Analyses of eye movement parameters in children with anisometropic amblyopia.

OBJECTIVE: To investigate the characteristics of eye movement in children with anisometropic amblyopia, and to compare those characteristics with eye movement in a control group. METHODS: 31 children in the anisometropic amblyopia group (31 amblyopic eyes in group A, 31 contralateral eyes in group B) and 24 children in the control group (48 eyes in group C). Group A was subdivided into groups Aa (severe amblyopia) and Ab (mild-moderate amblyopia). The overall age range was 6-12 years (mean, 7.83 ± 1.79 years). All children underwent ophthalmic examinations; eye movement parameters including saccade latency and amplitude were evaluated using an Eyelink1000 eye tracker. Data Viewer and MATLAB software were used for data analysis. RESULTS: Mean and maximum saccade latencies, as well as mean and maximum saccade amplitudes, were significantly greater in group A than in groups B and C before and after treatment (P < 0.05). Mean and maximum saccade latencies were significantly different among groups Aa, Ab, and C (P < 0.05). Pupil trajectories in two detection modes suggested that binocular fixation was better than monocular fixation. CONCLUSIONS: Eye movement parameters significantly differed between contralateral normal eyes and control eyes. Clinical evaluation of children with anisometropic amblyopia should not focus only on static visual acuity, but also on the assessment of eye movement.

Characteristics of peripheral refractive errors in eyes of patients with non-amblyopic myopic anisometropia.

BACKGROUND: This study aims to investigate relative peripheral refractive (RPR) characteristics in children with non-amblyopic myopic anisometropia and explore potential associations between relative peripheral refractive errors (RPRE) and myopia. METHODS: Relative peripheral refractive errors were assessed in 64 children diagnosed with non-amblyopic myopic anisometropia utilizing multispectral refraction topography (MRT). Two eyes of each patient were divided into into the more myopia eyes group (ME) and the fellow eyes group (FE). Evaluated parameters encompassed total defocus values (TRDV), defocus values at eccentricities spanning 0 to 15 degrees (RDV-15), 0 to 30 degrees (RDV-30), 0 to 45 degrees (RDV-45), as well as superior (RDV-S), inferior (RDV-I), temporal (RDV-T), and nasal (RDV-N) positions. RESULTS: The study revealed a noteworthy contrast in TRDV values between Group ME (0.52 ± 0.36) and Group FE (0.17 ± 0.41), with a substantial significance (P < 0.0001). While no significant RDV-15 difference emerged between Group ME (0.01 ± 0.05) and Group FE (-0.01 ± 0.07) (P > 0.05), a meaningful RDV-30 difference existed between Group ME (0.11 ± 0.14) and Group FE (0.03 ± 0.19) (P = 0.0017). A significant discrepancy in RDV-45 was also observed between Group ME (0.39 ± 0.29) and Group FE (0.13 ± 0.34) (P < 0.001). Notably, RDV-I and RDV-T positions demonstrated marked differences between Group ME and Group FE (P < 0.0001), whereas no significant disparity was noted in RDV-S and RDV-N positions (P > 0.05). CONCLUSION: Eyes exhibiting greater myopia manifested more hyperopic peripheral defocus in the context of anisometropia. MRT as a novel ophthalmic evaluation technique, holds promising potential for broader clinical applications in the future.

Anisometropia and Amblyopia Outcomes in Early Versus Late Resolution of Congenital Nasolacrimal Duct Obstruction in Older Infants.

