March 2019


News in brief

Shedding light on genetics of AMD

Scientists from the National Eye Institute identified genes that are associated with AMD, a discovery that could lead to new treatment pathways for this leading cause of blindness and vision loss in those older than 65. “If we were conducting a criminal investigation, prior research would have localized different crime syndicates to 52 streets within 34 zip codes. These latest findings identify actual suspects—direct targets that we can more closely investigate,” lead investigator Anand Swaroop, PhD, said in a press release statement. Conducting RNA analysis from more than 400 donor retinas with and without AMD—the first study to analyze transcriptional RNA in the context of AMD—the researchers searched for genetic variants that regulate gene expression, which led them to six target disease genes. They combined this knowledge with data from earlier studies and identified three other target AMD genes. Overall, this research suggests 20 new candidate genes that could play a role in AMD. In the course of this study, the team developed EyeGEx, a retinal gene expression database that can be used by other vision researchers looking at other diseases.

Ratnapriya R, et al. Retinal transcriptome and eQTL analyses identify genes associated with age-related macular degeneration. Nat Genet. 2019. Epub ahead of print.

Low-stress training a boon to acquiring surgical skills

A study of 15 medical school students with aspirations to be surgeons found that training in a low-stress environment seemed to enhance their ability to master surgical skills. According to the research published in Scientific Reports, they were able to master microsurgical suturing and cutting in as little as five sessions lasting 1 hour each. “It appears that by removing external stress factors associated with the notoriously competitive and harsh lifestyle of surgery residencies, stress levels during inanimate surgical training plummet,” Ioannis Pavlidis, PhD, said in a press release statement. “In five short sessions these students, approaching surgery for fun or as a hobby, had remarkable progress achieving dexterity levels similar to seasoned surgeons, at least in these drills.”

Pavlidis I, et al. Absence of stressful conditions accelerates dexterous skill acquisition in surgery. Sci Rep. 2019;9:1747.

Stats on eye trauma hospitalizations

A review of eye trauma hospitalizations from 2001 to 2014 found a decrease in primary eye trauma as a cause for admission and an increase in eye trauma as a secondary diagnosis among admittees. The latter increase, according to Iftikhar et al., was due to an increase in the number of falls among elderly patients. Primary orbital fracture was the most common diagnosis for primary trauma while contusion and adnexa were the most frequent diagnoses for secondary trauma.

Iftikhar M, et al. Changes in the incidence of eye trauma hospitalizations in the United States from 2001 through 2014. JAMA Ophthalmol. 2019;137:48–56.

Minimizing endothelial cell loss due to Descemet’s membrane stamping

Stamping an orientation reference on Descemet’s membrane for transplantation can result in endothelial cell loss in that area. A study by Newman et al., however, found that endothelial cell loss due to stamping can be minimized by using a smaller, F-shaped stamp and by using prestripped tissue vs. preloaded tissue.

Newman LR, et al. Minimizing endothelial cell loss caused by orientation stamps on preloaded Descemet membrane endothelial keratoplasty grafts. Cornea. 2019;38:233–237.

Malyugin ring for chamber stability in some cataract cases

In a recent study, Sharma et al. describe a novel use of a Malyugin ring, usually employed for pupil expansion, for chamber stability in open-sky cataract cases. Sharma et al. wrote that using the Malyugin ring under the margins of the host cornea can stabilize the chamber in the presence of positive vitreous pressure to allow for safe capsulorhexis creation and cataract removal. They find this technique is especially useful in cases with a hypermature cataract and a non-dilating pupil where the patient requires a triple procedure.

Sharma VK, et al. Novel use of Malyugin ring to avoid intraoperative positive vitreous pressure during triple procedure. J Cataract Refract Surg. 2019. Epub ahead of print.

Global consensus on definition of limbal stem cell deficiency

In 2012, the Cornea Society established the Limbal Stem Cell Working Group in order to develop a globally accepted definition and diagnostic criteria for limbal stem cell deficiency (LSCD). In January they released a consensus. Overall, the definition describes LSCD as “an ocular surface disease caused by a decrease in the population and/or function of corneal epithelial stem/progenitor cells; this decrease leads to the inability to sustain normal homeostasis of the corneal endothelium.” The working group goes on to list the different classifications of LSCD, diagnosis, and staging based on clinical presentation.

Deng SX, et al. Global consensus on definition, classification, diagnosis, and staging of limbal stem cell deficiency. Cornea. 2019;38:364–375.

Topography-guided versus wavefront-optimized LASIK

A prospective comparative study of topography-guided versus wavefront-optimized LASIK found that both resulted in safe and effective refractive surgery. However, topography-guided LASIK resulted in fewer higher order aberrations, especially ocular trefoil, corneal total HOAs, and coma, according to Kim et al. Overall, uncorrected distance visual acuity of 0.0 logMAR or better occurred in 90.7% of eyes that received either topography-guided or wavefront-optimized treatments. 

1. Kim J, et al. Comparison of surgical outcomes with topography-guided versus wavefront-optimized LASIK for myopia. J Cataract Refract Surg. 2019. Epub ahead of print.

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