July 7, 2021

The most important ophthalmology research updates, delivered directly to you.
The Lens is expanding into the podcast world! The Lens Pod is an educational podcast created by medical students in collaboration with experts in Ophthalmology. Our first episode features Dr. Thomas Oetting, comprehensive ophthalmologist and residency program director at the University of Iowa, who shares with us what medical students should know before their first experience in comprehensive ophthalmology. Find us on Spotify or our website. Happy listening!

How much are you learning from The Lens?

Journal of Surgical Education

After a long day in clinic, there is nothing more refreshing than sitting down and reading some primary literature. Just kidding. That’s why we made The Lens: to help readers like you learn about new research in a quick, digestible manner. We administered a 14-question multiple choice quiz about recent studies in the field of ophthalmology to 59 medical student subscribers. 7 questions were based on articles that were summarized in The Lens, and 7 questions were based on articles that were not summarized (the questions were found to be similarly difficult in a sample of people who did not subscribe to The Lens). Lens subscribers correctly answered 51.1% of Lens items, compared to 42.9% of non-Lens items (p=0.022), indicating that you retain information that you’ve read here in The Lens. Adjusting for confounders, each additional month of reading The Lens was associated with a 2.7% improvement in Lens item quiz score (p=0.022). We were very happy to find that The Lens is providing value to our readers by helping them learn and retain information about recent developments in ophthalmology!

How soon is too soon for bilateral cataract surgery?

JAMA Ophthalmology

In the United States, cataract surgery is currently performed ~1-2 weeks apart; yet there is no standard internationally. Immediate sequential cataract surgery (ISBCS), in which both eyes are operated on the same day, has gained attention in recent years. However, complication rates and refractive outcomes remain unknown. In this retrospective cohort study of 1.8 million patients, Owen et al. compared refractive outcomes from those who underwent immediate vs delayed bilateral cataract surgery. Immediate bilateral cataract surgery was associated with worse best correct (BCVA) and uncorrected (UCVA) visual acuity outcomes by 1.64 and 2.79 letters, respectively. Though it was retrospective, this study suggests that outcomes may be worse with immediate bilateral surgery. Further research is needed to determine if these small effect sizes are clinically relevant.

A Dangerous Relationship: Visual and Cognitive Impairment


While the eyes may be the window to the soul, could they also be the reflection of the mind? The relationship between visual impairment (VI) and cognitive impairment (CI) has long been investigated due to similarities in risk factors and repercussions of both conditions, including physiological, psychosocial, and economic stress. While studies have suggested the two impairments to be correlated, hypotheses remain regarding a possible bidirectional causal relationship between the two. To further assess this, a meta-analysis of 40 studies studying VI and CI was conducted and it confirmed a correlation; those with VI had an over 2-fold increased odds of having CI (OR: 2.38 [95% CI: 1.84-3.07]) or clinically diagnosed dementia (OR: 2.43 [95% CI: 1.48-4.01]). However, having CI was not a risk factor for VI and no causal relationship could be proven. With the worldwide number of individuals suffering from VI and CI by the year 2050 estimated to be 1 billion and 152 million, respectively, these ailments have become major public health issues and this study highlighted the value of screening for VI and CI.

Eyelid Squamous Cell Cancer

British Journal of Ophthalmology

Sun exposure and skin cancer are important considerations in Ophthalmology too! Although squamous cell carcinoma (SCC) has a low incidence rate, it is the second most common cause of malignancy in the eyelid. The authors studied 117 patients in a retrospective study with histologically proven eyelid SCC from 2009 to 2020. Among these patients, there was no significant difference in gender nor laterality of the tumor; the mean age of diagnosis was 73.7 years with a mean time from onset of symptoms to diagnosis of 6 months. The study found that male gender, tumor location in the upper medial eyelid, and lymph node metastases were significant negative predictors for disease specific survival. Additionally, they found that the eighth edition of the American Joint Committee on Cancer (AJCC) Staging manual was significantly better at predicting DSS than the 7th edition. This study highlights key epidemiologic features of eyelid SCC and suggests that AJCC 8 should be used to stage these patients.


Can color vision testing diagnose dysthyroid optic neuropathy? 

Graefes Archive for Clinical and Experimental Ophthalmology  

Could color vision testing make the diagnosis of dysthyroid optic neuropathy more black and white? Dysthyroid optic neuropathy (DON) is a severe manifestation of thyroid eye disease that is diagnosed from clinical features such as decreased best corrected visual acuity, changes in color vision, and relative afferent pupillary defect. The diagnosis of DON is challenging due to a lack of standardized criteria, and there is no reliable means of early detection. The Arden color vision test is a computer-generated color vision test used to identify acquired color deficiencies. This cross-sectional retrospective study assessed patterns of color vision deficiencies among patients with DON. Medical chart review of 92 eyes with DON revealed that 91 eyes had a pathologic blue-yellow (tritan) deficiency, even in the absence of visual field defects or changes in best corrected visual acuity. The sensitivity of the tritan test (98.9%) was higher than that of red-green (protan) testing (61.9%). The authors conclude that tritan deficiency is a sensitive indicator of optic nerve compression in DON patients. The Arden color vision test can be used to identify various other neuro-ophthalmic pathologies in addition to DON, which may similarly present without changes in visual field or visual acuity. 


Proptosis Reduction and Post-Operative Extraocular Muscle Expansion in Patients with Thyroid Eye Disease

Graefe’s Archive for Clinical and Experimental Ophthalmology

How can we better predict the amount of proptosis reduction a patient will have after surgery? Deep lateral orbital wall decompression is a procedure that decreases proptosis among patients with thyroid eye disease (TED), but results vary among patients. Extraocular muscle (EOM) expansion after decompression, particularly lateral rectus muscle (LRM) expansion, is a common post-procedural finding that may interfere with subsequent proptosis reduction. This was a single-center, retrospective study of 77 patients (133 sides) who underwent deep lateral orbital wall decompression. The amount of orbital fat removed was positively correlated with proptosis reduction, whereas the rate of LRM expansion was negatively correlated. The cross-sectional trigone area was positively correlated with the rate of LRM expansion, whereas the pre-operative cross-sectional LRM area and amount of orbital fat removed were negatively correlated with the rate of LRM expansion. These findings may be helpful to predict proptosis reduction after deep lateral orbital wall decompression and enable surgeons to pre-operatively plan additional orbital bony and fat decompression if necessary.

Question of the Week

A 46-year-old female presented with blurry vision, photopsia, and floaters in both eyes. The patient lives on a farm and has regular exposure to chickens and pheasants. There is a family history of glaucoma and retinal detachment. On exam she has a visual acuity of 20/40 (20/20 one year ago) and there is 2+ cell in the anterior vitreous OU. Dilated fundus exam reveals clumps of pigmented cells scattered throughout the vitreous. Serologic workup includes a negative ACE level, RPR/TPPA, and PPD but is HLA-A29 positive. The patient received a course of oral prednisone and returned with improved visual acuity two weeks later. The vitreous debris partially cleared and dilated fundus exam revealed the features depicted below. What is the most likely diagnosis?
    A. Syphilitic choroiditis
    B. Coccidiomycosis
    C. Multiple evanescent white dot syndrome
    D. Birdshot retinochoroidopathy

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Quiz Answer: D
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