Evaluation of the effect of the amount of energy on intraocular pressure and corneal endothelial cell density in Nd:YAG laser capsulotomy

Session Details

Session Title: PCO

Session Date/Time: Monday 15/09/2014 | 14:30-16:00

Paper Time: 15:12

Venue: Capital Hall B

First Author: : H.Chawla INDIA

Co Author(s): :    M. Singh   T. Dewan   S. Vashisht        

Abstract Details

Purpose:

To evaluate the amount of rise in intraocular pressure and decrease in corneal endothelial cell density in relation to amount of energy used in Neodymium yttrium aluminum garnet laser posterior capsulotomy, and to state the upper limit of energy up to which laser can be safely undertaken without the need for ocular hypotensive drugs.

Setting:

Department of Ophthalmology, PGIMER and Dr. Ram Manohar Lohia Hospital, New Delhi, India

Methods:

This is a cross sectional observational study conducted on 181 eyes who underwent Nd YAG Laser posterior capsulotomy using Zeiss laser model VISULAS II. 3- 4mm of Posterior capsule opacification (PCO) overlying the pupillary axis was removed. Total energy used for a patient, depending on thickness of PCO, was grouped into three groups: Group A (0-40 mJ), Group B (40-80 mJ) and Group C (> 80 mJ). Outcome variables measured were IOP and corneal endothelial cell density (CD). IOP were recorded at 1 hour, 2 hour, 3 hour, 4 hour, 1 day, 1 week, and 1 month post laser. Rise of IOP were grouped as mild rise (< 5 mm Hg), moderate rise (5-9 mm Hg), severe rise (≥10 mm Hg) above the baseline.

Results:

The study population had a mean age of 45.8± 0.512. Significant difference of IOP was noted in group C as compared to group A(p=<0.001) and Group B(p=0.002) at all time periods. Maximum rise of IOP were noted at 2nd hour in group B and at 4th hour post laser in group C. Also no significant decrease in corneal endothelial cell density was noted in any group at 1 week (p=0.54) and at 1 month (p=0.46).

Conclusions:

Using higher energy levels (>40 mJ) for Nd YAG posterior capsulotomy increases the risk of IOP rise. If total energy levels used are < 40 mJ, prophylactic use of IOP lowering agents can be avoided. However, energy used for posterior capsulotomy doesn’t affect corneal endothelium in pseudophakes.

Financial Interest:

NONE