PURPOSE: Congenital nasolacrimal duct obstruction is a known risk factor for amblyopia and anisometropia. The purpose of this study was to investigate whether the rate of anisometropia and amblyopia development differed based on the age at CNLDO resolution in older infants. METHODS: This retrospective chart review at a single tertiary children's hospital from 2007 to 2017 compared early versus late spontaneous resolution (cutoff 12 months) and intervention (cutoff 15 months) groups presenting at ≥9 months of age, comparing visual outcomes, including anisometropia (≥1 D of sphere or cylinder) and amblyopia (≥2 levels difference in Teller acuity or optotype testing). Parents/guardians were contacted by phone for missing data on spontaneous resolution or intervention status. RESULTS: A total of 462 patients were included (152 early; 310 late group). The early group presented at a median age of 12.0 (interquartile range: 10.0, 13.0) months, while the late group presented at 21.0 (interquartile range: 15.0, 32.0) months. Unilateral disease occurred in 62% and 59%, respectively. Anisometropia was seen in (12/102) 12% of early versus (25/243) 10% of late patients (p = 0.686, 95% CI: -0.059, 0.088), and amblyopia in (4/131) 3% of early versus (14/286) 5% of late patients (p = 0.322, 95% CI: -0.061, 0.018). In patients presenting <24 months without undergoing surgery, spontaneous resolution occurred in 76% between 12 and 24 months (n = 41). CONCLUSIONS: Anisometropia and amblyopia rates did not significantly differ between early and delayed intervention for congenital nasolacrimal duct obstruction in this retrospective cohort presenting beyond 9 months of age to a children's hospital. This study found frequent late spontaneous resolution.

[Quantitative comparison of binocular suppression of patients with anisometropic amblyopia and ametropic amblyopia].

Objective: To explore the differences in clinical characteristics and interocular interactions between patients with anisometropic amblyopia and ametropic amblyopia. Methods: Cross-sectional study. The newly diagnosed anisometropic (the binocular difference in spherical equivalent≥1.00 D) amblyopia patients and ametropic amblyopia patients (aged 4 to 6 years) in Beijing Tongren Hospital from January 2020 to December 2022 were involved. Patients were further categorized by the refractive status after cycloplegia, including hyperopia, myopia, astigmatism, hyperopia with astigmatism, myopia with astigmatism, mild anisometropia and severe anisometropia. Quantitative measurements of best-corrected visual acuity (logMAR), stereoacuity (transformed to log units), perceptual eye position and interocular suppression were performed, and the differences between groups were analyzed. The rank sum test was used for statistical evaluation. Results: The average age of 45 ametropic amblyopia patients (21 males and 24 females) and 84 anisometropic amblyopia patients (48 males and 36 females) was 5.0 (4.0, 5.0) years and 5.0 (4.0, 6.0) years, respectively. The interocular differences in spherical equivalent [2.56 (1.50, 4.19) D vs. 0.25 (0.13, 0.56) D] and best-corrected visual acuity [0.40 (0.18, 0.70) logMAR vs. 0.07 (0.00, 0.12) logMAR] were larger in patients with anisometropic amblyopia than those with ametropic amblyopia. The anisometropic amblyopia patients had worse stereoacuity [2.60 (2.00, 2.90) log arcsec vs. 2.00 (2.00, 2.30) log arcsec] and deeper suppression [20.0% (13.3%, 40.0%) vs. 10.0% (0, 23.3%)], compared with the ametropic amblyopia patients. The differences were all statistically significant (P<0.05). The suppression and stereoacuity between patients with hyperopic anisometropic amblyopia [suppression, 30.0% (17.5%, 50.0%); stereoacuity, 2.90 (2.30, 2.90) log arcsec] and astigmatic anisometropic amblyopia [suppression, 10.0% (0, 20.0%); stereoacuity, 2.00 (2.00, 2.30) log arcsec] were significantly different (P<0.05). The differences of suppression and stereoacuity between patients with severe (binocular difference in spherical equivalent>2.50 D) [suppression, 30.0% (20.0%, 53.3%); stereoacuity, 2.90 (2.57, 2.90) log arcsec] and mild anisometropia [suppression, 20.0% (0, 30.0%); stereoacuity, 2.00 (2.00, 2.90) log arcsec] were also statistically significant (P<0.05). Conclusions: Patients with anisometropic amblyopia have deeper binocular suppression, worse stereoacuity and more severe binocular interaction abnormality than those with ametropic amblyopia. The severity of anisometropia affects the degree of the interaction abnormality.

Choroid vascular changes in hyperopic anisometropia amblyopia using SS-OCTA.

