Table 2.

Inclusion and exclusion criteria at screening.

Inclusion criteria	Exclusion criteria
Age 18-65 years, from ReCYLa Diagnosis of moderate or severe RPb (grading severity scale score>1 point) Visual function enough to tolerate and see through the optic filters during daily activities Written informed consent provided	Underwent any ocular surgery within the previous 6 months Involvement in any other ongoing clinical trial Pregnancy and lactation or under hormonal treatment Allergy or hypersensitivity to melatonin Previous or current therapy with melatonin Autoimmune diseases NSAIDc and others anti-inflammatory drug treatment Psychiatric disorders or under any psychotropic medication

^aReCYL: Retina Castilla y León.

^bRP: retinitis pigmentosa.

^cNSAID: nonsteroidal anti-inflammatory drug.