Abstract
Abstract: :
Porpose: To evaluate the influence of spherical correction in high ametropias on concordance of frequency doubling technology (FDT) exams. Methods: Twenty patients with high spherical ametropias underwent to FDT exams (threshold C–20) with and without correction. To minimized learning, all patients performed a screening test before starting the study. The sequence of exams was randomized. A ranking for agreement between the two exams was performed from 0 to 4 according to the adjacency of significant points and level of significance (0 meaning exact agreement). Only left eyes were included. Statistic analysis was performed with paired t–test and linear regression. Results: Age ranged from 13 to 73 years old (mean of 46,66 ±18,23). Spherical equivalent ranged from +13,00 to –16,25 D (mean of –6,81D ±8,83). There was no difference regarding mean of MD, with or without correction (–7,05 dB ±6,13 and –6,99dB ±6,22 respectively, p=0,918) as also for mean of PSD (6,19 dB ±1,905 and 6,609 dB ±3,071; p=0,469). There was no significant association between the ranking of agreement and the spherical equivalent (R–Sq=0,2%, p=0,866). Conclusion: FDT exams with or without spherical equivalent correction in high ametropias give similar results.
Keywords: perimetry • myopia • hyperopia