Vol 44: Issue: 9 Month: September 2018
SMILE VS LASIK
Small-incision lenticule extraction (SMILE®) appears to provide the same efficacy and safety as LASIK, but how does it compare in terms the early recovery of the visual function? A prospective case series compared two groups of 23 patients undergoing the procedures. The postoperative contrast sensitivity was better in the LASIK group at day one and day seven, but not at the one month mark. No significant differences in visual acuity efficacy, or safety were found between the two groups throughout the follow-up. The objective scatter index assessed by double-pass aberrometry was better after LASIK on the first postoperative day but not after. The patient-reported quality of vision was significantly worse in the small-incision lenticule extraction group than in the LASIK group on day seven. Global satisfaction did not differ between groups throughout the study. Significant correlations were found between contrast sensitivity and aberrometry in both groups at all examinations. A Chiche et al., JCRS, “Early recovery of quality of vision and optical performance after refractive surgery: Small-incision lenticule extraction versus laser in situ keratomileusis”, Vol 44, #9, 1073–1079.
PREVALENCE OF OCULAR SURFACE DYSFUNCTION
How common is ocular surface dysfunction in cataract surgery candidates? A prospective study of 120 patients (69% women) found abnormal osmolarity in 56.7% and abnormal MMP-9 in 63.3%. Some 39% presented with positive corneal staining on presentation, 7.5% had epithelial basement membrane dystrophy and 1.6% had Salzmann nodules. More than half of 100 survey respondents reported symptoms suggestive of ocular surface dysfunction. In the asymptomatic group of 46 patients, 85% had at least one abnormal tear test and 48% had both tests abnormal. Overall, 80% of 120 patients had at least one abnormal tear test result suggestive of ocular surface dysfunction, and 40% had two abnormal results. The researchers conclude that preoperative testing and treatment could improve visual outcomes. PK Gupta et al., JCRS, “Prevalence of ocular surface dysfunction in patients presenting for cataract surgery evaluation”, Vol 44, #9,1090–1096.
PSEUDOPHAKIC REFRACTIVE ERROR
A prospective study compared prediction formulas using a single type of IOL and a single surgeon. The Barrett Universal II formula and Hill-RBF methods predicted more eyes within ±0.25D and ±0.5D of objective refraction at one-week, one-month and three-month follow-ups with PCI biometry. Corneal steepening counteracted hyperopic changes caused by posterior IOL migration in postoperative weeks one to four. Four weeks postoperatively, continued posterior IOL migration caused a mean hyperopic shift. The investigators believe the Hill-RBF formula represents a new generation of data-driven calculators and its self-learning nature will likely drive it to superiority over time. HB Wallace et al. JCRS, “Predicting pseudophakic refractive error: Interplay of biometry prediction error, anterior chamber depth, and changes in corneal curvature”, Vol 44, #9, p1123–1129.