Electrophysiological testing of visual function after mirror telescope implantation: a case report

• Published in: Documenta ophthalmologica 2016-12, Vol.133 (3), p.171-181
• Main Authors: Kremláček, Jan, Jirásková, Naďa, Nekolová, Jana, Šikl, Radovan, Kuba, Miroslav
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Clinical Case Report; Evoked Potentials, Visual; Female; Humans; Lenses; Macular Degeneration - physiopathology; Macular Degeneration - rehabilitation; Male; Medicine; Medicine & Public Health; Ophthalmology; Pattern Recognition, Visual - physiology; Telescopes; Visual Acuity; Visual Perception - physiology; Visual Prosthesis - standards
• ISSN: 0012-4486; 1573-2622
• DOI: 10.1007/s10633-016-9563-9

Purpose The implantation of an intraocular telescope increases life quality in patients with end-stage age-related macular degeneration (AMD). The present study monitored changes in electrophysiological markers of visual processing before and during seventeen months after a novel mirror telescope implantation in two patients (OV—male 90 years, MZ—female 70 years) with the final-stage form of AMD. Methods Visual evoked potentials were recorded to high-contrast pattern-reversal (PR-VEP for check size 40′ and 10′), low-contrast motion-onset stimuli (in visual periphery M-VEP M20°, and in central part M-VEP C8°), and event-related potentials (ERPs) in the oddball visual paradigm. Results MZ’s more systematic responses showed attenuation and prolongation of the M-VEP M20° and the PR-VEP 40′ immediately after the telescope implantation with a slow amplitude recovery with unchanged prolonged latency. The implantation completely eradicated the M-VEP C8° without any restoration. The PR-VEP 10′ were not readable. Only a part of OV’s PR-VEP 40′ and M-VEP M20′ were of a repeatable and expected morphology. These OV’s VEPs were consistent with MZ’s findings. The ERPs did not show any effect of implantation in both patients. Post-implantation visual acuity and reaction time overcame the pre-implantation levels. Conclusions The mirror telescope preserved peripheral vision in contrast to classic telescopes; however, the telescope concurrently reduced the luminance of the magnified retinal image, which was likely responsible for the prolongation of the VEP latencies.