month in VT group was obtained by multiple linear regression analysis (p < 0.001, R2 = 0.747).ConclusionsA combined treatment of visual training and patching is effective for obtaining a predictable improvement of VA, CS, and binocularity in patching-resistant amblyopic children.

Binocular function in the aging visual system: fusion, suppression, and stereoacuity.

Changes in vision that occur in normal healthy aging can be seen in fundamental measures of monocular vision. However, the nature of the changes in binocular vision with age remain unclear. A total of 28 older (53-66 years) and 28 younger adults (20-31 years) were enrolled in this study. We performed a battery of tests to assess differences in monocular contrast thresholds and various binocular visual functions including dichoptic masking weight and strength, the binocular balance point for fused stimuli, and stereoacuity in the aging and control groups. Aging significantly increased monocular contrast thresholds (p < 0.001). Although this suggests that aging reduces the effective "input gain" to vision, we also found a significantly elevated contribution of those weaker signals to interocular suppression (p < 0.001). Consequently, there was no significant net difference in the strength of interocular suppression (p = 0.065). We did not find a significant difference of absolute balance point between the two groups (p = 0.090). Lastly, the mean stereoacuity was worse in the older group compared to the younger group (p = 0.002). Our findings confirm previous results showing differences in contrast sensitivity and stereoacuity with aging. Furthermore, we find a change in interocular suppression that is a possible consequence of the change in contrast sensitivity. It is suggestive of a cortical system that maintains a homeostatic balance in interocular suppression across the lifespan.

Significant loss of retinal nerve fibre layer and contrast sensitivity in people with well controlled HIV disease: implications for aging with HIV.

Antiretroviral therapy has decreased the prevalence of retinal opportunistic infections in people living with HIV (PLWH). However, abnormalities in visual function are evident and may be associated with an early onset of aging in PLWH. In this study, we examined the Retinal Nerve Fibre Layer (RNFL) thickness and visual function in PLWH and HIV non-infected controls in Malaysia. Cross-sectional study. Two hundred and two (202) PLWH without retinal opportunistic infection and 182 age-matched, HIV seronegative individuals were enrolled. PLWH were recruited from the Infectious Disease clinic at the University Malaya Medical Centre. Controls were recruited among the hospital staff and community volunteers. RNFL thickness was measured with spectral domain optical coherence tomography (SDOCT). Visual functions include visual acuity using LogMAR chart and contrast sensitivity using Pelli- Robson Chart. All PLWH (mean age 46.1 years ± 9.9 years) in the study were on ART and 61.2% had a CD4+ T-cell count more than 500 cell/μl. The mean visual acuity was similar between the two groups (LogMAR 0.05 vs. 0.07, p = 0.115). Contrast sensitivity was lower in PLWH compared to HIV seronegative individuals (1.90 vs 1.93, p = 0.032). RNFL thickness was significantly thinner in the temporal quadrant for PLWH compared to controls (68.89 μm vs 74.08 μm, p = 0.001). Changes in RNFL thickness and contrast sensitivity were seen in PLWH despite their relatively young age and well controlled HIV disease. The changes reflect structural and functional deficits, and could have long-term implications on their health trajectory.

Hypoxia impairs reaction time but not response accuracy in a visual choice reaction task

We investigated the effect of hypoxia on the reaction time (RT) and response accuracy of pilots performing a visual choice reaction task that corresponded to the scanning of helmet mounted display (HMD) symbology. Eighteen male military pilots performed the task in a hypobaric chamber at two simulated altitudes (92 m and 4572 m) in a single-blinded repeated measures and counter-balanced design. The visual stimuli were displayed in low and high contrast and at a 30- and 50-degree field of view (FoV). We measured the pilots' RT and response accuracy. Using an eye tracker, we measured the pilot's glance time at each stimulus location. Finally, we collected subjective ratings of alertness. The results show that hypoxia increased the RT and glance time. Lowering the stimulus contrast and increasing the FoV further increased the RT, independent of hypoxia. These findings provide no evidence for hypoxia-induced changes in visual contrast sensitivity or visual field. Instead, hypoxia seemed to affect RT and glance time by reducing alertness. Despite the increased RT, the pilots maintained their accuracy on the visual task, suggesting that visual scanning of HMD symbology may be resistant to the effects of acute hypoxia.

