Frequency-doubling perimetry after photorefractive keratectomy

Area of Science:

• Ophthalmology
• Visual Science

Background:

• Myopic patients often undergo refractive surgery like photorefractive keratectomy (PRK).
• Accurate visual field testing is crucial for diagnosing ocular conditions, including glaucoma.

Purpose of the Study:

• To assess the impact of PRK on frequency-doubling perimetry (FDP) patterns.
• To determine if PRK-induced corneal changes affect FDP results in myopic eyes.
• To evaluate the safety of using FDP for glaucoma screening post-PRK.

Main Methods:

• 16 myopic patients (spherical equivalent > -7.0D) underwent PRK; fellow eyes served as controls.
• Frequency-doubling perimetry (FDP) was used to measure Mean Defect (MD) and Pattern Standard Deviation (PSD).
• Corneal zones were analyzed for Median Zone Contrast Sensitivity (MZCS) preoperatively and at 2 weeks, 3, and 6 months post-PRK.

Main Results:

• No significant differences in PSD or MZCS were found between PRK-treated eyes and controls at any time point.
• Longitudinal analysis showed no variations in FDP parameters across different corneal zones.
• A significant correlation between ablation depth, MD, and MZCS was observed in treated eyes up to 2 weeks post-surgery.

Conclusions:

• PRK-induced corneal modifications do not appear to influence FDP results.
• FDP remains a reliable tool for the early diagnosis of glaucoma, even after PRK.
• The study supports the continued use of FDP in clinical practice for myopic patients who have undergone refractive surgery.