Macular and retinal nerve fiber layer thickness in unilateral anisometropic or strabismic amblyopia

Short-Term Morpho-Functional Changes before and after Strabismus Surgery in Children Using Structural Optical Coherence Tomography: A Pilot Study

PURPOSE

To evaluate the immediate alterations in the thickness of the macular ganglion cell-inner plexiform layer (mGCIPL), peripapillary retinal nerve fiber layer (RNFL), inner retinal layer (IRL), and outer retinal layer (ORL) using spectral domain optical coherence tomography (SD-OCT) subsequent to strabismus surgery in pediatric patients diagnosed with horizontal esotropia.

METHODS

Twenty-eight eyes from twenty-one child patients who had undergone uncomplicated horizontal rectus muscle surgery due to strabismus were included. Measurements of RNFL, mGCL-IPL, IRL, and ORL using structural OCT were conducted both before the surgery and one month after the surgical procedure. Importantly, a control group comprising 14 healthy eyes, matched for age and significant refractive error (<3.00 diopters), was included in the current analysis.

RESULTS

Our analysis indicated no significant disparity before and after surgery in terms of best-corrected visual acuity (BCVA), RNFL, IRL, and ORL. Conversely, concerning the macular ganglion cell layer-inner plexiform layer analysis, a substantial increase in mGCL-IPL was observed following the surgical intervention. The mean mGCL-IPL measured 60.8 ± 9.2 μm at baseline and 66.1 ± 13.2 μm one month after the surgery (p = 0.026). Notably, comparison between the strabismus group at baseline and the healthy group revealed a significant reduction in mGCL-IPL in the strabismus group (60.8 ± 9.2) compared to the healthy control group (68.3 ± 7.2; p = 0.014).

CONCLUSIONS

Following strabismus surgery, our observations pointed towards a thickening of the mGCL-IPL layer, which is likely attributable to transient local inflammation. Additionally, we identified a significant differentiation in the mGCL-IPL complex between the pediatric patient group with strabismus and the control group.

Evaluation of the macular sensitivity and retinal ganglion cell layer in unilateral amblyopia

PURPOSE

To assess macular sensitivity and fixation pattern obtained by microperimetry and ganglion cell complex (GCC) obtained by optical coherence tomography (OCT) in cases with unilateral amblyopia and to compare with control.

METHODS

The study was conducted with 30 patients with amblyopia, aged 5-18 years, and 30 control eyes of healthy children in the same age group. Participants underwent full ophthalmological examination. Macular sensitivity, stabilization, and location of fixation values were measured using microperimetry. The GCC values were obtained by OCT. Measurements were compared between amblyopic eyes, fellow eyes, and controls. Any correlation between GCC, macular sensitivity, and fixation was investigated. P < 0.05 was considered statistically significant.

RESULTS

The mean age was 10.13 ± 3.49 years in the amblyopia group and 11.53 ± 2.7 years in the control group. Three groups were formed: amblyopic eyes (Group 1, n = 30), fellow eyes (Group 2, n = 30), and control eyes (Group 3, n = 30). The macular sensitivity values were found highest in the control group (P = 0.007). Bivariate contour ellipse area 1, which is the numerical value of fixation stabilization, was measured to be the lowest in the control group (P < 0.0001). In the analysis among the three groups, no significant difference was observed in terms of the GCC (P = 0.229). In the correlation analyses, a significant correlation was detected between macular sensitivity and GCC values in amblyopic eyes.

CONCLUSION

In amblyopic eyes, the macular sensitivity was significantly lower and the GCC thickness was found to be in a positive correlation with macular sensitivity.

The Relationship between Fixation Stability and Retinal Structural Parameters in Children with Anisometropic, Strabismic and Mixed Amblyopia

(1) Background: Amblyopia is an ocular condition leading to structural and functional changes. The relationship between these changes is complex and remains poorly understood. (2) Methods: Participants included 31 children aged 5 to 9 years with strabismic (n = 9), anisometropic (n = 16) and mixed (n = 6) unilateral amblyopia, and 14 age-matched non-amblyopic children. The 95% and 63% Bivariate Contour Ellipse Area (BCEA), axial length, Foveal Avascular Zone (FAZ) area, center macular thickness and volume were assessed. The relationship between these parameters was explored. (3) Results: Statistically significant differences were found among the four groups in best corrected distance visual acuity (BCVA) (p < 0.001), BCEA 95% (p = 0.002) and BCEA 63% (p = 0.002), but not in the FAZ area, central macular thickness, central macular volume and axial length. Eyes with amblyopia had poorer BCVA and larger fixation instability than controls. Inter-ocular differences were more significant in patients with strabismic amblyopia, particularly in BCVA (p = 0.003), central macular thickness (p < 0.001) and central macular volume (p = 0.002). In amblyopic eyes, BCEA 95% and 63% were correlated with BCVA, but not with the FAZ area. (4) Conclusion: Amblyopia is associated with a reduction in fixation stability and BCVA, although there is a general lack of correlation with structural changes, suggesting a complex interaction between anatomy and function in amblyopia.

