Vermont Subscriber
Answer: ICD-9 code 368.8 (Other specified visual disturbances) may be the right diagnosis code, but before you settle on it, ask your ophthalmologist for clarification.
"Curtain effect" usually means that the patient has a retinal detachment. If this is the case, code for the retinal detachment and update your records. If the ophthalmologist doesn't give you anything besides "curtain effect," report 368.8.