Erkan Unsal, Turkey

Aim:
To evaluate the distribution of drugs according to the eye volume according to the mathematical formulas, regardless of the elimination of drugs, in intraocular drug applications.

Materials & Methods:
Anterior camera depth (ACD), iris thickness (IT), lens thickness (LT) and axial lengths (AL) of 100 consecutive patients undergoing intravitreal medication were measured with the IOL Master. Mean eye volume was determined by using axial lengths of the cases. Approximate the volume of the lens and the volume of iris were removed from the eye volume. The remaining volume (Vitreous + posterior camera volume + anterior camera volume) was defined as the drug dispersion volume (DDV). In the calculation of the volume, the eye was considered as a sphere and calculated using the formula 4 / 3πr3. The lens volume was 0.2 ml for 50 years and 0.26 ml for 69 years. The mean iris volume was accepted as iris cylinder and subtracted from the volume of the pupil region, and the πhr2 formula was used to calculate 0.064 ml.

Results:
The mean axial length were 21.5 mm (20.6-22) in 5 cases (Group 1), 23 mm (22-25) in 86 cases (Group 2), 28 mm (25-31) in 9 cases (Group 3). Average eye volume was calculated as 4/3 * 3,14 * 10,753 = 5,201ml and average DDV was calculated as 5,201- (0,26 + 0,064) = 4,877 ml in Group 1. Average eye volume was calculated as 4/3*3,14*11,53=6,367 ml and average DDV was calculated as 6,367-(0,26+0,064)=6,043 ml in Group 2. Average eye volume was calculated as 4/3*3,14*143=11,488 ml and average DDV was calculated as 11,488-(0,26+0,064)=11,164 ml in Group 3.

Discussion:
In case of intraocular drug administration, all cases are administered the same dose. In cases with different eye volumes, does the same dose of drug administration have the same effect?

Contact Details:

Erkan Unsal
Istanbul Education and Research Hospital
Istanbul
Turkey
Cell Phone : 05052382250
Work Phone : 05052382250
Email : erkanunsal@gmail.com