The Effect of Amblyopia Treatment with Patching on Ocular Alignment

PURPOSE: To evaluate the effect of patching on ocular alignment in children with unilateral amblyopia. METHODS: We evaluated the change in ocular alignment during and after patching in patients who had started amblyopia treatment with patching, and analyzed the aspects of change according to the cause and severity of amblyopia, type and magnitude of deviation, type of refractive error, and age at initiation. A change of eight prism diopters (PD) or more in horizontal deviation, or two PD or more in vertical deviation was considered significant. RESULTS: A total of 209 patients were enrolled; 135 had amblyopia associated with anisometropia, 50 with strabismus, 19 with combined cause, and 5 with deprivation. After patching, there was no change in distant deviation in 177 patients (84.7%), while a decrease was noted in 23 patients (11.0%) and an increase in nine patients (4.3%). The angle of deviation decreased in 7.4% of anisometropic amblyopia, 20.0% of strabismic amblyopia, 10.5% of combined amblyopia, and 20.0% of deprivation amblyopia. The angle of deviation increased in 4.4% of anisometropic amblyopia, 5.3% of combined amblyopia, and 40.0% of deprivation amblyopia. The angle of deviation decreased in 24.2% of exodeviation, and 21.6% of esodeviation, but there was no change in vertical deviation among the studied patients. The angle of deviation decreased in 31.9% of patients with deviation greater than 8 PD. The change did not differ according to severity of amblyopia, type of refractive error, or age. Among the successes, decrease in deviation was more common until they achieved equal visual acuity between both eyes, while the increase during tapering of patching. CONCLUSIONS: Change in ocular alignment may occur after patching in some patients with amblyopia, and seems to be more frequent in cases associated with horizontal deviation greater than 8 PD.

2014 updated recommendations for preschool vision screening: Guidelines for Filipino children entering the Philippine public school system

@#In 2004, the University of the Philippines Manila published the Philippine Guidelines on Periodic Health Examination (PHEX): Effective Screening for Diseases among Apparently Healthy Filipinos. 1 The document was envisioned to “contribute… to the quality and efficiency of health care and health maintenance for all Filipinos… It was an appeal for rational medical decision-making, and an important step toward “equitable distribution of health and health resources.” The guidelines were prepared by designated task forces, with vision disorders, specifically vision impairment, and glaucoma identified as areas of interest. PHEX recommendations were drafted using standardized principles and a common protocol, with each statement undergoing four phases of development: (1) preparation of the evidence- based draft; (2) en banc meeting that gave panelists a chance to assess and revise the draft, where issues of feasibility, resource limitations, value judgment, and experts’ opinions were taken into account. A consensus was declared when at least 75% agreed on a recommendation; (3) for unresolved issues, modified Delphi technique was employed by correspondence until a consensus was reached or a maximum of three circulations were accomplished. If still unresolved, the issue was labeled as such and included in the final draft; (4) lastly, a public forum was conducted before the final draft was written. In this manner, the recommendations for Screening for Visual Impairment were written by the Task Force for Vision Disorders.

Reduction of Deviation Angle During Occlusion Therapy: In Partially Accommodative Esotropia with Moderate Amblyopia

PURPOSE: To evaluate changes in ocular alignment in partially accommodative esotropic children age ranged from 3 to 8 years during occlusion therapy for amblyopia. METHODS: Angle measurements of twenty-two partially accommodative esotropic patients with moderate amblyopia were evaluated before and at 2 years after occlusion therapy. RESULTS: Mean deviation angle with glasses at the start of occlusion treatment was 19.45+/-5.97 PD and decreased to 12.14+/-12.96 PD at 2 years after occlusion therapy (p<0.01). After occlusion therapy, 9 (41%) cases were indications of surgery for residual deviation but if we had planned surgery before occlusion treatment, 18 (82%) of patients would have had surgery. There was a statistical relationship between increase of visual acuity ratio and decrease of deviation angle (r=-0.479, p=0.024). CONCLUSIONS: There was a significant reduction of deviation angle of partially accommodative esotropic patients at 2 years after occlusion therapy. Our results suggest that occlusion therapy has an influence on ocular alignment in partially accommodative esotropic patients with amblyopia.

Update in the Diagnosis and Treatment of Strabismus

Strabismus is defined as an ocular misalignment. Since it can cause not only impaired visual function but also social handicap and tremendous emotional stress, the care of patients with strabismus should include psychological and social aspects. Although strabismus is one of the major fields in pediatric ophthalmology and neuro-ophthalmology, its precise mechanism and etiology are still unknown. It can be inherited from strabismic parents, or be derived from the anomalous structure, neurologic deficits, and refractive errors. The diagnosis of strabismus can be made by covering one eye, and the degree of strabismus can be quantified by the alternate prism cover test. Recently MRI is used widely for the diagnosis of various anomalous orbital and muscular structures, especially to investigate heterotopia of extraocular muscle pulley. The treatment modalities for strabismus are either surgical or nonsurgical. Surgical treatments can be made by recession or resection of the involved extraocular muscle. The adjustable suture technique was introduced in 1970s, which has been the gold standard among surgical treatment modalities. Nonsurgical treatments include prism, glasses, bifocal lenses, and drugs. A young strabismic patient may have amblyopia and decreased stereoacuity due to abnormal interaction between the sound eye and the deviating eye. Once amblyopia is detected, immediate treatment is needed to correct the visual dysfunction. Recent efforts to elucidate the mechanisms of strabismus are believed to unravel the mysterious pathophysiology in the near future.

The Influence of Fusional Vergence on the Postoperative Ocular Alignment in Intermittent Exotropia

The purpose of this study was to evaluate the influence of fusional vergence on the ocular alignment after surgery in intermittent exotropia. We evaluated fusional convergence and divergence with rotary prism. We examined 44 patients with intermittent exotropia who were followed up postoperatively for at least 6 months from January 1995 to June 1998. The angle of deviation was measured preoperatively, 1 week after surgery and on the last follow-up day. We evaluated the break and recovery point of fusional convergence and divergence at near and far at each measurement of angle of deviation. The subjects were divided into two groups according to the deviation at the last visit : Orthophoria group and Undercorrection group. Orthophoria group was defined as having the deviation equal to or less than 15 delta of exodeviation, and undercorrection group was defined as having the deviation more than 15 delta of exodeviation. In Orthophoria group, break point and recovery point of convergence were 28.07 delta and 26.34 delta at near, 25.52 delta and 22.55 delta at far. The break point and recovery point of divergence were 18.21 delta and 12.38 delta at near, 12.70 delta and 7.73 delta at far. In Undercorrection group, break point and recovery point of convergence were 25.86 delta and 24.71 delta at near, 25.20 delta and 25.80 delta at far. The break point and recovery point of divergence were 18.86 delta and 13.29 delta at near, 17.90 delta and 15.40 delta at far. There was no significant difference between two groups. According to the change from deviation at postoperative 1 week to final deviation, the subjects were divided into four groups. We evaluated the difference of fusional convergence and divergence, according to the change of angle of deviation between postoperative 1 week and the last follow-up day, but there was no significant difference. In conclusion, we can not find any significant influence of fusional vergence on the ocular alignment after surgery in intermittent exotropia.