Chloroquine Retinopathy

Presenting Symptom: Ring scotoma. Pathology: Retinopathy. Clinical: The patient was a 33-year old female who had taken chloroquine (250 mg/day) over a 5-year period for rheumatoid arthritis. She then noted that letters appeared to drop out of the printed page, portions of faces became indistinct, and she lost fixation on a golf ball she was about to hit. The visual acuity measured 20/30 but visual fields showed a ring scotoma; both fundi showed annular loss of pigment epithelium about the fovea with preservation of the central epithelium. This latter produced the typical bull's eye appearance which is characteristic of chloroquine retinopathy. Thioridazine (Mellaril®), used in psychotherapy, may cause a pigmentary degeneration of the retina when used in large doses. Other phenothiazines may have a similar effect. The retinopathy consists of spotty clumping of the pigment which affects the entire fundus and causes irreversible loss of vision. Disease/ Diagnosis: Chloroquine retinopathy