Anisometropic Amblyopic Patients Research Articles

Macular thickness in unilateral amblyopia as measured by optical coherence tomography: a meta analysis

To offer a clue for the etiology of amblyopia by systematically comparing the macular thickness measured by optical coherence tomography (OCT) between the amblyopic eye and the fellow normal eye in patients with unilateral amblyopia. Databases including Wanfang, PubMed and others were searched, and data were extracted after quality assessment, then the Meta analysis was performed by the RevMan 5.02 software. Four studies using the time-domain OCT (TD-OCT) were enrolled in the analysis and all those were anisometropic amblyopic patients. The only one study showed that the foveal minimum thickness is thicker in the amblyopic eyes than the fellow ones (P = 0.045). The meta analysis indicated the amblyopic eyes were 6.82 µm (P < 0.05, 95% CI: 2.81-10.83) thicker in the fovea (1 mm diameter region ). Five trials using the spectral-domain OCT (SD-OCT) were included in the analysis. It showed no significant difference in the foveal minimum thickness between amblyopic and fellow eyes. Also, no significant difference were detected in either anisometropic or strabismic subgroup (P = 0.50). Amblyopic eyes were 7.38 µm thicker in the fovea (1 mm diameter region) (P < 0.05, 95% CI: 3.13 -11.63) and significant difference in the anisometropic subgroup while no significant difference in the strabismic subgroup were detected. The macular fovea is thicker in the amblyopic eyes than the fellow ones by the use of OCT, so it is effective to measure the macular thickness of amblyopia in searching evidence for the etiology of amblyopia.

The Relationship between Higher-order Aberrations and Amblyopia Treatment in Hyperopic Anisometropic Amblyopia

PurposeTo investigate the relationship between higher-order aberrations (HOAs) and amblyopia treatment in children with hyperopic anisometropic amblyopia.MethodsThe medical records of hyperopic amblyopia patients with both spherical anisometropia of 1.00 diopter (D) or more and astigmatic anisometropia of less than 1.00 D were reviewed retrospectively. Based on the results of the amblyopia treatment, patients were divided into two groups: treatment successes and failures. Using the degree of spherical anisometropia, subjects were categorized into mild, moderate, or severe groups. Ocular, corneal, and internal HOAs were measured using a KR-1W aberrometer at the initial visit, and at 3-month, 6-month, and 12-month follow-ups.ResultsThe results of the 45 (21 males and 24 females) hyperopic anisometropic amblyopia patients who completed the 12-month follow-up examinations were analyzed. The mean patient age at the initial visit was 70.3 months. In total, 28 patients (62.2%) had successful amblyopia treatments and 17 patients (37.8%) failed treatment after 12 months. Among the patient population, 24 (53.3%) had mild hyperopic anisometropia and 21 (46.7%) had moderate hyperopic anisometropia. When comparing the two groups (i.e., the success and failure groups), ocular spherical aberrations and internal spherical aberrations in the amblyopic eyes were significantly higher in the failure group at every follow-up point. There were no significant differences in any of the HOAs between mild and moderate cases of hyperopic anisometropia at any follow-up. When the amblyopic and fellow eyes were compared between the groups there were no significant differences in any of the HOAs.ConclusionsHOAs, particularly ocular spherical aberrations and internal spherical aberrations, should be considered as reasons for failed amblyopia treatment.

Study of the visual deficits pattern in strabismic and anisometropic amblyopia

To elucidate the difference in the pathogenesis between strabismic and anisometropic amblyopia. It was a case-control study.We used psychophysical methods, including grating acuity, edge contrast sensitivity, contrast sensitivity function tests, and examined the visual functions of 150 cases from 8 to 40-year-old. Then we applied the Origin 8.0 software for statistical analysis of experimental data, we did the correlation analysis between the grating acuity, edge contrast sensitivity and optotype acuity, and the similarity comparison of the contrast sensitivity function curve between the strabismic and anisometropic amblyopia. The grating acuity had a strong correlation with optotype acuity, the correlation value was 0.81. The grating acuity of the strabismic group was roughly 15% lower than the whole abnormal population, for any given level of optotype acuity; the edge contrast threshold had a weak correlation with optotype acuity, the correlation value was 0.24. Anisometropia, for a given level of optotype acuity, had edge contrast thresholds that were 15% higher (worse) than the whole population, while strabismic and strabismic-anisometropia had edge contrast thresholds that are 17% lower (better) than the whole population. The CSF of all amblyopic eyes were reduced in comparison with the non-amblyopic eye of the same person, the peak sensitivity shifted toward to the low spatial frequency region, the CS curve was depressed especially in the middle and high spatial frequencies, there were no significant difference, but at low frequency area(1.0 c/d) there were statistically significant between the two types of amblyopia(t = 2.239, P < 0.05). There were differences in the patterns of visual loss between strabismic and anisometropic amblyopic patients.