Absolute prediction of relative changes in contrast sensitivity with aberrations using a single metric of retinal image quality.

Metrics of retinal image quality predict optimal refractive corrections and correlate with visual performance. To date, they do not predict absolutely the relative change in visual performance when aberrations change and therefore need to be a-posteriori rescaled to match relative measurements. Here we demonstrate that a recently proposed metric can be used to predict, in an absolute manner, changes in contrast sensitivity measurements with Sloan letters when aberrations change. Typical aberrations of young and healthy eyes (for a 6 mm pupil diameter) were numerically introduced, and we measured the resulting loss in contrast sensitivity of subjects looking through a 2 mm diameter pupil. Our results suggest that the metric can be used to corroborate measurements of visual performance in clinical practice, thereby potentially improving patient follow-ups.

Structure-function associations between contrast sensitivity and widefield swept-source optical coherence tomography angiography in diabetic macular edema.

To evaluate the relationship between contrast sensitivity (CS) and widefield swept-source optical coherence tomography angiography (WF SS-OCTA) vascular metrics in diabetic macular edema (DME) was the purpose. This prospectively enrolled cross-sectional observational study included 61 eyes of 48 patients that were tested with the quantitative CS function (qCSF) test on the same day as imaging with WF SS-OCTA (PLEX® Elite 9000, Carl Zeiss Meditec) 3 × 3, 6 × 6, and 12 × 12mm scans. Outcomes included visual acuity (VA) and multiple qCSF metrics. Vascular metrics included vessel density (VD) and vessel skeletonized density (VSD) in the superficial (SCP) and deep capillary plexus (DCP) and whole retina (WR) and foveal avascular zone (FAZ) parameters. Mixed effects multivariable linear regression models controlling for age, lens status, and diabetic retinopathy stage were performed. Standardized beta coefficients were calculated by refitting the standardized data. SS-OCTA metrics had a significant association with CS and VA. The effect size of OCTA metrics was larger on CS compared to VA. For example, the standardized beta coefficients for VSD and CS at 3cpd (βSCP = 0.76, βDCP = 0.71, βWR = 0.72, p < 0.001) were larger than those for VA (βSCP = - 0.55, p < 0.001; βDCP = - 0.43, p = 0.004; βWR = - 0.50, p < 0.001). On 6 × 6mm images, AULCSF, CS at 3cpd, and CS at 6cpd were significantly associated with VD and VSD in all three slab types (SCP, DCP, and WR), while VA was not. Structure-function associations in patients with DME leveraging the qCSF device suggest microvascular changes on WF SS-OCTA are associated with larger changes in contrast sensitivity than VA.

The effect of small incision lenticule extraction on contrast sensitivity.

The improvements due to small incision lenticule extraction (SMILE) in vision, e.g., in spherical equivalent (SE) and visual acuity (VA), has been widely recognized. However, the contrast sensitivity (CS) change after SMILE was not certain. Here, we investigated the effect of SMILE on CS before, 1 day after and 7 days after surgery and then clarified the corresponding mechanism by using a perceptual template model (PTM). In addition, the relationship among SE, VA, and CS was discussed. The quick contrast sensitivity function (qCSF) was applied to measure CS with high precision and accuracy. We found that (1) CS was significantly improved 1 day after SMILE and was also increased 7 days after the surgery, (2) CS improvements were dependent on spatial frequency and external noise, (3) the increase in CS was due to the decreased internal additive noise and an enhanced perceptual template, and (4) Greater SE improvements predicted better VA improvements 1 day after SMILE, and a positive correlation between SE improvements and AULCSF improvements 7 days after SMILE was observed. These findings help us better understand the effect of SMILE and provide effective indicators for future visual research.

