PurposeTo describe the clinical manifestations of herpes simplex keratitis (HSK) in a tertiary referral center in South Korea and to determine whether ascorbic acid treatment prevents recurrence of herpetic epithelial keratitis.MethodsThis retrospective cohort study included all consecutive patients with herpetic keratitis referred to our center from January 2010 to January 2015. Clinical features, ocular complications, and recurrences were recorded.ResultsIn total, 149 eyes of the 133 patients (72 male and 61 female) were followed for an average of 24.6 ± 13.2 months. Sixteen (12.0%) patients had bilateral HSK. The most frequent HSK subtype was epithelial keratitis (49.7%), which was followed by stromal keratitis (23.5%). Epithelial keratitis was the most likely subtype to recur. Complications occurred in 122 (81.9%) eyes. The most common complication was corneal opacity. Recurrences were observed in 48 (32.2%) eyes. The recurrence rates were lower in the prophylactic oral antiviral agent group (16 / 48 eyes, 33.3% vs. 49 / 101 eyes, 48.5%) and the ascorbic acid treatment group (13 / 48 eyes, 27.1% vs. 81 / 101 eyes, 70.3%) compared with the groups without medications. Univariate logistic regression analysis revealed that both factors significantly reduced the risk of recurrence (acyclovir: odds ratio, 0.25; 95% confidence intervals, 0.12 to 0.51; ascorbic acid: odds ratio, 0.51; 95% confidence intervals, 0.20 to 0.91).ConclusionsThis retrospective study described the clinical findings of HSK in a tertiary referral center in South Korea. Prophylactic oral antiviral agent treatment and oral ascorbic acid administration may lower the risk of recurrence.

Purpose of reviewWe review recent studies comparing intraocular lens (IOL) formulas with an emphasis on selection of the highest performing formulas based on patient axial length, age, and history of previous corneal refractive surgery. Recent findingsThe Barrett Universal II formula based on a theoretical model has consistently demonstrated high accuracy. The Olsen four-factor formula using ray tracing optics and the Hill-RBF calculator using artificial intelligence have also demonstrated good prediction results after being updated. Notably, the Kane formula, incorporating artificial intelligence, has overall shown the best performance for all axial lengths. Although newly developed and updated IOL formulas have improved refractive prediction in patients with short or long axial length eyes or prior history of corneal refractive surgery, these challenging cases still require special consideration. The Barrett True-K formula has shown accurate results regardless of preoperative data in eyes with previous myopic refractive surgery. SummaryAdvancements in optical biometry and IOL calculation formulas continue to improve refractive outcomes. The clinician can optimize refractive outcomes in the majority of patients with the use of formulas that have shown consistent results and accuracy in several large studies.

Purpose of reviewModern phacoemulsification machines apply ultrasound through a variety of settings and parameters to remove a cataract. Using these new technologies efficiently is critical for both reducing surgical times and improving postoperative outcomes. The present article reviews recent findings in phacodynamics to explore the optimum use of ultrasound in cataract surgery. Recent findingsIn studies seeking to determine the optimum parameters in both fluidics and power, increased power and aspiration does not necessarily equate to more efficiency. New developments, such as torsional ultrasound, micropulse, and burst mode have shown increased efficiency in randomized control trials and in-vitro compared with conventional ultrasound. Regarding vacuums, the venturi pump has demonstrated greater efficiency compared with the peristaltic pump. We also explore other parameters, such as chamber pressure and tip selection. Meta-analyses on femtosecond-laser assisted cataract surgery (FLACS) have shown similar long-term visual outcomes compared to conventional cataract surgery.