Clinical Outcome of Retreatment after Refractive Surgery

PURPOSE: To evaluate the clinical outcome of retreatment after refractive surgery. METHODS: Retrospective analysis of 38 eyes of 24 patients who received retreatment surgery after refractive surgery from August 2008 to May 2013 was performed. Pre-initial surgery characteristics and the reason for retreatment were investigated, and preand post-retreatment uncorrected visual acuity, best corrected visual acuity, safety index, efficacy index, predictability, and postoperative complication were also investigated. RESULTS: Age at initial refractive surgery and retreatment were 28.50 +/- 7.29 years (17-49 years) and 31.21 +/- 6.49 years (21-49 years). Reasons for retreatment were myopic regression in 36 eyes (94.7%) and overcorrection in two eyes (5.3%). Methods of retreatment were laser subepithelial keratomileusis (LASEK) in 31 eyes (81.6%) and laser-assisted in situ keratomileusis (LASIK) in seven eyes (18.4%). Safety index values for all were above 1.0 and efficacy index values were 0.92, 0.93, and 0.95 in postoperative examination at 1 month, 3 months, and 6 months, respectively. No eye showed a decrease in best corrected visual acuity. One eye had transient hyperopia after retreatment, and two eyes had postoperative corneal opacity, but no eye experienced significant alteration in visual prognosis. CONCLUSIONS: Retreatment after refractive surgery was an efficient and safe clinical course in our clinic. No long-term complications were observed, and uncorrected visual acuity and refractive errors significantly improved after retreatment. In particular, LASEK can be considered as a safe and efficient retreatment modality without risk of keratectasia.

Formula Comparison for Intraocular Lens Power Calculation Using IOL Master and Ultrasound for the ZCB00 IOL

PURPOSE: To evaluation the accuracy of the IOL power calculation formulae measured by IOL Master(R) and applanation ultrasonography for the Tecnis ZCB00 IOL. METHODS: We performed a retrospective study of 170 eyes in 121 patients who underwent cataract surgery in our hospital with AMO Tecnis ZCB00 IOL.s. The SRK/T formula was used to predict the patient's implanted IOL power. Differences in the predicted refractive errors between IOL Master(R) and ultrasonography were analyzed and factors attributed to the differences were also analyzed. Three months after cataract surgery, mean numeric error and mean absolute error were analyzed. RESULTS: SRK/II and SRK/T formulas calculated using ultrasonography showed differences compared to the same formulas calculated using IOL Master(R), in which hyperopic shift was also demonstrated. No definite factor was attributed to the differences between the 2 methods. Although the 3 formulas of IOL Master(R) showed no significant difference in refractive errors, the SRK/T formula calculated using IOL Master(R) showed the least mean absolute and numeric errors. CONCLUSIONS: IOL Master(R) is considered more suitable when determining proper AMO Tecnis ZCB00 IOL power in cataract surgery. The hyperopic shift should be considered when calculating the IOL power using only ultrasonography.

Comparison of the Efficacy between Time and Spectral Domain Optical Coherence Tomography for the Identification of Vitreomacular Interface

PURPOSE: To compare the efficacy of time domain (TD) and spectral domain (SD) optical coherence tomography (OCT) in determining vitreomacular interface (VMI). METHODS: VMIs were evaluated with TD and SD OCT images crossing the fovea horizontally in 69 eyes (mean age 52.7 +/- 15.4 years) and were classified as follows: (1) no vitreomacular separation (VMS), (2) incomplete VMS, and (3) unknown. RESULTS: In TD OCT, no VMS was observed in 2 eyes (2.9%), incomplete VMS in 2 eyes (2.9%), and unknown in 65 eyes (94.2%). In SD OCT, no VMS was observed in 31 eyes (45.0%), incomplete VMS in 13 eyes (18.8%), and unknown in 25 eyes (36.2%). In 31 eyes with no VMS on SD OCT, 29 eyes (93.5%) presented unknown on TD OCT (p<0.0001). In 13 eyes with incomplete VMS on SD OCT, 2 eyes (15.4%) showed incomplete VMS and 11 eyes (84.6%) showed unknown on TD OCT (p<0.0001). TD OCT was also non-informative in all 25 eyes with unknown on SD OCT. CONCLUSIONS: SD OCT allows better visualization of VMI than TD OCT, especially in patients with no VMS.

Acute Zonal Occult Outer Retinopathy, Responsive to an Immunosuppressive Agent: A Case Report

PURPOSE: To report a case of acute zonal occult outer retinopathy (AZOOR), initially misdiagnosed as retrobulbar optic neuritis, which was responsive to an immunosuppressive agent. CASE SUMMARY: A 28-year-old female with photopsia and a visual field defect in the left eye was referred to a hospital. There were no fundus abnormalities to explain her left visual field defect. Neurologic examination and brain MRI were normal. The patient was diagnosed with retrobulbar optic neuritis and treated with high-dose steroids. Four months after the onset of symptoms, she visited our hospital. Visual acuity was hand motion in the left eye. No relative afferent pupillary defect in the left eye and no anterior segment or fundus abnormalities were observed. A visual field examination of the right eye was normal and revealed field defect in the left eye. No abnormality was noted in the visual evoked potential test or fluorescein angiography. All examinations of the right eye were normal. In the left eye, fundus autofluorescence showed a hyperautofluorescent spot at the posterior pole, there was a decreased response in electroretinography and spectral domain optic coherence tomography showed that the junction between the photoreceptor inner and outer segments (IS/OS) was faintly visible only in the fovea. With the presumptive diagnosis of AZOOR, the patient was treated with an immunosuppressive agent. Visual acuity improved to 20/80 in the left eye at 10 months after the onset of symptoms. CONCLUSIONS: Electroretinogaphy is essential to diagnose AZOOR in patients with photopsia, visual field defect and minimal or no fundus changes, especially in a young women. There is currently no proven standard treatment, however immunosuppressive agents may be helpful.