Stereoacuity after Successful Occlusion Therapy in Children with Anisometropic Amblyopia

Purpose: To compare the stereoacuity between patients with anisometropic amblyopia who were treated and achieved normal visual acuity (VA) and normal children and evaluate the factors associated with stereoacuity.Methods: We retrospectively reviewed the records of 37 pediatric patients with anisometropic amblyopia who recovered to normal VA with glasses and occlusion treatment (amblyopia group) and 34 normal children (control group). The Worth 4-dot test, Lang II test, Titmus test, and TNO test were performed to measure stereoacuity. Clinical characteristics were compared between the two groups, and factors affecting stereoacuity outcomes were also analyzed in the amblyopic group.Results: The mean age at diagnosis of amblyopia was 5.3 ± 1.4 years, and the mean VAs at diagnosis were 0.41 ± 0.24 and 0.06 ± 0.07 in amblyopic and fellow eyes, respectively. The mean duration of occlusion was 19.00 ± 9.44 months, and VA of amblyopic eyes improved to 0.04 ± 0.04 after occlusion treatment. The patient characteristics did not differ significantly between the two groups, except for the final VA of the amblyopic eye. The final mean logarithm of minimal angle of resolution VA of the amblyopic eye in the amblyopia group was significantly worse than that in the control group. The number of patients with normal stereoacuity was significantly lower in the amblyopia group than in the control group on Lang II, Titmus, and TNO tests. Factors associated with poor stereoacuity were severe amblyopia in the Lang II test and poor post-treatment VA of the amblyopic eye in the Titmus test.Conclusions: Stereoacuity was worse in the amblyopia group than in the control group, despite normal visual development. The depth of amblyopia and post-treatment VA were associated with stereoacuity outcomes. Thus, VA improvement should be closely monitored in the amblyopic eye to obtain good stereoacuity.

Effect of refractive error type in the amblyopic eyes on factors for treatment success in anisometropic amblyopia

To investigate the factors for treatment success in anisometropic amblyopia according to the spherical equivalent (SE) type of amblyopic eyes. Medical records of 397 children with anisometropic amblyopia aged 3 to 12 years who presented in a secondary referral eye hospital during 2010 ~ 2016 were retrospectively reviewed. Anisometropia was defined as ≥ 1 diopter (D) difference in SE, or ≥ 1.5 D difference of cylindrical error between the eyes. According to the SE of amblyopic eyes, patients were categorized into hyperopia (SE ≥ 1D), emmetropia (− 1 < SE < + 1) and myopia (SE ≤ − 1D) groups. Treatment success was defined as achieving interocular logMAR visual acuity difference < 0.2. Multivariate logistic regression was used to analyze the factors for treatment success. Significant factors for the amblyopia treatment success in hyperopia group (n = 270) were younger age [adjusted odds ratio (aOR) (95% confidence interval, CI) = 0.529 (0.353, 0.792)], better BCVA in amblyopic eyes at presentation [aOR (95% CI) 0.004 (0, 0.096)], longer follow-up period [aOR (95%CI) = 1.098 (1.036, 1.162)], and no previous amblyopia treatment history [aOR (95% CI) 0.059 (0.010, 0.364)]. In myopia group (n = 68), younger age [aOR (95% CI) 0.440 (0.208, 0.928)] and better BCVA in amblyopic eyes [aOR (95% CI) 0.034 (0.003, 0.469)] were associated with higher odds of treatment success. There was no significant factor for treatment success in emmetropia group (n = 59) in this population. The refractive error type of amblyopic eyes at presentation affects the factors for treatment success in anisometropic amblyopia.

EFFECT OF PART-TIME PATCHING THERAPY ON VISUAL OUTCOME IN PATIENTS WITH ANISOMETROPIC AMBLYOPIA VISITING AFIO RAWALPINDI

Objective: To determine the effect of amblyopia patching therapy on visual outcome in young and adults at 6th and 12th week. Study Design: Quasi-experimental study. Place and Duration of Study: Armed Forces Institute of Ophthalmology Rawalpindi, Pakistan, from Sep 2018 to Jan 2020. Methodology: Out of 110, follow up was successfully completed by 91 eyes. Subjects were divided into young and adult based on age. Age ranging from 5-12 years included in the young group and adult group included those ranging from 13-20 years. Anisometropic amblyopia was considered. Amblyopia due to any other disease were excluded. Subjects were advised patching therapy daily for 4 hours in the affected eye. Follow up was 3 weekly for 12 weeks and the effect of patching therapy was assessed by visual improvement. Statistical analysis was done with SPSS version 21. Result: Out of 91 eyes with amblyopia, 51 (56.6%) were included in the young group while 40 (43.4%) were included in the adult group. In the young group, visual improvement was seen in 40 (78.4%) while in the adult group 24 (60%) showed improvement in vision. Mean visual improvement in young was 1.66 ± 1.099 while 1.03 ± 0.944 in the adult group. Maximum visual improvement in both groups was seen till the 6th week of patching. Conclusion: Patching therapy is effective even at later ages too. However, continuing patching for more than 6 weeks doesn’t show much improvement in vision.

