Purpose: To study the effectiveness of an erbium:YAG (Er:YAG) laser in removing nuclei of various densities.
Setting: University clinic.
Methods: This nonrandomized prospective clinical study included 147 consecutive cataractous eyes: Group 1 (n = 71) had conventional ultrasound, and Group 2 (n = 76) had surgery with the Er:YAG laser. The 2 groups were further classified by cataract density. Patients were examined 6 months postoperatively to evaluate surgical time, intraocular pressure (IOP), pachymetry, endothelial cell loss, and visual acuity.
Results: With ultrasound cataract surgery, there were no significant changes in IOP compared with the preoperative measurements. Laser treatment of 3+ and 4+ cataracts resulted in IOP increases of 12.6% and 18.2%, respectively, compared with 1+ and 2+ cataracts (P<.001). Slight endothelial cell losses occurred in all cases. With ultrasound, the mean decrease was 2.8%, and with laser surgery, the results were similar except for a significant decrease of 13.4% with 4+ cataracts. There was a correlation between pachymetry and surgical time when the trauma related to surgical time and hydrodynamic flow in the anterior chamber was assessed. With ultrasound, the visual acuity was similar with all types of cataract; with the laser, similar normal values were seen with 1+ and 2+ cataracts but decreased values were seen with 3+ cataracts and lower values with 4+ cataracts-0.43 compared to 0.84 best corrected visual acuity with same-density cataracts treated with ultrasound (P<.0005). Patients with 4+ cataracts treated with the laser developed more complications than those treated with ultrasound.
Conclusions: The Er:YAG laser was as effective and reliable as ultrasound in removing soft and medium-density cataracts. With dense cataracts, the surgical length produced more trauma and complications during laser treatment than during ultrasound treatment.