Comparison of epidemiologic factors and eye manifestations of twin children with controls.

PURPOSE: The present study was aimed to compare the epidemiological and ocular findings of twin children in comparison with non- twin age matched individuals as their control. METHODS: In this cross sectional study, a total of 90 twins (180 cases) were compared with 182 non- twin matched children. All the study participants were examined by a comprehensive ophthalmic examination including measurement of the best corrected visual acuity (BCVA), cycloplegic refraction, ocular deviation, strabismus as well as the anterior and posterior ophthalmic examinations. Demographic information of children were collected by using an organized questionnaire. Monozygotic twins were considered if there were similarity of their phenotypic characteristics and gender, otherwise the twins were considered as dizygotic. RESULTS: The mirror- image twins (MIT) was defined according to the laterality of symmetrical ocular characteristics of twins. In this study, the mean age of the study participants was 7.08±4.42 and 7.58±3.99 years in twins and non-twins groups, respectively (P=0.253). Among the twins, 27 (30%) were monozygotic. Refractive form of MIT was seen in 5 twins (2.8%). The spherical refractive error was more hyperopic in twins compared to non- twins (P=0.041). BCVA in the twin group (0.07±0.16LogMAR) was significantly worse than non-twins (0.03±0.08LogMAR, P < 0.001) and higher percentage of them were amblyopic (37.2% versus 10.4%, P=0.005). Twin and controls had strabismus in 17.2% and 1.6%, respectively (P < 0.001). Regarding the comparison between mono- and dizygotic twins, more significant percentage of monozygotic twins had amblyopia (P=0.004) and strabismus (P=0.047). Multivariate analysis showed significant correlation among low gestational age and female gender, low birth weight and seizure. CONCLUSION: Female sex, less gestational age, low birth weight, amblyopia and strabismus were significantly higher in twins. Therefore, it is important to check their refractive error, amblyopia and strabismus to prevent their further complications.

Virtual Reality Game Playing in Amblyopia Therapy: A Randomized Clinical Trial.

PURPOSE: To compare the visual outcome of occlusion therapy with virtual reality game playing as a new therapy for children with amblyopia. METHODS: This randomized clinical trial was performed on 50 children between 4 and 10 years old who had unilateral amblyopia. They were randomly divided into virtual reality and patching groups (n = 25 in each). The virtual reality group was trained binocularly using the virtual reality games through a head set for 1 hour per day 5 days a week for 4 weeks. Patients in the patching group occluded their non-amblyopic eyes 2, 4, and 6 hours for mild (best corrected visual acuity [BCVA] 0.2 to 0.3 logarithm of the minimum angle of resolution [logMAR]), moderate (0.3 to 0.6 logMAR), and severe (worse than 0.6 logMAR) amblyopia, respectively. RESULTS: The mean BCVA based on logMAR units improved significantly in both groups (P < .0001), but the difference between the two groups was not significant (P = .59). BCVA based on the responded letters improved in both groups (virtual reality: P = .0001, patching: P = .001), and change in BCVA in the virtual reality group was higher than in the patching group (P = .002). CONCLUSIONS: Virtual reality game playing was equal or superior to patching in an analysis of linear and letter BCVA, respectively. Therefore, applying this new amblyopia therapy is recommended. [J Pediatr Ophthalmol Strabismus. 2021;58(3):154-160.].

Management of Consecutive Exotropia.

PURPOSE: To determine the clinical characteristics and surgical outcomes of medial rectus (MR) advancement with or without lateral rectus (LR) recession in patients with consecutive exotropia. METHODS: This interventional case series was performed on patients with consecutive exotropia of more than 15 prism diopters (PD) at least 6 months after the esotropia surgery. All patients were operated using either unilateral or bilateral MR muscle advancement with or without simultaneous LR recession. Ocular deviation at far and near distances, adduction limitation, and exoshift were investigated at the follow-ups of 1 week, as well as 1, 3, and 6 months after the surgery. Operation was considered successful when the postoperative far deviation was <10 PD. RESULTS: Thirty patients were evaluated. The mean amount of MR advancement was 5.69 ± 1.33 mm with the mean dose response of 4.7 ± 3.3 and 4.55 ± 4.01 PD at 3 and 6-month follow-ups, respectively. Success rate was reduced from 93% at week 1 to 73% at month 6 due to postoperative exodrift, especially during the first 3 months. Preoperative exotropia was the only contributing factor in our study. CONCLUSIONS: MR advancement was an effective surgical method for consecutive exotropia correction, especially in cases with MR underaction. Bilateral MR advancement and/or LR recession are suggested in cases with higher preoperative exodeviation. The presence of postoperative exodrift indicates longer follow-ups for patients.

