Recent updates on myopia control: preventing progression 1 diopter at a time Purpose of review Myopia refers to a refractive state of the eye that can predispose to visually significant ocular disease. The prevalence of myopia is increasing worldwide. Researchers internationally have been investigating methods to slow down its progression to prevent sight-threatening complications. In this article, we perform a review of the current literature discussing interventions for preventing pediatric myopic progression. Recent findings Various interventions, including lifestyle modification, optical methods, and pharmacologic approaches, have been proposed to help control myopic progression. Increasing time spent outdoors can help prevent myopia onset, but has a clinically questionable effect on progression of myopia. Contact lenses that reduce peripheral retinal hyperopic defocus represent a new area of research and may hold promise as an effective intervention in myopia control. Orthokeratology shows moderate reduction rates in myopic progression whereas atropine drops, even at low doses, show the most impressive effect on slowing myopia. Summary Atropine eye drops, followed by orthokeratology lenses, are the most effective in slowing down axial elongation and myopic progression. Guidelines for use and the target populations for such interventions have not been well established and more research is warranted in these areas. Treatment should be tailored to each patient.

Effectiveness of intracorneal ring segments for keratoconus Purpose of review To review the efficacy of intrastromal corneal ring segments (ICRS) for keratoconus and with other interventions such as contacts lens, keratoplasty, and corneal collagen cross-linking. Recent findings Changes in ICRS thickness and size, combination of procedures, and the adaptation of a more sophisticated classification system have broadened our application of ICRS. Recent studies have shown the long-term efficacy of ICRS in visual acuity, keratometry, and astigmatism. Summary Studies have demonstrated the short-term and long-term efficacy of ICRS implantation in patients with keratoconus.

Hyperopic small-incision lenticule extraction Purpose of review Small-incision lenticule extraction (SMILE) has shown great promise in the treatment of myopia; however, the literature is less extensive in its hyperopic counterpart. The purpose of this review is to detail the recent advancements and outcomes of SMILE in the treatment of hyperopic eye disease. Recent findings SMILE has demonstrated similar visual outcomes, regression rates, centration ability, safety profiles, and wound healing as hyperopic laser-assisted in situ keratomileusis (LASIK). Lenticule preservation and implantation show further promise in the correction of higher degrees of hyperopia. Summary Based on the current literature, SMILE represents a viable surgical alternative to LASIK in the correction of hyperopia. Lenticule intrastromal keratoplasty and small-incision lenticule intrastromal keratoplasty may be able to correct severe hyperopia in patients who would not otherwise be candidates for refractive surgery.

Small-aperture strategies for the correction of presbyopia Purpose of review The recent scientific literature provides evidence of long-term results with small-aperture corneal inlays, as well as new evidence from a multicenter postmarket study of small-aperture intraocular lenses (IOLs) and early reports of the use of topical agents for presbyopia correction through pupil constriction. The field of small-aperture optics is growing and changing rapidly. Recent findings This article reviews what is known to date about various small-aperture optics platforms, including a posterior chamber IOL, add on device, corneal inlay, contact lenses, and pupil-constricting drops. Additionally, the impact of small-aperture technologies on light perception and visual performance, as well as the relative merits of monocular versus binocular small apertures are discussed. Summary Small-aperture optics are a dynamic, physiologic solution to the problem of presbyopia. They are effective throughout the range of accommodation loss and in pseudophakia. Small-aperture optics offer an opportunity to improve vision in presbyopes with and without cataracts. In some forms, they may also be able to reduce the impact of aberrations or improve vision in eyes with corneal irregularities, scars, or iris damage.

Long-term outcomes of permanent keratoprosthesis Purpose of review To provide an update on recent advances in keratoprosthesis surgery with a focus on long-term outcomes. Recent findings Reports over the past year have focused on long-term outcomes showing good anatomical and functional results. In addition, preoperative diagnosis and surgical modifications that can impact postoperative outcomes are discussed. Outcomes of primary keratoprosthesis as an option for patients with poor prognosis for traditional keratoplasty are also presented in this review. Summary Keratoprosthesis is an option for visual rehabilitation in select patients. Current 5-year outcomes are promising but improvements in glaucoma prevention and management are needed to enhance long-term results.