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

PurposeThe 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).MethodsProspective, 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.ResultsEighty 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.ConclusionsIntravitreal 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 among Patients with Diabetic Mellitus Type II

Introduction: Eye being one of the target organs of diabetes mellitus has many pathological consequences, one possibly being contrast sensitivity. Contrast sensitivity is required for daily activities like in situations of low light, fog or driving at night. The study was conducted to find out contrast sensitivity among diabetic&#x0D; Methodology: A hospital based descriptive cross- sectional study of contrast sensitivity was conducted among type II diabetics with or without retinopathy at Kathmandu Medical College from April to December 2018. Patient demographics and comprehensive clinical examinations findings were recorded in a specially designed proforma. Convenience sampling was done and informed consent was taken.&#x0D; Leas symbol low contrast test 10M was used for contrast sensitivity testing. The contrast levels of the test lines on the five pages are 25%, 10%, 5%. 2.5%and 1.2%. Data was analyzed in excel and SPSS (version21). Results were expressed in frequency, percentage and mean as required. Association of contrast sensitivity with age, gender, duration of diabetes, blood sugar level and diabetic retinopathy was tested using chi square test.&#x0D; Results: Among the 45 study population, female to male ratio was 1:2. Age ranged from 25 to 76 years with maximum patients in the age group 51-60 years. Blood sugar was controlled in 33.33%. Contrast sensitivity was decreased in 40%. Among the patients with decreased contrast sensitivity, blood sugar was uncontrolled in 66.67%. Similarly, 72.2% of participants with decreased contrast sensitivity had no diabetic retinopathy. The association of contrast sensitivity with age of the patient, gender, duration of diabetes mellitus, blood sugar level and diabetic retinopathy was not statistically significant with p values 0.34, 0.52, 0.07, 1 and 0.89 respectively. &#x0D; Conclusion: Contrast sensitivity can be decreased among patients with type II diabetes mellitus irrespective of gender, age of the patient, duration of diabetes, control of blood sugar and presence or absence of diabetic retinopathy.

SMILE for Hyperopia With and Without Astigmatism: Results of a Prospective Multicenter 12-Month Study

To investigate the safety and effectiveness of small incision lenticule extraction (SMILE) in patients who have hyperopia with or without astigmatism. This was a prospective multicenter trial including 374 eyes of 199 patients treated by SMILE for hyperopia using the VisuMax femtosecond laser (Carl Zeiss Meditec AG). Inclusion criteria were sphere up to +6.00 diopters (D), cylinder up to 5.00 D, and maximum hyperopic meridian up to +7.00 D, with preoperative corrected distance visual acuity (CDVA) of 20/25 or better. The optical zone was 6.3 mm with a transition zone of 2 mm. The minimum lenticule thickness was set at 25 µm in the center and at 10 µm at the edge. Patients were examined at 1 day, 1 week, and 1, 3, 6, 9, and 12 months after surgery. Standard refractive surgery outcomes analysis was performed. The preoperative spherical equivalent was +3.20 ± 1.48 D (range: +0.25 to +6.50 D). At the 12-month follow-up visit, 81% of eyes treated were within ±0.50 D and 93% of eyes were within ±1.00 D of intended correction. A total of 1.2% of eyes lost two or more lines of CDVA at the 12-month follow-up visit, and 83% were at least 20/20, corresponding to a safety index of 1.005 at 12 months. Of the 219 eyes with plano target, 68.8% had an uncorrected distance visual acuity of 20/20 or better and 88% were at least 20/25 uncorrected at 12 months. There were no statistically significant changes in contrast sensitivity. SMILE was found to be an effective treatment method for the correction of compound hyperopic astigmatism, demonstrating a high level of efficacy, predictability, safety, and stability. [J Refract Surg. 2022;38(12):760-769.].

КОНТРАСТНАЯ ЧУВСТВИТЕЛЬНОСТЬ И МИКРОДВИЖЕНИЯ ГЛАЗ КАК МАРКЕРЫ АДАПТАЦИИ И РЕАДАПТАЦИИ В МОДЕЛЬНОМ ЭКСПЕРИМЕНТЕ ПО ИЗУЧЕНИЮ ВЛИЯНИЯ ИЗМЕНЕНИЙ ГРАВИТАЦИИ

