Comparison of Corneal Endothelial Status in Phacoemulsification With Different Powers in Hard Cataract: Prospective Randomized Study
Purpose
To compare the corneal endothelial status of patients with hard cataract (5.0-6.9) undergoing Coaxial microincision cataract surgery using ultrasound powers of 1%, 5%, 10% and 20% in terms of Corneal endothelial cell loss, co-efficient of variation, percentage of hexagonal cells and corneal thickness over a period of one year.
Methods
One hundred-sixty patients of senile cataract grade 5.0-6.9 (LOCS III) were randomized into 4 groups on the basis of ultrasound power used during COMICS. All cases were operated at vacuum setting of 300 mmHg and micropulse at 50 pulse per second. The power setting was kept at 1%, 5%, 10% and 20% for the 4 study arms respectively. Preoperative and postoperative note of corneal endothelial status (using non contact specular microscope), visual acuity and IOP were made at day1, 1 week, 1, 3 ,6, 9 and 12 months.
Results
At the end of 1 year: Mean± SD value of endothelial cell density in 1% group was significantly higher than 5% (p<0.026), 10% (p<0.001) and 20% (p<0.001) groups. Mean± SD value of ECL and % ECL loss from the baseline was significantly lower in 1% group than 5%, 10% and 20% groups (p<0.001). (1%<5%, 10%<20%). In 1% group coefficient of variation of cell size returned to the baseline earlier (around 1 month) than in the 20% group (around 6 months). Significantly higher fall in the % hexagonal cell count in the 20% group when compared to 1% group (p<0.001).
Conclusion
Preservation of corneal endothelium by lesser decrease in endothelial cell density, lesser percentage of endothelial cell loss, lesser increase in coefficient of variation, and central corneal thickness and greater percentage of hexagonal cells in 1% group is attributable to lower ultrasound power used as opposed to 5%, 10% and 20% groups.