Re: Saxena et al.: Steroids versus no steroids in nonarteritic anterior ischemic optic neuropathy: a randomized controlled trial (Ophthalmology. 2018;125:1623–1627)

Abstract

I read with interest the article by Saxena et al1Saxena R. Singh D. Sharma M. et al.Steroids versus no steroids in nonarteritic anterior ischemic optic neuropathy: a randomized controlled trial.Ophthalmology. 2018; 125: 1623-1627Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar on oral prednisone treatment for nonarteritic anterior ischemic optic neuropathy in nondiabetic patients. I agree with the authors that the ophthalmology community has been frustrated and confused by the conflicting literature on the benefit of steroids for nonarteritic anterior ischemic optic neuropathy.2Lee A.G. Biousse V. Should steroids be offered to patients with nonarteritic anterior ischemic optic neuropathy?.J Neuroophthalmol. 2010; 30: 193-198Crossref PubMed Scopus (46) Google Scholar Saxena et al determined that the mean final best-corrected visual acuity (BCVA) did not differ between the steroid-treated and untreated groups and concluded that the effects of oral prednisone were “clinically unimportant.” However, a comparison of the mean final BCVA does not provide a comprehensive picture. The authors’ own data showed a greater mean improvement in BCVA in the steroid-treated group. Further, BCVA is an incomplete measure of central vision. Contrast sensitivity is frequently overlooked and ignored, but particularly important as an outcome measure for optic nerve disease. Peripheral vision (visual field) recovery may have been different between the 2 groups. Small improvements in contrast sensitivity or peripheral vision may be functionally meaningful. In a devastating condition such as nonarteritic anterior ischemic optic neuropathy, treatment effect should be considered at the level of the individual patient. Withholding prednisone represents the loss of a chance for benefit. A better analysis for determining whether prednisone may benefit a particular patient is the number needed to treat (NNT). The NNT determines the number of patients who must be treated to prevent a negative outcome (e.g., further loss of ≥2 lines of BCVA owing to worsening compartment syndrome) or to create a positive outcome (e.g., improvement of ≥3 lines of BCVA) in 1 patient. The authors may be able to calculate some NNT values from their available data, although a larger number of subjects would be desirable. Given the demonstrated tolerability of oral prednisone in nondiabetic patients and the lack of any alternatives, a fairly high NNT might be acceptable to patients—particularly those with greater degrees of vision loss. I encourage the authors to continue their work using their excellent study protocol and clinical resources, add contrast sensitivity and visual field to their data, repeat their study, and determine the NNT for various outcome measures. Steroids versus No Steroids in Nonarteritic Anterior Ischemic Optic Neuropathy: A Randomized Controlled TrialOphthalmologyVol. 125Issue 10PreviewTo examine the role of oral steroid therapy in the treatment of nondiabetic cases of acute nonarteritic anterior ischemic optic neuropathy (NAAION). Full-Text PDF Re: Saxena et al.: Steroids versus no steroids in nonarteritic anterior ischemic optic neuropathy: a randomized controlled trial (Ophthalmology. 2018;125:1623-1627).OphthalmologyVol. 126Issue 12PreviewBrown1 commented on the study by Saxena et al,2 regarding the role of steroid therapy in nonarteritic anterior ischemic optic neuropathy (NA-AION); that study concluded that “Oral steroids in acute NAAION did not improve the visual acuity significantly… although VER [visual evoked response] was better in the steroid group.” Brown1 rightly stated that in that study2 “a comparison of the mean final BCVA [best-corrected visual acuity] does not provide a comprehensive picture. The authors’ own data showed a greater mean improvement in BCVA in the steroid-treated group. Full-Text PDF ReplyOphthalmologyVol. 126Issue 6PreviewThe aspect raised by the letter to the editor from Brown is indeed one that merits mention. The authors agree with the opinion expressed, that outcome measures pertaining to central vision include many more than visual acuity alone. However, because the presenting visual acuity in cases of nonarteritic anterior ischemic neuropathy is often very low, it precludes the possibility of performing a reliable visual field or contrast sensitivity examination. In a previous publication, we have described the changes in contrast sensitivity and visual fields in cases of nonarteritic anterior ischemic neuropathy over a 3-month period. Full-Text PDF