Dose-Response-Relationship between Number of Laser Burns and IOP Reduction in Cyclophotocoagulation : An Animal Study

Abstract EN

Purpose.

The relationship between number of laser burns of cyclophotocoagulation (CPC) and intraocular pressure (IOP) reduction is unknown.

This animal model was established to reveal a possible dose-response-relationship between the number of applied laser burns and the IOP lowering effect.

Methods.

30 chinchilla bastard rabbits were divided into 5 groups and treated with either 1, 5, 10, 20, or 30 CPC burns, respectively.

IOP was followed up for 1 week.

IOP reduction of a single 30-burn treatment was compared with a fractionated treatment (three sessions; one week in between; 10 burns/session).

Results.

IOP reduction increases nonlinearly with the number of CPC burns (max.

-6.1±1.4 mmHg).

Fractionated treatment shows similar IOP reduction with less complications and more constant results compared to single session treatment.

Conclusions.

The study reveals a complex relationship between IOP reduction and the number of CPC burns.

Fractionated CPC gives comparable IOP reduction at a higher degree of safety.