Visual perception plays a crucial role in providing the brain with the information it needs to make decisions, build a picture of the world, and adapt to changing environmental conditions. Under conditions of "dry" immersion, which simulates the effects of weightlessness on the human body, contrast sensitivity and tremor eye movements were studied under changing environmental conditions. The study involved 10 volunteers (mean age 30.8±4.6 years). The contrast sensitivity of the visual system was recorded using the method of visocontrastometry. We presented the Gabor elements with a spatial frequency: 0.4; 0.8; 1.0; 3.0; 6.0 and 10.0 cycle/deg. The parameters of eye micromovements, i.e., the amplitude and frequency of eye tremor oscillations, were recorded using an optical system providing high-frequency video recording. The measurements were carried out the day before immersion in the immersion bath, on days 1, 3, 5, and 7 of “dry” immersion, as well as the next day after its completion. A change in contrast sensitivity in the range of low and high spatial frequencies, as well as in the amplitude of eye micromovements, was established. The data obtained today are a new step in the search for methods for an objective assessment of the functional state under changing environmental conditions.

Analysis of Changes in High-order Aberration and Contrast Sensitivity After Epiblepharon Surgery.

To investigate changes in corneal anterior high-order aberration (HOA) and contrast sensitivity (CS) before and after epiblepharon surgery. A retrospective observational analysis of the degree of corneal erosion, HOAs and CS was conducted in the OD and OS, respectively, before and after epiblepharon surgery. The correlations between corneal erosion, HOAs, and CS were analyzed. Forty-nine patients were included in the study. Among the anterior HOAs, total HOA, coma, and trefoil showed significant improvement after surgery ( P = 0.003, P = 0.009, and P = 0.018, respectively). In the CS test, there was a significant improvement in CS after surgery at 1.1 cycles per degree (cpd) under photopic conditions, regardless of glare. Preoperative correlation analysis between HOAs and corneal erosion showed a significant positive correlation with total HOA ( P = 0.001) and coma ( P = 0.001). Preoperative correlation analysis between CS and corneal erosion showed a significant negative correlation at 1.1 cpd with glare under photopic conditions ( P = 0.049). A negative correlation was also observed between CS under mesopic and photopic conditions and total HOA both before and after surgery. Significant improvement in corneal anterior HOAs and CS at 1.1 cpd under photopic conditions was observed after epiblepharon surgery. Total HOA of anterior cornea showed a negative correlation with CS. A decrease in HOAs and recovery of corneal erosion after epiblepharon surgery will help improve CS.

Contrast Sensitivity Changes after Phototherapeutic Keratectomy in Heterozygote Granular Corneal Dystrophy Type 2

Purpose: Contrast sensitivity, the ability to distinguish the relative difference in luminance of an object from its surrounding or adjacent objects, is a useful measure of visual function. In granular corneal dystrophy type 2 (GCD2), opacity of the corneal stroma causes deterioration in visual function. We compared the contrast sensitivity of GCD2 patients before and after phototherapeutic keratectomy (PTK) to evaluate the perioperative visual function in these patients.Methods: This study included 22 eyes of heterozygote GCD2 patients. The visual acuity and contrast sensitivity were measured before and after PTK. The contrast sensitivity was measured in mesopic and photopic background luminances, with glare (G) levels of 0-2 (G0, G1, and G2, respectively) and spatial frequencies at 1.5, 3, 6, 12, and 18 cycles per degree (cpd).Results: The contrast sensitivity increased after PTK at 1.5 and 3 cpd in mesopic and photopic conditions with G0-2 glare (p &lt; 0.05). At 6 cpd, the contrast sensitivity increased in the mesopic condition with G1 glare, and in the photopic condition with G0-2 glare (p &lt; 0.05). However, there was no change in contrast sensitivity at any glare level at 12 and 18 cpd after PTK.Conclusions: In GCD2 patients, the contrast sensitivity increased significantly after PTK. The vision of GCD2 patients, which is decreased due to corneal opacity, is improved after PTK.

Assessing contrast sensitivity change in retinal diseases with use of yellow-amber NoIR glasses.

