Cycloplegic Refraction in Hyperopic Children: Effectiveness of a 0.5% Tropicamide and 0.5% Phenylephrine Addition to 1% Cyclopentolate Regimen

PURPOSE: To evaluate the effectiveness of a cycloplegic regimen using 0.5% tropicamide and 0.5% phenylephrine (Tropherine, Hanmi Pharm), in addition to 1% cyclopentolate, in hyperopic children. METHODS: The medical records of hyperopic patients below the age of 14 years who had undergone cycloplegic retinoscopy were retrospectively reviewed. Cycloplegic refractions were performed using one of two cycloplegic regimens. Regimen 1 was a Tropherine-added regimen comprising the administration of one drop of 1% cyclopentolate followed by two to three drops of Tropherine added at 15-minute intervals. Regimen 2 was a cyclopentolate-only regimen comprising the administration of three to four drops of 1% cyclopentolate at 15-minute intervals. The mean difference between noncycloplegic and cycloplegic refraction was compared between the two regimens. RESULTS: A total of 308 eyes of 308 hyperopic children were included. The mean difference (±standard deviation) in the spherical equivalent (SE) between cycloplegic and noncycloplegic refraction was significantly larger in regimen 2 than in regimen 1, with values of +1.70 ± 1.03 diopters (D) and +1.25 ± 0.89 D, respectively (p=0.001). The SE change after cycloplegia was significantly different between the two regimens only in patients aged 5 years or younger (p=0.001), particularly in those with high hyperopia with an SE ≥5 D (p=0.005) or fully accommodative esotropia (p=0.009). There was no significant difference between the two regimens in patients older than 5 years, regardless of the presence of high hyperopia or fully accommodative esotropia. CONCLUSIONS: The Tropherine-added regimen exerted a weaker cycloplegic effect than the cyclopentolate-only regimen, particularly in children under the age of 5 years with high hyperopia or fully accommodative esotropia. However, the difference in refraction between the two regimens was small. A Tropherine-added regimen can be effective in hyperopic children, with less associated discomfort than the instillation of cyclopentolate.

Long-Term Results of Intermittent Exotropia Surgery: Comparison between Motor and Functional Success

PURPOSE: To evaluate the long-term surgical success rate (>3 years) and contributing success factors considering motor and sensory criteria for patients with intermittent exotropia. METHODS: Fifty-four patients who received surgery for intermittent exotropia and were followed-up for a minimum of 3 years, including reoperation, were retrospectively evaluated. The first procedure was unilateral recession and resection in 50 patients and bilateral lateral rectus recession in 4 patients. Patients were classified as achieving a good, fair or poor outcome based on motor and sensory criteria. Success rate and associated factors such as postoperative alignment, exotropia type, first surgical procedure, and proportion of patients receiving reoperations were analyzed. RESULTS: The mean follow-up period after the first surgery was 4.81 +/- 1.30 years. The good outcome was achieved in 32 patients (59.3%), fair in 14 patients (25.9%), and poor in 8 patients (14.8%) considering motor criteria only. The good outcome was achieved in 29 patients (51.9%), fair in 12 patients (22.2%), and poor in 14 patients (25.9%) when considering combined motor/sensory (functional) criteria. No patient who received bilateral lateral rectus recession as the first procedure belonged to the good outcome group (p = 0.03 by motor criteria and p = 0.044 by functional criteria). Patients who received reoperation were significantly more likely to be in the good and fair groups (p = 0.009 by motor criteria and p = 0.02 by functional criteria). CONCLUSIONS: Long-term surgical results of intermittent exotropia in this Korean population revealed 85.2% motor success rate and 74.1% functional success rate. Early postoperative overcorrection was not associated with long-term success. Recession and resection procedure and reoperations were significantly associated with better outcome based on motor and functional criteria. Diligent reoperations after the first surgery could possibly contribute to good long-term functional outcome in intermittent exotropia patients.

