Recurrence of amblyopia after occlusion therapy.

PURPOSE: To determine the stability of visual acuity (VA) after a standardized occlusion regimen in children with strabismic and/or anisometropic amblyopia. DESIGN: Retrospective, population-based, consecutive observational case series. PARTICIPANTS: Four hundred forty-nine patients younger than 10 years who underwent an occlusion trial for amblyopia and were observed until there was a recurrence of amblyopia or for a maximum of 1 year after decrease or cessation of occlusion therapy. METHODS: We performed a retrospective chart review of all patients treated by occlusion therapy for strabismic and/or anisometropic amblyopia at our institution over a 34-year period. Of the 1621 patients identified in our database, 449 met the eligibility criteria and were included in this study. Patients having at least a 2 logarithm of the minimum angle of resolution (logMAR)-level improvement in VA by optotypes or a change from unmaintained to maintained fixation preference during the course of occlusion therapy were included. A recurrence of amblyopia was defined as > or =2 logMAR levels of VA reduction or reversal of fixation preference within 1 year after a decrease or cessation of occlusion therapy. MAIN OUTCOME MEASURE: Recurrence of amblyopia after a decrease or cessation of occlusion therapy and its relationship with patient age and VA of the amblyopic eye at the time of decrease or cessation of occlusion therapy. RESULTS: Of 653 occlusion trials, 179 (27%) resulted in recurrence of amblyopia. The recurrence was found to be inversely correlated with patient age. There was no statistically significant association between the recurrence of amblyopia and VA of the amblyopic eye at the end of maximal occlusion therapy. CONCLUSIONS: There is a clinically important risk of amblyopia recurrence when occlusion therapy is decreased before the age of 10 years. The risk of recurrence is inversely correlated with age (P<0.0001).

Long-term outcome of pediatric aphakic glaucoma.

PURPOSE: To determine the long-term outcome in pediatric patients with aphakic glaucoma. METHODS: A retrospective analysis of 130 patients diagnosed with aphakic glaucoma between 1969 and 2004 was performed. A total of 36 patients (55 eyes) were included in this study after excluding those who had cataract extraction after age 10 and those patients with other ocular conditions, systemic syndromes, traumatic cataracts, congenital glaucoma, or inadequate follow-up (less than 1 year). Outcome variables studied included visual acuity, number of medication changes required over the course of the follow-up, maximum number of medications used at a time for more than 6 months to control intraocular pressures, and surgical interventions required. Mean follow-up period was 18.7 years (range, 6.9-35 years). RESULTS: At the time of last follow-up, 54.5% of the patients had visual acuity 20/40 or better, 34.5% had 20/50 to 20/200, and 11% had acuity worse than 20/200. During the course of follow-up, 34% required 1 to 2 medication changes for controlling glaucoma, 33% required 3 to 5 medication changes, and 33% required 6 or more medication changes. Thirty-six percent of the eyes required a maximum of 1 to 2 medications for more than 6 months during the course of follow-up, 33% required 3, and 31% required 4 or more medications for controlling intraocular pressure. Of the 55 eyes, 15 eyes (27%) required surgical intervention. Six of the 15 eyes (40%) required 1 surgery, 8 eyes (53%) required 2 to 3 surgeries, and 1 eye (7%) required 4 to 6 surgeries. CONCLUSION: Patients with glaucoma after pediatric cataract surgery can have a good visual outcome although multiple medications and surgical interventions may be required to control the glaucoma.

Characteristics and course of patients with deteriorated monofixation syndrome.