Motor and Sensory Outcomes of Infantile Exotropia: A 10-Year Study (2008-2017).

PURPOSE: We aimed to determine the long-term motor and sensory outcomes of patients with infantile exotropia. METHODS: In this longitudinal retrospective (historical cohort) study, the records of 76 patients with infantile exotropia were Studied. Subjects with constant exotropia manifesting before the age of 1 year who were at least 5 years old at recruitment time between 2008 and 2017 were included. RESULTS: The medical records of 26 patients were excluded due to not participating in follow-up examinations or having incomplete records. In total, 54 infantile exotropic patients (51.9% male) with a mean age of 11.1 ± 6.8 years and follow-up of 4.99 ± 3.58 years were studied. Postoperative sensory outcomes (central stereopsis [<60 sec/arc], peripheral fusion [60-3,000 sec/arc], and non-stereopsis [>3,000 sec/arc]) were observed in 38.9%, 38.9%, and 21.2% of patients, respectively. In terms of postoperative motor outcomes, 69%, 24%, and 7% were achieved as orthophoria, residual exotropia, and consecutive esotropia, respectively. Patients with a higher surgical age (p = 0.022) and better visual acuity (p = 0.004) had significantly better sensory outcomes, while higher preoperative deviation resulted in more suppression (p = 0.039, rs = 0.218). CONCLUSIONS: With rates of 69% for motor success and 78.8% for sensory success, surgical outcomes of infantile exotropic patients seems to be favorable. Further studies are recommended to verify our findings.

Slanted versus Augmented Recession for Horizontal Strabismus.

PURPOSE: To compare the surgical outcomes of slanted versus augmented recession in patients with horizontal strabismus. METHODS: In this randomized clinical trial, a total of 100 esotropic (ET) and exotropic (XT) patients with a high AC/A ratio which was defined as a difference of ≥ 10 prism diopters (pd) between the distance and near deviations were included if the patients had a distance deviation ≥ 15 pd. Patients were randomly assigned into the slanted (n = 26 in ET and n = 24 in XT group) and augmented recession groups (n = 25 in ET and n = 25 in XT group). In the slanted group, recession was performed on the superior and inferior poles of the muscle based on the distance and near deviations, respectively, while in the augmented recession group, the muscles were recessed 1.00 or 1.50 mm more than the standard amount according to the distance and near difference between 10 and 20 pd or > 20 pd, respectively. RESULTS: The mean age was 9.8 ± 9.6 years and 63% were female. There was a significant postoperative reduction of difference in convergence excess in ET cases compared to patients who underwent the augmented recession procedure (12.65 ± 6.16 vs 8.64 ± 6.1 pd, P = 0.014). Among our XT groups, there was no significant difference in postoperative reduction in the XT angle in the slanted group compared with the augmented group (P > 0.05). CONCLUSION: Slanted recession is recommended in convergence excess ET patients. In XT patients, either slanted or augmented recession may be chosen according to the priority and experience of the surgeon.

Comparison between patching and interactive binocular treatment in amblyopia: A randomized clinical trial.

