CRYOTHERAPY

INTRODUCTION

• Different methods to create chorioretinal adhesion.

• Adhesion produced by all treatment is between the retina and pigment epithelium, but referred to as chorioretinal adhesion.

CRYOTHERAPY

• Scholer; Freezing creates inflammation in the area of application.

• Linde instrument employed CO2 or N2O as cryogenic agents.

• Works on Joule-Thompson principal.

Effects on the tissue

• Cryo causes dissolution of cellular membrane.Intracellular ice causes mechanical damage with rupture of cellular membrane.

• Strength of adhesion between retina and RPE is proprotional to the intensity of application.

*Light - Barely perceptible *Medium - Faintly grey *Heavy - Opaque lesion

Development of adhesion over time

• Gains strength rapidly after second day to reach maximum on 10-12 days

• Heavy burns-1175mg

Uses

• Prophylactic treatment of breaks.• Localized area of detachment.• Prophylactic treatment of areas of

abnormal vitreoretinal adhesion.• Anterior retinal cryopexy.

Advantages & Disadvantages

• Can be applied through full thickness sclera.

• Can be applied through hazy media.• Can be safetly used over LPCN&Art.• Has little effect on sclera.• Break down of BRB.• Greater intravitreal dispersion of RPE.• CME is more