November 17, 2021

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

In this week's issue

  • A global survey found consensus for postlaminar optic nerve infiltration, involvement of optic nerve transection, and extrascleral tissue infiltration as high-risk features in retinoblastoma
  • Recombinant human nerve growth factor (rhNGF) was safe but ineffective in glaucoma
  • Collateral vessel extension measured by OCTA correlated with worse anatomic and visual outcomes in CRVO and BRVO

Risks and Benefits of Myopia Control


To see or not to see? The worldwide prevalence of myopia has been steadily increasing. As such, an extensive review of the literature was performed to determine whether the benefits of slowing myopia progression by 1 diopter (D) outweigh potential risks of treatment, mainly contact lens wear. Data regarding the risks of developing myopia-induced sight-threatening conditions was used to develop a model to predict the effect of myopia on VI and the years of VI that could be prevented with myopia control. Each 1-D increase in myopia results in a 58%, 20%, 21%, and 30% increase in the risk of developing the sight-threatening conditions myopic maculopathy, open-angle glaucoma, posterior subcapsular cataract, and retinal detachment, respectively. Additionally, myopia control leading to a reduction of 1-D in those with myopia of -3 D and -8 D leads to a reduction in predicted mean years of visual impairment by 0.74 and 1.21 years, respectively. For myopia control, the number needed to treat to prevent 5 years of visual impairment is between 4.1 and 6.8, the number needed to harm for loss of vision was 38. Therefore, the results of this study indicate that the benefits of myopia control outweigh the risks in terms of the onset of potential sight-threatening conditions and number of years of visual impairment.

High-Risk Features of Retinoblastoma

JAMA Ophthalmology

I’ll take histopathology for $1000. Globe- and vision-sparing options are available for the management of early retinoblastoma without high-risk features. However, consensus regarding the definition of high-risk features is lacking. To address this issue, an online survey was circulated to 52 oncologists and pathologists managing retinoblastoma worldwide. Participants were asked to indicate which of the listed pathologic features they regarded as high-risk. Of the 27 individuals who responded, 100% identified postlaminar optic nerve infiltration, involvement of optic nerve transection, and extrascleral tissue infiltration as high-risk features. Other potentially high-risk features had more variability: >3 mm choroidal invasion (25, 93%), microscopic scleral infiltration (23, 85%), ciliary body infiltration (20, 74%), trabecular meshwork invasion (18, 67%), iris infiltration (17, 63%), anterior chamber seeds (14, 52%), laminar optic nerve infiltration (13, 48%), combination of prelaminar and laminar optic nerve infiltration and <3 mm choroidal invasion (11, 41%), <3 mm choroidal invasion (5, 19%), and prelaminar optic nerve infiltration (2, 7%). The results of this survey indicate that the criteria for risk stratification in retinoblastoma are variable. As globe salvage treatment options continue to evolve, clear delineation of high-risk histopathologic features will help guide clinical study design and patient care planning.

rhNGF for Neuroenhancement in Glaucoma

American Journal of Ophthalmology

Studies have shown that recombinant human nerve growth factor (rhNGF) enhances RGC structure, function, and survival - but will it work for humans with optic nerve damage? Gala et. al investigated the safety, tolerability, and efficacy of rhNGF eye drops on a cohort of glaucoma patients. NGF is a naturally occurring peptide that promotes differentiation, survival, and axon and dendrite growth of neurons throughout the nervous system. This study was a phase 1b randomized, double-masked clinical trial that included 60 glaucoma patients and 60 individual eyes. Patients were randomized to receive either 180 μg/ml rhNGF or vehicle control eye drops in both eyes, three times daily for 8 weeks, with a 24-week post-treatment follow-up. The investigators found that the safety profile of the 180 μg/ml rhNGF eye drops was excellent, with no systemic treatment-emergent serious adverse events. However, they found no statistically significant improvement in neuroenhancement of the optic nerve post-treatment. Although this particular trial did not achieve positive visual outcomes, the potential for neuroprotection and enhancement based on success in animal trials warrants further studies of rhNGF's efficacy in glaucoma patients. And if rhNGF eye drops do become part of standard glaucoma management in the future, we’re all waiting in anticipation to see what color cap the bottle will have. 