PURPOSE: To compare the effect of amblyopia therapy on cases who received interactive binocular treatment (I-BiT™) with those who received standard patching of the dominant eye with placebo I-BiT™. METHODS: In this randomized clinical trial, 38 unilateral amblyopic children (3-10 years old) were studied. All unilateral amblyopic children who had best corrected visual acuity (BCVA) worse than 0.30 logMAR or a difference of two Snellen lines of BCVA between their two eyes were included, and children who did not complete at least 75% of amblyopia treatment were excluded from this study. Eventually, a total of 19 and 21 subjects were included in case and control groups, respectively. Cases played I-BiT™ games, while controls had standard patch therapy and played with placebo I-BiT™ games, both for one month. All subjects were examined at baseline and after one-month therapy. RESULTS: BCVA improved significantly in both groups after one-month treatment (case: P = 0.003, control: P < 0.001), while in comparison with each other, there was not any difference between them (P = 0.52). Although stereopsis improved in the case (P < 0.001) and control (P < 0.001), there was no significant difference between them pre and post-therapy. Our children played games for about 6 h total during one month in both groups, and their compliance was 87.5% and 76% in cases and controls, respectively. Two children were excluded due to their lower compliance of playing I-BiT™ games (n = 38). CONCLUSIONS: I-BiT™ game and patching with placebo game had similar BCVA improvement in amblyopic children after one-month treatment. It is suggested to conduct further randomized clinical trials with a larger sample size and longer duration of study and assessment of its recurrence.

Reoperation in Horizontal Strabismus and its Related Risk Factors.

This study was performed to determine the surgical outcomes and the related risk factors of second operation in patients with residual horizontal deviations. In this interventional case series study, a total of 119 patients with a history of reoperation were included (39 exotropia and 80 esotropia). Cases with consecutive strabismus, muscular palsy, systemic disease, lack of ocular fixation, and those, who had vertical deviation and Dissociated Vertical Deviation (DVD)>5 Prism Diopters (pd) were excluded. Medial Rectus (MR) resection in residual Exotropia (XT) and Lateral Rectus (LR) resection in residual Esotropia (ET) were performed. Unilateral or bilateral operations were considered if the preoperative residual deviation was < 20 pd or > 20 pd, respectively. Success of the reoperation was considered if the postoperative angle of deviation was ≤ 10 pd. Unilateral and bilateral MR resection was performed in 26% and 74% of patients with XT, respectively, with greater dose response in unilateral cases (2.8 versus 2.6 mm/pd). Successful surgical outcomes were observed in 94.9% of patients with XT. Unilateral and bilateral LR resection was also performed in patients with residual ET, each in 50% of patients. Unilateral cases showed greater dose-response compared to bilateral ones (2.6 versus 2 mm/pd) and successful surgical outcomes were observed in 83.8% of patients with ET. No variable was found as a risk factor of reoperation in both groups. In conclusion, both LR and MR resection are easy and predictable surgical approaches with high success rate in patients with residual ET and XT. Generally, MR resection is more effective than LR resection. Unilateral operation is less recommended in the residual exotropic group, due to its lower success compared to the bilateral operation. Unfortunately, none of the mentioned variables were found to be the risk factor of reoperation in the sampled patients.

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.

The relationship between abduction deficit and reoperation among patients with infantile esotropia.

AIM: To determine the relationship between abduction deficit and reoperation among patients with infantile esotropia (IET). METHODS: The records of 216 patients (432 eyes) with IET who underwent surgery, from 2010 to 2015 were studied. Patients with IET whose deviation appeared before 6mo of age and had stable preoperative deviation in two examinations with at least 2wk apart and a minimum 3mo postoperative follow up were included. Cases with early onset accommodative esotropia, congenital cataract, retinopathy of prematurity (ROP), manifest nystagmus, fundus lesions, neurologic and ophthalmic anomalies, 6th nerve palsy and Duane's syndrome were excluded. Preoperative abduction deficit was considered from -1 to -3 grading scale. Three months after surgery, children were classified into no-need reoperation [deviation≤15 prism diopters (PD)], and need-reoperation groups (deviation>15 PD). RESULTS: In this retrospective study, 117 female and 99 male patients with the mean surgical age of 4.7±6.4y were included. Reoperation rate was 33.3% and 16.0% in IET patients with and without abduction deficit, respectively in patients who had a history of late surgery. Abduction deficit increased the odds of reoperation by 82% [OR=1.82, 95% confidence interval (CI) =1.05 to 3.19, P=0.003] in patients who had a history of late surgery (>2 years old, P=0.021). Abduction deficit was improved significantly after operation (P<0.001). CONCLUSION: Based on our results, abduction deficit can be considered as a risk factor of reoperation in IET patients who are operated at the age of more than 2y.

