Purpose : To evaluate the efficacy of pattern visual evoked potentials (PVEP), standard automated perimetry (SAP), short-wavelength automated perimetry (SWAP), contrast sensitivity (CS), stereoacuity testing in detecting subclinical visual impairment in visually asymptomatic patients with multiple sclerosis (MS) and no history of optic neuritis
Methods : Twenty-seven eyes of 27 patients (7 males, 20 females, average age 33.81 ± 9.33 years) with confirmed diagnosis of MS, underwent PVEP with 60-minute arc and 15-minute arc check sizes, SAP (Humphrey 750-II, program central 30-2, SITA standard strategy), SWAP (Humphrey 750-II, program central 30-2 full-threshold strategy), CS with CSV1000E chart, Stereoacuity by the Randot stereoacuity (RSA) test. They were age and sex matched with twenty seven healthy volunteers as a control group.
Results : Stereoacuity score was significantly reduced in MS group compared with controls (p=0.007). P100 latency time for both 60-minute arc and 15-minute arc was significantly prolonged in MS group compared with controls (p=0.005, p=0.002 respectively). P100 amplitude for both check sizes significantly reduced in MS group compared with controls (p<0.001). When comparing MS patients with the control group significant differences were found for SAP mean deviation (MD), SWAP MD, SAP pattern standard deviation (PSD), SWAP PSD (p<0.001). By considering predefined criteria, asymptomatic MS patients have shown abnormal stereoacuity in 22.2%, abnormal VEP in 40.7%, abnormal CS in 37%, abnormal SAP in 44% and abnormal SWAP in 37% of patients.
Conclusion : Our results showed the probable presence of subclinical visual impairment among MS patients without optic neuritis history and no visual symptoms. This emphasizes the importance of the follow-up programs, even in asymptomatic patients with MS. Comparison of multiple tests could help in better understanding of silent visual impairment. However, performing VEP and perimetry test together are useful choices in the regular assessment of these patients.
Iranian Journal of Ophthalmology 201325(1):45-52 © 2013 by the Iranian Society of Ophthalmology