The visual outcome of anisometropic amblyopia after laser-assisted in-situ keratomileusis surgery

PurposeTo evaluate the visual outcomes of patients with anisometropic amblyopia after laser in-situ keratomileusis (LASIK) surgery.Patients and methodsLASIK was performed in 24 anisometropic amblyopic eyes of 24 patients. All eyes were amblyopic and received the standard amblyopia treatment (occlusion and/or optical penalization). The mean age of the patients was 21.62 ± 9.55 SD years, ranging from 6 to 42 years. The mean myopic error ± SD was -5.7 ± 2.25 (range from −11.5 to −3.25) and the mean hypermetropic ± SD was +3.5 ± 0.95.ResultsThe preoperative mean uncorrected visual acuity ± SD was 0.11 ± 0.06 and became 0.56 ± 0.18, whereas the preoperative mean best corrected visual acuity was 0.39 ± 0.13 and became 0.57 ± 0.17 6 months postoperatively. Uncorrected visual acuity of all patients improved significantly about three or more lines in Snellen's chart. The best corrected visual acuity of about 79% of the patients improved by one or more lines in Snellen's chart.ConclusionLASIK is an effective option for the correction of high myopic or hypermetropic anisometropia.RecommendationsLASIK surgery could be recommended in all types of anisometropic amblyopic patients in whom traditional management failed and who were intolerable to glasses or contact lenses. Amblypoia management should be continued postoperatively. Further studies are recommended to assess factors affecting anisometropic amblyopia management by LASIK, such as age, refraction, depth of amblyopia and response to conventional therapy.

Refractive lens exchange for a multifocal intraocular lens with a surface-embedded near section in mild to moderate anisometropic amblyopic patients

To evaluate visual and refractive outcomes in amblyopic patients who had bilateral implantation of a multifocal intraocular lens (IOL) with a surface-embedded near section. Cathedral Eye Clinic, Belfast, Northern Ireland, United Kingdom. Comparative case series. Anisometropic amblyopic patients having bilateral implantation of Lentis Mplus multifocal IOLs were examined for distance and near visual acuities, contrast sensitivity, defocus curves, extent of crowding, reading speed, stereoacuity, and Quality of Vision (QoV) questionnaire scores preoperatively and at 3-month intervals during 12 months. A +3.00 diopter (D) reading addition IOL was used in all eyes. Twenty-eight eyes (14 patients) (mean age 59.4 years) were included. In the nonamblyopic eye, the mean uncorrected distance visual acuity (UDVA) was 0.16 logMAR ± 0.17 (SD), the mean corrected distance visual acuity (CDVA) was 0.02 ± 0.07 logMAR, and the mean near acuity was M 0.5 (Jaeger [J] 2 = logRAD 0.1) or better. In the amblyopic eye, the means were 0.30 ± 0.14 logMAR, 0.21 ± 0.11 logMAR, and M 0.8 (J4 = logRAD 0.3) or better, respectively. Bilateral reading speeds (mean 137.73 ± 28.7 words per minute [wpm]) surpassed unilateral nonamblyopic eye speeds (mean 130.6 ± 29.4 wpm). The mean QoV scores improved from 7.78 ± 10.23 preoperatively to 1.92 ± 5.21 at 12 months. No glare or halos were reported; 1 patient had mild starburst symptoms at 1 year. Patients rated distance and near vision as excellent. Anisometropic amblyopic patients may benefit from bilateral implantation of the multifocal IOL; no unwanted side effects were detected.

