Contrast Sensitivity In Group Research Articles

Central contrast sensitivity perimetry discriminates between glaucomatous and non-glaucomatous eyes.

Glaucoma is an optic neuropathy which causes irreversible vision loss. Standard perimetry, which is essential for glaucoma diagnosis, can only detect glaucomatous visual filed loss when considerable structural damage has occurred. Contrast sensitivity is one of the visual function tests that is reduced in eyes with glaucoma. It is known to be affected in pre-perimetric stages of glaucoma. The objective of this study was to investigate the discriminating ability of central contrast sensitivity perimetry in eyes with and without glaucoma. The study employed a cross-sectional study design. The study participants were made of two groups; eyes diagnosed with glaucoma by an ophthalmologist based on visual field test and optical coherence tomography (OCT) and age- and sex-matched controls who were declared free from glaucoma. Static contrast sensitivity (CS) was measured in the central 10° of visual field using a custom psychophysical test. There were 45 eyes with glaucoma and 45 age- and sex-matched controls in this study. The static CS in the glaucoma group was significantly reduced in 9 out of the 13 tested locations in the central 10° of the visual field. The mean static CS at 5°, 10°, superior hemifield and inferior hemifield were all significantly reduced in the glaucoma patients compared to the controls. Static CS measurement is a sensitive approach that can be utilized to aid in the detection of glaucoma. The use of static CS can be adopted in the development of a cost-effective yet sensitive screening tool for the detection of glaucoma.

Evaluation value of subjective visual quality examination on surgical indications of the early cataracts based on objective scatter index values.

To evaluate the subjective visual functions of early cataracts patients and assess their surgical indications. Eyes were separated into a control group (Group A without cataract) and two early cataracts groups (Group B with 2.0 ≤ OSI < 3.0 and Group C with 3.0 ≤ OSI < 4.0). The objective scatter index (OSI), modulation transfer function cut-off frequency (MTF cut-off), and Strehl ratio (SR) values were applied to measure objective visual functions. The contrast sensitivity (CS) and scores of the questionnaires (QOL and VF-14) characterized subjective visual functions. Above visual functions were compared among three groups. Postoperative visual functions in Group B and C were analyzed to assess the outcome of surgery. Ninety two subjects (126 eyes) were included in the study. All objective visual function in Group B were significantly better than Group C (all P < 0.01), but worse than Group A (all P < 0.01). Except for 1.5 c/d CS, subjective visual function in Group A were significantly better than Group B and C (all P < 0.05), but there was no significant differences between Group B and C. As for eyes that underwent surgery in Group B and C, all visual functions significantly improved after surgery (P < 0.05), except for 1.5 c/d CS in Group C. There were no significant differences among the three groups after surgery. The subjective visual function can be impaired in early cataracts patients with OSI < 3.0, whose objective visual functions were statistically better than patients with OSI ≥ 3.0. These patients can benefit equally from surgery as patients with OSI ≥ 3.0. Subjective visual functions can be used as surgical indications for these patients.

Study of visual functions with multifocal versus monofocal intraocular lenses after phacoemulsification in patients with age-related cataract

Early visual rehabilitation and targeting emmetropia using small incisions and foldable IOLs is the main objective of modern cataract surgery, the so termed ‘refractive cataract surgery’. This current single-center prospective study assessed the clinical outcomes and thus patient satisfaction of multifocal IOLs over monofocal IOLs. To study visual functions with a refractive –diffractive type multifocal versus monofocal intraocular lenses after phacoemulsification in patients with age related cataract. 40 patients undergoing phacoemulsification for decreased vision due to age related cataract were randomly divided into 2 groups. Patients in group 1 underwent multifocal IOL [refractive –diffractive type] implantation and patients in group 2 underwent confocal IOL implantation. Postoperatively, patients were followed up for 90 days and assessed for unaided visual acuity for distance, intermediate and near vision, contrast sensitivity using Pelli-robson chart. At the end of the study, uncorrected visual acuity for distance (UDVA) was 6/9 in 65% patients in group 1 while 50% had uncorrected visual acuity of 6/9 in group 2. Uncorrected intermediate visual acuity (UIVA) in group 1 was N10 or better in 55% patients while in group 2, 75% patients had N24. Uncorrected near visual acuity (UNVA) in group 1 was N6 in 35% patients and N8 in 35% while in group 2, 75% patients had N18 vision, A paramount statistical difference was seen in the two groups.(p=0.001). The mean contrast sensitivity in group 1 was 2.04+/-0.23 and group 2 was 2.20+/-0.07(although statistically significant but within normal limits). None of the patients in any group had any significant complaint of glare or haloes. Mutifocal IOLs decrease the spectacle dependence of patients without compromising the subjective visual functions