PURPOSE: To observe and understand the structural changes in choroidal vessels in eyes with hyperopic anisometropic amblyopia using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: A total of 44 patients were enrolled in this study: 22 children with hyperopic anisometropic amblyopia and 22 age-matched controls. SS-OCTA was used to scan the 6*6 mm macular area of their eyes. The average choroidal thickness (CT) and choroidal capillary flow area (CC) in a 3 mm diameter area centered on the macular area were obtained. The choroidal vascularity volume (CVV) was automatically extracted and 3D reconstructed by inbuild software, and the three-dimensional choroidal vascularity index (3D-CVI) was calculated. The effect of amblyopia on the choroidal vessel structure was assessed using generalized linear estimating equations (GEEs) corrected for axial length, sex, age, and best-corrected visual acuity. RESULTS: The CC was greater in amblyopic eyes than in fellow eyes (P = 0.014) but was not significantly different from that in control eyes (P = 0.963). After correcting for sex, age, axial length, and visual acuity using GEEs, the mean CT in the amblyopic eyes was greater than that in the fellow eyes (P = 0.030) but was not significantly different from that in the control eyes (P = 0.160). The 3D-CVI in amblyopic eyes was higher than that in control eyes (P = 0.038) but was not significantly different from that in fellow eyes (P = 0.407). The three-dimensional choroidal vascularity volume (3D-CVV) was higher in amblyopic eyes than in fellow eyes (P = 0.046) and control eyes (P = 0.023). CONCLUSIONS: We found that eyes with hyperopic anisometropic amblyopia demonstrated higher CT, CC and 3D-CVV values than the contralateral eyes after correction, while the 3D-CVI was unchanged. Compared with control eyes, amblyopic eyes had higher 3D-CVV and 3D-CVI values but similar CT and CC values. Amblyopic eyes may have different choroidal vascular structures from fellow and control eyes.

Effectiveness of Laser Refractive Surgery to Address Anisometropic Amblyogenic Refractive Error in Children: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the published literature assessing the safety and effectiveness of laser refractive surgery to treat anisometropic amblyogenic refractive error in children aged ≤ 18 years. METHODS: A literature search of the PubMed database was conducted in October 2021 with no date limitations and restricted to publications in English. The search yielded 137 articles, 69 of which were reviewed in full text. Eleven articles met the criteria for inclusion and were assigned a level of evidence rating. RESULTS: The 11 included articles were all level III evidence and consisted of 1 case-control study and 10 case series. Six studies used laser-assisted in situ keratomileusis (LASIK), 1 used photorefractive keratectomy (PRK), 1 used refractive lenticule extraction/small incision lenticule extraction, and the rest used a combination of LASIK, PRK, laser epithelial keratomileusis (LASEK), or refractive lenticule extraction/small incision lenticule extraction. Five studies enrolled patients with anisometropic myopia, 2 studies enrolled patients with anisometropic hyperopia, and the remainder were mixed. Although all studies demonstrated an improvement in best-corrected visual acuity (BCVA), the magnitude of improvement varied widely. As study parameters varied, a successful outcome was defined as residual refractive error of 1 diopter (D) or less of the target refraction because this was the most commonly used metric. Successful outcomes ranged between 38% and 87%, with a mean follow-up ranging from 4 months to 7 years. Despite this wide range, all studies demonstrated an improvement in the magnitude of anisometropia. Regression in refractive error occurred more frequently and to a greater degree in myopic eyes and eyes with longer follow-up, and in younger patients. Although one study reported 2 free flaps, most studies reported no serious adverse events. The most common complications were corneal haze and striae. CONCLUSIONS: Findings from included studies suggest that laser refractive surgery may address amblyogenic refractive error in children and that it appears to decrease anisometropia. However, the evidence for improvement in amblyopia is unclear and long-term safety data are lacking. Long-term data and well-designed clinical studies that use newer refractive technologies in standardized patient populations would help address the role of refractive surgery in children and its potential impact on amblyopia.