Update on Bowman layer transplantation Purpose of review Bowman layer transplantation is a novel technique that may stabilize progressive ectatic corneal changes in eyes with keratoconus, which are too steep or too thin for ultraviolet corneal crosslinking or intracorneal ring segments. In this way, patients can maintain stable vision with contact lenses, and avoid or postpone more invasive corneal transplants, such as penetrating keratoplasty or deep anterior lamellar keratoplasty. This review aims to summarize the currently available literature on Bowman layer transplantation. Recent findings Bowman layer transplantation seems to be a promising, minimally invasive procedure for managing advanced keratoconus with a reported 5-year success rate of 84%. The procedure allows patients to maintain acceptable visual acuity with glasses or contact lens correction. Although graft preparation and surgical technique can be challenging, adaptation of technologies, such as femtosecond laser and intraoperative anterior segment optical coherence tomography, may help overcome these barriers to enable Bowman layer transplantation to become a more widely adopted procedure. Summary Bowman layer transplantation may offer an alternative, less invasive treatment option for eyes with advanced, progressive keratoconus.

Femtosecond laser-assisted deep anterior lamellar keratoplasty Purpose of review A survey of the recent literature of deep anterior lamellar keratoplasty using femtosecond laser technology. Recent findings There are several recent reports in the literature assessing technique and outcomes of deep anterior lamellar keratoplasty done with a femtosecond laser trephination. Most of these reports are laboratory studies and small case series with short-term outcomes. The laser technology is expensive and may not produce better results than conventional manual techniques. However, there are several theoretical advantages to femtosecond laser incisions in deep anterior lamellar keratoplasty that should be explored, including possible increased success of Descemet's membrane separation from stroma during surgery as well as postsurgical astigmatism benefits, earlier suture removal, and increased wound strength and healing. Summary Femtosecond laser trephination in the setting of DALK may improve the technique by decreasing the number of descemet's membrane ruptures and improving short-term and long-term outcomes as compared with manual techniques. However, there is no consensus on a standardized approach for wound design or postoperative management. The literature would benefit from a prospective randomized controlled trial.

Ultrathin Descemet stripping automated endothelial keratoplasty Purpose of review Endothelial keratoplasty has evolved tremendously since its inception. Thick Descemet stripping automated endothelial keratoplasty (DSAEK) grafts have made sway for slimmer ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK). This review discusses the recent literature comparing outcomes of UT-DSAEK, DSAEK, and Descemet membrane endothelial keratoplasty (DMEK). Recent findings DMEK provides quick visual recovery and has remarkably low incidence of graft rejection. However, the learning curve is long compared to DSAEK. UT-DSAEK utilizes donor grafts less than 100-μm thick. Recent studies comparing DMEK and UT-DSAEK have shown DMEK has better visual outcomes with similar rejection rates. Summary UT-DSAEK remains an excellent surgical option for endothelial keratoplasty in eyes with complex anterior segment anatomy. The visual outcomes after UT-DSAEK have been shown to be superior when compared with DSAEK. Recent studies show that DMEK provides better visual outcomes compared with UT-DSAEK.

Update on Descemet membrane endothelial keratoplasty Purpose of review To provide an update on new perspectives on Descemet membrane endothelial keratoplasty (DMEK). Recent findings Preloaded DMEK grafts allow optimization of DMEK surgery time and reduce costs of the procedure, which is allowing the procedure to become more easily performed as reflected in the increasing number of cases. The surgical technique in the United States differs from the technique in Europe, but outcomes have been similar. Hemi-DMEK and quarter-DMEK have shown similar outcomes to conventional DMEK with respect to corneal transparency and visual acuity. Three-year follow-up of hemi-DMEK has also shown stability in endothelial cell count while maintaining corneal transparency. Summary DMEK is becoming more accepted as the procedure of choice for treating endothelial failure. However, challenges with the surgical technique have limited wider implementation of this lamellar corneal transplantation. Preloaded DMEK provides one solution for the surgical challenges associated with the procedure while also reducing costs. Variations in the surgical technique for DMEK, including hemi-DMEK and quarter-DMEK, allow for central corneal clarity similar to traditional DMEK, but both result in lower endothelial cell density (ECD).