Peripapillary RNFL thickness in nonexudative versus chronically treated exudative age-related macular degeneration

Abstract

Dear Editor: We read with interest the paper “Peripapillary RNFL thickness in nonexudative versus chronically treated exudative age-related macular degeneration” written by Yau et al.1Yau G.L. Campbell R.J. Li C. Sharma S. Peripapillary RNFL thickness in nonexudative versus chronically treated exudative age-related macular degeneration.Can J Ophthalmol. 2015; 50: 345-349Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar They have reported no deleterious effect of multiple anti–vascular endothelial growth factor injections on retinal nerve fibre layer (RNFL) in patients with wet age-related macular degeneration (AMD) in comparison to noninjected fellow eyes with dry AMD. Interestingly, they observed a higher mean RNFL thickness value in injected eyes, which was solely related to thickening in the temporal quadrant. They related this finding to the spread of macular edema to the peripapillary area. We want to congratulate the authors on these valuable observations; however, some issues need to be raised concerning the current study. It has been recently showed that RNFL measurements need to be adjusted according to the axial length of the eye.2Hirasawa K. Shoji N. Yoshii Y. Haraguchi S. Determination of axial length requiring adjustment of measured circumpapillary retinal nerve fiber layer thickness for ocular magnification.PLoS One. 2014; 12: e107553Crossref Scopus (18) Google Scholar No data are presented regarding the refractive status of the patients in the current study. Moreover, Lee and Yu showed significant thinning in RNFL but no other significant change in other optic nerve head parameters in dry AMD eyes when compared with control eyes, which is lacking in the current study.3Lee E.K. Yu H.G. Ganglion cell-inner plexiform layer and peripapillary retinal nerve fiber layer thicknesses in age-related macular degeneration.Invest Ophthalmol Vis Sci. 2015; 56: 3976-3983Crossref PubMed Scopus (62) Google Scholar Therefore, RNFL thickness comparisons between wet and dry AMD eyes should be interpreted cautiously.