Clinical Consideration of Strabismus in Monozygotic Twins

PURPOSE: The concordance of strabismus in monozygotic twins was examined in order to study the role of genetics in the different types of strabismus. METHODS: The medical charts of 39 pairs of monozygotic twins (63 of 78 subjects had strabismus) dated between May 1985 and December 2005 were reviewed retrospectively. We analyzed each case by refraction, type of strabismus, age of onset, amount of deviation, and stereopsis. RESULTS: Twenty-three of 39 pairs of twins (59%) showed phenotypic concordance; 15 of 21 pairs showed intermittent exotropia (71%), five of nine pairs showed infantile esotropia (55%), and three of four pairs showed partially accommodative esotropia (75%). All pairs with accommodative esotropia showed discordance. One discordant pair showed infantile esotropia, one expressed infantile esotropia, and another expressed sensory exotropia due to congenital cataract. CONCLUSIONS: The concordance rate of monozygotic twins was 59% in this study. Partially accommodative esotropia and intermittent exotropia had high concordance rates of strabismic phenotypes in monozygotic twins. Based on the results of this study, it is suggested that there may be a strong genetic component regarding these types of strabismus. Concordant pairs of monozygotic twins showed similarity in onset, deviation angle, postoperative result, and recurrence.

Clinical Consideration of Strabismus in Monozygotic Twins

PURPOSE: The concordance of strabismus in monozygotic twins was examined in order to study the role of genetics in the different types of strabismus. METHODS: The medical charts of 39 pairs of monozygotic twins (63 of 78 subjects had strabismus) dated between May 1985 and December 2005 were reviewed retrospectively. We analyzed each case by refraction, type of strabismus, age of onset, amount of deviation, and stereopsis. RESULTS: Twenty-three of 39 pairs of twins (59%) showed phenotypic concordance; 15 of 21 pairs showed intermittent exotropia (71%), five of nine pairs showed infantile esotropia (55%), and three of four pairs showed partially accommodative esotropia (75%). All pairs with accommodative esotropia showed discordance. One discordant pair showed infantile esotropia, one expressed infantile esotropia, and another expressed sensory exotropia due to congenital cataract. CONCLUSIONS: The concordance rate of monozygotic twins was 59% in this study. Partially accommodative esotropia and intermittent exotropia had high concordance rates of strabismic phenotypes in monozygotic twins. Based on the results of this study, it is suggested that there may be a strong genetic component regarding these types of strabismus. Concordant pairs of monozygotic twins showed similarity in onset, deviation angle, postoperative result, and recurrence.

Accuracy of Surgeon-Selected Ablation Center in Active Eye-Tracker-Assisted Advanced Surface Ablation-Photorefractive Keratectomy (ASA-PRK)

PURPOSE: To evaluate the accuracy of the surgeon-selected ablation center in active eye-tracker-assisted ASA-PRK and to identify factors influencing the ablation center. METHODS: This retrospective study included 109 eyes of 62 patients who underwent active eye-tracker-assisted ASA-PRK (VISX STARTM S4 with ActiveTrakTM System). The location the surgeon-selected ablation center and its distance from the center of the entrance pupil were analyzed by corneal topography (EyeSys Corneal Analysis SystemTM with pupil finding software). The factors influencing centration were investigated. RESULTS: The mean decentration was 0.24+/-0.13 mm (range 0.04 to 0.83 mm). One-hundred and five eyes (96%) were within 0.5 mm of the pupillary center. Supero-nasal displacement of the ablation center occurred most frequently in 44 eyes (40%) after ASA-PRK. The decentration amount was not dependant on factors related to the patient, the surgeon, or the surgery. There was no significant correlation between the amount of decentration and the vertical scale bar of the ActiveTrakTM icon on the screen representing the distance from the pupil center determined by the tracking system, to the surgeon-selected ablation center. CONCLUSIONS: This method of tracking the ablation center, which was selected by the surgeon according to each patient's specific pupil decentration with the active eye tracking system, was highly accurate and effective in avoiding severe decentration in ASA-PRK.