Introducing a new method of retinoscopy for refraction of infants and young children: The �Mirza� tele lens retinoscopy

Purpose: This study aimed to evaluate the refractive error of the uncooperative infants and children with the new method of retinoscopy called the tele-lens (�Mirza�) retinoscopy. Methods: In the �Mirza� tele-lens retinoscopy, the examiner placed the trial lenses in 1/3 distance between the tested eye person and peephole of the retinoscope (22.2 cm far from the spectacle plane). First, the optical calculations were done to find the correction factors for this new method of retinoscopy. Second, the dry standard and �Mirza� tele-lens retinoscopy were performed in 78 eyes from 39 children aged 7�12 years with good cooperation and next, the procedure was repeated using cyclopentolate drops and then the results of the two methods were compared, and at the end, the dry �Mirza� tele-lens retinoscopy was done in the 60 eyes of 31 uncooperative infants with a mean age of 21.85 ± 8.79 months for evaluating the feasibility of the �Mirza� tele-lens retinoscopy procedure. The intraclass correlation coefficient (ICC) and Bland�Altman plot for assessment of agreement between the findings of two retinoscopic methods in dry and cyclo conditions were used. Results: The comparison between the dry standard and �Mirza� tele-lens retinoscopic results with means of 1.39 ± 1.43 and1.36 ± 1.39, respectively were not statistically significant (p > 0.05). Besides, comparing the mean cycloplegic results of two methods (standard vs. �Mirza� tele-lens), the difference was not statistically significant (2.37 ± 1.44 vs. 2.41 ± 1.37) (p > 0.05). Moreover, Two-way repeated measures ANOVA revealed no significant retinoscopy method � use of drops interaction (P = 0.103) in comparing two methods of the standard and �Mirza� tele-lens retinoscopy. ICC results indicated high agreement between two methods in both dry (ICC = 0.993) and cyclo (ICC = 0.989) conditions. Conclusions: The �Mirza� tele-lens retinoscopy method can be performed with satisfactory results in infants and children who do not cooperate for the standard procedure of measuring the refractive errors. © 2020 Spanish General Council of Optometr

Evaluation of visual evoked potential binocular summation after corneal refractive surgery

Purpose: To explore whether visual evoked binocular summation is affected in eyes with refractive errors after refractive surgery. Methods: Twenty participants (6M, 14F) aged 20�35 years (mean 26.7 ± 4.4) were assessed through pattern-reversal visual evoked potential viewing with their every eye (first right eye and then left eye) and then with both eyes while wearing their best correction before undergoing surgery. Also, parameters of the P100 component of pattern-reversal visual evoked potential were evaluated after 3 months of refractive surgery in two different check sizes. Monocular and binocular amplitudes and latencies of P100 wave and binocular summation index were compared between before and after surgery. Results: Monocular visual evoked potentials elicited by two different high-contrast checkerboard-patterned stimuli were significantly reduced in P100 wave amplitude (P 0.05). Similar to monocular findings of P100 wave amplitude, on binocular viewing, the mean value of pattern-reversal visual evoked potential amplitude was significantly reduced (P < 0.05), and P100 wave latency was prolonged (P < 0.05) after refractive surgery in participants. Also, the mean postoperative binocular summation index value as compared to that in the preoperative was significantly lesser (P < 0.05) for the subject in this study. Conclusions: Refractive surgery can degrade binocular visual performance throughout the change in visual evoked potential binocular summation. However, monocular function deteriorates less than binocular function after refractive surgery. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature