Question of the Week

1. In a survey of oncologists and pathologists who manage retinoblastoma, 100% of respondents noted which of the following to be a high-risk feature of retinoblastoma?

A. Post-laminar optic nerve infiltration

B. Pre-laminar optic nerve infiltration

C. Iris infiltration

D. Anterior chamber seeding

2. True or False: There was no significant difference in best corrected visual acuity in a 52-week period for neovascular AMD patients treated with Ranibizumab (brand name Lucentis) versus its biosimilar (SB11).

A. True

B. False

3. What was the key outcome of a randomized study where patients chose glasses prescriptions based on results from standard subjective refraction versus autorefraction?

A. Patients preferred standard subjective refraction

B. Patients preferred autorefraction

C. Patients were ambivalent between the two

4. True or False: hyperosmolar drops lead to a clinically (and statistically) significant reduction in early morning corneal edema.

A. True

B. False

Answer

Answers: A, A, C, B

1. A. Post-laminar optic nerve infiltration

High-risk Features of Retinoblastoma

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.

2. A. True

Ranibizumab versus its Biosimilar in Patients with Neovascular Age-Related Macular Degeneration

Biosimilars are theoretically similar to their brand-name equivalents, but are they the equivalent in practice? Neovascular Age-related Macular Degeneration (nAMD) is a leading cause of blindness and visual impairment across the world, and is associated with $575 million in cost of care. The standard of care has been brand-name anti-VEGF injections. Introduction of biosimilars could reduce cost and improve access to care. The authors sought to study the efficacy and safety of Ranibizumab (RBZ) versus its biosimilar (SB11) over a 52 week period. In this phase III randomized control trial of 705 participants with nAMD, patients were randomized 1:1 to monthly intravitreal injections of 0.5 mg RBZ or SB11. Results showed that there was no significant difference between the change in best-corrected visual acuity (-0.6 letters, 90% CI: -2.1 to 0.9) nor in the adverse event rate (SB11: 31.0%, RBZ 29.7%, p > 0.05). Overall, this study showcases that SB11, a biosimilar of RBZ, and RBZ have comparable efficacy and safety over 52 weeks.

3. C. Patients were ambivalent between the two

QuickSee Autorefractor as a Low-Cost Alternative to Subjective Refraction

Better one or better two? In this randomized cross-over clinical trial of 400 adult participants in Southern India, the investigators assessed the accuracy of the QuickSee portable autorefractor (AR) compared to standard subjective refraction (SR) and patient preference of glasses prescription by either method. They found that spherical equivalents were strongly correlated between SR and AR (r=0.97). Of the 75.2% of patients who completed follow-up, 50.5% preferred glasses prescribed with SR and 49.5% preferred glasses prescribed using AR (P=0.86). Self-reported patient experiences did not favor one form of refraction over another. This novel study supports the wider acceptability of the QuickSee autorefractor as an efficacious and low-cost mode of refraction. As such, the authors recommend that this autorefractor can reduce the global burden of uncorrected refractive errors by providing adequate refraction without the need to highly trained personnel in resource-limited and remote settings.

4. B. False

Hyperosmolar Eye Drops Ineffective For Fuchs’

Let’s take it back to high school chemistry! The gold standard treatment of Fuchs’ endothelial corneal dystrophy is Descemet membrane endothelial keratoplasty (DMEK), but hyperosmolar eye drops have been posited as a non-surgical option. In this double-masked, randomized control trial of 68 participants, investigators assessed the efficacy of hyperosmolar eye drops on corneal edema resolution in subjects with Fuchs’ dystrophy after early morning eye opening. One eye of each participant was randomized to hyperosmolar eye drop treatment and the fellow eye was randomized to artificial tears placebo. Baseline corneal thickness after eye opening was 626 μm and 622 μm in the treatment and placebo arms, respectively. Hyperosmolar eye drops were not found to have a clinically relevant effect on early morning corneal edema, as the decrease in corneal edema at one hour after eye opening in the treatment and control eyes was not statistically or clinically significant (between-arm difference, 0.7 μm, 95% CI, −2.0 to 3.5; P = 0.59). In addition, eyes treated with hyperosmolar eye drops were more likely to experience adverse effects. These results do not support the routine use of hyperosmolar eye drops for the treatment of corneal edema in eyes with Fuchs’ dystrophy.