Long-term effects of early/late-onset visual deprivation on macular and retinal nerve fibers layer structure: A pilot study

BACKGROUND/AIMS

Tomographic analysis of macular and peripapillary retinal nerve fibers layer (RNFL) thickness in patients with history of congenital (CC) and developmental cataract (DC).

METHODS

Analysis of macular and RNFL thickness using a spectral-domain optical coherence tomography was performed. Retinal layers thickness was measured using the internal segmentation software. Measurements of affected (unilateral and bilateral), contralateral eyes and control eyes were compared.

RESULTS

Patients with history of CC or DC (n = 13 and 11 respectively) and 35 healthy control subjects were enrolled. Thicker inner and outer nuclear layers (INL, ONL) and thicker ONL were found when CC and DC group when compared to controls respectively. Bilateral CC showed the most relevant differences. Slight thickening of CC inner retinal layers were found when compared to DC. Increased superonasal RNFL thickness was found in CC group when compared to DC and controls. Thickening of RNFL of contralateral unaffected eyes of unilateral CC were found when compared to controls.

CONCLUSION

Significant macular and RNFL thickness changes between CC, DC patients and controls that partially involve also contralateral unaffected eyes of unilateral congenital cataract were found. CC and DC groups show significant differences only in inner retinal layers thickness. Our data suggest that early visual deprivation may influence retinal arrangements occurring during development involving predominantly the outer nuclear layer and para/perifoveal inner retinal layers, and confirm that early treatment of CC allow to achieve better long-term visual outcome. Moreover functional and structural data support the hypothesis that unilateral amblyopia is not exclusively an unilateral issue.

Macular pigment optical density of hyperopic anisometropic amblyopic patients measured by fundus reflectometry

Purpose

Hyperopic anisometropia is a major cause of amblyopia and may be associated with macular pigment optical density (MPOD) reduction. To explore whether the MPOD changes in hyperopic anisometropic amblyopia, we measured the MPOD using fundus reflectometry in eyes with hyperopic anisometropic amblyopia and normal vision.

Methods

This was a cross-sectional study conducted from January 2017 to June 2017. Forty subjects (25 males and 15 females) between the ages of 6 and 10 years were recruited. The subjects' eyes were divided into two groups: amblyopic eyes (best-corrected visual acuity (BCVA) not more than 20/25 or BCVA of two eyes differing by two or more lines) and fellow eyes. All enrolled subjects underwent a comprehensive ophthalmic examination, including extraocular motility assessment, cover-uncover testing, and refractive error (noncycloplegic), BCVA, axial length (AL), macular foveal thickness (MFT) and MPOD (Visucam^® 200, Carl Zeiss Meditec AG, Germany).

Results

The MPOD of amblyopic and fellow eyes was 0.12 ± 0.03 log units and 0.13 ± 0.04 log units, respectively, with a significant difference (P = 0.026). The MFT of amblyopic and fellow eyes was 241.28 ± 13.95 and 237.13 ± 16.02 μm, respectively, revealing that the MFT was significantly higher in amblyopic eyes than in fellow eyes (P = 0.028). Conversely, there was no correlation between the MPOD and MFT in the two groups.

Conclusions

This study is the first to report that the MPOD is decreased in hyperopic anisometropic amblyopia. In this study, no correlation between the MPOD and MFT was found. In the future, factors that induce a decrease in the MPOD in eyes with hyperopic anisometropic amblyopia should be explored in a large-sample study with follow-up observation.

Retinal nerve fiber layer thickness in amblyopia

Purpose

To report retinal nerve fiber layer thickness (RNFLT) in eyes with amblyopia compared with contralateral healthy eyes.