Comparison of the visual quality at 1 year following femtosecond laser-assisted LASIK, wavefront-guided femtosecond LASIK and small incision lenticule extraction for myopia and astigmatism

Objective: To investigate mesopic contrast sensitivity (CS) and high-order aberrations after femtosecond laser-assisted LASIK (FS-LASIK), wavefront-guided femtosecond LASIK (WF-LASIK) and small incision lenticule extraction (SMILE) for myopia and astigmatism. Methods: In this case-control study, 212 eyes of 108 patients with myopia and astigmatism from September 2014 to September 2016 were treated by refractive surgery. There were 34 males (66 eyes) and 74 females (146 = eyes), aged 27 (24, 32) years. They were divided into 3 groups, with 37 patients (71 eyes), 35 patients (69 eyes) and 36 patients (72 eyes) treated by FS-LASIK, WF-LASIK and SMILE, respectively. Refraction diopters, corneal tomography, wavefront aberrations and contrast sensitivity were evaluated before and at 12 months after surgery. The results of different groups were compared by rank sum test. Results: At 12 = months of follow-up, 69 eyes (97.18%) treated by FS-LASIK, 67 eyes (97.10%) by WF-LASIK and 69 eyes (95.83%) by SMILE had the uncorrected distance visual acuity of 20/20 or better. Fifty-nine eyes (83.10%) treated by FS-LASIK, 60 eyes (86.96%) by WF-LASIK and 61 eyes (84.72%) by SMILE had better postoperative uncorrected distance visual acuity than preoperative corrected distance visual acuity. Surface regularity index of the WF-LASIK group decreased from 0.11 (0.07, 0.28) to 0.07 (0.06, 0.20) (Z=-2.662, P=0.008), which was less than that of the FS-LASIK and SMILE groups (Z=-3.236, -3.118, P=0.001, 0.000). Surface asymmetry index of the WF-LASIK group increased from 0.34 (0.25, 0.43) to 0.38 (0.30, 0.52) (Z=-2.140, P=0.032), which was less than that of the FS-LASIK and SMILE groups (Z=-2.910, -3.779, P=0.004, 0.000). The root mean square of high-order of the FS-LASIK group increased from 0.32 (0.27, 0.41) to 0.53 (0.40, 0.65) (Z=-6.228, P=0.000), which was more than that of the WF-LASIK and SMILE groups (Z=-3.595, -4.806, P=0.000, 0.000). Coma of the WF-LASIK group increased from 0.16 (0.11, 0.24) to 0.26 (0.15, 0.37) (Z=-3.816, P=0.000), which was less than that of the FS-LASIK group (Z=-3.528, P=0.000). Spherical aberration of the FS-LASIK and WF-LASIK groups increased from 0.10 (0.05, 0.21) and 0.08 (0.04, 0.12) to 0.24 (0.13, 0.34) and 0.15 (0.09, 0.26), respectively (Z=-5.141, -4.864, P=0.000, 0.000), which were more than that of the SMILE group (Z=-2.549, -4.682, P=0.011, 0.000). CS of the WF-LASIK group at 12 cycles per degree (c/d) increased from 1.34 (1.18, 1.48) to 1.48 (1.34, 1.63) (Z=-2.985, P=0.003), which was more than that of the FS-LASIK and SMILE groups (Z=-3.194, -2.977, P=0.001, 0.003). CS with glare of the WF-LASIK group at 12.0 c/d increased from 1.26 (1.18, 1.34) to 1.34 (1.34, 1.63) (Z=-3.608, P=0.000), which was more than that of the FS-LASIK and SMILE groups (Z=-4.033, -2.913, P=0.000, 0.004). Conclusions: FS-LASIK, WF-LASIK and SMILE achieved ideal visual outcomes at 12 months postoperatively. WF-LASIK treated eyes showed the best corneal symmetry, the least increase of high-order aberrations and the best visual quality among three kinds of surgeries. (Chin J Ophthalmol, 2020, 56: 118-125).

