The Corneal Endothelial Protective Effect of Soft Shell Technique in Cataract Surgery

PURPOSE: To evaluate the efficacy and safety of soft shell technique (SST) to reduce corneal endothelial damage during cataract surgery. METHODS: Cataract surgery was performed in thirty five eyes using SST with Healon and Viscoat , and in thirty five eyes with Healon alone as a control group. The corneal parameters such as corneal thickness, cell density, hexagonality, and the coefficient of variance were evaluated. RESULTS: The mean central corneal thickness in the control group was 533.1 +/- 34.9micrometer before surgery and 549.1 +/- 34.3micrometer at one week after surgery. The difference in corneal thickness was statistically significant (p<0.01). However, in the SST group, the change in corneal thickness before and after surgery was not statistically significant (529.5 +/- 36.3micrometer, 536.0 +/- 36.9micrometer, respectively). There were statistically significant changes in cell density after surgery in both groups. The results for the control group were 2478.5 +/- 319.7/mm2 before surgery and 1861.9 +/- 109.1/mm2 at 3 months after surgery. The result for the SST group were 2571.2 +/- 256.5/mm2 before surgery and 2107.2 +/- 374.1/mm2 at 3 months after surgery. The rate of endothelial cell loss at 3 months after surgery was smaller in the SST group (19%) than in the control group (25%). The coefficient of variance and hexagonality were normalized at one week after surgery in SST group. CONCLUSIONS: These results suggest that SST is effective in protecting corneal endothelial cells during cataract surgery, providing better results in the early postoperative period.

A Case of Juvenile Xanthogranuloma of the Corneoscleral Limbus

PURPOSE: Juvenile xanthogranuloma usually affects the anterior uvea before the age of 1 year, and it may less frequently involve the corneoscleral limbus. We report a case of juvenile xanthogranuloma of the corneoscleral limbus in a 7-year-old boy. METHODS: A 7-year-old boy was referred for the evaluation of a painless limbal mass in the left eye, noticed 1 month previously. On examination, the visual acuity was 16/20 (OD) and 10/20 (OS) without correction, and the corrected visual acuity was 20/20 in both eyes. The other ocular findings were normal, except for an elevated, well circumscribed, smooth surfaced mass measured 9x6 mm at the upper temporal corneoscleral limbus of the left eye. After the excision of the mass, the frozen biopsy and the immunohistochemical staining for CD68 and S100 protein were performed. RESULTS: The lesion consisted of a red-brown, vascular, and raised mass. Histopathologically, there was a chronic granulomatous inflammation with stromal fibrosis, which included many giant cells immunoreactive for CD68 and S100 protein. There was no evidence of recurrence during follow-up period of 5 months and 20 months. CONCLUSIONS: The case was diagnosed as juvenile xanthogranuloma by the clinical and histopathologic findings. The juvenile xanthogranuloma of the corneoscleral limbal involvement is very rare and it can be treated with the surgical excision for the purpose of improvement of cosmetic problems without any recurrence. It seems to have very good prognosis when completely excised.

The Change of Ocular Aberration after LASIK Surgery

PURPOSE: To evaluate the change of ocular aberration after LASIK using Zernike's polynomial expansions. METHODS: Sixty eyes of thirty consecutive patients that underwent LASIK were examined prospectively. The ocular aberration was measured with Hartman-Shack aberrometer (WASCA Wavefront Analyzer, USA) at postoperative 30, 90, and 180 days. The postoperative values were compared with that of preoperation. RESULTS: The average age is 27.6 years old. The range of preoperative refractory error were from -3.00 Diopter (D) to -11.00 D. The increase of spherical and triangular coma aberrations (4.7- fold and 3.5- fold, respectively), with respect to preoperative values. There were statistically significant differences between preoperative and postoperative high order RMS at the postoperative 180 days (p<0.05). CONCLUSIONS: The postoperative increases of RMS in higher order aberration, coma aberration, triangular aberration was observed.

Reliability of Refractive Measurement by Hand-held Autorefractor

PURPOSE: We tried to evaluate the reliablility of refractive measurement by hand-held autorefractor (HHAR). METHODS: Ninety patients (180 eyes) with simple refractive error were divided into three groups (30 patients each) according to their ages. Group I is under 6 years old; group II, from 7 to 15 years old; and group 3, over 16 years old. Under cycloplegics, three measuring methods of refraction using table top autorefractor (Model 599, Zeiss Humphrey, USA), hand-held autorefractor (Retinomax K-plus, Nikon, Japan) and skiascope (Heine beta 200, Germany) were performed and we compared each spherical and cylindrical value in 3 groups. RESULTS: There was no significant difference in both spherical and cylindrical value between HH-AR and skiascope in all groups (PI, sph=0.579, PI, cyl=0.708, PII, sph=0.801, PII , cyl=0.730, PIII , sph=0.816, PIII, cyl=0.754) . But there was significant difference in both spherical and cylindrical value between table top autorefractor and skiascope in group I (PI,sph=0.019, PI,cyl=0.030, PII,sph=0.405, PII,cyl=0.392, PIII,sph=0.876, PIII,cyl=0.747). CONCLUSIONS: We believe that hand-held autorefractor can be a useful instrument to measure refractive power without serious error, especially in patients who have difficulty with table top autorefractor.