S0000B: Vitamin E and/or Selenium in Preventing Cataract and Age-Related Macular Degeneration in Men on SELECT SWOG-S0000

DISEASE CHARACTERISTICS: * Enrolled on the Selenium and Vitamin E Prostate Cancer Prevention Trial (SELECT) SWOG-S0000 * Diagnosis of 1 of the following: * Age-related macular degeneration (AMD) at baseline or at follow-up * Cataract or a cataract extraction at follow-up (Closed for accrual as of 10/01/29) * Participants with a prior diagnosis of cataract at baseline followed by another cataract event (cataract diagnosis or a cataract extraction) at follow-up are not eligible * Participants with a prior diagnosis of cataract at baseline followed by a diagnosis of AMD at follow-up are eligible PATIENT CHARACTERISTICS: * See Disease Characteristics PRIOR CONCURRENT THERAPY: * Not applicable