Related Experiment Videos
Postreceptoral contribution to macular dysfunction in retinitis pigmentosa
B Falsini1, G Iarossi, V Porciatti
1Eye Clinic, Catholic University, Rome, Italy.
Investigative Ophthalmology & Visual Science
|December 1, 1994
Summary
Retinitis pigmentosa affects both outer and inner retinal layers, unlike cone dystrophy or X-linked congenital retinoschisis. Macular dysfunction in retinitis pigmentosa may worsen with age.
Area of Science:
- Ophthalmology
- Retinal Diseases
- Electrophysiology
Background:
- Retinitis pigmentosa (RP) is a group of inherited disorders characterized by progressive vision loss.
- Macular dysfunction is a common feature of RP, but the specific retinal layers affected are not fully understood.
Purpose of the Study:
- To investigate the sites of macular dysfunction in retinitis pigmentosa (RP).
- To differentiate RP-related macular dysfunction from that seen in cone dystrophy (CD) and X-linked congenital retinoschisis (XLR).
Main Methods:
- Focal electroretinograms (FERGs) were recorded in normal subjects and patients with RP, CD, and XLR.
- FERG fundamental and second harmonic components, reflecting outer and inner retinal activity respectively, were analyzed.
- The ratio of fundamental to second harmonic amplitude was used to assess relative outer and inner retinal function.
Main Results:
- Patients with RP showed reduced FERG fundamental and second harmonic amplitudes, with an increased fundamental-second harmonic ratio.
- CD patients had reduced amplitudes but a normal ratio, indicating outer and inner retinal involvement.
- XLR patients exhibited a selective loss of the second harmonic, leading to an increased ratio.
Conclusions:
- Macular dysfunction in RP involves both outer (receptoral) and inner (postreceptoral) retinal sites.
- In contrast, CD and XLR show more selective outer or inner retinal dysfunction.
- Postreceptoral dysfunction in RP may increase with age.