Advancements in intraocular lens power calculation formulas.

PURPOSE OF REVIEW: We 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 FINDINGS: The 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. SUMMARY: Advancements 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.

Efficient use of ultrasound in cataract surgery.

PURPOSE OF REVIEW: Modern 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 FINDINGS: In 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. SUMMARY: Though conventional cataract surgery remains highly effective, surgeons have increasing options for customizing their ultrasound settings and phacoemulsification techniques.

Recent developments in anterior capsulotomy for cataract surgery.

PURPOSE OF REVIEW: Successful anterior capsulotomy is an important step in cataract surgery. This article reviews the various anterior capsulotomy techniques available to surgeons to optimize the step, including those that have become available since the introduction of femtosecond-laser-assisted cataract surgery (FLACS). Studies comparing the relative advantages of each technique will be emphasized. RECENT FINDINGS: Manual continuous curvilinear capsulorhexis (CCC) and FLACS remain the two most widely studied techniques for achieving anterior capsulotomy. Each technique has been shown to be effective for a wide range of patients and cataract surgery complications. Meta-analyses have shown that FLACS provides similar results to manual CCC for long-term cataract surgery outcomes. Several alternative methods for anterior capsulotomy have been described, which aim to provide some of the advantages of laser capsulotomy at a lower cost; among these, precision pulse capsulotomy (PPC) and selective laser capsulotomy (SLC) have been investigated the most in the literature so far. SUMMARY: Cataract surgeons have an increasing number of techniques for anterior capsulotomy available. Manual CCC and FLACS remain the most widely used, and most well studied. The latest techniques, PPC and SLC, have shown promise in the few studies performed since they were introduced.

Clinical Results and Utility of Herpesviruses Multiplex Polymerase Chain Reaction: Assessment of Aqueous Humor Samples From Patients With Corneal Endotheliitis and High Intraocular Pressure.

PURPOSE: The main purpose of this study was to evaluate herpesvirus infection in patients with corneal endotheliitis and high intraocular pressure (IOP) using multiplex polymerase chain reaction (PCR) in aqueous humor samples. MATERIALS AND METHODS: This was a retrospective, observational study of immunocompetent patients living in South Korea. Eligible subjects had typical corneal endotheliitis with an IOP≥21 mm Hg or required antiglaucoma medication. Multiplex PCR was performed using aqueous humor samples obtained at first visit to detect the DNA of 6 herpesviruses. RESULTS: Forty-two eyes from 42 patients with >6 months' follow-up were analyzed. Of these, 16 were herpesvirus-positive: 3 herpes simplex virus 1, 3 varicella-zoster virus, 9 cytomegalovirus, and 1 Epstein-Barr virus. Eyes with coin-shaped or fine keratic precipitates (kps), high IOP, and a low baseline endothelial cell count were more likely to show a positive result on multiplex PCR. Univariate analysis showed that male sex (P=0.014), a previous history of uveitic glaucoma (P=0.048), and the presence of fine kps (P=0.031) were significantly associated with a positive PCR result. On multivariate analysis, male sex (P=0.010) and a previous history of uveitic glaucoma (P=0.031) showed a significant positive association. CONCLUSIONS: Cytomegalovirus was the most commonly detected herpesvirus in patients with corneal endotheliitis and high IOP. A positive PCR result was seen more frequently in male individuals and patients with fine kps or a history of uveitic glaucoma.