Current Issue

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In this week’s issue

• A cohort study of NASA astronauts found that those who developed spaceflight-associated neuro-ocular syndrome during one long-duration mission were highly likely to develop it again on subsequent missions.
• Strabismus surgery is undervalued by Medicare, as evidenced by a surgical cost analysis underscoring the need for fair compensation to address the growing shortage of strabismus surgeons and ensure patient access to care.
• For acute acquired comitant esotropia, augmented medial rectus recession surgery achieved significantly better long-term eye alignment, fusion, and quality-of-life outcomes than botulinum toxin A injection.

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JAMA Ophthalmology

Predicting spaceflight-associated neuro-ocular syndrome

Seeing beyond Earth. Spaceflight-associated neuro-ocular syndrome (SANS) is associated with long-duration spaceflight (LDSF), and includes optic disc edema (ODE), chorioretinal folds, globe flattening, and hyperopic refractive error. Pathophysiology is unclear, but SANS is diagnosed in about 70% of astronauts that participate in LDSF. Risk factors for SANS remain unknown. This cohort study sought to identify mission trends amongst NASA astronauts diagnosed with SANS or ODE who have traveled at least twice to the International Space Station. A retrospective analysis was conducted of 16 astronauts’ ocular testing from missions between 2007 to 2024. 6 of these astronauts were diagnosed with SANS during their first mission, 1 was diagnosed during their second mission, and 9 remained non-SANS throughout the two missions. SANS diagnoses from previous LDSF were highly associated with SANS diagnoses in future LDSF. Although the sample size for this study was small, it serves as the first report of predictors of SANS. This increased awareness can guide treatment and the development of prevention strategies. 

American Journal of Ophthalmology (AJO)

The price of alignment: what strabismus surgery really costs

It’s time to straighten out the costs of strabismus surgery. The shortage of strabismus surgeons has continued to grow over the last decade, raising significant concerns about its impact on patients and their access to care. This economic decline is likely driven by the lower compensation of pediatric ophthalmologists, with recent reimbursement cuts poised to further exacerbate strabismus surgeons. This retrospective study used time-driven activity-based costing (TDABC) to quantify and compare the cost drivers of strabismus surgery. The average day-of-surgery costs were $4420 among 690 strabismus surgeries, with 324 (47%) being pediatric. Each additional muscle contributed to the overall costs, adding $768 for horizontal muscles, $976 for vertical muscles, and $498 for inferior oblique muscles. Adjustable suture use added $1023 and reoperations added $823. An ambulatory surgery center setting and fellow second surgeon were able to lower costs by $813 and $512 respectively. Although limited to a single academic institution and excluding the costs of postoperative visits, this study found that strabismus surgery may be undervalued by Medicare. The ongoing decline in the number of strabismus surgeons is creating significant gaps in patient access to care. Policymakers and ophthalmologists are encouraged to work toward appropriate compensation for these subspecialized surgeries in ophthalmology.

British Journal of Ophthalmology

Augmented medial rectus recession vs. botulinum toxin for AACE

Which treatment keeps eyes straighter, longer? Acute acquired comitant esotropia (AACE), a sudden inward turning of the eyes with no ocular motility limitation, can be treated with either botulinum toxin A (BTXA) injection or strabismus surgery, but the optimal approach remains debated. This prospective clinical trial compared 63 patients treated with BTXA (n=31) or augmented medial rectus recession (aMRc) (n=32) for AACE of 6-24 months duration. At 12 months, aMRc achieved higher success (93.8% vs 64.5%) and more stable alignment, with only 6.3% showing residual deviation >10 prism diopters versus 35.5% in the BTXA group. Surgery significantly increased divergent fusional amplitude (FA) and eliminated diplopia more effectively. Quality-of-life scores improved in both groups, though improvement in self-perception, general function, and diplopia were greater after aMRc. Multivariate analysis identified treatment type and pre-treatment convergent FA at near as predictors of recurrence. These results suggest aMRc provides superior long-term motor, sensory, and functional outcomes for AACE, particularly in patients with disease duration of greater than 6 months.