An optimized voxel-based morphometry study in the evaluation of brain structural abnormalities in anisometropic amblyopia patients

Objective To investigate possible neural mechanism of anisometropic amblyopia by analysing the whole brain volume changes both in grey matter and white matter using optimized voxel-based morphometry (VBM).Methods Twelve anisometropic amblyopia patients and 12 age,gender and handedness matched healthy volunteers underwent 3-dimensional (3D) fast spoiled gradient echo (FSPGR)sequence scanning on 1.5 Tesla MR system.Raw data was processed and analyzed using statistical parametric mapping (SPM)5.Results Compared to healthy controls,the grey matter exhibiting significantly decreased volume in patients included right cuneus,bilateral occipital gyrus,right middle frontal gyrus,left middle temporal gyrus,right superior temporal gyrus,right precuneus,and middle part of right cingulate gyrus ( clusters ＞ 10).The grey matter showing increased volume in patients included right cerebellum,right parahippocampal gyrus,left precentral gyrus,and left superior frontal gyrus (clusters ＞ 10).The white matter volume in bilateral optic radiation and internal capsule,especially right optic radiation,decreased significantly in patient group (clusters ＞ 10 ).No white matter showed significantly increased volume in patient group.Conclusion VBM can be used to investigate the changes of grey matter volume and white matter volume in the whole brain of anisometropic amblyopia children,it provides a method to illustrate the presumed neuro-mechanism from a morphologic point of view. Key words: Amblyopia; Anisometropia; Brain; Magnetic resonance imaging

A pilot study on characteristics of microsaccadic eye-movements in anisometropic amblyopia

To quantitatively investigate the characteristics of the microsaccadic eye-movements in anisometropic amblyopia and to evaluate the using value of high-speed eye-movement recording in objective and quantitative evaluation and diagnosis of amblyopia. From September in 2010 to March in 2011, 19 cases of anisometropic amblyopic patients (19 amblyopic eyes as group AM and 19 their sound eyes as group AS) and 19 cases of subjects with normal corrected visual acuities (19 dominant eyes as group ND and 19 non-dominant eyes as group NN) were recruited from the outpatient clinic at Tianjin Eye Hospital. A high-speed eye-movement recording system was used to monocularly record the fixational eye-movements of subjects' both eyes. A Matlab routine was used to detect and analyze the microsaccadic components of eye-movement waveforms. The microsaccadic amplitudes, peak velocities, occurrence rates, inter-microsaccadic intervals, cumulative probabilities of all groups were analyzed and compared using Origin8.0 and Matlab2008 statistics toolbox. The mean microsaccadic amplitude of group AM (0.76 ± 0.07)° was larger than groups AS, ND and NN (F = 49.95, P = 0.000). The mean peak velocity of group AM (79.72 ± 5.64)°/s was faster than groups AS, ND and NN (F = 4.93, P = 0.004). The mean occurrence rate of group AM (1.52 ± 0.08) Hz was less than groups AS, ND and NN (F = 120.39, P = 0.000). The mean inter-microsaccadic interval of group AM (537.40 ± 65.47) ms was longer than groups AS, ND and NN (F = 4.41, P = 0.007). The amplitude dependent cumulative probability curve of group AM shifted to right compared with other groups and its amplitude 0.67° ± 0.06° at half cumulative probability was obviously increased compared with other groups (F = 203.05, P = 0.000). Microsaccadic amplitude, peak velocity, occurrence rate, inter-microsaccadic interval and cumulative probability could be used as the parameters for objective and quantitative evaluation of eye-movement function in amblyopia. High-speed eye-movement recording could provide useful assistance in evaluation of eye-movements in amblyopic patients.

Rapid, High-Accuracy Detection of Strabismus and Amblyopia Using the Pediatric Vision Scanner

Purpose. The Pediatric Vision Scanner (PVS) detects strabismus by identifying ocular fixation in both eyes simultaneously. This study was undertaken to assess the ability of the PVS to identify patients with amblyopia or strabismus, particularly anisometropic amblyopia with no measurable strabismus. Methods. The PVS test, administered from 40 cm and requiring 2.5 seconds of attention, generated a binocularity score (BIN, 0%-100%). We tested 154 patients and 48 controls between the ages of 2 and 18 years. BIN scores of amblyopic children and controls were measured, and 21 children received sequential PVS measurements to detect any changes in BIN resulting from amblyopia treatment. Results. With the pass/refer threshold set at BIN 60%, sensitivity and specificity were 96% for the detection of amblyopia or strabismus. Assuming a 5% prevalence of amblyopia or strabismus, the inferred positive and negative predictive values of the PVS were 56% and 100%, respectively. Fixation accuracy was significantly reduced in amblyopic eyes. In anisometropic amblyopia patients treated successfully, the BIN improved to 100%. Conclusions. The PVS identified children with amblyopia or strabismus with high sensitivity and specificity, while successful treatment restored normal BIN scores in amblyopic patients without strabismus. The results support the hypothesis that the PVS detects strabismus and amblyopia directly. Future strategies for screening by nonspecialists may thus be based on diagnostic detection of amblyopia and strabismus rather than the estimation of risk factors, allowing for rapid, accurate identification of children with amblyopia early in life when it is most amenable to treatment.

