Energy Delivery to Eye in Phaco-Emulsification Using Dodick Laser Photolysis System

BACKGROUND:
Age- related cataract is the main cause of blindness and visual impairment worldwide. Surgery is the only treatment currently available for lens opacity. It is the most frequently performed procedure in ophthalmology. There are many different advantage and disadvantages. Today, ultrasound phaco-emulsification is the most performed method for surgery. One of alternative energy forms is laser photolysis. The aim of this study was to evaluate the mean energy delivery to eye using Dodick laser photolysis for phaco-emulsification.

METHODS:
76 eyes from 76 patients at Aban Eye Clinic in Esfahan were introduced to study. Cataract density was rated preoperatively using lens opacity classification system III (LOCS III) on 0 to +4 density scale. Lenses with +4 nuclear density scales were excluded. Finally 67 eyes were operated with ARC Dodick laser photolysis system throw 2.8 mm clear corneal incision. Delivered energy was recorded.

FINDINGS:
Of 67 patients, 39 (58.2%) were male and 28 (41.8%) were female, and had a mean age of 58.3+12.8 (14-84 years). There was no statistically significant difference between age of male patients (56.5+12.8) and female patients (60.7+11.9) (p=0.18).
Mean delivered energy to eyes was 4.5+2.6 joules for nucleuses with density of +1, +2 and +3 mean delivered energy was calculated as 3.32+2.60 , 3.7+2.59 and 5.7+2.23 joules respectively. Finally it was reverted that there was a direct relationship between delivered energy and nuclear density (p=0.00001, r=0.57).

CONCLUSION:
In spite of the lower amount of energy used, as the preoperative hardness of lens nucleus or lengthening of operation cannot be predicted before surgery, this technique is not well- accepted ; hopefully with resolving of technical problems in the future, it can be used more properly.

KEY WORDS:
Phaco-Emulsification, Photolysis, Laser, Cataract, Dodick, Small incision