Purpose:The purpose of this study was to assess change of contrast sensitivity (CS) in subjects having retinal diseases with yellow-amber no infrared (NoIR) glasses used as low vision aid (LVA).Methods:We examined CS in 82 low vision (LV) subjects having retinal diseases with Pelli Robson Chart at 1 m distance before and after wearing yellow-amber NoIR glasses. We also found type of retinal affection and macular optical coherence tomography (OCT) features.Results:The distance and near best-corrected visual acuity (BCVA) was, respectively, 0.68 ± 0.17 (median = 0.70) and 0.72 ± 0.25 (median = 0.70) logmar units. The pre-LVA CS was 0.52 ± 0.29 (median = 0.3) and post- LVA was 0.52 ± 0.28 (median = 0.45) logunits (mean reduction = -0.002 ± 0.24; Median reduction = 0; P = 0.909). The pre-LVA and post-LVA CS showed a negative correlation with logmar distance BCVA [r = -0.090; P = 0.317 and r = -0.152; P = 0.090 respectively]. The pre-LVA and post-LVA CS showed a negative correlation with logmar near BCVA [r = -0.114; P = 0.207 and r = -0.054; P = 0.549 respectively]. The CS did not improve in subjects having macular degeneration, pathological myopia, hereditary maculopathy, and diabetic retinopathy. The macular OCT features like fluid, exudates, scars, drusens, traction, and hole did not significantly influence CS both at pre-LVA and post-LVA stage.Conclusion:This is the first study with yellow-amber NoIR glasses which blocks “both ultraviolet and infrared light.” The subjects having macular degeneration, pathological myopia, hereditary maculopathy, and diabetic retinopathy did not improve in CS with filters. The correlation values showed that filters may improve CS in subjects having good baseline BCVA.

Changes in contrast sensitivity after surgery for intermittent exotropia

To determine whether intermittent exotropia (IXT) surgery affects contrast sensitivity (CS), this retrospective study evaluated the changes in monocular and binocular CS and the binocular summation ratio (BSR) quantified as the ratio between the values of the binocular and the better monocular CS score (BSR = binocular CS score/better monocular CS score) after surgery for IXT. The subjects were patients who had undergone IXT-correcting surgery with a postoperative follow-up of > 3 months and had pre- and postoperative records of Mars CS test scores. In total, 64 patients (128 eyes) were evaluated. Both the binocular and monocular CS scores of the operated eyes were significantly worse on postoperative 1 day than the preoperative scores, but they were recovered after 1 week. The monocular CS scores of the operated eyes were significantly worse than those of the non-operated eyes until 1 week. There was no significant difference in monocular CS scores between the one-muscle and two-muscle surgeries and in binocular CS scores between the successful alignment and overcorrection groups even on the first day after surgery. The mean BSR was significantly decreased until postoperative month 1, however, recovered to preoperative levels after month 3. In conclusion, IXT-correcting surgery may temporarily worsen the CS, but it is recovered to preoperative levels. Thus, changes in CS in the immediate postoperative period after strabismus surgery should not be of concern.

Contrast Sensitivity Testing in Age-Related Macular Degeneration Using Motion Diamond Stimulus.

PurposeThis study was performed to characterize changes in contrast sensitivity (CS) that occur in patients with age-related macular degeneration (AMD) using a novel test, the motion diamond stimulus (MDS).MethodsThis was a cross-sectional study in which 20 subjects with unilateral exudative AMD (eAMD) and contralateral dry AMD received 3 assessments: the Pelli-Robson (PR) CS Chart, the MDS test, and a visual function questionnaire-25 (VFQ-25). CS results from the PR, and MDS tests were compared across 3 groups: eyes with eAMD vs dry AMD, eAMD vs control, dry AMD vs control. Healthy, undilated eyes from another study served as the control group. Significance was determined using ANOVA analysis for the MDS output parameters (α: overall contrast threshold, β: adaptability of the visual system) and PR logCS. Patients were also administered the VFQ-25 to assess vision-related quality of life.ResultsThe ANOVA of the MDS data demonstrated a significant difference in visual function according to the β parameter of the 3 groups, but no significant difference in the α parameter. PR CS results for the 3 groups were significantly different, further supporting the MDS results. Post-hoc analysis showed a significant difference in β and PR log CS between the eAMD and control eyes.ConclusionThe MDS test is valuable in discerning CS impairments in patients with AMD. It can provide further insight into the visual changes experienced by patients with AMD and has potential to quantify visual function changes that are not found on visual acuity testing alone.