Methods

In this cross-sectional study, we included patients with anisometropic amblyopia, strabismic amblyopia, and mixed amblyopia. All subjects underwent complete ophthalmic examination, including RNFLT measurement with time-domain OCT (Stratus OCT) and scanning laser polarimeter (GDX VCC). A paired "t" test was used to compare average and quadrant-wise RNFL thickness between the amblyopic and contralateral normal eyes. In addition, an analysis of variance test was used to compare various RNFL thickness parameters between the three groups.

Results

A total of 33 eyes of 33 subjects with anisometropic amblyopia, 20 eyes of 20 subjects with strabismic amblyopia, and 38 eyes of 38 subjects with mixed amblyopia were included. In the anisometropic amblyopia group, the average RNFLT in the amblyopic eye was 98.2 μm and 99.8 μm in the fellow normal eye (P = 0.5), the total foveal thickness was 152.82 μm (26.78) in the anisometropic eye and 150.42 μm (23.84) in the fellow eye (P = 0.38). The difference between amblyopic and contralateral normal eye for RNFL and macular parameters was statistically insignificant in all three groups. The RNFL thickness in four quadrants was similar in the amblyopic and non-amblyopic eye between all three groups and statistically non-significant.

Conclusion

Our study showed that RNFL thickness was similar in amblyopic and non-amblyopic eyes between all three amblyopia groups.

Retinal ganglion cell complex thickness at school-age, prematurity and neonatal stressors

PURPOSE

To investigate the association between the ganglion cell complex (GCC) thickness at early school-age and prematurity and other neonatal factors.

METHODS

Cross-sectional study. The sample included very preterm children with gestational age (GA) below 32 weeks or birthweight below 1500 g enrolled in a follow-up program (n = 101) and a comparison group of term-born children (n = 49). Ganglion cell complex (GCC) thickness was measured at 4-8 years using high-quality optical coherence tomography (OCT) images. Data on neonatal and postnatal features were extracted from clinical records; analyses included mixed linear models.

RESULTS

Ganglion cell layer (GCL) and retinal nerve fiber layer (mRNFL) were thicker in term than in preterm born children (2.9 μm and 2.4 μm respectively, p < 0.001). Within the preterm group, lower GA was associated with a decrease in total GCL (0.7 μm per week, p < 0.001). Being small for GA was associated with further thinning in both layers (1.4 and 2.8 µm). Postnatal corticosteroids therapy and severe brain lesion were associated with thinning in the total GCL of 6 µm (p < 0.001) and 4.1 µm (p = 0.002), respectively, and shock was associated with thinning in total mRNFL of 6 µm (p < 0.001).

CONCLUSIONS

Lower GA or birthweight are associated with thinning of GCC layers. When performing an OCT examination at school-age and a decrease in GCC thickness is observed, it may be relevant to ask about a history of prematurity, and further enquire about neonatal shock, postnatal corticosteroids therapy or severe brain lesion that are related to additional decrease in GCC thickness.

The features of diagnosis and treatmentof unilateral concomitant strabismus with visual fixation defect in preschool children

BACKGROUND:Particular difficulties in treatment of children with monolateral strabismus are associated with the presence of severe amblyopia in the squinting eye in combination with a visual fixation defect (acentral or intermittent). AIM:To assess the anatomical and functional status of children with visual fixation defects, to find out the causes of failures in treatment of this group of patients, to determine the tactics of their management. MATERIALS AND METHODS:The study included 92 children of preschool age (from 3 to 7 years) with monolateral concomitant strabismus. The follow-up period for the children ranged from 12 to 72 months. The average age of the examined children was 4.6 1.1 years. Three variants of visual fixation were identified in the squinting eye: central visual fixation (CVF) 68 eyes; intermittent visual fixation (IVF ) 7 eyes; and acentral visual fixation (AVF) 17 eyes. All patients underwent a comprehensive examination: visometry; strabometry; autorefractometry; determination of the critical frequency of light flashes; assessment of visual fixation; optical coherence tomography of the retina. All children underwent passive and active pleoptics. RESULTS:The visual acuity of children with CVF significantly increased due to pleoptics. At the same time in cases of IVF and even more in those of AVF, visual acuity remained significantly lower than that of the fixating eye, pleoptics were ineffective in this group of patients. In patients with CVF, the critical frequency of light flashes of the squinting eye increased in statistically significant figures, while in IVF and AVF, the difference between squinting and fixing eye remained. According to OCT data, changes in the macular area were detected in 18 (75%) eyes in patients with IVF and AVF, which allows us to distinguish organic pathology from amblyopia. CONCLUSIONS:In children with monolateral strabismus, it is necessary to determine visual fixation of the squinting eye. At IVF and AVF, it is mandatory to conduct optical coherence tomography of the macular area to exclude organic pathology. In patients with monolateral concomitant strabismus with IVF and AVF, surgery on oculomotor muscles is indicated.

