Abstract
Purpose: :
The purpose of this clinical study is to show that use of oral antipsychotic medications effect intraocular pressure. Patients taking oral antipsychotic medications seem to have a lower IOP than is expected for their cup size.
Methods: :
This investigation is a prospective, nonrandomized, unmasked, double arm clinical investigation. 489 eyes of 245 consecutive patients at Advanced Eye Center had intraocular pressure(IOP), cup/disc ratio (c/d), race, age, and participation in use of oral antipsychotic medications recorded. 166 patients (331 eyes) were assigned to group 1, and were not using any oral antipsychotic medications. 79 patients (158 eyes) were assigned to group 2, and were using oral antipsychotic medications. Excluded patients include post surgical, acute red eye, use of prescription eye drops, PXE, use of oral steroids, use of marijuana within 24 hrs, glaucoma, and ocular hypertension. Goldman applanation tonometry was used with Fluress topical eye drop. C/D ratio was determined by use of 90D lens and direct ophthalmoscope. To determine whether IOP was lower than expected for a given cup size, a ratio of IOP per c/d ratio was evaluated. The average cup pressure quotent (CPQ);IOP per c/d ratio , was determined for both group 1 and group 2 patients. These two values were compared. The mean IOP between group 1 and group 2 was also compared.
Results: :
Group 1 patients ranged in age from 11-91 yrs, group 2's range was 10-82 yrs., with mean age 43, and 45 respectively. Group 1 race distribution was 195 Caucasian, 76 Hispanic, 56 AfroAmerican, 2 Asian. Group 2 distribution was 120 Caucasian,28 Hispanic, and 12 AfroAmerican. Mean IOP for group 1 patients not taking oral antipsychotic medications was 14.72mmHg with standard deviation 2.30. Group 2 patients taking oral antipsychotic medications was 12.74mm Hg with standard deviation of 2.92. This difference in mean IOP was a highly statistically significant difference , with p value less than 0.001, and Cohen d=0.75. This showed a large effect. Also, the mean cup pressure quotient, CPQ, (IOP/c/d) was measured for both groups. Group 1 had a mean CPQ of 54.63mmHg with a s.d. of 20.48, group 2 had a mean CPQ of 41.29mmHg with a s.d. of 19.08. This also showed a highly statistically significant difference in means with p less than 0.0001, cohen d=0.67. This is a large effect.
Conclusions: :
There is a highly statistically significant difference in means of the CPQ ,cup pressure quotient, (IOP/(c/d)) for patients taking oral antipsychotic medications or not, (p approx. 0.0, t-test). The data shows a large effect,Cohen’s d = 0.67. There is also a highly statistically significant difference in means of introcular pressure between the two groups of patients (p approx 0.0, t-test) Cohen's d=.75.
Keywords: intraocular pressure • optic disc • optic nerve