Etiology and Outcomes of Acquired Pediatric Sixth Nerve Palsies.

BACKGROUND: Acquired sixth nerve (CN6) palsies in children may be benign or associated with an underlying neurologic condition. In children who presented with isolated (no associated neurologic or ophthalmic symptoms or signs) CN6 palsies, the rate of newly diagnosed neurologic disorders (such as tumors) is unclear. Moreover, the factors associated with spontaneous resolution and amblyopia in children with acquired CN6 palsies are unknown. METHODS: We retrospectively reviewed the charts of all children younger than 18 years diagnosed with CN6 palsy at our institution from 2010 to 2020. We recorded ophthalmologic and neurologic history and examination findings, neuroimaging results, etiology of CN6 palsy, and outcomes including spontaneous resolution and amblyopia. We assessed etiologies of isolated and nonisolated CN6 palsies as well as frequency and factors associated with spontaneous resolution and amblyopia (in children ≤7 years). RESULTS: One hundred seventy-two children met inclusion criteria. Twenty CN6 palsies (12%) were isolated at presentation. Most isolated cases were presumed postviral or postvaccination (50%) or idiopathic (30%), but 2 cases (10%) were associated with newly diagnosed tumors. Spontaneous resolution occurred in 59% of CN6 palsies at a median of 12.3 weeks and was associated with older age (P = 0.03) and nontumor etiology (P = 0.006). Amblyopia developed in 18% of children at risk, exclusively in those with anisometropia, pre-existing strabismus, or younger than 12 months. CONCLUSIONS: Our findings and chart reviews suggest that approximately 10% of isolated acquired pediatric CN6 palsies are associated with a newly diagnosed brain tumor. This risk must be discussed with parents when considering immediate vs delayed neuroimaging. In addition, infants and children ≤7 years with secondary amblyogenic risk factors (anisometropia or pre-existing strabismus) require close follow-up to monitor and treat amblyopia.

Does anisometropia affect the ciliary muscle thickness? An ultrasound biomicroscopy study.

PURPOSE: To compare the ciliary muscle thickness (CMT) of the normal fellow eye to that of the amblyopic eye using ultrasound biomicroscopy (UBM) in patients with unilateral anisometropic amblyopia. METHODS: Thirty patients with unilateral anisometropic amblyopia were involved. The patients were divided into two groups: 19 hyperopic and 11 myopic. Axial length (AL) was measured with optic biometry and anterior chamber depth (ACD), iris area, and CMT were measured with UBM. RESULTS: The mean age was 34.10 ± 6.61 years. The mean spherical difference between two eyes was 2.59 diopter (D) in hyperopic patients and 3.77D in myopic patients. In the hyperopic patients, nasal CMT1(nCMT), temporal CMT1(tCMT), tCMT2, and tCMT3 values were statistically thinner in amblyopic eyes than healthy eyes (p = 0.036, p = 0.003, p = 0.023, p = 0.005, respectively). ACD values were statistically lower in amblyopic eyes (2.78 ± 0.26 mm) than healthy eyes (2.90 ± 0.21 mm) (p < 0.001). In the myopic patients, nCMT1, nCMT2, nCMT3, tCMT1, tCMT2, and tCMT3 values were statistically thicker in amblyopic eyes than healthy eyes (p = 0.003, p = 0.003, p = 0.005, p = 0.003, p = 0.003, p = 0.019, respectively). ACD values were statistically higher in amblyopic eyes (3.20 ± 0.30 mm) than healthy eyes (3.06 ± 0.29 mm) (p = 0.004). Also, there was no significant difference in the iris area between the amblyopic and normal eyes of the myopic and hyperopic patients (p > 0.05). CONCLUSIONS: Amblyopic eyes in patients with unilateral myopic anisometropia have thicker CMT and deeper ACD than healthy eyes. Conversely, amblyopic eyes in patients with unilateral hyperopic anisometropia have thinner CMT and shorter ACD than healthy eyes. There is a positive correlation between AL and CMT.