Influence of one or two horizontal muscle surgeries on OCT findings

We investigate the effects of differences between one or two horizontal rectus muscle surgeries (recession ± resection) on the central macular thickness (CMT), subfoveal choroidal thickness (SFCT), and retinal nerve fiber layer (RNFL). Measurements of the CMT, SFCT, and RNFL in patients who underwent horizontal rectus muscle surgery were obtained using optical coherence tomography (OCT). Patients were grouped as those who had undergone rectus muscle recession surgery (Group 1) and those who had undergone rectus muscle recession + resection surgery (Group 2). The CMT, SFCT, and RNFL in patients were measured preoperatively and 1 day, 1 week, 1 month, 3 months, and 6 months postoperatively. A total of 65 eyes of 50 patients were analyzed retrospectively. The average age of the 25 patients in Group 1 was 8.96 ± 7.966 years (min 3, max 38). The average age of the 25 patients in Group 2 was 15.17 ± 6.806 years (min 2, max 34). The comparison of the preoperative and the 1-day and 1-week postoperative values revealed an increase in CMT and SFCT in Group 1 and Group 2. There were no significant differences between the two groups. It was observed that this increase reached the preoperative values after 1-3 months and 6 months in both groups. There was no statistically significant change in the RNFL. Rectus muscle surgery (recession±resection) caused an increase in CMT and SFCT in the early stage, which was possibly caused by the altered choroidal microcirculation resulting from mechanical traction during surgery and by postoperative inflammation. There was no difference between one or two muscle surgeries.

Inter-Ocular Symmetry of Vascular Density and Retinal Thickness in Unilateral Anisometropic Amblyopia

Background

Inter-ocular symmetry of macular vascular anatomy in healthy subjects has been well documented in previous optical coherence tomography angiography (OCTA) studies. In our present study, we have demonstrated that the presence of anisometropic amblyopia in one eye does not alter this unique feature significantly. We investigated whether the presence of unilateral anisometropic amblyopia due to moderate amounts of hyperopia and/or astigmatism would have any significant influence on measurements of retinal thickness (RT) and superficial vessel density (SVD) in adult subjects.

Subjects and methods

In the study group, both eyes of 21 adult subjects with unilateral anisometropic amblyopia were enrolled. Only one eye of an age-matched control group including 33 subjects was randomly selected. RT and SVD were measured in foveal and parafoveal retinal areas and compared in amblyopic eyes, their fellow eyes and in the control group. Inter-ocular symmetry of RT and SVD in amblyopic and fellow eyes were investigated by using correlation analysis.

Results

There were statistically significant inter-ocular correlations of foveal and parafoveal RT in amblyopic and fellow eyes (P < 0.0001, for both). Foveal and parafoveal RT of the control group were not statistically different from amblyopic eyes (P = 0.072 and P = 0.46, respectively). There was no difference between foveal SVD of amblyopic eyes and control group (P = 0.10) and a significant inter-ocular correlation was found between amblyopic and fellow eyes (P = 0.029).

Conclusion

For our adult subjects, none of the investigated OCTA parameters of the amblyopic eyes were found to be statistically different from those of age-matched controls. The preservation of inter-ocular symmetry in the amblyopic and fellow eyes implies that the influence of anisometropic amblyopia in one eye would be relatively small and negligible on routine OCTA examination.

Analysis of Macular Vessel Density and Foveal Avascular Zone in Adults with Amblyopia