Graded versus ungraded inferior oblique anterior transposition in patients with asymmetric dissociated vertical deviation.

PURPOSE: To report the surgical outcomes of graded versus ungraded inferior oblique anterior transposition (IOAT) in treatment of patients with asymmetric dissociated vertical deviation (DVD) and bilateral inferior oblique overaction (IOOA). METHODS: A total of 74 eyes of 37 patients with asymmetric DVD (interocular difference of ≥5Δ) and bilateral IOOA of > +1 were included in this randomized clinical trial. In the ungraded group (n = 18), both inferior oblique muscles were sutured at the inferior rectus level; in the graded group (n = 19), the inferior oblique muscles of eyes with more DVD were sutured at the level of the inferior rectus and inferior oblique muscles of eyes with less DVD were sutured 2 mm posterior to the level of the inferior rectus muscle. RESULTS: DVD was significantly reduced in each group (P < 0.001 for both). Although the postoperative mean difference of asymmetry of DVD was less in the ungraded group compared to the graded group (1.2 ± 1.9 vs 3.2 ± 1.2 [P = 0.001]), the absolute amounts of reduction of DVD asymmetry were similar (4.3 ± 2.3 vs 4.4 ± 3.1 [P = 0.78]). IOOA and V patterns were also reduced postoperatively. CONCLUSIONS: Each method of IOAT was effective in reducing DVD, asymmetry, IOOA, and V patterns.

Inferior Oblique Overaction: Anterior Transposition Versus Myectomy.

PURPOSE: To compare the efficacy of inferior oblique myectomy and anterior transposition for correcting inferior oblique overaction (IOOA). METHODS: This retrospective study was conducted on 56 patients with IOOA who had either myectomy or anterior transposition of the inferior oblique muscle from 2010 to 2015. The authors compared preoperative and postoperative inferior oblique muscle function grading (-4 to +4) as the main outcome measure and vertical and horizontal deviation, dissociated vertical deviation (DVD), and A- and V-pattern between the two surgical groups as secondary outcomes. RESULTS: A total of 99 eyes of 56 patients with a mean age of 5.9 ± 6.5 years were included (47 eyes in the myectomy group and 52 eyes in the anterior transposition group). There were no differences in preoperative best corrected visual acuity, amblyopia, spherical equivalent, and primary versus secondary IOOA between the two groups. Both surgical procedures were effective in reducing IOOA and satisfactory results were similar between the two groups: 61.7% and 67.3% in the myectomy and anterior transposition groups, respectively (P = .56). After adjustment for the preoperative DVD, there was no statistically significant difference between the two groups postoperatively. The preoperative hypertropia was 6 to 14 and 6 to 18 prism diopters (PD) in the myectomy and anterior transposition groups, respectively. After surgery, no patient had a vertical deviation greater than 5 PD. CONCLUSIONS: Both the inferior oblique myectomy and anterior transposition procedures are effective in reducing IOOA with similar satisfactory results. DVD and hypertropia were also corrected similarly by these two surgical procedures. [J Pediatr Ophthalmol Strabismus. 2017;54(4):232-237.].

The Incidence of Reoperation and Related Risk Factors Among Patients With Infantile Exotropia.

PURPOSE: To determine the incidence and related risk factors of reoperation among patients with infantile exotropia who were operated on at Imam Hossein Medical Center, Tehran, Iran, from 2001 to 2015. METHODS: In this study, 82 children (55 girls and 27 boys) with infantile exotropia were divided into two groups 3 months after their first operation: children with horizontal deviation of 10 prism diopters (PD) or less (n = 64; success group) and those with horizontal deviation greater than 10 PD (n = 18; failure group). Patients with deviation of 20 PD or greater were indicated for reoperation. Factors including age at the first operation, preoperative angle of deviation, inferior oblique muscle overaction, dissociated vertical deviation, and A- or V-pattern in relation to reoperation were studied. Sensory status of children older than 5 years was also evaluated using Worth 4-dot and Titmus tests. RESULTS: Reoperation was indicated in 18.3% (n = 15) of patients after 11.5 ± 19 months of follow-up. Preoperative angle of deviation (P < .001) and surgical approach (P = .017) were statistically different between the failure and success groups. The majority of patients (71%) achieved fusion and gross stereopsis (< 3,000 seconds of arc) after surgery. CONCLUSIONS: According to the results, 18.3% of patients with infantile exotropia, especially those with more preoperative exotropia, needed reoperation to achieve good alignment. Although the recession-resection method had better motor results, the authors could not recommend it as a first operation for all patients with infantile exotropia because it was only performed on patients with amblyopia. Gross stereopsis and binocular fusion were seen in the majority of patients. [J Pediatr Ophthalmol Strabismus. 2017;54(1):22-30.].

