Abstract
Purpose: :
To characterize the psychophysical and electrophysiological visual function findings in patients with AINR and illustrate differential diagnostic features from retinitis pigmentosa (RP).
Methods: :
Goldmann visual fields (GVFs), pattern-reversal visual evoked potentials (PVEPs), and rod-driven, mixed and cone-driven flash electroretinograms (ERGs) from 20 patients (M/F=7/13, 51.9±13.4 years old, paraneoplastic, n=5) with serologically confirmed AINR were analyzed. The patterns of GVF loss; the presence of amplitude loss, timing delay, and morphological abnormalities for both PVEPs and ERGs; and the presence of asymmetric findings between eyes were investigated.
Results: :
Patients presented with multiple anti-retinal and/or anti-optic nerve auto-antibodies (auto-Abs) in 11/20 of cases (anti-alpha-enolase positive, n=9; anti-recoverin, n=1). GVFs showed optic nerve (ON) and/or retinal ganglion cell (RGC)-related defects (blind spot enlargement, central or centro-cecal scotomas, and bundle defects) in 65% of cases (13/20) and asymmetric loss in 75% (15/20). Unlike RP, ring scotomas and constriction with peripheral islands were absent in most (75-80%) of cases. PVEPs were delayed in 85% of cases, including patients with 20/20 acuity and normal central fields. Interocular timing and/or amplitude PVEP asymmetry was seen in 65% of cases each, and in all but one case (95%). Rod-driven and mixed ERGs ranged from non-recordable (30 and 10%, respectively) to normal but asymmetric amplitudes (40-45%). Although photopic ERGs were reduced in 70% of patients and delayed in 60% (flicker) to 90% (transient) of cases, transient responses were always recordable. Asymmetric photopic amplitude loss was apparent in 35-40% of cases.
Conclusions: :
Unlike RP, in addition to presence of circulating Auto-Abs, patients with AINR commonly have: GVF loss patterns attributable to ON/RGC damage, alone or combined with retina-driven changes; VEP timing delays; an unusually high proportion of normal rod/mixed but abnormal cone ERGs; and interocular asymmetry in visual function loss. Our study confirms that AINRs can be differentiated from RP not only clinically (S.S. Iyer-Radhakrishnan et al. ARVO 2009; 50: E-Abs. 975) but also by functional diagnostic testing.
Keywords: autoimmune disease • retina • clinical (human) or epidemiologic studies: prevalence/incidence