Purpose: To quantify and compare the foveal avascular zone (FAZ) and the whole, parafoveal and foveal vessel density of superficial (SCP) and deep capillary plexus (DCP) in amblyopic eyes of adults and age-matched controls.Methods: This cross-sectional study involved 52 eyes from 34 subjects aged 18 to 45 years. Optical coherence tomography angiography (OCTA) was performed to all participants and SCP, DCP and FAZ were evaluated. SPSS (Statistical Package for the Social Sciences) 23 was used for data analysis.Results: Eighteen of 34 subjects (52,9%) were amblyopic and 16 (47,1%) of them controlled. Mean subject age was 31.2 years in the amblyopia group and 28.3 years in the control group. The mean FAZ measurements were 0.28 ± 0.08 in amblyopic eyes, 0.29 ± 0.08 in fellow eyes and 0.3 ± 0.11 in control eyes. The whole, foveal and parafoveal vessel density of SCP in both 3x3-mm and 6x6-mm scans were not statistically different in amblyopic eyes, fellow eyes and control eyes. In 6x6-mm scans, the whole, and parafoveal vessel density of DCP were significantly lower in amblyopic eyes than controls. There was no statistically significant difference in 3x3-mm scans about DCP.Conclusion: OCTA revealed lower vessel density in DCP of amblyopic eyes than fellow eyes and controls in adults.

Macular Thickness in Moderate to Severe Amblyopia

PURPOSE

To compare the macular retinal thickness of moderately to severely amblyopic eyes with non-amblyopic eyes as controls.

METHODS

This case control study was conducted on 56 children aged 4 to 10 years old (64.3% female subjects). Twenty-eight children had unilateral amblyopia (28 amblyopic eyes as cases and 28 normal fellow eyes as internal controls) and 28 children had normal visual acuity in both eyes and were considered as external controls (n = 56 eyes). Among our cases, 14 had strabismic amblyopia and 14 had anisometropic amblyopia. Macular retinal thickness was measured using optical coherence tomography at the center and in 1-, 3-, and 6-mm rings.

RESULTS

Best-corrected visual acuity of the amblyopic eyes was less than that of the internal and external controls, and the best-corrected visual acuity of their fellow eyes was also less than that of the external controls. Thickness of the central macula and a 1-mm ring area in the amblyopic eyes was higher than that of both internal and external controls. Difference of central macular thickness ≥20 μm between two eyes of the amblyopic children was significantly more than non-amblyopic subjects.

CONCLUSIONS

Based on the results of this study, the macular retinal thickness was significantly higher in moderate to severe amblyopic eyes compared to their fellow eyes and external controls. This might be due to macular developmental disorders in amblyopic eyes. Therefore, optical coherence tomography imaging is recommended if subtle macular abnormalities are suspected in moderate to severe amblyopic eyes.

Decreased severity of age-related macular degeneration in amblyopic eyes

AIM

To evaluate whether people with age-related macular degeneration (AMD) and a history of amblyopia have equal severity of AMD in both eyes.

METHODS

Billing records were used to locate all people with a history of amblyopia and AMD evaluated between 1 January 2003 and 1 June 2015 at a single ophthalmology institute. Two ophthalmic graders blinded to amblyopia status determined the severity of AMD in each eye using fundus photos and a validated grading scale.

RESULTS

A total of 14 people were found to have AMD and a documented history of amblyopia. Average patient age was 77.0 years and average best corrected visual acuity was 20/160 in eyes with a history of amblyopia and 20/40 in fellow eyes without amblyopia. Eyes with a history of amblyopia were found to have a lower AMD severity score (mean lower score: -1.38; paired t-test P=0.019). Of the 11 people with asymmetric disease severity, 10 individuals had worse AMD in the non-amblyopic eye while one person had worse AMD in the amblyopic eye (P=0.0067).

CONCLUSIONS

Our pilot study suggests that eyes with a history of amblyopia may manifest decreased severity of AMD compared with non-ambylopic eyes in the same patient. Further research is warranted to investigate this clinical observation.

Interocular Comparison of Anterior and Posterior Segment Findings and Laterality in Hyperopic Anisometropia

OBJECTIVES

To investigate the laterality and the differences in anterior and posterior segment findings in hyperopic patients with anisometropia between their eyes using spectral domain optical coherence tomography and LenStar LS-900 device.

METHODS

This prospective institutional study included hyperopic anisometropic patients with and without amblyopia, aged between 6 and 40 years. The refractive error and the values of keratometry, axial length (AL), central corneal thickness (CCT), peripapillary retinal nerve fiber layer (RNFL) thickness, and central macular thickness (CMT) obtained using the RK-F1 autorefractor, LenStar LS-900, and Spectralis optical coherence tomography were compared between the higher hyperopic and fellow eyes.