The role of Interactive Binocular Treatment system in amblyopia therapy.

PURPOSE: To determine the role of Interactive Binocular Treatment (I-BiT™) as a complementary method of patching in amblyopia therapy. METHODS: In this randomized clinical trial study, 50 unilateral amblyopic children (25 male/25 female) between 3 and 10 years with either best corrected visual acuity (BCVA) ≤20/30 in the amblyopic eye or a difference of BCVA ≥ 2 lines between the two eyes were included. They were randomly classified into the case and control groups (25 in each). Patching was recommended in both groups, and cases also received I-BiT™. Cases were asked to play I-BiT™ games through appropriate glasses with conjugate colored filters. Moving and fixed targets were shown to the amblyopic and non-amblyopic eyes, respectively. Playing games was continued 20 min in each session for 5 days a week within one month (total time: 6.6 h). Patching was continued for one month more in both groups to evaluate the continuous effect of I-BiT™. BCVA was measured at baseline, one month after beginning I-BiT™, and one month after cessation of I-BiT™. RESULTS: BCVA of amblyopic eyes in cases and controls were 0.34 ± 0.14 and 0.33 ± 0.17LogMAR at baseline which improved to 0.17 ± 0.14 and 0.26 ± 0.17 at one month, respectively. The difference was significant in each group (p < 0.001 for cases and p = 0.024 for controls) with more improvement in the case group (p < 0.001). One month after cessation of I-BiT™, BCVA difference between the two groups was not statistically significant. There was no case with recurrence of amblyopia. CONCLUSION: Based on our results, I-BiT™ seems to be effective in amblyopia therapy accompanied with patching. We recommend comparing I-BiT™ alone with patching in further studies. ClinicalTrials.gov Identifier: NCT02740725.

Prevalence of Amblyopia and Refractive Errors Among Primary School Children.

PURPOSE: To determine the prevalence of amblyopia and refractive errors among 7 to 12-year-old primary school children in Tehran, Iran. METHODS: This population-based cross-sectional study included 2,410 randomly selected students. Visual acuity was tested using an E-chart on Yang vision tester. Refractive errors were measured by photorefractometry and cycloautorefraction. Strabismus was checked using cover test. Direct ophthalmoscopy was used to assess the anterior segment, lens opacities, red reflex and fundus. Functional amblyopia was defined as best corrected visual acuity ≤20/40 in one or both eyes with no anatomical problems. RESULTS: Amblyopia was present in 2.3% (95% CI: 1.8% to 2.9%) of participants with no difference between the genders. Amblyopic subjects were significantly younger than non-amblyopic children (P=0.004). Overall, 15.9% of hyperopic and 5.9% of myopic cases had amblyopia. The prevalence of hyperopia ≥+2.00D, myopia ≤-0.50D, astigmatism ≥0.75D, and anisometropia (≥1.00D) was 3.5%, 4.9%, 22.6%, and 3.9%, respectively. With increasing age, the prevalence of myopia increased (P<0.001), that of hyperopia decreased (P=0.007), but astigmatism showed no change. Strabismus was found in 2.3% of cases. Strabismus (OR=17.9) and refractive errors, especially anisometropia (OR=12.87) and hyperopia (OR=11.87), were important amblyogenic risk factors. CONCLUSION: The high prevalence of amblyopia in our subjects in comparison to developed countries reveals the necessity of timely and sensitive screening methods. Due to the high prevalence of amblyopia among children with refractive errors, particularly high hyperopia and anisometropia, provision of glasses should be specifically attended by parents and supported by the Ministry of Health and insurance organizations.