JAMA Network Open
Disparities in DR outcomes despite treatment adherence
Even showing up to every appointment cannot outpace inequality. Diabetic retinopathy (DR) is a leading cause of visual impairment, affecting 26% of individuals with diabetes in the US. This study seeks to evaluate how social determinants of health impact DR incidence, complications, and management in patients with type 2 diabetes mellitus (T2DM). A 10 year retrospective analysis was performed using TriNetX data from 70 U.S. health systems. Adults with T2DM were divided into socially deprived and non-socially deprived cohorts based on ICD-10 codes related to SDOH (e.g. housing instability, food insecurity, and financial hardship) and matched. For patients without adherence issues, social deprivation was associated with increased DR risk (HR 1.44, 95% CI 1.35-1.54) and treatment utilization. These patients received equal or greater use of anti-VEGF injections, laser therapy, and vitrectomy, suggesting more advanced disease at presentation rather than under-treatment. Disparities were especially pronounced in men and Hispanic adults. These findings underscore that access and adherence alone cannot offset systemic inequities driving vision loss. Rather, ophthalmic care must integrate social risk screening, early intervention, and cross-specialty coordination.

Journal of Neuro-Ophthalmology

AI vs. neuro-ophthalmologists in imaging analysis

Can AI see what we see? OpenAI’s GPT-4 Vision model can analyze a wide range of images uploaded by users, but can it truly “see” through the lens of a neuro-ophthalmologist? Hess screen and automated visual field tests are common imaging tools in neuro-ophthalmology used to localize visual pathway disorders. To evaluate GPT-4 Vision’s interpretive ability, researchers presented the chatbot with five classic abnormal Hess screen charts representing third, fourth, and sixth cranial nerve palsy, Brown syndrome, and inferior orbital wall fracture with inferior rectus entrapment. They also provided five representative automated visual field grayscale maps corresponding to lesions of the optic nerve, optic chiasm, optic tract, optic radiations, and occipital lobe. GPT-4 Vision was asked to select the best option among the five choices in each question. GPT-4 Vision correctly identified 2 out of 5 Hess screen abnormalities and 3 out of 5 visual field patterns. However, even when it chose the correct diagnosis, several analytical errors were noted, including misidentifying the physiologic blind spot as a central scotoma. Given the variability in accuracy and the presence of flawed analytical interpretation, the use of AI in neuro-ophthalmic imaging remains limited at this time. 

Ranibizumab for macular edema following CRVO/BRVO - 2010

Keep your friends close, but your anti-VEGF injections closer… The BRAVO and CRUISE trials looked to find the best course of treatment for macular edema in the setting of branch and central retinal vein occlusions. Prior to this, laser therapy had proven to be ineffective and patients were simply observed with little hope in visual improvement. In the BRAVO and CRUISE trials, patients with macular edema following BRVO (n=397) and CRVO (n=392) were randomized to receive monthly intravitreal injections of 0.3 or 0.5 mg of ranibizumab or sham injections.

Key Points

• For BRVO, an increase in at least 15 letters in BCVA at 6 months was seen in 55.2% (0.3 mg) and 61.2% (0.5 mg) of patients compared to only 28.8% in the placebo arm; for CRVO, the respective groups yielding 46.2% (0.3 mg), 47.7% (0.5 mg), and 16.9% (placebo)
• Central foveal thickness at 6 months following BRVO/CRVO had decreased by a mean of 337/434 microns (0.3 mg) and 345/452 microns (0.5 mg) in the ranibizumab groups compared to 158/168 microns in the placebo group
• The BRAVO trial saw more placebo patients (54.5%) receive rescue grid laser compared with the 0.3 mg (18.7%) and 0.5 mg (19.8%) ranibizumab groups

The importance of this study was showing that anti-VEGF injections were effective in treating macular edema following retinal vein occlusions leading to marked improvement in visual acuity while still maintaining a very low risk of complications.