The aim of this study is to evaluate the efficacy and safety of oral minocycline (100mg/d), administered for 6 months, for the treatment of patients with retinitis pigments(RP).

Retinitis Pigmentosa (RP)is a sort of inherited blinding disorders and no effective or safe treatment are widely applied for it. The worldwide prevalence of RP is estimated to be 1/5000. RP is characterized by degeneration of peripheral rod photoreceptor(PR) and associated retinal pigment epithelium(RPE) cells. Nyctalopia and visual field constriction are common symptoms. Cone degeneration and associated loss of central vision are typically followed later.

Minocycline, a secord-generation, semi-synthetic tetracycline antibiotic, is a highly lipophilic molecule and can easily pass through the blood-brain barrier. Several animal experiments and clinical trials have reported that minocycline exert anti-apoptotic, anti-inflammatory and antioxidant effects in treating neurodegenerative diseases.

We propose to test the effect and safety of oral minocycline for retinitis pigmentosa.

Inclusion Criteria:

• Clinical diagnosis of Retinitis Pigmentosa: nyctalopia, visual field constriction and loss of central vision; degeneration of peripheral rod photoreceptor and retinal pigment epithelium cells.
• Age from 18 to 60 years old.
• BCVA >20/100(0.2) at least in one eye.
• Full-field cone electroretinogram amplitude to 30-Hz flashes >0uV at least in one eye.
• Written informed consent is provided.

Exclusion Criteria:

• Glucocortticoids or tetracycline were used within 3 months.
• Vitamin A, DHA and other neurotrophic drugs were used within 3 months.
• Other ocular diseases or fundus diseases except cataract: glaucoma, diabetic retinopathy, retinal detachment.
• Tetracycline or minocycline allergy or intolerance.
• Renal or hepatic insufficiency.
• History of thyroid neoplasm.
• History of idiopathic intracranial hypertension.
• Pregnant or lactating females.