Induced glare testing — an underutilized test in evaluating visual disability in patients presenting with symptomatic cataracts

Background: Cataract increases intraocular light scatter which affects the retinal image contrast and sensitivity. Symptomatic patients with cataract complain of a drop in the quality of vision or glare affecting daily routine even with preserved visual acuity. This study was aimed to quantify the drop in the glare induced visual acuity (VA) and contrast sensitivity (CS) in different morphological types of cataracts. Material and methods: This was an observational study on a prospective cohort, conducted at a tertiary-care centre in South-India. Patients admitted for cataract surgeries between March and September 2017 with BCVA ≥ 6/60 (Snellen) and ≥ 40 years were enrolled. LogMAR VA and CS were measured pre and post-operatively, with and without glare induction using brightness acuity tester. Patients were sub-categorised based on morphology and the presence of glare as a symptom. Paired-t test for the pre- and post-operative values and analysis with Bonferroni’s adjustment were the statistical methods used. Results: Data of 78 patients were sub-categorised and analysed. Glare induction with high glare was significant in all the studied groups. LogMAR VA was affected most in group 3 (0.20, 10 letters, p < 0.05) and the CS in group 2 (0.62, 4.1 step drop, p < 0.05). Patients who had glare as a symptom had an average greater drop in LogMAR VA (0.30, p = 0.01) and CS (–0.29, p = 0.03) when induced with a high glare. Conclusions: All morphological types of cataracts affect VA and CS to a greater extent in conditions of bright lighting. Glare induced VA and CS testing is a sensitive and an adjunct tool to traditional high contrast VA testing, in evaluating the visual dysfunction of patients presenting with symptomatic cataracts.

CONTRAST SENSITIVITY AND HIGH ORDER ABERRATIONS AFTER FEMTOSECOND LASIK AND IMPLANTABLE COLLAMER LENSES IN CORRECTION OF HIGH MYOPIA

Purpose: To compare visual quality (UCVA, BCVA, and contrast sensitivity) and optical quality (Highorder aberrations) of Femtosecond assisted LASIK and implantable collamer lens implantationin correction of high myopia. Methods: This study was non-randomized comparative prospectiveconsecutive interventional study. It included 31 eyes with high myopia (≥ -6 Ds) of 21 patientsattended to the outpatient ophthalmic clinic of Sohag university hospitals from the period fromJan.2016 to Jan.2017. The patients were divided into two groups depending on: Degree of myopia,corneal thickness and corneal tomography. Group A (14 eyes) of 12 patients were subjected toimplantable collamer lenses implantation and Group B (17 eyes) of 9 patients were subjected tofemtosecond assisted LASIK. Results: Postoperative data in both groups was, in Group A (ICLgroup) showed UCVA was (0.188±0.123) and UCVA of Group B (Femtosecond assisted LASIK)was (0.105±0.06) with (p-value <0.133). BCVA of Group one (ICL) was (0.171±0.114) and thatof Group two was (0.105±0.04) with (p-value <0.174). Spherical error in Group A was (0.321±0,590) and that of Group B (-0.75±0.31) postoperative with (p-value <0.001*). Cylindrical errorwas (-0.392±0.318) and Group two was (-0.750±0.204) with (p-value <0.00*). Spherical equivalent inGroup A was (-0.00±0.433) and that of Group B was (-1.12±0.748) with (p-value <0.004*). Contrastsensitivity of Group A was (132.57±39.99) and that of Group B (102.857±23.688), with (p-value<0.075). There wasnit significant difference in RMS Group A (0.770±0.21) and that of Group B(1.15±0.53) with (p-value <0.22). There was significant difference in mean values of sphericalaberrations of Group A (-0.13±0.9123), Group B (0.781±0.406) with (p-value <0.001*) , coma ofGroup A (0.131±0.0649), Group B (0.4600±0.2075) with (p-value <0.011*) and trefoil high orderaberrations of Group A (-0.151±0.09), Group B (0.282±0.11) with (p-value <0.03* . Conclusion:Both implantable collamer lens and femtosecond assisted LASIK proved good visual qualityregarding visual acuity and contrast sensitivity in photopic conditions. For optical quality bothinduced high order aberrations which were more in Femtosecond assisted group.

Macular Inner Retinal Layer Thickness in Relation to Photopic and Mesopic Contrast Sensitivity in Healthy Young and Older Subjects.

