Yuichi Kaji — Page 3 | Search PubMed

PubMedDate not supplied

Progression of pellucid marginal degeneration and higher-order wavefront aberration of the cornea.

PURPOSE: To report the time course of changes in corneal wavefront aberrations in a patient with pellucid marginal degeneration. CASE: A 59-year-old man with pellucid marginal degeneration was followed-up annually with slit-lamp microscopy and videokeratography for 11 years. The anterior corneal height data of the videokeratography were expanded into the set of orthogonal Zernike polynomials to calculate wavefront aberrations for the central 3-mm cornea. OBSERVATIONS: Although the patient complained of gradual deterioration of vision, there was no evident sign of disease progression on slit-lamp examination and visual acuity measurement. Color-coded maps of videokeratography showed slight deterioration over time, but no remarkable and decisive changes were seen. Coma-like aberration displayed a gradual, but apparent increase with a 1.67-fold worsening (0.473 microm to 0.792) during the 11-year follow-up period. Spherical-like aberration remained almost stable throughout the observation period. There were no obvious changes in crystalline lens and retina. CONCLUSIONS: The results suggest that increases in coma-like aberrations of the cornea reflect the subclinical progression of pellucid marginal degeneration over the years.

Corneal Diseases↗

PubMedDate not supplied

Five-year follow-up of photorefractive keratectomy for myopia.

PURPOSE: To analyze long-term results of photorefractive keratectomy (PRK) for myopia and myopic astigmatism. METHODS: This retrospective study included 15 eyes of 8 patients who were examined annually for 5 years after PRK. The Nidek EC-5000 laser with an ablation zone of 5.0 mm was used. Evaluations included spherical equivalent manifest refraction, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal haze, and corneal astigmatism calculated by Fourier analysis of videokeratography data. RESULTS: A tendency toward myopic regression was most evident within the first postoperative year, with manifest refraction changing from +0.80 +/- 1.62 D at 1 week to -0.45 +/- 0.70 D at 1 year postoperatively (P = .007). Regression continued after the second postoperative year. There was a statistically significant difference between manifest refraction at 2 years (-0.36 +/- 0.75 D) and 5 years (-1.11 +/- 1.12 D) (P = .002). Postoperative UCVA stabilized from 3 months up to 3 years, but slightly deteriorated at 4 years and thereafter due to the myopic refractive shift. BSCVA remained stable throughout the 5-year follow-up period. Several eyes developed mild corneal haze after surgery, but haze was minimal in the majority of patients by 1 year and continued to fade over time. The asymmetry component of the cornea significantly increased after surgery, with all postoperative values significantly higher than before PRK (P < .05). Higher order irregularity increased after surgery, with a statistically significant difference between preoperative and 1 year postoperative (P < .05), but values after 2 years were not different from preoperative baseline. CONCLUSION: Fifteen eyes with a baseline refraction of -3.00 to -9.00 D had PRK with the Nidek EC-5000 laser and a 5-mm-diameter ablation zone. Myopic regression occurred in the first year, with continued mild regression of approximately -0.75 D between 2 and 5 years. Nevertheless, the results show the procedure was relatively safe and effective in this group.

Adult↗