Multifocal visual evoked potentials in amblyopia due to anisometropia.

To investigate multifocal visual evoked potentials (mfVEP) of the amblyopic and fellow eye in amblyopia due to anisometropia. We recorded mfVEP in both eyes of 15 anisometropic amblyopic patients and 15 normal control subjects. The responses from the central 7.0 degrees arc of the visual field were measured, and changes in latency and amplitude were compared between the amblyopic, fellow, and normal control eyes. There was a significant difference in the latency and amplitude of mfVEP between the amblyopic and fellow eyes. The responses in the central region of the visual field (rings 1 and 2) had a longer latency and smaller amplitude in the amblyopic eye. In contrast, there was no difference in mfVEP latency or amplitude between the fellow eye and normal control eyes. These results suggest that mfVEP may be used as an alternative objective method for diagnosis and monitoring of anisometropic amblyopia.

Electrophysiological Detection of Delayed Postretinal Neural Conduction in Human Amblyopia

To evaluate macular function and neural conduction along postretinal visual pathways in amblyopic patients. Twenty-five anisometropic amblyopic patients (mean age, 7 ± 1.9 years; visual acuity [VA]: 0.44 ± 0.27 logMAR in amblyopic [AM] eyes and 0.023 ± 0.067 logMAR in sound [SE] eyes) and 25 age-similar control subject ([CE] eyes, VA of 0.0 ± 0.0 logMAR in both eyes) were enrolled. In AM, SE, and CE eyes, simultaneous pattern electroretinograms (PERGs) and visual evoked potentials (VEPs) were recorded in response to checks reversed at the rate of two reversals/second stimulating macular or extramacular areas (the check edge subtended 15 minutes and 60 minutes of visual arc, respectively). Nonsignificant differences (ANOVA, P > 0.005) were observed in PERG, in VEP responses to the 60-minute stimulus, and in retinocortical time with the 60-minute stimulus (RCT; the difference between VEP P100 and PERG P50 implicit times) between AM, SE, and CE eyes. AM eyes showed a significant (P < 0.005) increase in VEP P100 implicit time and in RCT in response to the 15-minute stimulus, compared with the values observed in SE and CE eyes. In AM patients, the interocular difference in VA was significantly (Pearson's test, P < 0.005) related to the interocular difference VEP P100 latencies and RCT with the 15-minute stimulus. Amblyopic eyes showed abnormal visual cortical responses only when the macular area was stimulated (increase in VEP P100 implicit times with the 15-minute stimulus). This functional impairment, in the presence of normal macular function (PERG responses similar to control eyes) may be attributable to a delay in postretinal neural conduction (increase in RCT).

Implantation of the multifocal ReSTOR apodised diffractive intraocular lens in adult anisometropic patients with mild to moderate amblyopia

Aim:To assess subjective and objective parameters of visual function after implantation of the AcrySof ReSTOR in amblyopic patients.Methods:Phacoemulsification and IOL implantation were performed in six eyes of three patients with...

The use of the scanning laser ophthalmoscope in the evaluation of amblyopia

Purpose: The purpose of this study was to evaluate amblyopic patients with scanning laser ophthalmoscope microperimetry to determine whether the scanning laser ophthalmoscope data provide useful information in our understanding of amblyopia Methods: In this retrospective case series, clinical data of 46 patients with amblyopia were examined after treatment for anisometropic or strabismic amblyopia. Ten normal patients served as controls. All patients were tested with the scanning laser ophthalmoscope for the presence of macular scotomata. Scanning laser ophthalmoscope findings were assessed within each group and between groups. Results: A macular scotoma was found in the amblyopic eye of 25 of 26 anisometropic amblyopic patients and all 20 strabismic amblyopia patients. Twenty of 26 patients with anisometropic amblyopia had a relative scotoma in the nonamblyopic eye. All 20 patients with strabismic amblyopia had a nonamblyopic eye scotoma. None of the control patients had a scotoma in either eye. Several clinical features were correlated to scotoma findings. Conclusions: The scanning laser ophthalmoscope proved to be a useful tool for the assessment of some features of amblyopia. A scotoma was identified in not only the amblyopic eye of each amblyopic patient, but also in almost all of the nonamblyopic, presumably “normal” eyes. Thus, ocular effects of amblyopia may not be strictly limited to the amblyopic eye.

