BACKGROUND: Haloes causing difficulties during the night driving are one of the common complications of photorefractive keratectomy (PRK). The presumed reason for this phenomenon is the different refraction of light through the treated and untreated areas of the cornea. Its magnitude is proportional to the ratio between the treated area and pupil size. At nighttime, when the pupil dilates, rays from treated and untreated areas of the cornea reach the retina at different foci and produce haloes. We investigated whether dapiprazole, a miotic alpha-blocker drug, would be helpful in reducing night haloes in patients after PRK. METHODS: Twenty-four patients who complained of night haloes after PRK participated in our study. All were given dapiprazole 0.5% before night driving. Change in pupil size was recorded, and all patients completed a questionnaire on changes in the severity of haloes after instillation of dapiprazole. RESULTS: Improvement was described as very significant in five patients, moderate in ten and slight in seven. There was no improvement in two patients. The only side effect was slight irritation, which resolved within 1 h. CONCLUSION: Our results demonstrate that dapiprazole improves the subjective discomfort caused by night haloes in post-PRK patients.
BACKGROUND:Haloes causing difficulties during the night driving are one of the common complications of photorefractive keratectomy (PRK). The presumed reason for this phenomenon is the different refraction of light through the treated and untreated areas of the cornea. Its magnitude is proportional to the ratio between the treated area and pupil size. At nighttime, when the pupil dilates, rays from treated and untreated areas of the cornea reach the retina at different foci and produce haloes. We investigated whether dapiprazole, a miotic alpha-blocker drug, would be helpful in reducing night haloes in patients after PRK. METHODS: Twenty-four patients who complained of night haloes after PRK participated in our study. All were given dapiprazole 0.5% before night driving. Change in pupil size was recorded, and all patients completed a questionnaire on changes in the severity of haloes after instillation of dapiprazole. RESULTS: Improvement was described as very significant in five patients, moderate in ten and slight in seven. There was no improvement in two patients. The only side effect was slight irritation, which resolved within 1 h. CONCLUSION: Our results demonstrate that dapiprazole improves the subjective discomfort caused by night haloes in post-PRK patients.