A Randomized Trial of Binocular Dig Rush Game Treatment for Amblyopia in Children Aged 7 to 12 Years.

PURPOSE: To compare visual acuity (VA) improvement in children aged 7 to 12 years with amblyopia treated with a binocular iPad game plus continued spectacle correction vs. continued spectacle correction alone. DESIGN: Multicenter randomized clinical trial. PARTICIPANTS: One hundred thirty-eight participants aged 7 to 12 years with amblyopia (33-72 letters, i.e., approximately 20/200 to 20/40) resulting from strabismus, anisometropia, or both. Participants were required to have at least 16 weeks of optical treatment in spectacles if needed or demonstrate no improvement in amblyopic-eye visual acuity (VA) for at least 8 weeks prior to enrollment. METHODS: Eligible participants (mean age 9.6 years, mean baseline VA of 59.6 letters, history of prior amblyopia treatment other than spectacles in 96%) were randomly assigned to treatment for 8 weeks with the dichoptic binocular Dig Rush iPad game (prescribed for 1 hour per day 5 days per week) plus spectacle wear if needed (n = 69) or continued spectacle correction alone if needed (n = 69). MAIN OUTCOME MEASURES: Change in amblyopic-eye VA from baseline to 4 weeks, assessed by a masked examiner. RESULTS: At 4 weeks, mean amblyopic-eye VA letter score improved from baseline by 1.3 (2-sided 95% confidence interval [CI]: 0.1-2.6; 0.026 logMAR) with binocular treatment and by 1.7 (2-sided 95% CI: 0.4-3.0; 0.034 logMAR) with continued spectacle correction alone. After adjusment for baseline VA, the letter score difference between groups (binocular minus control) was -0.3 (95% CI: -2.2 to 1.5, P = 0.71, difference of -0.006 logMAR). No difference in letter scores was observed between groups when the analysis was repeated after 8 weeks of treatment (adjusted mean: -0.1, 98.3% CI: -2.4 to 2.1). For the binocular group, adherence data from the iPad indicated that slightly more than half of the participants (58% and 56%) completed >75% of prescribed treatment by the 4- and 8-week visits, respectively. CONCLUSIONS: In children aged 7 to 12 years who have received previous treatment for amblyopia other than spectacles, there was no benefit to VA or stereoacuity from 4 or 8 weeks of treatment with the dichoptic binocular Dig Rush iPad game.

Surgical Timing for Congenital Ptosis Should Not Be Determined Solely by the Presence of Anisometropia.

PURPOSE: Timing of surgery in children with congenital ptosis is a critical component of care, and anisometropia is frequently cited as an indication for early intervention. The purpose of this study is to evaluate the change in refractive error following surgery for congenital ptosis to better inform decisions regarding the timing of surgery. METHODS: A retrospective review of clinical records was performed on patients who underwent surgical correction of congenital ptosis in an academic oculoplastic surgery practice from 2002 to 2017. Patients with complete preoperative and postoperative refractive data were included in the study. Changes in refractive error following surgery were analyzed. RESULTS: Among 184 pediatric patients who underwent ptosis surgery during the study period, 56 patients (71 eyes) met inclusion criteria. The mean age at surgery was 5.1 years. Mean refractive error change in all the operated eyes was a 0.82 D decrease in spherical equivalent (p = 0.1920) and a 0.40 D increase in cylinder (p = 0.0255). There were no statistically significant changes in spherical equivalent or cylinder in the control eyes. CONCLUSIONS: The authors data did not show movement toward normalization of refractive error following ptosis surgery. In fact, it showed a statistically significant worsening of astigmatism following surgery. Because refractive error does not improve following surgery, anisometropia should not be the sole indication for early surgery in congenital ptosis.

The Best of Both Worlds: Adaptation During Natural Tasks Produces Long-Lasting Plasticity in Perceptual Ocular Dominance.