Evaluation of relationship of ocular parameters and depth of anisometropic amblyopia with the degree of anisometropia

(1) To find out the relationship of the depth of amblyopia with the degree of anisometropia, in untreated cases of anisometropic amblyopia without strabismus, for both myopic and hypermetropic individuals. (2) To find out the relationship between various ocular parameters, such as axial length and corneal curvature, with the degree of anisometropia between the two eyes. This prospective study was conducted between January 2001 and March 2003, in 85 cases of untreated anisometropic amblyopia, who attended the author's out patient department. All these patients were subjected to a meticulous ocular examination, with special emphasis on (1) refraction under cycloplegia (2) best corrected visual acuity (3) measurement of axial length by A Scan (4) keratometry . The depth of amblyopia was calculated in two ways: (1) By finding out decimal visual acuity for each eye and subsequently calculating their difference. (2) By converting the Snellen acuity into Log MAR units, which was calculated by finding the Logarithm of the reciprocal of the decimal visual acuity for the two eyes, followed by calculating the difference between the two. The difference in refraction between the two eyes as a measure of anisometropia, was determined by the difference in spherical equivalent between the refraction for each eye. On comparing hypermetropic and myopic cases, a significant correlation was found between depth of amblyopia and the degree of anisometropia, in both myopic and hypermetropic patients. The correlation coefficients were however, found to be greater for hypermetropic than myopic individuals. It was observed that the difference between the axial length of the two eyes contributed to a major part of anisometropia, more so in myopic cases. The depth of amblyopia correlates with the degree of anisometropia in previously untreated anisometropic amblyopia patients.

Small-target random dot stereogram and binocular suppression testing for preschool vision screening.

New, small-target (< 1 degree) random dot stereogram (STRDS) and binocular suppression (STBS) tests appropriate for preschool vision screening were developed to correct the shortcomings of previous such tests, particularly missed cases of anisometropic amblyopia such as found with some RDS-based testing. In Experiment 1, the tests were administered to 14 patients with current or a recent history of moderate (< or = 20/60) anisometropic amblyopia, or with accommodative esotropia or monofixation syndrome. All subjects had good binocularity (< or = 100" contour stereoacuity). In Experiment 2, the new tests were administered in a screening setting to a group of 112 three- to five-year-olds to determine testability. Visual acuity, cover testing, and photoscreening were administered as control measures. In Experiment 1, eleven of the 14 patients failed both tests. Two anisometropic amblyopes passing one or both tests had an acuity < or = 20/30 in the worse eye and < or = 25" stereoacuity. Three anisometropic amblyopia patients failing the STRDS passed another RDS test with similar disparity but a larger target size, confirming a report34 that anisometropic amblyopes may pass RDS testing with parafoveal stereopsis despite the presence of central suppression. The STRDS and STBS tests indicated 80% and 96% specificity, respectively, with the original methodologies; STRDS specificity increased to 95% with retesting with a different methodology. Administration time was 30 sec to 60 sec per test. Small-target RDS or suppression testing may be more effective for strabismus and amblyopia screening of preschoolers than previous RDS test formats.

The Contrast Sensitivity Function and Childhood Amblyopia

We measured contrast sensitivity function and visual acuity in both eyes of strabismic and anisometropic amblyopic patients. There was a linear relationship between contrast sensitivity function and visual acuity in the amblyopic eye. As visual acuity decreased, the contrast sensitivity function decreased along the contrast sensitivity axis, and peak sensitivity shifted to lower spatial frequencies. After patching therapy, when visual acuity reached 20/20 in each eye, suggesting that the amblyopia was cured, there continued to be statistically significant difference in the contrast sensitivity functions between the eyes. The contrast sensitivity function from the previously amblyopic eye was depressed compared to the nonamblyopic eye. A comparison between patients with strabismic and anisometropic amblyopia showed that, when matched for visual acuity, the contrast sensitivity functions were similar for both the nonamblyopic and amblyopic eyes. However, a large difference was found between the amblyopic and nonamblyopic eyes of each group.