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May 4, 2022


The most important ophthalmology research updates, delivered directly to you.
 

In this week's issue

  • Mindfulness meditation for one hour per day may lower IOP in ocular hypertensive patients
  • Repeated low-level red-light therapy shows promising results in slowing myopia progression in children
  • Including corneal central thickness and corneal resistance factor gene loci in polygenic risk scores improves a predictive model for keratoconus
  • Vascular endothelial stem cells may play a role in angiogenesis seen in many ophthalmologic conditions

A lit new treatment: red-light therapy to halt myopia in children

Ophthalmology

Your favorite childhood game of Red Light, Green Light may be more beneficial than you thought. A cohort of 246 children received treatment with either repeated low-level red-light (RLRL; n=117) and single-vision spectacle (SVS) or SVS alone (n=129) over 12 months and were assessed for changes in axial length and spherical equivalent refraction (SER). RLRL was delivered by at-home treatments with 650nm wavelength light at 1600 lux twice daily for three minutes, five days a week. After 12 months, participants who received RLRL treatment showed axial elongation of 0.13mm (95%CI: 0.09-0.17) and SER progression of -0.20D (95%CI: -0.29D- -0.11D) while those with SVS treatment alone showed axial elongation of 0.38mm (95%CI: 0.34-0.42mm) and SER progression of -0.79D (95%CI: -0.88D- -0.69D). These significant differences between treatment outcomes highlight the potential of RLRL use in myopic control in this population, especially given the fact that no adverse events were seen during RLRL treatment. As this study was only conducted with participants of one ethnicity, future studies with increased diversity may provide more insight on this treatment.

Polygenic risk scores for keratoconus

JAMA Ophthalmology

Inheritance of most diseases cannot be solved with a simple Punnett square and keratoconus is no exception! Polygenic risk scores are a tool used in translational genomics research to estimate the risk of disease phenotype based on the presence or absence of multiple genetic variants associated with the condition. Keratoconus is a partially heritable disorder that involves progressive thinning and steepening of the corneal contour, causing visually significant irregular astigmatism that may require rigid contact lenses or even corneal transplant for correction. Central corneal thickness (CCT) and corneal resistance factor (CRF) are two highly heritable traits that are reduced in patients with keratoconus. Researchers hypothesized that including variants of CCT and CRF gene loci in polygenic risk scores for keratoconus may improve these models. A genome-wide association study was performed of 129,665 patients from four cohorts of different ancestries, and identified 369 CRF and 233 CCT loci, 36 and 114 of which had not been previously reported in the literature, respectively. A total of 29 CRF loci and 24 CCT loci were associated with keratoconus. Including CRF- and CCT-associated variants in polygenic risk scores for keratoconus increased the predictive value of these models, measured by the area under the receiver operating characteristic curve (AUROC) (CRF: 0.705-0.756, CCT: 0.715-0.755). By identifying genetic variants associated with CCT, CRF, and keratoconus, this study may help guide future study of keratoconus pathophysiology and inheritance.

Mind over matter: mindful meditation to lower intraocular pressure?

American Journal of Ophthalmology

Can a little meditation a day keep the ophthalmologist away? Ocular hypertension (OHT) is defined as intraocular pressure (IOP) > 21 mmHg without optic nerve, retinal nerve fiber layer, or visual field abnormalities. As the most important modifiable risk factor for the development of primary open-angle glaucoma is increased IOP, many OHT patients are started on IOP-lowering eye drops. However, medical treatment can cause adverse side effects, financial concerns, and psychological stress, motivating researchers to find non-pharmacological methods to decrease IOP. This prospective, randomized controlled trial of 60 OHT patients investigated whether 6 weeks of mindfulness meditation could change IOP. Participants were randomized to a meditation group (mindfulness meditation for 1 hour daily) or control group (no intervention). At 6 weeks, there was a significant decrease in IOP (23.05 ± 1.17 to 19.15 ± 1.45 mmHg) in the mindfulness meditation group, as well as a significant difference in change in IOP between the mindfulness meditation group (3.93 ± 1.47) and non-intervention group (0.17 ± 0.58). The study also demonstrated a significant improvement in participant quality of life and significantly decreased serum cortisol levels in the mindfulness meditation group as compared to the control group. While this study took place over a short duration, excluded those with systemic comorbidities, and possibly introduced bias secondary to the Hawthorne effect, it suggests that mindfulness meditation may be one non-pharmacological option to help lower IOP in patients with OHT.

Potential role of stem cells in angiogenesis: the good and the bad

IOVS

Could stem cells be responsible for hypoxia-induced angiogenesis? Angiogenesis leading to retinal or choroidal neovascularization can cause drastic visual consequences in patients with age-related macular degeneration and diabetic retinopathy. The cells responsible for angiogenesis in response to hypoxia have long been a mystery. One potential mediator is local Vascular Endothelial Stem Cells (VESCs). In addition to being CD31+ CD45- like all endothelial cells (ECs), VESCs are identified by their unique cell surface marker CD157, also known as Bst1. This study aimed to confirm the presence of VESCs in adult mouse retina and choroid and developed a protocol to isolate single cells using Fluorescence-Activated Cell Sorting (FACS). VESCs made up 1.6% and 4.5% of ECs in the retina and choroid respectively with predominance in veins and post-capillary venules. VESCs formed more EC networks compared to CD157- ECs (4.21% vs. 0.27% for retina-derived cells, 8.59% vs 0.14% for choroid-derived cells). Limitations to this study include the inability to conclude whether VESCs are responsible for in vivo angiogenesis which could be determined with fate-mapping and most importantly, if VESCs are present in humans. If the latter is confirmed, further research could elucidate if VESCs could be targeted in treatments for pathological neovascularization or conversely for revascularization in ischemic tissue.

Pediatrics 

New tablet-based method to assess visual acuity in children

BMC Ophthalmology

If we can’t keep kids away from their tablets, why not bring a new visual acuity test to them? Refractive amblyopia is a common cause of visual impairment among children. It remains a public health concern for which timely screening and management are essential. There is high demand for reliable technologies that facilitate visual acuity assessments. This study aimed to evaluate the reliability of a tablet-based near visual acuity test adapted to the pediatric population, the eMOVA test (electronic Measurement Of Visual Acuity), by comparing visual acuity measured with a more standard test (Rossano-Weiss test). This prospective study included 100 children, ages 3 to 8, who received a pediatric eye examination between September 2016 and June 2017. The mean difference in near visual acuity between both tests was -0.06 logMAR (95% CI -0.10 - 0.02, p = .006), with the eMOVA test reporting higher near visual acuities. The eMOVA test may be a clinically reliable test to assess near visual acuity in children, but further studies with larger samples and varied settings are needed. Tablet-based visual acuity assessments for children remain a promising option.

Question of the Week

A 55-year old man with a 10-year history of poorly controlled diabetes and medication non-compliance returns to your clinic for a first diabetic retinopathy (DR) screening. Dilated fundus exam is shown below.
These exam findings demonstrate what level of DR severity?
 
A. Severe non-proliferative DR
B. Non-high-risk proliferative DR
C. High-risk proliferative DR
D. Inactive/involuted proliferative DR

 
Keep scrolling for answer or click here

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Answer: C
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