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October 20, 2021


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

In this week's issue

  • For visual field testing, SITA Standard and SITA Faster appear equivalent for mild or suspect glaucoma, but transitioning to SITA Faster may conceal disease progression in those with moderate and advanced disease
  • A large portion of patients with early-onset drusen maculopathy (EODM) carried rare complement factor H variants
  • Neutrophil elastase appears to contribute to the development of diabetic retinopathy

Does Slow and Steady Win the Visual Field Testing Race? 

Ophthalmology

Now you see it, now you don’t. There are multiple methods of measuring visual field progression and the most common tool is the Humphrey Field Analyzer. Many practices use the Swedish Interactive Testing Algorithm (SITA) Standard sequence which takes approximately 7 minutes per eye. Other practices use the SITA Fast (4 minutes per eye) or the SITA Faster (3 minutes per eye). In this retrospective longitudinal study of 421 patients, investigators sought to determine how visual field measurements (specifically mean deviation) differ between SITA Standard and SITA Faster in glaucomatous eyes of varying severities. In mild and suspect disease eyes, there were no significant differences in mean deviation between the Standard and Faster sequences. However, compared to the Standard sequence, the Faster sequence resulted in a 0.87 dB mean deviation improvement in moderate glaucomatous eyes and a 1.49 dB improvement in advanced glaucomatous eyes. As a result, transitioning to the Faster sequence may conceal some disease progression in moderate and advanced glaucoma.

Genotypic Associations in Early-Onset Drusen Maculopathy

JAMA Ophthalmology

Genomics research has a different take on fishing for compliments. Genetic mutations affecting the complement system have been associated with an increased risk of nonexudative age-related macular degeneration (AMD). Although the precise etiology of AMD remains unclear, the complement system has gained attention as a potential therapeutic target with clinical trials investigating recombinant protein supplementation. Relatively little is known about genetic associations in Early Onset Drusen Maculopathy (EODM), which presents similarly to AMD, with drusen and subsequent vision loss beginning at a younger age. In a case-control study comparing 89 patients with EODM to 91 patients with AMD, researchers explored the genotypic and phenotypic characteristics of EODM using 52 genetic variants associated with AMD. A genetic risk score calculated with these variants was lower in patients with EODM compared to AMD (1.03 vs 1.60; p = 0.002). This finding indicates that single nucleotide variants used to calculate the score may be less prevalent in patients with EODM. However, the odds of having EODM were higher in patients who had rare variants of the CFH gene (odds ratio 7.2; 95% CI 2.7-19.6; p < 0.01), suggesting that complement factor H mutations are associated with this disease. This association may have implications for genetic counseling and therapeutic approaches targeting the CFH gene or the factor H protein.

The role of neutrophils in diabetic retinopathy

IOVS

What is the most common white blood cell with multilobed nuclei and stainable cytoplasmic granules seen on a smear? Neutrophils; and we’re starting to learn more about their role in the pathogenesis of diabetic retinopathy (DR). Prolonged hyperglycemia resulting in chronic subclinical inflammation contributes to changes seen in DR, however researchers sought to define the role of inflammatory immune cells in this process. Neutrophils contribute to our innate immunity by killing pathogens and sounding the alarm for infection. In that process, they secrete enzymes such as proteases and elastases that can clear invaders but can damage our own cells (including the blood vessel endothelium). In the current study, the role of neutrophil elastase (NE) was investigated in the pathogenesis of DR. Diabetes was induced in NE-deficient mice, mice treated with NE inhibitors, or mice overexpressing human alpha-1 antitrypsin. Outcomes measured included retinal superoxide generation, inflammation, leukostasis, and capillary degeneration. In mice diabetic for either 2 or 8 months, genetic deletion or pharmacologic inhibition of NE resulted in significant reductions in diabetes-induced retinal capillary degeneration. Leukocyte mediated endothelial cytotoxicity, superoxide levels, and retinal inflammation were also found to be reduced through deletion/inhibition of NE. These findings provide novel insights into the role of neutrophils in DR and present a potential pharmacologic target for future treatments.

Do Blue-blocking Lenses Reduce Eye Strain From Extended Screen Time?

American Journal of Ophthalmology

If you thought popping on blue-light glasses would save your eyes from eighteen straight hours of Netflix, think again. There is very little data to support the use of blue-light glasses. To address this evidence gap, the authors conducted a double-masked randomized controlled trial to investigate if blue-blocking lenses are effective in alleviating ocular symptoms associated with computer use. Objective and subjective eye strain measures did not differ based on advocacy type (positive or negative) or spectacle intervention type (blue-blocking or clear lens). Providers should use this information to judiciously counsel patients on the merits, especially the cost-benefits, of utilizing blue-light blocking glasses.

Glaucoma

Face Masks and Visual Field Defects During COVID-19

Journal of Glaucoma

The AAO recommends the use of face masks for patients at all times. This study sought to identify the influence that tapping and not-tapping a facemask to the patient’s face had on their visual field tests as well as the fogging of their glasses. This randomized cross sectional study included 13 patients (26 eyes) from a glaucoma out-patient center and measured visual field testing randomized in either sequence 1 (Octopus visual field examination without tape sealing, followed by examination with tape sealing) or sequence 2 (examination with, followed by without tape sealing). The results for the visual field examinations with and without tape sealing differ significantly for mean difference (MD) (0.39 dB, 95% CI: 0.07-0.70 dB); showing greater defects in visual fields in patients that did not tape their masks. With the continued use of facemasks in clinics, practitioners should consider the impact that they have on visual field testing.

Global & Public Health

Pediatric cataract effects on mental health

American Journal of Ophthalmology

Beyond vision: what mental health challenges are associated with childhood cataracts? The relationship between visual disability from childhood cataract and mental health disorders was assessed among 485 cases and an equal number of age- and sex-matched controls. Children with cataract were twice as likely to have a mental health disorder (particularly neurodevelopmental disorder) as those without cataracts (10.5% and 5.2% respectively). This was especially true among those age three or younger. Notably, children with cataract had a 4-fold greater burden of anxiety compared to controls. These data reveal the importance of assessing mental vulnerability of children with cataract. Support of their educational, developmental, and psychological needs may improve long term outcomes associated with this disease. 

Question of the Week

A 40-year-old man presents to Ophthalmology clinic with concern for visually significant glare while driving at night. He has also noticed a change in the color of his right eye over the last year. He denies symptoms of eye pain, redness, or discharge. The unaffected iris appears brown with no color irregularity. Significant features of the appearance and slit lamp exam of the right eye are shown in the images below. These findings are absent in the left eye.
What is the most likely diagnosis?
a.     Posner-Schlossman Syndrome
b.     Congenital heterochromia
c.     Fuch’s Heterochromic Iridocyclitis
d.     Waardenburg’s Syndrome


 
Keep scrolling for answer or click here
 

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Quiz Answer: c
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