To examine relationships between the thicknesses of ganglion cell (GC)-related macular layers and central photopic or mesopic contrast sensitivity (CS) in healthy eyes. Measurements were made in 38 young and 38 older healthy individuals. Total, inner, and outer retinal layer (IRL) thicknesses were measured in the macula region through spectral-domain optical coherence tomography (SD-OCT) across three subfields, or rings, centered at the fovea: central foveal, pericentral, and peripheral. Ganglion cell complex and circumpapillary retinal nerve fiber layer thicknesses were also measured. Low-spatial-frequency CS for gratings presented at the central 10° visual field were measured through computerized psychophysical tests under photopic and mesopic conditions. Relationships were examined by uni- and multivariate regression analysis. Peripheral IRL thickness emerged as the only independent predictor of photopic CS (P = 0.001) in the young group and of photopic (P = 0.026) and mesopic CS (P = 0.001) in the older group. The slopes of regression lines used to predict CS from peripheral IRL thickness were significantly different for pair-wise comparisons of both photopic CS and age group (P = 0.0001) and mesopic CS (P = 0.0001) and age group. These models explained 37% of the variability in photopic CS and 36% of the variability in mesopic CS. Macular IRL thinning likely due to GC loss was related to reduced photopic and mesopic CS in older healthy eyes. In contrast, in the young eyes, a thicker macular IRL, possibly indicating transient gliosis, was associated with reduced CS.

The contrast sensitivity of different decentration values after implantation of multifocal intraocular lens

Objective To compare the contrast sensitivity of different decentration values after implantation of multifocal intraocular lens (IOL)in eyes. Methods Twenty-two patients (32 eyes)received phacoemulsification cataract extraction and implantation of multifocal IOL and the decentration values of IOLs and the contrast sensitivity were recorded at 1 week, 1 month and 6 months after the surgery. According to the different decentration, they were divided into group A( 0.6 mm). Then, the law of contrast sensitivity changes among three groups were compared. Results At 1 week, 1 month and 6 months, there were not statistically significant differences in the contrast sensitivity at 1.5cpd, 3.0cpd and 6.0cpd spatial frequency between group A and group B(P>0.05). However, the contrast sensitivity of group C decreased obviously and the difference was statistically significant(P 0.05). Conclusion Decentration after multifocal IOL implantation would influence the postoperative contrast sensitivity in varying degrees. Key words: Lens, intraocular, multifocal; Decentration; Contrast sensitivity

Postoperative ocular higher-order aberrations and contrast sensitivity: Femtosecond lenticule extraction versus pseudo small-incision lenticule extraction

To evaluate and compare changes in contrast sensitivity and ocular higher-order aberrations (HOAs) after femtosecond lenticule extraction (FLEx) and pseudo small-incision lenticule extraction (SMILE). Singapore National Eye Centre, Singapore. Retrospective case series. Patients had femtosecond lenticule extraction (Group 1) or pseudo small-incision lenticule extraction (Group 2) between March 2010 and December 2011. The main outcome measures were manifest refraction, HOAs, and contrast sensitivity 1, 3, 6, and 12months postoperatively. Fifty-two consecutive patients (102 eyes) were recruited, 21 patients (42 eyes) in Group 1 and the 31 patients (60 eyes) in Group 2. The uncorrected and corrected distance visual acuities were significantly better in Group 2 than in Group 1 at 12months (P = .032). There was no significant increase in 3rd- or 4th-order aberrations at 1year and no significant difference between the 2 groups preoperatively or postoperatively. At 1year, there was a significant increase in mesopic contrast sensitivity in Group 2 at 1.5 cycles per degree (cpd) (P = .008) that was not found in Group 1, and photopic contrast sensitivity at 6.0 cpd was higher in Group 2 (P = .027). These results indicate that refractive lenticule extraction is safe and effective with no significant induction of HOAs or deterioration in contrast sensitivity at 1year. Induction of HOAs was not significantly different between both variants of refractive lenticule extraction. However, there was significant improvement in photopic contrast sensitivity after pseudo small-incision lenticule extraction, which persisted through 1year. No author has a financial or proprietary interest in any material or method mentioned.

Visual and optical performances of multifocal intraocular lenses with three different near additions: 6-month follow-up.