Evaluation of the efficacy, safety, and stability of posterior chamber phakic intraocular lenses for correcting intractable myopic anisometropic amblyopia in a pediatric cohort

Background Myopic anisometropic amblyopia in pediatrics is one of the most challenging clinical situations that can face an ophthalmologist. Conventional correction modalities for myopic anisometropia, using spectacles, contact lenses, and/or occlusion therapy, may not be suitable for some pediatric patients or for some ocular conditions. This may lead to the development of anisometropic amblyopia. The aim of the present study was to evaluate the visual and the refractive efficacy, safety, and stability of Posterior Chamber Phakic Intraocular Lenses (PC-pIOLs) for correcting myopic anisometropic amblyopia in a pediatric cohort. Methods This case series, prospective, interventional study was conducted at Watany Eye Hospital, Cairo, Egypt. It comprised children and teenagers with myopic anisometropic amblyopia and unsuccessful conventional therapy. After implantation of Intraocular Collamer Lenses “ICLs” (Visian ICL, Model V4c, STAAR Surgical, Monrovia, California, USA), postoperative follow-up visits were scheduled, with automated refraction and Pentacam imaging performed. Results The study enrolled 42 eyes of 42 patients. The age range was 3 to 18 years (mean ± SD = 10.74 years ±4.16). The mean preoperative spherical equivalent (SE) was − 12.85 D ± 2.74. The results declared a significant improvement in the postoperative Corrected Distance Visual Acuity “CDVA” (P value < 0.01) and SE (P value < 0.01). The efficacy index had a value of 1.18 ± 0.3 and the safety index was 1.09 ± 0.24. The follow-up visits had a mean ± SD of 14.67 months ±16.56 (range of 1 to 54 months). The results showed a refractive stability, with statistically insignificant improvements in the patients’ visual acuity and refractive status on evaluating the enrolled pediatrics during the follow-up visits compared to the first postoperative visits. No postoperative complications were encountered. Worthy of mention is that there was a significant (80%) non-compliance with the prescribed postoperative occlusion therapy. Conclusions The present study, with the longest reported follow-up range, declared the long-term efficacy, safety, and stability of Visian ICLs for correcting myopic anisometropic amblyopia in pediatrics. The reported non-compliance with occlusion therapy validates the early implantation of Visian ICLs in cases with failed conventional therapy to guard against anisometropic amblyopia.

Retinal Thickness and P-ERG Changes in Adult Patients With Anisometropic and Strabismic Amblyopia

Objective To investigate the changes of retinal thickness and P-ERG signals in adult patients with anisometropic and strabismic amblyopia. Methods Sixty patients with monocular adult amblyopia, including 30 anisometropic amblyopes (AA group) and 30 strabismic amblyopes (SA group), were enrolled in our study at the outpatient clinic of The Hefei First People’s Hospital Hospital of Anhui medical University from June 2019 to November 2020. Retinal nerve fiber layer (RNFL) thickness was measured within 3.4 mm diameter range surrounding the optic nerve, and ganglion cell complex (GCC) layer thickness within 6 mm diameter range surrounding the fovea by an Optovue RTVue OCT in both amblyopic and fellow eyes. The amplitude and latency of P50 and N95 in P-ERG were recorded by a Roland electrophysiology instrument under two stimulation conditions with different temporal and spatial frequencies that were designed to bias the parvocellular and magnocellular pathways respectively. Data between amblyopic and fellow eyes was statistically analyzed by paired t test. The correlation between axial length and parameters of OCT and P-ERG was examined by Pearson correlation test. Results (1) Changes in RNFL thickness: In the AA group, RNFL thickness in temporal sector was significantly thinner (p = 0.033), while that in the nasal, superior and inferior sectors increased (p < 0.05) compared with fellow eyes. In SA group, no significant difference (each sector p > 0.05) was found between amblyopic eyes and fellow eyes. (2) Changes in GCC thickness: Compared with fellow eyes, in the AA group, GCC layer thickness of amblyopic eyes was significantly increased (p = 0.039), whereas in the SA group, we did not find a significant difference between amblyopic eyes and fellow eyes (p > 0.05). (3) P-ERG stimulated mode biased the parvocellular pathway: When compared with fellow eyes (n = 15), in the AA group, the amplitudes of P50 (p = 0.004) and N95 (p = 0.038) were significantly decreased in amblyopic eyes, but no significant latent time difference (p > 0.05) was found. In the same stimulus pattern, no statistically significant difference (n = 15, p > 0.05) between amblyopic eyes and fellow eyes was found in the amplitude and latency of P50 and N95 in the SA group. (4) P-ERG stimulated mode biased the magnocellular pathway: The amplitude and latency of P50 and N95 showed no statistically significant difference (p > 0.05) in either the AA group or the SA group. (5) We found no significant correlation between axial length and OCT, P-ERG parameters (p > 0.05) in either group. Conclusion Our results showed that the alterations in structure and function of retina that could be seen in adult anisometropic amblyopia were not found in adult strabismic amblyopia group. The functional loss in anisometropic amblyopia was found to bias to a damage of partial ganglion cells by the parvocellular pathway. These findings indicated that the pathological mechanisms were different between anisometropic and strabismic amblyopia.