In human vision, one eye is usually stronger than the other. This is called ocular dominance. Extremely imbalanced ocular dominance can be found among certain patient groups, for example, in patients with amblyopia. Here, we introduce a novel method to rebalance ocular dominance. We developed an altered-reality system that subjects used to interact with the natural world, the appearance of which was changed through a real-time image process. Several daily adaptation sessions lasting 3 hr each reduced sensory ocular dominance in adults who were not diagnosed with amblyopia and improved vision in patients with amblyopia. Surprising additional strengthening was found over the subsequent 2 months, when subjects experienced natural vision only. Our method effectively trains subjects to use both eyes in the wide variety of everyday tasks. The transfer of this training to everyday vision likely produced the continuing growth in effects during the months after the training. These findings are promising for the application of this method in future clinical research on amblyopia.

ASYMMETRIC DIABETIC RETINOPATHY PROGRESSION IN PATIENTS WITH AXIAL ANISOMETROPIA.

PURPOSE: To investigate the differences in the progression of diabetic retinopathy (DR) in both eyes of patients with axial anisometropia. METHODS: A retrospective review was conducted on diabetic patients who had different axial lengths (difference greater than 1 mm) in each eye. The primary objective of this study was to analyze the differences in the progression of DR in both eyes of patients with axial anisometropia. Fundus images (fluorescein angiography and photographs of the fundus covering the Early Treatment Diabetic Retinopathy Study seven fields) were graded using the Early Treatment Diabetic Retinopathy Study DR grading system. Also, the severity of diabetic retinopathy was analyzed based on the axial length and subfoveal choroidal thickness. RESULTS: Thirty-four of 6,963 patients with DR were included after applying the exclusion and inclusion criteria. The mean age was 53.53 ± 12.20 years and duration of diabetes was 9.63 ± 7.73 years. The mean axial length of the longer and shorter eye was 26.21 ± 2.04 mm and 23.21 ± 1.73 mm, respectively (P < 0.001). In shorter eyes, 61.7% (21 of 34) of the eyes had proliferative diabetic retinopathy. In contrast to the shorter eye, only 8 of the longer eyes (8 of 34, 23.5%) had proliferative diabetic retinopathy (McNemar test, P < 0.001). In eyes with thin subfoveal choroidal thickness (<250 µm), the proliferative diabetic retinopathy ratio was significantly lower (P = 0.007). CONCLUSION: In patients with axial anisometropia, the longer eye had a lower degree of DR progression than the shorter eye. This result showed that elongation of the axial length had a protective effect against the progression of DR without individual confounding factors.

Factors related to amblyopia in congenital ptosis after frontalis sling surgery.

BACKGROUND: Amblyopia is a main concern in children undergoing frontalis sling surgery for repairing congenital ptosis. This study aimed to evaluate factors related to amblyopia in children undergoing frontalis sling surgery. METHODS: IRB-approved retrospective review of children under the age of 12 who received frontalis sling surgery. Preoperative demographic data, strabismus, margin reflex distance 1 (MRD1), lid fissure height, sling type, refraction errors, surgical outcome and amblyopia were evaluated. RESULTS: This study included 48 eyelid procedures performed in 38 patients. Median age was 4.0 years. Etiology was congenital ptosis in 42 eyes (87.5%) and blepharophimosis in 6 eyes (12.5%). Mersilene mesh was the sling material used in 36 eyes (75%), silicone in 6 eyes (12.5%), and polytetrafluoroethylene (PTFE) in 6 eyes (12.5%). Mean duration of follow-up was 27.8 ± 25.0 months (range, 3 to 128 months). Amblyopia was observed in 17 eyes (35.4%) at the final follow-up. Factors significantly associated with final amblyopia included blepharophimosis (p = 0.017), preoperative MRD1 ≤ - 1.0 mm (p = 0.038), preoperative lid fissure ≤4.5 mm (p = 0.035), preoperative anisometropia (spherical equivalent) (p = 0.011), and postoperative astigmatism (p = 0.026). CONCLUSIONS: Study results suggest that blepharophimosis, preoperative MRD1 ≤ - 1.0 mm, preoperative lid fissure ≤4.5 mm, preoperative anisometropia (spherical equivalent), and postoperative astigmatism are associated with amblyopia after frontalis sling surgery in patients with congenital ptosis.

