Time-efficiency assessment of guided toric intraocular lens cataract surgery: pilot study.

PURPOSE: To compare the time spent on toric intraocular lens (IOL) implantation during cataract surgery using a manual-marking vs a digital image-guided system (t Verion) for toric IOL alignment. SETTING: Instituto Oftalmológico Quirónsalud ophthalmology clinic, A Coruña, Spain. DESIGN: Experimental and longitudinal study. METHODS: A total of 98 eyes of 65 participants (68.2 ± 12.2 years) were divided into 2 groups: 49 eyes operated with toric IOL alignment using a manual-marking technique (manual group) and another 49 eyes operated using image-guided marking (Verion group). The primary variable for comparison between both groups was cataract surgery time. Other outcomes such as toric IOL misalignment, spherical equivalent, astigmatism, uncorrected distance visual acuity, and corrected distance visual acuity were also measured. RESULTS: The total cataract surgery time was 2:09 minutes shorter (P < .001) with the Verion system (12:12 ± 2:20 in 49 eyes operated) compared with the surgical procedure performed using manual marking (15:27 ± 3:04 in 49 eyes operated). One month after surgery, there were no statistical differences in terms of toric IOL misalignment between the Verion (3.38 ± 2.95 degrees) and the manual group (4.66 ± 3.95 degrees). No statistical differences were observed between groups for refractive and visual outcomes (P ≥ .05). CONCLUSIONS: The cataract surgery time was reduced when the procedure was assisted using the Verion system to align the IOL compared with manual marking, maintaining the same efficacy in terms of toric IOL misalignment, residual refraction, and visual acuity.

Feasibility of optical quality analysis system for the objective assessment of accommodation insufficiency: a phase 1 study.

PURPOSE: To assess differences in a new objective metric obtained with a double-pass technique between a group with accommodation insufficiency (AI) and a control group and to explore the diagnostic capabilities of this new tool in comparison to conventional procedures. METHODS: Retrospective cross-sectional case-control phase 1 study. Two groups with ages ranging from 8 to 18 years were recruited: AI and control group. The diagnostic criterion of AI was based on monocular accommodative amplitude (AA), 2 D below Hofstetter's calculation for minimum AA, and monocular accommodative facility (MAF), failing with minus lens and cut-off at ≤ 6 cycles per minute. Accommodative response with a double pass device (HD Analyzer, Visiometrics) was measured, performing an evaluation from +1.00 D to -3.50D (-0.5D steps), offering the width of the profile at 50% (WP) in minutes of arc. RESULTS: Differences were found between groups for the AA, MAF and MEM retinoscopy (p < 0.0001, p < 0.001, p = 0.037). The discriminative capacity of MEM retinoscopy for AI diagnosis was significant and the cut-off that maximized the sensitivity and specificity was > 0.5 D. Considering WP 50% in different points, the discriminative AI diagnosis capacities for the points of 2.0 D and 2.50 D were significant (ROC-AUC 0.78; p = 0.03 and p = 0.02). CONCLUSIONS: Double-pass system metric differed between patients with AI and control group, therefore the aim of a Phase I study was achieved. Further steps with higher sample sizes are required to evidence if the system really provides any advantage versus conventional methods in the diagnosis of AI.

Clinical assessment of chromatic aberration in phakic and pseudophakic eyes using a simple autorefractor.

We describe a psychophysical method and a simple setup - an autorefractor with a Scheiner disc, sequentially illuminated with red and blue lights - for the clinical assessment of the longitudinal chromatic aberration (LCA) in phakic and pseudophakic patients. This method applies to the unaccommodated eye, even in the presence of positive or negative refractive errors and astigmatism. It measures the chromatic difference of refraction as an estimate of LCA. We built a proof of concept from inexpensive and off-the-shelf optomechanical components with which we obtained the preliminary clinical results presented in the paper. We considered one control group of phakic patients and three groups of pseudophakic patients with monofocal implants of different designs and materials. The results, satisfactory and consistent with those reported by other researchers in related works, demonstrate the method and system feasibility.