Does macular laser alter the refraction in a diabetic with maculopathy? A pilot study
Purpose To determine whether macular photocoagulation has any effect on refraction in diabetics.Methods This was a prospective study of 12 eyes of 12 diabetics with refraction at 2 weeks before and at 4 weeks and 4 months after argon laser. This was combined with a questionnaire survey of attitude among ophthalmologists on prescribing spectacles for diabetics awaiting macular laser. The main outcome measure was the spherical equivalents (SEQ) before and after treatment.Results Only 36% of ophthalmologists surveyed would prescribe corrective lenses in patients waiting for macular photocoagulation. The median change in magnitude of SEQ at 4-6 weeks post-laser compared to pre-laser was 0.36 D (interquartile range 0.18-0.50 D). The median change in SEQ at 4 months was 0.25 D (interquartile range 0.12-0.56 D). These changes in SEQ from pre-treatment values were not statistically significant on Wilcoxon signed-rank test (p = 0.17 and 0.10, respectively). The correlation coefficient between difference and average SEQ was 0.02 (95% CI -0.14 to 0.19, p = 0.75) at 4 weeks and 0.11 (95% CI -0.06 to 0.275, p = 0.17) at 4 months, indicating no tendency for change in refraction with increasing ametropia.Conclusion This pilot study implies that argon laser photocoagulation in diabetic maculopathy does not alter refraction. Prescription of corrective lenses can be performed prior to laser therapy, if required.