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.

Prognostic Factors Predicting the Surgical Outcomes of Bilateral Lateral Rectus Recession for Patients with Concomitant Exotropia in Chiang Mai University Hospital.

Objective: To determine the preoperative variables affecting early and late favorable outcomes of bilateral lateral rectus recession surgery for concomitant exotropia. Material and Method: A retrospective study of 65 patients with concomitant exotropia (constant and intermittent) who had bilateral lateral rectus recession was conducted. The follow-up period was more than 1 year in all patients. Preoperative parameters were obtained and evaluated using univariate analysis. Results: Sixty-five patients with concomitant exotropia who underwent bilateral lateral rectus recession were included. In the early and late postoperative outcome, 78% and 82% of the patients were in the success group, respectively. Meanwhile, 22% and 18% were in the failure group, respectively. There was no association between postoperative outcome and preoperative variables i.e. age at onset (p = 0.841, 0.591), age at surgery (p = 0.564, 0.634), interval between onset and surgery (p = 0.506, 0.753), preoperative deviation (p = 0.278, 0.211), refractive error (p = 0.217, 0.136), anisometropia (p = 0.946, 0.946), phase of exotropia (p = 0.741, 0.013), A-V pattern (p = 1.000, 1.000), stereopsis (p = 0.841, 0.268) and amblyopia (p = 0.569, 0.567). Conclusion: Preoperative variables could not be used to predict the early and late postoperative outcome.

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.

A randomized trial of levodopa as treatment for residual amblyopia in older children.

OBJECTIVE: To assess the efficacy and short-term safety of levodopa as adjunctive treatment to patching for amblyopia. DESIGN: Randomized, placebo-controlled trial. PARTICIPANTS: One hundred thirty-nine children 7 to 12 years of age with residual amblyopia resulting from strabismus, anisometropia, or both combined (visual acuity [VA], 20/50-20/400) after patching. METHODS: Sixteen weeks of oral levodopa or placebo administered 3 times daily while patching the fellow eye 2 hours daily. MAIN OUTCOME MEASURES: Mean change in best-corrected amblyopic-eye VA at 18 weeks. RESULTS: At 18 weeks, amblyopic-eye VA improved from randomization by an average of 5.2 letters in the levodopa group and by 3.8 letters in the placebo group (difference adjusted for baseline VA, +1.4 letters; 1-sided P=0.06; 2-sided 95% confidence interval, -0.4 to 3.3 letters). No serious adverse effects from levodopa were reported during treatment. CONCLUSIONS: For children 7 to 12 years of age with residual amblyopia after patching therapy, oral levodopa while continuing to patch 2 hours daily does not produce a clinically or statistically meaningful improvement in VA compared with placebo and patching.

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.

Associations between hyperopia and other vision and refractive error characteristics.

