June 2020 - Volume 46 - Issue 6
MILD MYOPIC TARGET BOOSTS INTERMEDIATE VISION
Bilateral monofocal IOLs implanted with mild myopic targeting produce good intermediate vision while avoiding the problems associated with multifocal IOLs or monovision surgery, a new study suggests. The prospective study implanted one group of 30 patients with bilateral monofocal IOLs targeting plano to -0.25D and a second group targeted for -0.50D. Post-op defocus curve analysis showed a significant difference between Group 1 (emmetropia) and Group 2 (mild myopia) binocular vision, with Group 1 seeing significantly better than Group 2 at +1.00, +0.50 and 0, but significantly worse in all other points of the defocus. Patients in Group 2 at 0D of defocus curve (infinite) had a visual acuity close to 0 logarithm of the minimum angle of resolution (logMAR). The main outcome of Group 2 defocus curves was that, at defocus point 0D, even if the mean refraction was -0.67 0.15 × 160, mean uncorrected logMAR visual acuity was 0.0 ± 0.06. Broader optimisation of the target with patient-based formulas might be able to further improve outcomes, the researchers note.
P Vinciguerra et al., “Comparison of visual performance and satisfaction with a bilateral emmetropic vs a bilateral mild myopic target using a spherical monofocal intraocular lens”, Volume 46, #6, 839-843.
ORA INTRAOPERATIVE ABERROMETRY
While intraoperative aberrometry has produced promising results in astigmatism correction in post-corneal refractive patients, its role in less complicated cases is still being debated. A large retrospective study compared the outcomes of an intraoperative aberrometer (ORA) to the Barrett Universal II (Barrett II) and Hill-RBF 2.0 (Hill-RBF) intraocular lens (IOL) power calculation formulas in eyes without history of previous corneal refractive surgery. All three methods performed well regarding spherical equivalent predictive ability. However, supplementing preoperative formulas with intraoperative aberrometry did not improve refractive outcomes.
R Nikolas et al. “Intraoperative aberrometry vs modern preoperative formulas in predicting intraocular lens power”, Volume 46, #6, 857-861.
CUSTOMISED IRIS PROSTHESIS
Photophobia and glare are common problems in patients with congenital aniridia. A custom-made, flexible iris prosthesis appears to reduce these photic symptoms in congenital aniridia, a study of 50 patients (96 eyes) concludes. The custom-made prosthetic iris device greatly reduced the photic symptoms, with subjective reduction in photophobia and glare reported in 95.7% and 95.2% of cases, respectively. Implantation of the custom-made prosthetic iris device did not increase the risk for aniridia fibrosis syndrome. Intraoperative complications occurred in 14 eyes (14.6%), including 12 anterior capsule breaks and two posterior capsule breaks. The custom, flexible iris device was well tolerated in congenital aniridic eyes.
GB Figueiredo et al., “Long-term follow-up of a custom-made prosthetic iris device in patients with congenital aniridia” Volume 46, #6, 879-887.