Purpose : To compare the visual and optical outcomes of four multifocal intraocular lenses (IOLs) with three different near additions of +3.00 diopters (D), +3.75 D and +4.00 D.Methods : In this prospective study, 133 eyes of 88 patients were implanted with one of the following IOLs: AcrySof® ReSTOR® SN6AD1 (+3.00 D) for Group A, AcrivaUD Reviol BB MF 613 or BB MFM 611 (+3.75 D) for Group B, and AcrySof® ReSTOR® SN6AD3 (+4.00 D) for Group C. The visual acuity, refraction, intraocular pressure, tomography and corneal endothelial cell density (ECD) were compared between the three groups preoperatively and at 6 month postoperatively. Defocus curve, contrast sensitivity and higher order aberrations (HOAs) at 6 month postoperative visit were measured and compared.Results : There were no statistically significant differences in distance visual acuity, refraction, intraocular pressure or ECD among the three groups after 6 months (P > 0.05). The photopic contrast sensitivity in Group C was statistically better than in Group A (P < 0.05). The scotopic ocular aberration in Group B was statistically greater compared to that in Group A (P < 0.05). The highest near-visual peaks were -0.06 logMAR at a -2.50 D (40 cm) in Group A, -0.07 logMAR at -3.00D (33 cm) in Group B, and -0.06 logMAR at -3.50 D (29 cm) in Group C. Statistically significant differences in near and intermediate visual acuities were observed among the three groups at -2.00 D (50 cm), -2.50 D (40 cm), -3.50 D (29 cm) and -4.00 D (25 cm) (P < 0.01).Conclusion : AcrySof® ReSTOR® SN6AD1 IOLs (+3.00 D) and SN6AD3 (+4.00 D) IOLs provided the best intermediate and near vision, respectively. Both intermediate and near vision were comparatively better in the eyes with AcrivaUD Reviol BB MFM 611 IOLs or BB MF 613 IOLs (+3.75 D).

Contrast sensitivity in relapsing-remitting multiple sclerosis assessed by sine-wave gratings and angular frequency stimuli.

Previous studies have shown that multiple sclerosis (MS) affects the visual system, mainly by reducing contrast sensitivity (CS), a function that can be assessed by measuring contrast sensitivity function (CSF). To this end, we measured both the CSF for sine-wave gratings and angular frequency stimuli with 20 participants aged between 21 and 44 years, of both genders, with normal or corrected to normal visual acuity. Of these 20 participants, there were 10 volunteers with clinically defined MS of the relapsing-remitting clinical form, with no history of optic neuritis (ON), as well as 10 healthy volunteers who served as the control group (CG). We used a forced-choice detection paradigm. The results showed reduced CS to both classes of stimuli. Differences were found for sine-wave gratings at spatial frequencies of 0.5, 1.25, and 2.5 cycles per degree (cpd) (P < 0.002) and for angular frequency stimuli of 4, 24, and 48 cycles/360° (P < 0.05). On the one hand, comparing the maxima of the respective CSFs, the CS to angular frequency stimuli (24 cycles/360°) was 1.61-fold higher than that of the CS to vertical sine-wave gratings (4.0 cpd) in the CG; for the MS group, these values were 1.55-fold higher. On the other hand, CS in the MS group attained only 75% for 24 cycles/360° and 78% for 4.0 cpd of the 100% CS estimates found for the CG at the peak frequencies. These findings suggest that MS affects the visual system, mostly at its maximum contrast sensitivities. Also, since angular frequencies and sine-wave gratings operate at distinct levels of contrast in the visual system, MS seems to affect CS at both high and low levels of contrast.

Mesopic Visual Contrast Sensitivity in Patients with Major Depression

The present study evaluated the effects of major depression on visual contrast sensitivity (CS) at low mesopic luminance (.7 cd/m2 mean luminance), a condition that has been little explored in the literature. We measured spatial visual CS in 20 male volunteers aged 20 - 30 years, including 10 healthy individuals and 10 medicated individuals with major depression, to linear sine-wave gratings of .25, 1.0, and 4.0 cycles per degree (cpd) of visual angle using the psychophysical staircase method with forced choice. The average spatial visual CS in the depressed group was approximately 1.7 lower than the average spatial visual CS in the control group. However, the post hoc test showed significant differences only at the spatial frequencies of .25 and 1.0 cpd (p

Quality of life evaluation after implantation of 2 multifocal intraocular lens models and a monofocal model