PURPOSE: To investigate the association of hyperopia greater than +3.25 diopters (D) with amblyopia, strabismus, anisometropia, astigmatism, and reduced stereoacuity in preschoolers. METHODS: Three- to five-year-old Head Start preschoolers (N = 4040) underwent vision examination including monocular visual acuity (VA), cover testing, and cycloplegic refraction during the Vision in Preschoolers Study. Visual acuity was tested with habitual correction and was retested with full cycloplegic correction when VA was reduced below age norms in the presence of significant refractive error. Stereoacuity testing (Stereo Smile II) was performed on 2898 children during study years 2 and 3. Hyperopia was classified into three levels of severity (based on the most positive meridian on cycloplegic refraction): group 1: greater than or equal to +5.00 D, group 2: greater than +3.25 D to less than +5.00 D with interocular difference in spherical equivalent greater than or equal to 0.50 D, and group 3: greater than +3.25 D to less than +5.00 D with interocular difference in spherical equivalent less than 0.50 D. "Without" hyperopia was defined as refractive error of +3.25 D or less in the most positive meridian in both eyes. Standard definitions were applied for amblyopia, strabismus, anisometropia, and astigmatism. RESULTS: Relative to children without hyperopia, children with hyperopia greater than +3.25 D (n = 472, groups 1, 2, and 3) had a higher proportion of amblyopia (34.5 vs. 2.8%, p < 0.0001) and strabismus (17.0 vs. 2.2%, p < 0.0001). More severe levels of hyperopia were associated with higher proportions of amblyopia (51.5% in group 1 vs. 13.2% in group 3) and strabismus (32.9% in group 1 vs. 8.4% in group 3; trend p < 0.0001 for both). The presence of hyperopia greater than +3.25 D was also associated with a higher proportion of anisometropia (26.9 vs. 5.1%, p < 0.0001) and astigmatism (29.4 vs. 10.3%, p < 0.0001). Median stereoacuity of nonstrabismic, nonamblyopic children with hyperopia (n = 206) (120 arcsec) was worse than that of children without hyperopia (60 arcsec) (p < 0.0001), and more severe levels of hyperopia were associated with worse stereoacuity (480 arcsec for group 1 and 120 arcsec for groups 2 and 3, p < 0.0001). CONCLUSIONS: The presence and magnitude of hyperopia among preschoolers were associated with higher proportions of amblyopia, strabismus, anisometropia, and astigmatism and with worse stereoacuity even among nonstrabismic, nonamblyopic children.

[Efficacy and safety of continuous full-time patching therapy initiated in pure anisometropic amblyopic children aged 8 to 14 years].

OBJECTIVE: To investigate the efficacy and safety of full-time patching therapy of anisometropic amblyopia in children aged 8-14 years. METHODS: It was a prospective case series study.Forty-three patients with anisometropic amblyopia without strabismus (ranged from 8-14 years, mean 10.8 years) were included in this study. All of the patients received eye patching for the entire day, 29 days a month, during the first 3 months. Distance best corrected visual acuity in LogMAR units; cycloplegic refraction and contrast sensitivity function were performed on all the patients before treatment, at a month later of full-time patching therapy, and all recorded at 3 months later, and evaluation the spatial function with visual acuity, the area under the log contrast sensitivity function (AULCSF), the co-ordinates of the peak of the CSF (maximum sensitivity, Smax, and the spatial frequency at which it occurs, Frmax) and the cut-off spatial frequency. Difference among groups was evaluated by analysis of variance (One-Way ANOVA), and the Bonferroni test investigated the pairwise comparison of the groups. RESULTS: The degree of amblyopia and the D-value of binocular AULCSF of before full-cover treatment, after one month's and three months' full-cover treatment were -0.70 ± 0.30, -0.57 ± 0.29, -0.47 ± 0.28 and 0.78 ± 0.48, 0.63 ± 0.43, 0.53 ± 0.42, respectively, which showed statistically significant differences (F = 6.406, P < 0.01; F = 3.517, P = 0.028). The degree of amblyopia, the D-value of binocular AULCSF after three months' full-cover treatment had significant difference compared with those before full-cover treatment (P < 0.01; P = 0.02). There were statistically significant differences along with time in the best corrected visual acuity (BCVA) of the amblyopic eye, AULCSF and CutSF (F = 6.906, P < 0.01; F = 4.016, P = 0.02; F = 5.717, P < 0.01). The BCVA of the amblyopic eye, AULCSF and CutSF after three months' full-cover treatment had significant difference compared with those before full-cover treatment (P < 0.01; P = 0.028; P < 0.01). However, the BCVA, AULCSF of the normal eye, and Smax, Frmax of amblyopic eye showed no statistically significant differences among groups along with time (F = 0.243, P = 0.785; F = 0.265, P = 0.768; F = 0.949, P = 0.390; F = 2.934, P = 0.057). CONCLUSIONS: The present results show that continuous full-time patching in older children with anisometropic amblyopia improves visual acuity, and cut off spatial sensitivity with no serious complications. The use of continuous full-time patching in after-school children to improve amblyopia seems promising.