RESULTS

Eighty of the patients had hyperopic anisometropia with amblyopia and 30 of them had hyperopic anisometropia without amblyopia. The left eyes of the patients in this series were significantly more commonly affected. Axial length and CCT were significantly different between the higher hyperopic and the fellow eyes of all patients. In addition, the mean CMT and RNFL thickness of the higher hyperopic eyes were significantly higher than that of the fellow eyes.

CONCLUSIONS

During the process of emmetropization and development of the retina, higher hyperopic eyes in hyperopic patients with anisometropia and amblyopic eyes may have blurred and abnormal vision, leading to under-development of vision, significantly higher CCT, CMT, and RNFL thickness, more hyperopic refraction, and shorter AL in the affected eye.

Changes in macular parameters in different types of amblyopia: optical coherence tomography study

PURPOSE

The purposes of this study were to investigate the changes in macular parameters (thickness, volume) and peripapillary retinal nerve fiber layer (RNFL) thickness (RNFLT) in different cases of amblyopia versus the normal fellow eyes using optical coherence tomography (OCT) and to estimate the relationship of OCT changes with various defined patients' parameters.

DESIGN

This is a prospective, observational, cross-sectional case series.

METHODS

The method involved measuring the peripapillary RNFLT, macular thickness, and macular volume via spectral domain (OCT) in different types of amblyopia and comparing with the other fellow eyes. This study was conducted at the Mansoura Ophthalmic Center.

RESULTS

A total of 64 patients with different types of amblyopia were included. The mean central macular thickness (CMT) was 196.2±50.03 µm in the amblyopic eyes versus 167±12.76 µm in the fellow eyes (P=0.000), the mean average macular thickness was 265.80±12.77 µm in the amblyopic eyes versus 259.10±3.09 µm in the fellow eyes (P=0.000), the mean macular volume was 7.59±0.32 mm³ in the amblyopic eyes versus 7.34±0.071 mm³ in the fellow eyes (P=0.002), and the mean global RNFLT was 97.00±11.60 µm in the amblyopic eyes versus 78.50±13.05 µm in the fellow eyes (P=0.029). There was a discrepancy between the different amblyopic types. Age and the axial length were the only independent variables that statistically significantly correlated with the CMT.

CONCLUSION

The unilateral amblyopic eyes were prone to have a higher CMT and thicker global RNFL compared to those of the sound fellow eyes. Retinal variations between different types of the amblyopia differ from one type to another. The age could be considered as a predictor of the disease worsening and treatment prognosis. Further studies are required to emphasize these results.

Effect of myopic anisometropia on anterior and posterior ocular segment parameters

The purpose of this study is to investigate the differences in anterior and posterior segment parameters of more myopic eyes compared to fellow eyes using spectral domain optical coherence tomography and optical biometer device in patients with myopic anisometropia. This prospective cross-sectional study included 42 myopic anisometropic patients with and without amblyopia, aged between 7 and 40 years old. The refractive error and keratometry values, axial length (AL), central corneal thickness (CCT), peripapillary retinal nerve fiber layer thickness (RNFLT), and central macular thickness (CMT) were evaluated. Eighteen of the patients had myopic anisometropia with amblyopia, and the remaining 24 had myopic anisometropia without amblyopia. There were 23 female and 19 male patients with a mean age as 23.67 ± 10.12 years (range 7-40). The right eyes of the subjects significantly had a higher degree of myopia. There was a significant difference in mean best-corrected visual acuity (0.195 ± 0.234 vs. 0.011 ± 0.025 logMAR, p < 0.001), spherical equivalent refraction (-3.95 ± 1.38 vs. -1.04 ± 0.99 D, p < 0.001), AL (25.06 ± 1.27 vs. 23.99 ± 0.98 mm, p < 0.001), and RNFLT (89.24 ± 12.84 vs. 94.57 ± 10.81 μm, p < 0.001) between the more myopic and fellow eyes in all patients. On the contrary, there was no significant difference in CMT and anterior segment parameters including mean keratometry and CCT in all patients and either group. During the development of the myopic anisometropia, more myopic eyes have significantly more myopic refraction, longer AL and thinner RNFLT compared to the fellow eyes.