To compare vision-related quality of life using the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) in patients with 1 of 3 types of intraocular lenses (IOLs) and to correlate it with postoperative visual outcomes. Vissum Corporation-Instituto Oftalmológico de Alicante, Alicante, Spain. Comparative case series. This study comprised eyes having cataract surgery with bilateral implantation of a monofocal IOL (Group A), apodized multifocal IOL (Group B), or full diffractive multifocal IOL (Group C). Distance and near visual acuities, contrast sensitivity, and quality of life were evaluated preoperatively and postoperatively. The study enrolled 106 eyes (53 patients; age range 49 to 80 years). All groups had significant improvement in uncorrected and corrected distance visual acuities postoperatively (P ≤.05). Near vision outcomes were significantly better in Groups B and C (P ≤.01). Groups B and C had significantly less difficulty in some near tasks, such as reading the newspaper (A-B, P=.02; A-C, P=.02) or reading bills (A-B, P=.04; A-C, P=.004). Group C also had significantly less difficulty driving at night than Group B (P<.01). Near visual acuity and contrast sensitivity were significantly correlated with difficulty in near visual tasks in Groups B and C. Night-driving difficulty correlated significantly with contrast sensitivity in Group B. Patients with multifocal IOLs could perform several daily tasks at near and intermediate distances, with less night-driving limitation with the full diffractive IOL than with apodized multifocal and monofocal IOLs. No author has a financial or proprietary interest in any material or method mentioned.

Pupil cycle time and contrast sensitivity in type II diabetes mellitus patients: A pilot study

Context:Pupil cycle time (PCT) has been widely used for examination of ocular diabetic autonomic neuropathy (DAN).Aims:The primary aim of this study was to evaluate the difference of contrast sensitivity according to PCT results, and the secondary aim was to determine the factors associated with PCT difference for type II diabetes patients.Settings and Design:A clinical pilot study that included a total of 60 eyes of 60 type II diabetes patients.Materials and Methods:We divided all patients into three groups according to PCT results. Group A and Group C were composed of patients who had upper one third PCT and lower one third PCT, respectively. We analyzed difference of age, diabetes duration, hypertension duration, mean best corrected visual acuity (BCVA), mean spherical equivalent (SE), HbA1C, glomerular filtration rate (GFR), stage of diabetic retinopathy, and Cardiac Autonomic Function Score (CAFS). Contrast sensitivity and decrease of visual acuity by glare were also estimated and analyzed for 28 eyes of 28 non-proliferative diabetic retinopathy (NPDR) patients. Group [NPDR] A and Group [NPDR] C were defined as those who had lower one third PCT and upper one third PCT, respectively.Statistical Analysis:Statistical analysis was done using SPSS 17.0 software.Results and Conclusions:Each group contained 20 eyes. Significant differences between Group A and Group C were observed in duration of diabetes and CAFS (P ≤ 0.001 and P <0.001, respectively). Contrast sensitivity in Group [NPDR] A was significantly more than in Group [NPDR] C at all cpds (all P ≤ 0.001). We found that PCT can influence contrast sensitivity or glare in diabetes patients and also confirmed a significant correlation of PCT with CAFS and duration of diabetes.

Relationship between macular pigment and mesopic visual function in early age‐related maculopathy

Abstract Purpose Psychophysical studies have demonstrated that several parameters of visual function deteriorate in the early stages of age‐related maculopathy (ARM). This study was performed to analyze whether the variability in high (HC) and low (LC) ‐contrast visual acuity (VA) and contrast sensitivity (CS) at mesopic light level is attributable to differences in macular pigment optical density (MPOD) in early ARM patients. Methods Measurements were obtained from 40 eyes of adults (65 ± 7 years) with early ARM and 34 age‐matched healthy control eyes (67 ± 6 years). MPOD was estimated at the fovea using the Metropsis Test (Cambridge Research System). Visual acuity (VA) was measured with the best spectacle correction using high‐contrast (96%) and low‐contrast (10%) logMAR letter charts under mesopic luminance conditions (0.1 to 0.2 cd/m2). Mesopic contrast sensitivity (CS) was determined using the Pelli‐Robson chart. Results Foveal MPOD was 0.25 ± 0.14 in eyes without ARM and 0.29 ± 0.22 in eyes with early ARM. Mean mesopic high and low contrast logMAR VA and log CS were significantly worse in the ARM group than in the control group. There was no significant relationship between high HC‐VA and MPOD, LC‐VA and MPOD and between log CS and MPOD in both early ARM and control group. Conclusion No differences in MP optical density were found between eyes with and without early ARM. Mesopic visual function was unrelated to foveal macular pigment optical density in early age‐related maculopathy.