FREQUENCY AND ASSOCIATIONS OF MARCUS GUNN PHENOMENON IN CONGENITAL PTOSIS

Objective: To determine the frequency and various associations of Marcus Gunn Phenomenon in patients of congenital ptosis. Study Design: Cross-sectional observational study. Place and Duration of Study: Department of Ophthalmology, Khyber Teaching Hospital, Peshawar, from Jun to Sep 2020. Methodology: A total of 100 patients with congenital ptosis were included. Patients with any cause of secondary or acquired ptosis were excluded. Congenital ptosis was classified as simple and complex. Assessment for ptosis severity, presence of jaw winking ptosis, jaw winking severity, refractive error, amblyopia, strabismus, systemic association and family history for congenital ptosis was performed. Results: Simple congenital ptosis was the most common type overall (84%). A total of 60% patients were males and 40% were females. More than 90% of the patients had severe ptosis. Ninety eight percent cases had onset since birth. No patient had systemic association or positive family history. Nine percent frequency of Marcus Gunn Phenomenon was noted with congenital ptosis. All the patients with Marcus Gunn Phenomenon had unilateral presentation. Left eye was affected predominantly (88.89%). A total of 22.22% of the patients with Marcus Gunn Phenomenon had anisometropic amblyopia. No other ocular or systemic association of Marcus Gunn Phenomenon was observed. Conclusion: Simple congenital ptosis is the most common type of congenital ptosis. The authors report 9% frequency of Marcus Gunn Phenomenon with congenital ptosis and left side effected predominantly. Anisometropic amblyopia was the major ocular association of Marcus Gunn Phenomenon observed.

Factors for Treatment Success in Anisometropic Amblyopia: Effect of Refractive Errors of the Amblyopic Eyes

Purpose: To investigate the factors for treatment success in anisometropic amblyopia according to the spherical equivalent (SE) type of amblyopic eyes. Methods: Medical records of 397 children with anisometropic amblyopia aged 3 to 12 years during 2010~2016 were retrospectively reviewed. Anisometropia was defined as ≥1 diopter (D) difference in SE, or ≥1.5 D difference of cylindrical error between the eyes. According to the SE of amblyopic eyes, patients were categorized into hyperopia (SE ≥1D), emmetropia (-1< SE <+1) and myopia (SE ≤-1D) groups. Treatment success was defined as achieving interocular LogMAR visual acuity difference < 0.2. Multivariate logistic regression was used to analyze the factors for treatment success.Results: Significant factors for the amblyopia treatment success in hyperopia group (n=270) were younger age [adjusted odds ratio (aOR) (95% confidence interval, CI) = 0.60 (0.41-0.88)], larger astigmatism of sound eye [aOR (95% CI) = 0.04 (0-0.78)], better BCVA in amblyopic eyes at presentation [aOR (95% CI) = 0.01 (0-0.16)], longer follow-up period [aOR (95%CI)=1.1 (1.04-1.17)], and no comorbid strabismus [aOR (95%CI)= 0.25 (0.06-0.99)]. In myopia group (n=68), older age [aOR (95% CI) =0.45 (0.20-0.97)] and worse BCVA in amblyopic eyes [aOR (95% CI) = 0.04 (0-0.61)] were inversely associated with higher odds of treatment success. There was no significant factor for treatment success in emmetropia group (n=59).Conclusions: The type of refractive error of amblyopic eyes at presentation affects the factors for treatment success of anisometropic amblyopia.

