Hyperopic Amblyopic Eyes Research Articles

Choroidal vessel density in unilateral hyperopic amblyopia using en-face optical coherence tomography

BackgroundStructural changes of the choroid, such as choroidal thickening, have been indicated in amblyopic eyes with hyperopic anisometropia as compared to fellow or healthy eyes. The purpose of the present study was to investigate choroidal vascular density (CVD) in children with unilateral hyperopic amblyopia.MethodsThis study included 88 eyes of 44 patients with unilateral amblyopia due to hyperopic anisometropia with or without strabismus and 29 eyes of 29 age-matched normal controls. The CVD of Haller’s layer was quantified from en-face images constructed by 3-dimensional swept-source optical coherence tomography images flattened relative to Bruch’s membrane. The analysis area was a 3 × 3-mm square of macula after magnification correction. Relationships between CVD and other parameters [best-corrected visual acuity (BCVA), refractive error and subfoveal choroidal thickness (SFCT)] were investigated, and CVDs were compared between amblyopic, fellow, and normal control eyes.ResultsMean CVD was 59.11 ± 0.66% in amblyopic eyes, 59.23 ± 0.81% in fellow eyes, and 59.29 ± 0.74% in normal control eyes. CVD showed a significant positive relationship with SFCT (p = 0.004), but no relationships with other parameters. No significant differences in CVD were evident among amblyopic, fellow, and normal control eyes after adjusting for SFCT (p = 0.502).ConclusionsCVD was unrelated to BCVA, and CVD did not differ significantly among amblyopic, fellow and normal control eyes. These results suggest that the local CVD of Haller’s layer is unaffected in unilateral hyperopic amblyopic eyes.

Does the treatment of amblyopia normalise subfoveal choroidal thickness in amblyopic children?

PurposeRecent studies have found a choroidal thickening in amblyopic eyes and suggested that there might be a relationship between the choroid and amblyopia. The present study aimed to evaluate the effect of a six‐month treatment of amblyopia on choroidal thickness in anisometropic hyperopic amblyopic children.MethodsThirty‐two anisometropic hyperopic children with unilateral amblyopia were included in this prospective study. Subfoveal choroidal thickness was measured as the distance between the retinal pigment epithelium and the chorioscleral edge, by using spectral domain enhanced depth imaging optical coherence tomography. The treatment of amblyopia was performed based on the full correction of the refractive error with eyeglasses, a refractive adaptation phase and occlusion by patching the fellow eye.ResultsThe mean visual acuity of the amblyopic eyes significantly increased from 0.35 ± 0.3 to 0.16 ± 0.2 logMAR after the treatment (p < 0.001). The mean initial choroidal thickness was significantly higher in the amblyopic eyes than in the fellow eyes (p = 0.019). There were no significant differences between the pre‐ and post‐treatment mean choroidal thickness in the amblyopic eyes (p = 0.428) and in the fellow eyes (p = 0.343). The mean choroidal thickness was still higher in the amblyopic eyes than in the fellow eyes after the treatment (p = 0.006).ConclusionsAlthough a six‐month treatment of amblyopia increased the visual acuity of the anisometropic hyperopic amblyopic eyes, it could not significantly change choroidal thickness. Our results were in accordance with the conventional explanation, which suggests visual cortex and lateral geniculate nucleus abnormalities in the pathophysiology of amblyopia.

Cyclotherapy as a Technique to Expedite the Treatment of Hyperopic Amblyopia

Amblyopia is one of the most common causes of vision loss in children. This paper shows the efficacy of cyclotherapy in facilitating plus acceptance to expedite the treatment of refractive amblyopia. Three cases of hyperopic amblyopia underwent cyclotherapy. Best corrected visual acuity improved by at least one visual acuity line after cycloplegic refraction for all three patients as compared to dry manifest refraction. After treatment with cyclotherapy, acuities were equal to the initial cycloplegic refraction at the first followup visit with full spectacle correction. The full plus acceptance allowed for quicker resolution of refraction correction in the treatment of amblyopia. The use of cyclotherapy is effective in facilitating plus acceptance in hyperopic amblyopic eyes, and it expedites the resolution of amblyopia.

The relationship of axial length to cycloplegic refraction and keratometry in amblyopic eyes of hyperopic children

In nonamblyopic eyes of hyperopic children, axial length has a consistent mathematical relationship to cycloplegic refraction and keratometry such that estimated axial length = ([-0.04 × refraction] + 2.98) × (corneal radius)]. The purpose of this study is to determine whether the pathophysiology of amblyopia affects this relationship. This a prospective case series of children 5 to 16 years of age diagnosed with esotropia related to uncorrected hyperopia who underwent keratometry and optical biometry by the IOLMaster in addition to cycloplegic refraction. The equation was assessed in affected eyes of consecutive children with unilateral amblyopia (at least 2 lines interocular difference with refractive correction). Of the 23 identified children (16 males, 7 females, 5-14 years of age), all had a cycloplegic spherical equivalent of ≥+2.75 D in at least one eye, 14 were anisometropic (by >1.00 D), and none had myopia. Estimated and measured axial lengths of amblyopic eyes were strongly correlated (Pearson coefficient 0.9; 95% confidence interval, 0.79-0.96) and did not differ significantly by the 2-sided paired t test (P = 0.3; difference between means, 0.1). The two values differed by ≤ 0.5 mm for most eyes (20/23) and were within 0.9 mm for all eyes, similar to what has been described for nonamblyopic eyes. The intraocular relationship of axial length to cycloplegic refraction and keratometry in hyperopic nonamblyopic eyes is maintained in hyperopic amblyopic eyes. Thus, the pathophysiology of amblyopia in this setting does not involve a mismatch among these biometric variables.

Optic Disc Area and Retinal Area in Amblyopia

Purpose: To compare retinal area to optic disc rim area ratios of hyperopic normal, strabismic eyes with equal acuity, amblyopic, and fellow eyes. Methods: Neuroretinal rim areas of 293 amblyopic and fellow eyes, and 77 non-amblyopic hyperopic right eyes, and 84 non-amblyopic strabismic right eyes were measured by magnification corrected retinal photography and planimetry. Retinal area estimates were based on axial lengths. Inclusion criteria: All subjects had bilateral hyperopia. Patients with glaucoma or known optic nerve atrophy were excluded. The normal and strabismic groups had equal visual acuity in each eye better than 20/40. The amblyopic group had acuity worse than 20/40 in one eye uncorrectable with lenses and without gross anatomic defects. Results: The amblyopic group included 137 with strabismus and 89 with anisometropia exceeding 1.5 diopters. There were highly significant differences between the ratio of retinal area to optic disc rim area of the amblyopic and of normal eyes (unpaired t-test, p = 8.6 × 10-6), the amblyopic and strabismic right eyes (unpairedt−test, p = 4.22 × 10-8) as well between the fellow and amblyopic eyes (pairedt−test, p = 2.13 × 10-5). The difference between the normal and strabismic eyes without amblyopia was not significant (p = 0.82). There was a 20 percent increase in the retinal receptor areas of hyperopic amblyopic eyes as compared to hyperopic eyes without amblyopia despite reduced retinal areas in the amblyopic eyes. Dysplastic and/or asymmetric optic discs were present in 163 of 293 (56 percent) amblyopic patients, 47 of 84 (56 percent) strabismic, and 10 of 77 (13 percent) normal patients. Conclusions: The increase in the receptor area may be an explanation for diminished acuity and impaired visual function in amblyopic eyes.