Eyeworld

EW RESIDENTS 62 November 2018 by Alexis Flowers, MD, Alexander de Castro-Abeger, MD, MBA, Thomas A. Mendel, MD, PhD, Joshua M. Barnett, MD, PhD, and Laura L. Wayman, MD, Department of Ophthalmology, Vanderbilt University Medical Center density (ECD) loss, which delayed healing and led to slower visual recovery. There was no difference in DMDs, visual acuity, or incision thickness at 3 months. Methods This was a prospective study with the goal of enrolling 100 patients to power the study. The exclusion cri- teria were appropriate to avoid con- founders such as previous corneal problems, astigmatism greater than 2 diopters, previous eye trauma or injury and visual acuity targets that were not emmetropic. Patients were then randomly assigned to have ei- ther a 2.20 mm or a 2.85 mm main corneal incision. A single surgeon allowed for consistency in wound construction, but leads the reader to question whether the results can be generalized to other surgeons. The surgical procedure was relatively consistent; however, two different phacoemulsification tips were used to accommodate the two incision sizes. Did this difference impact the findings? The positive features of this study were: standardization of testing with the AS-OCT and specular microscopy, the author's explanation of the methods, and the statistical analysis. Results The authors reported in the results section that they enrolled 100 eyes from 100 patients and that 98% were included in the study out- comes (one was lost to follow-up and one with poor quality AS-OCT imaging, both lost from the 2.85 mm incision size group, reducing the study's sensitivity to detect differences in the compared groups). They demonstrated similar base- line characteristics (age, race, sex, uncorrected distance visual acuity, various corneal characteristics, etc.) without significant differences. The population in each group is described as predominantly New Zealand Europeans and 10% or less of Mãori, Asians and Pacific Island- ers, which is potentially limiting to the broader application of the study results. The authors described an increase in phacoemulsification time with higher scored cataracts by the Lens Opacities Classification System III as would be expected from prior studies, 1 and an increase in incision thickness up to 1 month. The primary outcomes were related to corneal incision healing: DMD, epithelial wound gaping, endothelial polymegathism, and corneal thickness up to 3 months after surgery. At 1 day and 1 month following surgery there was a significant difference (P=0.01 and 0.04, respectively) in DMD with higher detachments in the 2.20 mm incision group. This difference had resolved by the 1-month follow-up, and there was no DMD at the 3-month follow-up. The authors reported that the patients with DMD have lower preoperative ECD (P=0.01) and decreased UCVA at 1-day and 1-week follow-up as well as increased endothelial wound gap- ing and increased incision thickness at all follow-up times. Interestingly, the 2.20 mm incision group started with an average ECD that was about 130 cells/mm 2 lower than the 2.85 mm incision group, but this was not statistically significant (P=0.10). Ep- ithelial wound gaping was higher in the 2.85 mm incision group at day 1 (P=0.06), and endothelial wound gaping was higher in the 2.20 mm incision group (P=0.06). This had resolved in either case by 1 month. EyeWorld journal club Introduction This prospective, double-masked, randomized study aimed to compare post-cataract clear corneal incision wound integrity and endothelial cell characteristics between two inci- sional sizes using anterior segment optical coherence tomography (AS-OCT) and specular microscopy analysis. The premise of this study was that while advances in cataract surgery have led to smaller self-seal- ing clear corneal incisions, some studies have suggested these smaller incisions may actually be associated with decreased wound integrity. The authors argued the importance of this study based on the current culture of patients' high expecta- tions of expeditious visual recovery post-cataract surgery. They thought that understanding the factors that lead to good quality incisions could reduce the risk of endophthalmitis. The study compared two incision sizes, 2.85 mm and 2.20 mm, and followed patients for 3 months after uncomplicated cataract surgery. This distinguished the study from others, which only followed patients for 1 month postoperatively. They eval- uated incision architecture and en- dothelial cell damage using AS-OCT and specular microscopy and found that smaller incisions had high- er rates of Descemet's membrane detachments (DMDs), endothelial polymorphism, and endothelial cell Review of "OCT analysis of phacoemulsification A prospective randomized trial of 2.2 mm versus Laura Wayman, MD, vice chair for ed- ucation, Department of Ophthalmology, Vanderbilt University Medical Center Much effort has been directed toward achieving micro-incision- al cataract surgery, but just how beneficial is this? The Vanderbilt residents review an interesting study comparing different sub-3.0 mm incisions in the November issue of JCRS. —David F. Chang, MD, EyeWorld journal club editor Vanderbilt University Medical Center residents, from left: Thomas Mendel, MD, PhD, Alexander de Castro-Abeger, MD, MBA, Joshua Barnett, MD, PhD, and Alexis Flowers, MD

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