Virtual Reality Visual Training in an Adult Patient with Anisometropic Amblyopia: Visual and Functional Magnetic Resonance Outcomes

A case of an adult with anisometropic amblyopia who underwent a successful vision therapy program playing videogames in a virtual reality environment is described, reporting changes in conventional visual clinical data, as well as in brain activity. The patient was a 22 year old man on baseline examination that never previously wore correction for his anisometropia. After prescribing contact lens correction for the anisometropia and after 44 h of virtual reality-based vision therapy over a period of 1.5 years, the best corrected distance visual acuity (BCDVA) in the amblyopic eye improved from 0.05 to 0.5 (Sloan chart). One year after finishing the visual training, the BCDVA experienced a slight decrease to 0.4 (Sloan chart). Through the visual training, the patient gradually developed stereopsis. Likewise, changes were also detected after visual therapy on functional magnetic resonance imaging while the patient was viewing 2D and 3D stimuli. The preliminary results of this case show the potential of using virtual reality-based visual training as a treatment for adult amblyopia.

A Long Term Follow Up of Posterior Chamber Phakic Intraocular Lenses for Correcting Intractable Pediatric Myopic Anisometropic Amblyopia

Background Pediatric myopic anisometropic amblyopia is one of the most challenging clinical situations that can face an ophthalmologist. Conventional correction modalities for myopic anisometropic amblyopia, using spectacles, contact lenses, and/or occlusion therapy, may not be suitable for some pediatric patients or for some ocular conditions. This may lead to the development of amblyopia and loss of binocular vision. The aim of the present study was to evaluate the visual and refractive efficacy, safety, and stability of Posterior Chamber Phakic Intraocular Lenses (PC-pIOLs) for correcting pediatric myopic anisometropic amblyopia. Methods This case series, prospective, interventional study was conducted at Watany Eye Hospital, Cairo, Egypt. It comprised 42 eyes of 42 children with myopic anisometropic amblyopia and unsuccessful conventional therapy. After implantation of Intraocular Collamer Lenses “ICLs” (Visian ICL, Model V4c, STAAR Surgical, Monrovia, California, USA), postoperative follow up visits were scheduled, with subjective refraction and Pentacam imaging performed. Results The patients’ age range was 3 to 18 years (mean ± SD = 10.58 years ± 4.23). The mean preoperative SE was − 12.54 D ± 2.93. The results declared a significant improvement in the postoperative CDVA (P value < 0.01) and SE (P value < 0.01). The efficacy index had a value of 1.18 ± 0.3 and the safety index was 1.09 ± 0.24. The follow up visits had a mean ± SD of 14.67 months ± 16.56 (range of 1 to 54 months). The results showed a refractive stability, with slight (statistically insignificant) improvements in the subjective refraction between the first postoperative and the follow up visits. No postoperative complications were encountered. Conclusions The present study, with the longest reported follow up range, declared the long-term efficacy, safety, and stability of Visian ICLs for correcting pediatric myopic anisometropic amblyopia. The reported non-compliance with occlusion therapy validates the early implantation of Visian ICLs in cases of failed conventional therapy to guard against anisometropic amblyopia.

Alternative Flicker Glass: a New Anti-suppression Approach to the Treatment of Anisometropic Amblyopia

Introduction: Amlyopia always presents with monocular and binocular dysfunction. In this study, we aim to investage the efficacy of alternative occlusion using liquid crystal glasses versus continuous occlusion therapy using traditional patches for treating amblyopia. Methods: Eligible subjects with anisometropic amblyopia were randomized into two groups: alternative flicker glass (AFG) or patching group. In the AFG group, subjects were instructed to wear the flicker glasses for 1 hour a day. The AFG is a lightweight spectacle frame with liquid crystal lenses that provide direct square-wave alternating occlusion, which were pre-programmed at temporal frequency of 7Hz. In the patching group, the patients were prescribed to wear traditional patches for 2 hours a day. The best corrected visual acuity (BCVA), contrast sensitivity function (CSF) and stereoacuity were measured at the baseline, 3 and 12 weeks. Results: In this pilot study, a total of forty children were recruited, with twenty in the AFG group. Mean BCVA improved by 0.17±0.14logMAR (95% CI=0.10 to 0.23) in the AFG group, while 0.18±0.18logMAR (95% CI=0.09 to 0.26) in the patching group from baseline to 12 weeks. The improvement of BCVA in both groups were significant (both P＜0.01), while no significant difference between the groups (P=0.82). The CSF of both low and high spatial frequencies exhibited significant improvement at 12 weeks in the AFG group (P＜0.01, respectively), while just have a significant improvement at low spatial frequency in the patching group (P＜0.01). The stereoacuity significantly improved by 504.00±848.00 (95% CI= -900.88 to -107.12) arc seconds in the AFG group (P＜0.05), while 263.50± 639.55 (95% CI=-562.82 to 35.82) arc seconds in the patching group (P＞0.05). Conclusion: Alternative flicker glass was effective in improving both monocular and binocular function, which was most likely achieved by reducing the suppression and promoting binocular fusion. This therapy exhibited promise as an alternative method for amblyopia treatment.