Retinal Nerve Fibre Layer and Macular Thicknesses in Adults with Hyperopic Anisometropic Amblyopia

Objectives. This study compared the macular and retinal nerve fibre layer (RNFL) thicknesses and optic nerves of eyes with reduced vision due to anisometropia with the contralateral healthy eyes in adults using optical coherence tomography (OCT). Methods. This cross-sectional study was conducted in Atatürk State Hospital, Sinop, Turkey. Macular and RNFL thicknesses, optic nerve disc area, cup area, and horizontal and vertical cup-to-disc ratios obtained using a NIDEK RS-3000 SLO spectral domain OCT device were compared between the amblyopic and fellow eyes in 30 adults with anisometropic amblyopia 18–55 years old who were seen in our clinic with unilateral poor vision. Results. The mean macular thickness was 266.90 ± 23.22 µm in the amblyopic eyes and 263.90 ± 22.84 µm in the fellow eyes, and the mean RNFL thickness was 111.90 ± 12.9 and 109.70 ± 9.42 µm, respectively. The two thicknesses did not differ significantly between the amblyopic and fellow eyes. There were also no significant differences between the eyes in disc area, cup area, and horizontal-vertical cup/disc ratios. Conclusion. There does not seem to be a difference in macular thickness, peripapillary RNFL, or optic disc structures between the amblyopic and fellow eyes in adults.

The assessment of anterior and posterior ocular structures in hyperopic anisometropic amblyopia

Background

The aim of this study was to examine the relationship or differences in ocular structures of amblyopic eyes compared to fellow eyes in children and young adults with hyperopic anisometropic amblyopia.

Material/Methods

Hyperopic participants with anisometropic amblyopia, defined as the presence of best-corrected visual acuity differences of at least 2 Snellen lines and 1.5 diopters between amblyopic and fellow eyes, were studied. Using the IOL Master, Pentacam Scheimpflug imaging and Spectralis optical coherence tomography, the axial length, corneal curvature, and anterior chamber depth (ACD), as well as the thickness of the cornea, peripapillary retinal nerve fiber layer (RNFL), and macula, were compared between children and young adults and between their amblyopic and fellow eyes.

Results

In 53 participants with hyperopic anisometropic amblyopia, there were significant differences in the anterior corneal curvature, ACD and axial length between the amblyopic and fellow eyes of all the patients. The mean central macular thickness in the amblyopic eyes was significantly thicker (P=.001) in the group aged 5 to 12 years; however, this was not the case in the group aged 13 to 42 years. There was no significant difference in average RNFL thickness in either group.

Conclusions

We found significantly greater mean central macular thickness in anisometropic amblyopic eyes among participants aged 5 to 12 years, but not among those who were older. Similarly, the interocular differences in axial length parameters seemed to be related to the central macular thickness differences between the amblyopic and fellow eyes in the younger group.

Meta-analysis of retinal changes in unilateral amblyopia using optical coherence tomography

PURPOSE

To evaluate retinal changes in unilateral amblyopia using optical coherence tomography.

METHODS

Major literature databases were searched for relevant studies. The primary outcome parameters were foveal minimum thickness (FMT), mean foveal thickness (MFT), mean macular thickness (MMT), and peripapillary retinal nerve fiber layer (pRNFL) thickness. Efficacy estimates were evaluated by standardized mean difference (SMD) and 95% confidence interval (CI) for changes in the outcomes of interest.

RESULTS

This meta-analysis included 28 clinical trials involving 408 patients .The FMT, MFT, and MMT in the amblyopic eyes was significantly greater than that of the fellow eyes (SMD = 0.22, 95% CI 0.05-0.39, p = 0.011; SMD = 0.21, 95% CI 0.06-0.36, p = 0.005; SMD = 0.21, 95% CI 0.08-0.35, p = 0.002, respectively). Only FMT was significantly increased in the amblyopia group compared with the normal control group (SMD = 0.38, 95% CI 0.19-0.57, p&lt;0.00001). Analysis showed that pRNFL thickness in the amblyopic eyes was thicker than in the fellow eyes (SMD = 0.13, 95% CI 0.02-0.24, p = 0.016). We did not find that those outcome measures differ between strabismic and anisometropic amblyopia.

CONCLUSIONS

The pooled evidence indicates that the amblyopic process may involve the retina, especially the macula. A thicker foveola was found in the amblyopic eyes when compared with visually normal control eyes. Further larger-scale studies especially involving emmetropic normal subjects will be valuable.

