Retinitis pigmentosa and other dystrophies

Retinitis pigmentosa (RP) is an inherited retinal degeneration that affects predominantly peripheral visual fields. Macular edema may cause additional central visual acuity decrease. Fluorescein angiography and/or optical coherence tomography detect the presence of macular edema in 10-20% of RP patients. Macular edema can manifest at any stage of the disease and may be unilateral or bilateral. In X-linked forms, macular edema is very rare. The origin of macular edema in RP patients still remains poorly understood. The possible pathophysiological role of autoantibodies has been suggested (retinal, carbonic anhydrase, and enolase antibodies). Drug therapy is the primary treatment for macular edema in patients with R P. Systemic carbonic anhydrase inhibitors, such as oral acetazolamide or topical dorzolamide, still are the mainstay of initial therapy. If cystoid macular edema is refractory to acetazolamide, intravitreal corticosteroid injections could be administered. Intravitreal anti-vascular endothelial growth factor therapy has also been used in cases of macular edema persistence after oral acetazolamide therapy, though with uncertain results. Vitrectomy can also be proposed, but its role is not clear yet. Autoimmune retinopathies (AIRs) are a group of rare diseases characterized by acute or subacute progressive vision loss and are thought to be mediated by autoantibodies specific to retinal antigens. The AIRs encompass paraneoplastic syndromes, such as cancer-associated retinopathy and melanoma-associated retinopathy, and a larger group of AIRs that have similar clinical and immunological findings but without underlying malignancy. These diseases may also be complicated by macular edema.