BACKGROUND: Monofixation syndrome is characterized by small-angle strabismus with vergence fusional amplitudes and "peripheral fusion." Although it is thought to be a relatively stable condition, some patients with this syndrome deteriorate, resulting in an increasing heterotropia, sometimes associated with diplopia. Deteriorated monofixation syndrome is well known among clinicians; however, there are no studies describing the course and outcomes for these patients. PURPOSE: To assess the clinical characteristics, course, and response to therapy of patients with deteriorated monofixation syndrome. METHODS: We identified all patients from our database that had an ocular deviation of < or =8 Delta on simultaneous prism cover testing, peripheral fusion, and between 3000 and 67 seconds of stereoacuity (monofixators) who subsequently had an increase in their deviation to >8 Delta, loss of fusion, or diplopia. From this group we assessed patient clinical characteristics, course, and response to therapy. RESULTS: We identified 29 patients with deteriorated monofixation syndrome who subsequently underwent treatment. Treatment consisted of surgery in 28 patients and minus lens therapy in one patient. Of the study group, 28 (97%) of the patients had a history of esotropia and 20 patients (69%) had a history of amblyopia. Nine patients noted diplopia at the time of deterioration, which persisted in four patients after treatment. In all, 14 patients (48%) met the criteria for monofixation again after therapy, while 20 patients (69%) had successful motor alignment (< or =8 Delta). There was a trend toward poorer outcomes in the diplopic group when compared with the patients who did not have diplopia, although this was not statistically significant (P = 0.26 for regaining monofixation syndrome). Follow-up ranged from 1 month to 21 years. CONCLUSION: Though monofixation is considered a stable condition, some patients will deteriorate over time as demonstrated by an increase in the ocular deviation and loss of fusion. In this study 31% of our patients noted the onset of diplopia. Following treatment, 48% of the patients regained monofixation. Patients with diplopia following deterioration of their alignment may be less likely to regain good alignment or monofixation after treatment.

Amblyopia treatment outcomes.

PURPOSE: To determine the effectiveness and side effects of full-time occlusion for the treatment of amblyopia. METHODS: Patients with unilateral amblyopia secondary to strabismus, anisometropia, or a combination of the two were retrospective reviewed. All patients had full-time occlusion encompassing 24 hours per day or all waking hours, followed to a defined endpoint. Success was defined as 20/30 or better or equal visual acuity by fixation pattern between the two eyes. The ultimate goal was equal visual acuity. RESULTS: Six hundred patients fit the inclusion criteria. Mean follow-up after the cessation of full-time patching was 7.2 years. Eighty-nine percent were followed for more than 1 year. Mean age at last follow-up visit was 10.82 years. Ninety-six percent of patients attained a successful visual result. Sixty percent attained equal visual acuity. Younger patients required less occlusion time to endpoint and had a better visual outcome ( P < 0.0001). Initial visual acuity was significantly related to best visual acuity attained ( P < 0.0001). The incidence of occlusion amblyopia was 25.8%. CONCLUSIONS: Full-time occlusion produces excellent visual acuity results. It was shown to be effective with no long-term complications if patients proceed as directed.

The threshold for the detection of strabismus.

PURPOSE: To identify the threshold at which horizontal or vertical strabismus becomes reliably detectable by observers and to determine the effects of interpupillary distance, age, gender, and observer experience. METHODS: Six models of different gender, age, and interpupillary distance were digitally photographed in several predetermined gaze positions off-axis in the horizontal and vertical planes. Standardized distance, zoom factor, and lighting were used. The images were digitally altered to exactly superimpose one eye deviated and one eye aligned with the axis of the camera. This simulated horizontal and vertical strabismus ranged from 2.5 to 20 prism diopters (PD). The images were arranged in random order and presented to groups of lay and professional observers, and their responses were recorded. RESULTS: The statistically significant threshold for detecting esotropia, exotropia, and hypertropia was 12.5 PD. Hypotropia had a higher threshold of 20 PD. Observer experience and model age each had a significant effect on the ability to detect strabismus. CONCLUSION: Our study demonstrates a unique method for assessing the significance of different types and degrees of strabismus. Our findings may be used to help patients with strabismus as they consider others' perception of their ocular misalignment. Physicians can also use this information in making decisions regarding surgery.

Marginal myotomy of the minimally overacting inferior oblique muscle in asymmetric bilateral superior oblique palsies.

