Diagnostic Performance of the PalmScan VF2000 Virtual Reality Visual Field Analyzer for Identification and Classification of Glaucoma.

PURPOSE: To evaluate the diagnostic test properties of the Palm Scan VF2000Ⓡ Virtual Reality Visual Field Analyzer for diagnosis and classification of the severity of glaucoma. METHODS: This study was a prospective cross-sectional analysis of 166 eyes from 97 participants. All of them were examined by the HumphreyⓇ Field Analyzer (used as the gold standard) and the Palm Scan VF 2000Ⓡ Virtual Reality Visual Field Analyzer on the same day by the same examiner. We estimated the kappa statistic (including 95% confidence interval [CI]) as a measure of agreement between these two methods. The diagnostic test properties were assessed using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: The sensitivity, specificity, PPV, and NPV for the Virtual Reality Visual Field Analyzer for the classification of individuals as glaucoma/non-glaucoma was 100%. The general agreement for the classification of glaucoma between these two instruments was 0.63 (95% CI: 0.56-0.78). The agreement for mild glaucoma was 0.76 (95% CI: 0.61-0.92), for moderate glaucoma was 0.37 (0.14-0.60), and for severe glaucoma was 0.70 (95% CI: 0.55-0.85). About 28% of moderate glaucoma cases were misclassified as mild and 17% were misclassified as severe by the virtual reality visual field analyzer. Furthermore, 20% of severe cases were misclassified as moderate by this instrument. CONCLUSION: The instrument is 100% sensitive and specific in detection of glaucoma. However, among patients with glaucoma, there is a relatively high proportion of misclassification of severity of glaucoma. Thus, although useful for screening of glaucoma, it cannot replace the HumphreyⓇ Field Analyzer for the clinical management in its current form.

Comparison of three newer generation freely available intraocular lens power calculation formulae across all axial lengths.

Purpose: The aim of this study is to evaluate the accuracy of three newer generation formulae (Barrett Universal II, EVO, Hill-RBF 2.0) for calculation of power of two standard IOLs-the Acrysof IQ and Tecnis ZCB00 across all axial lengths. Methods: In this retrospective series, 206 eyes of 206 patients, operated for cataract surgery with above two IOLs over the last 6 months, were included in the study. Preoperative biometry measurements were obtained from LenstarLS900. By using recommended lens constants, the mean error for each formula was calculated and compared. Then, the optimized IOL constants were calculated to reduce the mean error to zero. Mean and median absolute errors were calculated for all eyes and separately for short (AL<22.5 mm), medium (22.5-24.5 mm), and long eyes (>24.5 mm). Absolute errors and percentages of eyes within prediction errors of ±0.25 D, ±0.50 D, ±0.75 D, and ±1.00 D were compared. Results: Prediction error with using recommended lens constants was significantly lower in the Barrett Universal II formula as compared to the other two formulae. However, after optimizing lens constants, there were no significant differences in the absolute errors between the three formulae. The formulae ranked by mean absolute error were as follows: Barrett Universal II (0.304 D), EVO (0.317 D), and Hill-RBF (0.322) D. There were no significant differences between absolute errors in the three formulae in each of the short-, medium-, and long-eye subgroups. Conclusion: With proper lens constant optimization, the Barrett Universal II, EVO, and Hill-RBF 2.0 formulae were equally accurate in predicting IOL power across the entire range of axial lengths.

Comparison of Post-Cataract Surgery Visual Outcomes and Quality of Life in Patients Bilaterally Implanted with Multifocal Intraocular Lenses.

INTRODUCTION: The present study compared visual outcomes in eyes with bilateral implantation of two multifocal intraocular lenses (MFIOLs)-the Eyecryl™ ACTV diffractive multifocal IOL (group 1) and AcrySof® IQ ReSTOR® multifocal IOL (group 2). METHODS: This was a prospective, two-group observational longitudinal study of 118 eyes from 59 patients conducted at Laxmi Eye Institute, Panvel, India. We evaluated the patients at 1, 3, and 6 months. We assessed visual acuity, contrast sensitivity, higher-order aberrations, reading speed, defocus curve, stereopsis, quality of life (QOL), and adverse events in these participants. RESULTS: The median (interquartile range) best-corrected distance visual acuity was 0.18 (0, 0.18) in group 1 and 0.18 (0, 0.18) in group 2 at 1, 3, and 6 months; the difference was not statistically significant (p = 0.48). The binocular defocus curve in both groups showed two peaks at 0.0 to -0.5 D and at -2.5 D. The mean (95% confidence interval) critical print size was significantly different between groups 1 and 2 at low illumination (0.918 [0.905, 0.931] vs 1.154 [1.128, 1.180]; p = 0.004). Contrast sensitivity was significantly better in group 1 under mesopic conditions but not under scotopic conditions. Though total QOL did not differ significantly between groups, the psychosocial quality of life was significantly better in group 1. About 23% of patients in group 2 reported unwanted images, compared with 0% in group 1 (p = 0.01). CONCLUSION: We found that the Eyecryl and AcrySof groups were comparable for best-corrected visual acuity, photopic contrast sensitivity, defocus curve, reading parameters, stereopsis, and quality of vision. However, the Eyecryl group had better mesopic contrast and a lower proportion of unwanted images. Psychosocial quality of life was significantly better in the Eyecryl group; however, satisfaction was similar between groups. The cost of one of the lenses is less than the other. Thus, individuals with limited resources may opt for the Eyecryl™ ACTV, with similar visual outcomes.