Comparison of Higher-Order Aberration and Contrast Sensitivity in Monofocal and Multifocal Intraocular Lenses

PurposeThe visual performance of pseudophakic eyes depends on the type of intraocular lenses (IOLs) that are implanted. Aspherical and multifocal IOLs have recently been developed to improve visual quality after cataract surgery, but multifocal IOLs can be associated with decreased contrast sensitivity (CS), halos, and glare. This study compares the visual performance of monofocal and multifocal IOLs by measurement of higher-order aberrations (HOAs) and CS values.Materials and MethodsHOAs and CS values of 42 eyes with implanted monofocal IOLs and 40 eyes with implanted multifocal IOLs were measured preoperatively and more than 6 months after surgery. In the multifocal IOL group, HOAs and CS values were also measured with addition of a trial lens of -0.5 diopter (D) to evaluate the compensatory effect on spherical aberration.ResultsCS values of the multifocal IOL group were significantly lower than those of the monofocal IOL group for all spatial frequencies tested (p < 0.01), and the spherical aberration was significantly higher in the multifocal IOL group than in the monofocal IOL group (p < 0.001). Addition of a -0.5 D lens to the multifocal IOL group decreased the difference in CS between the two groups (p = 0.003). ConclusionIncreased spherical aberration may contribute to lower CS in the multifocal IOL group. In such cases, CS can be improved by addition of a -0.5 D lens to compensate for the spherical aberration.

Relationship between optokinetic nystagmus response and recognition visual acuity

The aim of this study was to investigate the relation between recognition visual acuity (RVA) and optokinetic nystagmus (OKN) response exhibited to different bar sizes with varying contrast. OKN testing was performed in 52 children aged between 3 and 11 years. The children were evaluated in two groups according to their RVA. Group I consisted of 22 eyes with RVA equal to or better than 0.1 logMAR units. Group II consisted of 30 eyes with RVA 0.2-1 logMAR units. Each subject was seated 60 cm from the screen of Ophthimus device, and was exposed to consecutive black and white stripes of seven different spatial frequencies (0.08-1.6 cycle/degree). The narrowest bar that elicited OKN was identified, and then the OKN contrast threshold at this bar size was established. Twenty-one of the 22 eyes in Group I, and 26 of the 30 eyes in Group II exhibited 1.6 cycle/degree spatial frequency (P=0.287). In Group II, 88.9% of the 18 eyes with RVA 0.2-0.5 logMAR responded at this maximum spatial frequency, whereas the corresponding figure for the 12 eyes with RVA 0.6-1 logMAR was 83.3% (P=0.531). Contrast sensitivity (CS) significantly changed with age in Group I (P=0.006). When the eyes that responded at maximum spatial frequency in the two groups were compared, the mean CS in Group II was significantly lower than that in Group I (P=0.005). The results indicate no relation between spatial frequency threshold for OKN response and RVA in children. However, the children with RVA deficits had significantly lower CS.

Comparative evaluation of diode laser versus argon laser photocoagulation in patients with central serous retinopathy: A pilot, randomized controlled trial [ISRCTN84128484

BackgroundTo evaluate the efficacy of diode laser photocoagulation in patients with central serous retinopathy (CSR) and to compare it with the effects of argon green laser.MethodsThirty patients with type 1 unilateral CSR were enrolled and evaluated on parameters like best corrected visual acuity (BCVA), direct and indirect ophthalmoscopy, amsler grid for recording scotoma and metamorphopsia, contrast sensitivity using Cambridge low contrast gratings and fluorescein angiography to determine the site of leakage.Patients were randomly assigned into 2 groups according to the statistical random table using sequence generation. In Group 1 (n = 15), diode laser (810 nm) photocoagulation was performed at the site of leakage while in Group 2 (n = 15), eyes were treated with argon green laser (514 nm) using the same laser parameters. Patients were followed up at 4, 8 and 12 weeks after laser.ResultsThe mean BCVA in group 1 improved from a pre-laser decimal value of 0.29 ± 0.14 to 0.84 ± 0.23 at 4 weeks and 1.06 ± 0.09 at 12 weeks following laser. In group 2, the same improved from 0.32 ± 0.16 to 0.67 ± 0.18 at 4 weeks and 0.98 ± 0.14 at 12 weeks following laser. The improvement in BCVA was significantly better in group 1 (p < 0.0001) at 4 weeks. At 4 weeks following laser, all the patients in group1 were free of scotoma while 6 patients in group 2 had residual scotoma (p < 0.05). The mean contrast sensitivity in group 1 improved from pre-laser value of 98.4 ± 24.77 to 231.33 ± 48.97 at 4 weeks and 306.00 ± 46.57 at 12 weeks following laser. In group 2, the same improved from 130.66 ± 31.95 to 190.66 ± 23.44 at 4 weeks and 215.33 ± 23.25 at 12 weeks. On comparative evaluation, a significantly better (p < 0.001) improvement was noted in group 1.ConclusionDiode laser may be a better alternative to argon green laser whenever laser treatment becomes indicated in patients with central serous retinopathy in terms of faster visual rehabilitation and better contrast sensitivity. In addition, diode laser also has the well-recognized ergonomic and economic advantages.

Visual performance with multifocal intraocular lenses: Mesopic contrast sensitivity under distance and near conditions

Objective To evaluate distance and near visual performance under bright (photopic) and dim (mesopic) conditions in patients who had undergone uncomplicated cataract extraction with multifocal or monofocal intraocular lens (IOL) implantation. Design Prospective, nonrandomized, masked, comparative, observational case series. Participants Thirty-two eyes of 32 patients after zonal-progressive multifocal IOL implantation (Allergan Medical Optics Array SA-40N) and 32 eyes of 32 age-matched patients after monofocal IOL implantation (Allergan Medical Optics SI-40NB). Intervention All eyes underwent phacoemulsification and IOL implantation. Main outcome measures At 18 months after surgery, the monocular contrast sensitivity (CS) function was measured with sinusoidal grating charts at distance and near, at one photopic luminance level and 2 mesopic luminance levels (85, 5, and 2.5 candelas per square meter). Results Under bright conditions, CS at distance in the multifocal group was not statistically different ( P>0.01) from that in the monofocal group at any tested grating spatial frequency (1.5, 3, 6, 12, and 18 cycles per degree [cpd]). At low luminances, distance CS for the multifocal group was worse than that for the monofocal group at the highest test spatial frequencies (12 and 18 cpd; P<0.01). At near, photopic CS in the multifocal group was lower than at distance; patients with only a monofocal distance correction, however, could not detect the test gratings, even at the highest available contrast. With optimal near spectacle additions (i.e., using the distance correction of the multifocal IOL), there were no significant differences between the photopic near CS values for the multifocal and monofocal groups. When the luminance was decreased, near CS at all spatial frequencies was reduced in both groups. Contrast sensitivity in the near-corrected, multifocal group was significantly worse than in the near-corrected, monofocal group at high spatial frequencies (12 and 18 cpd). Conclusions This work supports the findings of earlier authors that the Array multifocal IOL, with its center-distance design, is distance biased. Distance CS is within normal limits under bright photopic conditions but shows deficits at higher spatial frequencies (more than approximately 12 cpd) under dim mesopic conditions. Near CS obtained with the multifocal IOL is below that which can be achieved by an appropriate monofocal near correction, for all spatial frequencies and illumination conditions.

Levodopa-carbidopa with occlusion in older children with amblyopia

Purpose: To study the role of levodopa-carbidopa in supplementing occlusion therapy in older children with strabismic or anisometropic amblyopia. Methods: A clinical study was performed on 40 amblyopic children (19 strabismic and 21 anisometropic), 6 to 18 years old (mean age, 10.9 years). They received an average dose of 1.86 mg/kg/day (1.33-2.36 mg/kg/day) of levodopa and carbidopa (4:1 ratio) or a placebo in 3 divided doses over a 4-week period, combined with full-time occlusion. The occlusion was continued for the study duration of 3 months. Early Treatment Diabetic Retinopathy Study visual acuity charts and Cambridge low-contrast gratings for contrast sensitivity (CS) were used to assess visual functions. Tolerance and compliance with occlusion and capsule consumption were assessed. Results: Visual acuity of the nonamblyopic eye did not deteriorate during the study in either group. CS decreased by 22 units in the levodopa group and increased in the placebo group by 53 units at the first month. The CS in the levodopa group recovered later by the third month of follow-up. Both the levodopa and the placebo groups showed significant improvement in visual function in the amblyopic eye (P <.001). Overall changes in logarithm of minimum angle of resolutionvalues and CS in the amblyopic eyes were similar in both groups (P >.05). Strabismic and anisometropic amblyopes did not behave differently. Drug tolerance, occlusion compliance, and capsule ingestion compliance were similar between the groups, with no significant side effects. Conclusions: Clinically, levodopa supplementation does not offer any advantage over occlusion alone. Moreover, the risk of occlusion amblyopia could increase with the use of drugs like levodopa that might affect the plasticity of the visual cortex. (J AAPOS 2002;6:368-72)