Comparison of clinical outcomes between Wavelight Allegretto Eye-Q and Schwind Amaris 1050RS in high myopic astigmatism

Purposes: To compare clinical outcomes between Wavelight Allegretto Eye-Q 400Hz and Schwind Amaris 1050RS in high myopic astigmatism. Methods: non-randomized, controlled, interventional study of 90 eyes with at least 1.5diopter astigmatism, assigned into two groups depends to the L machine and followed up three months post-op. Primary outcomes include uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), subjective refraction spherical equivalent (SRSE), cylinder, safety and efficacy indices, refractive predictability and stability; and optical aberration and contrast sensitivity changes after surgery. Besides, Alpins method about residual astigmatism is also analyzed and compared between groups. Results: Safety index of Schwind Amaris and Allegretto group is 1.011 ± 0.169 and 1.007 ± 0.055 (p = 0.510); effective index is 1 ± 0.032 and 0.991 ± 0.077 (p = 0.567; stability index is 0.003 and 0.1 (p = 0.134); predictability index within [±0.5D] after three-month postop is 91.1% and 95.6% (p = 0.398), respectively. Post-op residual astigmatism in Schwind Amaris and Allegretto group is -0.139 ± 0.22 and -0.183 ± 0.27 (p = 0.396). Regarding Alpins method in astigmatic analysis of Schwind Amaris and Allegretto groups: SIA (surgically induced astigmatism) is 1.792 ± 0.534 and 1.920 ± 0.588 (p = 0.284); AE (angle of error) is 1.04 ± 2.881 and -0.08 ± 3.790 (p = 0.119); CI (correction index) is 0.98 ± 0.107 and 1.02 ± 0.142 (p = 0.165); SAS (Success of Astigmatism Surgery) is 92.01 ± 12.77 and 89.78 ± 16.32 (p = 0.472), respectively. Contrast sensitivity and higher optical aberration changes after surgery between two groups are insignificant differences (p &gt; 0.05). Conclusions: Clinical outcomes of both lasers machine are good. There is no significant differences in residual astigmatism and high-order aberrations or contrast sensitivity changes after surgery between two groups.

Evaluation of contrast sensitivity in non-high-risk proliferative diabetic retinopathy treated with panretinal photocoagulation with and without intravitreal injections of ranibizumab.

To evaluate contrast sensitivity in non-high-risk, treatment-naïve proliferative diabetic retinopathy patients treated with panretinal photocoagulation and intravitreal injections of ranibizumab) versus panretinal photocoagulation alone. Sixty eyes of 30 patients with bilateral proliferative diabetic retinopathy were randomized into two groups: one received panretinal photocoagulation and ranibizumab injections (study group), while the other received panretinal photocoagulation alone (control group). All eyes were treated with panretinal photocoagulation in three sessions according to the Early Treatment Diabetic Retinopathy Study guidelines. Contrast sensitivity measurements were performed under photopic conditions (85 cd/m2) with the Visual Contrast Test Sensitivity 6500 chart, allowing for the evaluation of five spatial frequencies with sine wave grating charts: 1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree (cpd). Outcomes were measured in contrast sensitivity threshold scores among and within groups, from baseline to 1, 3, and 6 months. Fifty-eight eyes (28 in the study group and 30 in the control group) reached the study endpoint. A comparative analysis of changes in contrast sensitivity between the groups showed significant differences mainly in low frequencies as follows: at month 1 in 1.5 cpd (p=0.001) and 3.0 cpd (p=0.04); at month 3 in 1.5 cpd (p=0.016), and at month 6 in 1.5 cpd (p=0.001) and 3.0 cpd (p=0.026) in favor of the study group. In eyes of patients with non-high-risk proliferative diabetic retinopathy, panretinal photocoagulation treatment with ranibizumab appears to cause less damage to contrast sensitivity compared with panretinal photocoagulation treatment alone. Thus, our evaluation of contrast sensitivity may support the use of ranabizumab as an adjuvant to panretinal photocoagulation for the treatment of proliferative diabetic retinopathy.