MAY 10, 2011
This study's authors used 3-D corneal and anterior segment ocular coherence tomography (OCT) to evaluate the structural characteristics of clear corneal incisions and the duration of stromal edema caused by intentional hydration during cataract surgery. They found that stromal hydration lasted for at least one week.
These results surprise me. While there has been a lot of interest in stromal hydration and its role in preventing endophthalmitis, I don't think anyone thought it lasted this long.
Cataract surgery was performed on 23 patients (30 eyes) through a clear corneal incision created with a 2.4-mm blade. After confirming the water tightness of the clear corneal incision at the end of surgery, 15 randomly selected eyes received stromal hydration, and the remaining 15 eyes did not. The authors used corneal and anterior segment OCT to evaluate wound architecture one day, one week and two weeks after surgery. They found that there was a statistically significant difference in corneal thickness at the clear corneal incision between eyes with and without stromal hydration one day and one week after surgery (P < 0.001 and P < 0.05) but not at two weeks after surgery. On day one, gaping at the epithelial side was seen in 6.7 percent (two eyes), gaping at the endothelial side in 30 percent (nine eyes), misalignment of the roof and floor of incision in 40 percent (12 eyes) and local detachment of Descemet's membrane in 36.7 percent (11 eyes). However, these imperfections improved with time.
The authors note that the study's high detection rate of local Descemet's membrane detachment seems to be due to the high resolution and ability to acquire images three-dimensionally of the 3-D corneal and anterior segment OCT. They add that compared with contact gonioscopy, the 3-D corneal and anterior segment OCT used in this study is a noncontact and noninvasive method. This reduces the risk of infection when examining clear corneal incision architecture immediately after surgery.