Macular and retinal nerve fiber thickness in recovered and persistent amblyopia

The aim of this study was to investigate the presence of increased macular or retinal nerve fiber layer thickness (RNFLT) in amblyopic eyes, find if the increased macular or RNFLT is related to the lack of response in amblyopic eyes, and to explore whether the increased central macular thickness (CMT) in amblyopic eyes is purely related to the hyperopia. This is a prospective descriptive study. CMT and peripapillary RNFLT were measured by spectral-domain optical coherence tomography to evaluate 60 patients with unilateral-treated amblyopia (median age 11.00 year). Patients were divided into two groups: 33 patients in recovered amblyopia group and 27 patients in persistent amblyopia group. The mean CMT in the recovered group was 247.31 (±23.4) versus 246.8 (±32.7) µm (p = 0.95) for the persistent group. The mean peripapillary RNFLT was 99.13 (±12.1) versus 99.9 (±14.9) µm (p = 0.85) for the persistent group. In anisometropic amblyopia, there was no significant difference in CMT and RNFLT in either group. Also there was no relation between the type of refractive error and CMT or RNFLT. There was no significant difference in CMT and RNFLT in amblyopic eyes for both the recovered amblyopia group and the persistent amblyopia group to explain the lack of response in persistent amblyopic eyes. Additionally there was no relation between the type of refractive error and CMT or peripapillary RNFLT.

A comparison between amblyopic and fellow eyes in unilateral amblyopia using spectral-domain optical coherence tomography

Purpose

To compare the macular retinal thickness and characteristics of optic nerve head (ONH) parameters in amblyopic and fellow eyes in patients with unilateral amblyopia.

Patients and methods

A total of 21 patients with unilateral amblyopia (14 patients with anisometropic amblyopia, four patients with strabismic amblyopia, and three patients with both) were examined using spectral-domain optical coherence tomography. The mean age of the patients was 8.5±3.5 years. The examined parameters included the mean macular (full, inner, and outer), ganglion cell complex and circumpapillary retinal nerve fiber layer (cpRNFL) thicknesses, and ONH parameters (rim volume, nerve head volume, cup volume, rim area, optic disc area, cup area, and cup-to-disc area ratio).

Results

The amblyopic eyes were significantly more hyperopic than the fellow eyes (P<0.001). Among the macular retinal thickness parameters, the cpRNFL thickness (P<0.01), macular full retinal thickness (3 mm region) (P<0.01), and macular outer retinal thickness (1 and 3 mm regions) (P<0.05) were significantly thicker in the amblyopic eyes than in the fellow eyes, while the ganglion cell complex thickness, macular full retinal thickness (1 mm region), and macular inner retinal thickness (1 and 3 mm regions) were not significantly different. Among the ONH parameters, the rim area was significantly larger and the cup-to-disc area ratio was smaller in the amblyopic eyes than in the fellow eyes (P<0.05). None of the other ONH parameters were significantly different between the investigated eyes. The differences in the cpRNFL thickness and macular outer retinal thickness in the 1 mm region were significantly correlated with the difference in axial length (P<0.05, r=−0.48; P<0.01, r=−0.59, respectively) and refractive error (P<0.05, r=0.50; P<0.01, r=0.60, respectively). The other parameters were not significantly related to the difference in axial length, refractive error, or best corrected visual acuity.

Conclusion

We found significant differences in some of the morphological measurements between amblyopic and fellow eyes that appear to be independent of abnormalities in the visual cortex.

A 1-Year Review of Amblyopia and Strabismus Research

PURPOSE

This current review highlights some of the literature published in the past year from April 2013 to May 2014.

DESIGN

Literature Review.

METHODS

The present review is based on an extended search for pertinent articles on amblyopia and strabismus published during the specified period.

RESULTS

Many articles are often not very comparable to one another because of a lack of randomized clinical trials with most of the studies being retrospective in nature. There is often disagreement on some terminology. Typically, the definition of binocular vision is rarely related to the tests used for evaluating it.

CONCLUSIONS

The authors conclude that adult strabismus patients seem to gain benefits from corrective surgery not only for their ocular misalignment, but also for social anxiety levels that may be associated with improvements in their quality of life and disability levels.

One Year of Pediatric Ophthalmology and Strabismus Research in Review

PURPOSE

To highlight recent advances in amblyopia and strabismus.

DESIGN

Literature review.

METHODS

A literature search of articles published in the English language was performed in PubMed or MEDLINE between May 2012 and April 2013 using the terms amblyopia or strabismus. Articles deemed relevant were selected.

RESULTS

The review highlights articles that increase our understanding of strabismus and amblyopia as well as newer treatment strategies.

CONCLUSIONS

The review highlights some new information and possible future advances in amblyopia and strabismus.