Immediate Changes in IOP After Clear Corneal Microincision Versus Small-Incision Cataract Surgery

Tuesday, April 21, 2015: 11:16 AM
Room 4 (San Diego Convention Center)
Ken Hayashi, MD
Motoaki Yoshida, MD
Koichi Yoshimura, MD

To examine changes in intraocular pressure (IOP) in the immediate period after clear corneal micro-incision cataract surgery (MICS) and after small-incision cataract surgery (SICS).

Sixty-eight eyes of 34 patients scheduled for coaxial phacoemulsification were randomized to one of two groups; A) eyes that were to undergo a 2.0-mm MICS, and B) a 2.65-mm SICS.  At the conclusion of surgery, the IOP was adjusted to the range between 15-40 mmHg with stromal hydration.  The IOP was measured using a rebound tonometer preoperatively; at the conclusion of surgery; and at 3, 6, 9, 12, and 15 min. postoperatively.  The Seidel test and anterior segment-optical coherence tomography were performed at 20 min. postoperatively.

Mean IOP at the conclusion of surgery was 27.7±4.7 mmHg in the MICS group and 29.7±5.1 mmHg in the SICS group (P= 0.1239).  In both groups, mean IOP decreased to the preoperative level within 9 min. postoperatively, and did not change significantly for up to 15 minutes.  Mean IOP was similar between the MICS and SICS groups throughout the observation period (P≥ 0.1239).  Hypotony (≤10 mmHg), positive Seidel test, and loss of wound coaptation were not detected in all eyes.

After adjusting the IOP to a relatively high level at the conclusion of surgery, the IOP decreased by 9 min., and was stable within 15 min. without hypotony.  The IOP was comparable between eyes after MICS and SICS, and both incisions virtually closed within 20 min. postoperatively.