PURPOSE: We report the surgical results of marginal myotomy of a minimally overacting inferior oblique muscle in conjunction with traditional recession or myectomy of the greater overacting inferior oblique muscle in 10 patients with asymmetric bilateral superior oblique palsies and asymmetric inferior oblique overaction. METHODS: Ten consecutive patients with bilateral superior oblique palsies had a hypertropia in primary position (5-28 PD) and unequal inferior oblique overaction (0 to +2 in the lesser overacting inferior oblique muscle, +2 to +4 in the greater overacting inferior oblique muscle). Reversal of the hypertropia was noted in ipsilateral oblique upgaze. All patients underwent a recession or myectomy of the greater overacting inferior oblique muscle and a marginal myotomy of the lesser overacting inferior oblique muscle. RESULTS: Seven patients had no vertical deviation in primary position, 2 patients had a residual hypertropia of 2 to 3 PD, and 1 patient had a residual hypertropia of 8 PD. The abnormal head position present preoperatively in 8 patients was eliminated or greatly improved after surgery. Postoperatively all but 1 inferior oblique overaction was graded as 0 to trace. Mean follow-up time was 19 months (range, 1.5-68 months). CONCLUSIONS: In bilateral superior oblique palsies with asymmetric inferior oblique overaction, a mildly overacting inferior oblique muscle can be corrected by marginal myotomy, combined with a recession or myectomy of the greater overacting inferior oblique muscle. This procedure can reduce or eliminate the hypertropia in primary position while minimizing the possibility of residual inferior oblique overaction.

Risk of amblyopia recurrence after cessation of treatment.

BACKGROUND: Although amblyopia can be successfully treated with patching or atropine, there have been few prospective studies of amblyopia recurrence once treatment is discontinued. METHODS: We enrolled 156 children with successfully treated anisometropic or strabismic amblyopia (145 completed follow-up), who were younger than 8 years of age and who received continuous amblyopia treatment for the previous 3 months (prescribed at least 2 hours of daily patching or prescribed at least one drop of atropine per week) and who had improved at least 3 logMAR levels during the period of continuous treatment. Patients were followed off treatment for 52 weeks to assess recurrence of amblyopia, defined as a 2 or more logMAR level reduction of visual acuity from enrollment, confirmed by a second examination. Recurrence was also considered to have occurred if treatment was restarted because of a nonreplicated 2 or more logMAR level reduction of visual acuity. RESULTS: Recurrence occurred in 35 (24%) of 145 cases (95% confidence interval 17% to 32%) and was similar in patients who stopped patching (25%) and in patients who stopped atropine (21%). In patients treated with moderately intense patching (6 to 8 hours per day), recurrence was more common (11 of 26; 42%) when treatment was not reduced prior to cessation than when treatment was reduced to 2 hours per day prior to cessation (3 of 22; 14%, odds ratio 4.4, 95% confidence interval 1.0 to 18.7). CONCLUSIONS: Approximately one fourth of successfully treated amblyopic children experience a recurrence within the first year off treatment. For patients treated with 6 or more hours of daily patching, our data suggest that the risk of recurrence is greater when patching is stopped abruptly rather than when it is reduced to 2 hours per day prior to cessation. A randomized clinical trial of no weaning versus weaning in successfully-treated amblyopia is warranted to confirm these observational findings.

The minimum occlusion trial for the treatment of amblyopia.

OBJECTIVE: To determine whether the traditional regimen of three intervals of full-time occlusion (FTO) for amblyopia without any measurable improvement in visual acuity constitutes an adequate trial. DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Sixty-four children younger than 10 years of age with unilateral amblyopia. METHODS: The medical records of patients treated for amblyopia in a university outpatient clinic were reviewed. Patients who underwent one FTO interval without an improvement in visual acuity followed by at least one additional FTO interval were included in the study. MAIN OUTCOME MEASURES: Improvement in visual acuity. RESULTS: Sixty-four patients underwent 81 occlusion trials consisting of one FTO interval without improvement followed by one or more FTO intervals. Visual acuity improved after the second FTO interval in 25 (31%) of the trials. Of the 44 occlusion trials consisting of two FTO intervals without improvement, visual acuity improved after the third FTO interval in 12 (27%) of the trials. Of the 11 occlusion trials consisting of three FTO intervals without improvement followed by one or more additional FTO intervals, acuity did not improve with any of the trials. CONCLUSIONS: A minimum of three intervals of FTO is necessary to determine whether an amblyopia patient will be unresponsive to occlusion therapy. After three FTO intervals without improvement, additional FTO is unlikely to result in an improvement in visual acuity.