To assess the differences in optical performance of 9 multifocal IOLs using the same optical bench and to propose a possible comparison for surgeons. Rothschild Foundation, Paris, France. Experimental study. Nine IOLs (Acrysof Restor +3.0 diopter [D] SN6AD1, Acrysof Restor +4.0 D SN60D3, Acrysof aspheric monofocal SN60WF, Acri.Lisa 366D, Finevision Micro F, Tecnis ZM900, and Rezoom, Diffractiva Diff-s, and Lentis Mplus +3.0 D) were tested using the same optical bench that complies with International Organization for Standardization standard 11979 requirements. The through-focus modulation transfer functions (MTFs) were compared, and the image of the United States Air Force (USAF) target was taken while each IOL was at far, intermediate, and near focal points. The through-focus MTF of the trifocal IOL showed a peak in the intermediate range that was not present with monofocal and bifocal IOLs. The USAF target images showed similar resolution with all IOLs for far focal points. Diffractive IOLs showed better resolution for near focal points, and the only sharp image in the intermediate range was obtained using the trifocal IOL. There was a significant difference in the degree of near, intermediate, and distance quality of the image with the various types of multifocal IOLs in vitro. Intermediate vision was more prominent with the trifocal IOL. Dr. Gatinel has a proprietary interest in the optical frame used (Patent WO2011092169 [A1] 2011-08-04). Dr. Houbrechts has no financial or proprietary interest in any material or method mentioned.

Purpose.: To investigate the application of anterior corneal and ocular aberrations in detecting mildly ectatic corneas. Methods.: This studyretrospectively reviewed the data of 220 eyes separated into three groups by the NIDEK Corneal Navigator System automated corneal classification software: normal (N) (n = 123); forme fruste keratoconus (N topography with contralateral KC) (n = 34); and KC (n = 63). Anterior corneal and ocular aberrations were obtained with the optical path differencescan and compared using a Kruskal-Wallis test. Evaluation of these data to discriminate between the three groups was assessed using a Receiver-Operating Characteristic curve analysis. Results.: Corneal and ocular tilt, vertical coma, and trefoil were significantly different in the FFKC as compared with the N group. The discriminant functions between the FFKC and the N group, and between the KC and the N group reached an area under the receiver operating characteristic curve of 0.98 and 0.96, respectively. Conclusion.: Indices generated from corneal and ocular wavefront can identify very mild forms of ectasia that may be undetected by Placido-based neural network programs.

Purpose.: Measuring corneal biomechanical properties may help detect keratoconus suspect corneas and eliminate the risk of ectasia after LASIK. Methods.: Data of 504 eyes separated into three groups were retrospectively reviewed: normal (n = 252), keratoconus suspect (n = 80), and keratoconus (n = 172). Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured with an ocular biomechanics analyzer. Results.: Mean corneal hysteresis was 10.6 ± 1.4 (SD) mm Hg in the normal group, compared with 10.0 ± 1.6 mm Hg in the keratoconus suspect group and 8.1 ± 1.4 mm Hg in the keratoconus group. The mean CRF was 10.6 ± 1.6 mm Hg in the normal group compared with 9.7 ± 1.7 in the keratoconus suspect group and 7.1 ± 1.6 mm Hg in the keratoconus group. Mean CH and CRF were significantly different between the three groups (P < 0.001). Conclusions.: CH and CRF alone cannot be used to identify keratoconus suspect corneas. Analyzing signal curves obtained with the biomechanics analyzer may provide additional valuable information for selecting qualified patients for refractive surgery.

Purpose: To evaluate risk factors associated with keratoconus in a case-control setting. Methods: This single center, prospective, case-control study was carried out from May 2014 to November 2017 at the Rothschild Foundation (Paris, France). Two hundred two patients with keratoconus and 355 control patients were investigated and followed by a single ophthalmologist. Data regarding multiple variables were gathered, including eye rubbing, pattern of eye rubbing, dominant hand, allergies, history of dry eye, screen time, sleep position, and night-time work. Results: After multivariable analysis, the following variables showed significant results: eye rubbing with knuckles [odds ratio (OR) = 8.29; 95% confidence interval (CI): 3.92–18.26, P < 0.001] or fingertips (OR = 5.34; 95% CI: 2.44–12.21, P < 0.001), a history of dry eye (OR = 4.16; 95% CI: 2.3–7.7; P < 0.001), male sex (OR = 4.16; 95% CI: 1.47–11.89; P < 0.001), screen time (OR = 1.02; 95% CI: 1.01–1.04; P < 0.001), prone sleep position (OR = 11.63; 95% CI: 3.88–38.16), and side sleep position (OR = 10.17, 95% CI 3.84–33.73). Conclusions: This study shows a strong correlation between eye rubbing and keratoconus, particularly when rubbing is performed with the knuckles. Additional associations were identified which may merit future investigation as risk factors, including sleep position, night-time work, and screen time.