Schizophrenia, psychotropic medication, and cataract

Objective: To compare the distribution of cataract types between psychiatri c patients diagnosed with schizophrenia and the general population not expo sed to psychotropic medication, and to compare cataract prevalence between users and nonusers of various psychotropic medications in the general commu nity. Design: Case-control. Participants: A total of 151 (93%) eligible patients from a community menta l health service and 3271 (83%) eligible residents from the Melbourne Visua l Impairment Project (VIP) were examined. Main Outcome Measures: All patients 40 years of age and older from a commun ity mental health service and residents of nine randomly selected areas of Melbourne were eligible. Best-corrected distance visual acuity was determin ed using a 4-m logarithm of the minimum angle of resolution (LogMAR) chart. The presence of cataract was determined by photographs or slit-lamp examin ation using direct and indirect retroillumination, Anterior, cortical, nucl ear, and posterior subcapsular cataracts were measured. Participants from t he Melbourne VIP were classified as to whether they had taken benzodiazepam s, phenothiazines, thioxanthenes, butyrophenols, tricyclic antidepressants, or monoamine oxidase inhibitors for at least 12 months during their lifeti me. Results: The distribution of cataract type varied between persons with and without schizophrenia. Anterior subcapsular (ASC) cataract was significantl y more prevalent (26%) in participants with schizophrenia from the communit y mental health service than Melbourne VIP participants (0.2%) not exposed to psychotropic medication (chi-square, 1 degree of freedom = 605.5, P = 0. 001). This remained significant after controlling for age (odds ratios = 25 0, 95% confidence interval = 83.3, 1000). The distribution of the age-relat ed cataract was similar across all groups of psychotropic medication users with the exception of the phenothiazine users. They had less of all types o f the age-related cataracts, despite being slightly older than the control group (mean age, 60.0 vs. 58.4, t test = 0.85, P = 0.40). However, only cor tical cataract in the phenothiazine group was statistically lower (chi-squa re, 1 degree of freedom = 3.96, P = 0.047). Conclusion: This study has identified the need to investigate whether other newer agents, especially high-potency medications, cause ASC opacities if a certain threshold of exposure to psychotropic medications must be attaine d to develop cataract, or if schizophrenia itself is associated with catara ct formation.