Visual outcomes from collateral vessels in CRVO and BRVO


Collateral damage? Central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO) are common retinal vascular pathologies that can lead to vision impairments. Due to the hemodynamic alterations, collateral blood vessels gradually develop within the retina to help maintain blood flow in the eyes of affected patients. In this cross-sectional case series, researchers investigated the relationship between presence of collateral vessels measured by OCT/OCTA and final anatomical or functional outcomes including central macular thickness (CMT), foveal avascular zone (FAZ), and best corrected visual acuity (BCVA). Collateral vessels were detected in 29% of CRVO and 100% of BRVO patients. Collateral vessel extension correlated with worse anatomic and visual outcomes: a negative correlation with final BCVA and positive correlation with higher CMT and larger FAZ. The use of OCTA to identify and characterize collateral vessel development is a more sensitive approach than biomicroscopic fundus exams that may miss vessels deeper within the retina. The correlations found in this study provide greater insight into the role of collateral vessels on visual outcomes that could be used as a prognostic factor in RVO.


Bruch's Membrane Opening Rim Area and Glaucoma Progression

Journal of Glaucoma

Can other methods replace the traditional retinal nerve fiber layer thickness and visual field testing for monitoring glaucoma? This study sought to determine the best diagnostic measurement for early glaucoma and disease progression. Investigators compared Bruch’s membrane opening rim area (BMO-MRA), the peripapillary retinal nerve fiber layer thickness (RNFLT) and visual field index (VFI) according to glaucoma severity. This retrospective cross-sectional study included 121 eyes, 73 with open angle glaucoma and 48 normal. The tipping points of RNFLT for VFI and BMO-MRA were estimated using broken stick regression models. The tipping point of the RNFLT for the VFI was 88.62 μm (95% CI, 79.59 to 97.65; P = 0.001). The tipping point of the RNFLT for BMO-MRA was 60.00 μm (95% CI, 48.28 to 71.72; P = 0.220). Above the tipping point, BMO-MRA decreased with a decrease in the RNFLT (slope = 0.0135 [95% CI, 0.0115 to 0.0155]; P < 0.001); below the tipping point, BMO-MRA did not decrease significantly. This study determined that with the progression of glaucoma, BMO-MRA decreased more rapidly, and this preceded a decrease in the RNFLT followed by a decrease in the VFI. As such, the measurement of BMO-MRA via OCT may be helpful in monitoring disease progression in early stages of glaucoma. 

Public Health

Alcohol and refractive error

Drug and Alcohol Dependence

Myopia has been commonly linked to several comorbid conditions as a precipitating factor as well as a resultant condition. Menéndez Acebal et. al explore the association between alcohol and myopia. Between 1999 and 2018, 15,642 university graduates took part in the study. Every two years participants were mailed a validated food frequency questionnaire assessing alcohol intake and alongside this, data on myopia development or progression was collected. With each 10-gram increase in alcohol consumption, the OR for myopia incidence/progression over the course of the subsequent ten years was 1.05 (95% CI 1.01-1.09). If future studies demonstrate causality, alcohol intake may result in an increase in risk of myopia. 

Question of the Week

A 48-year-old male with no significant past medical history presents with blurred vision, a drooping right upper eyelid, and right sided headache. His headache started two weeks ago, followed by the onset of a droopy eyelid and blurred vision only two days ago. The patient denies any other symptoms nausea, vomiting, focal sensory loss or weakness, slurred speech, facial droop, or gait instability. Exam was notable for a relative afferent pupillary defect and the abnormalities pictured below.
What is the most likely cause of this clinical progression?
a.     Posterior communicating artery aneurysm
b.     Horner’s syndrome
c.     Myasthenia gravis
d.     Carotid artery dissection

Keep scrolling for answer or click here

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