Optical coherence tomography of the effects of stromal hydration on clear corneal incision architecture

Purpose

To evaluate the effects of stromal hydration on clear corneal incision (CCI) architecture immediately after surgery using anterior segment optical coherence tomography (AS-OCT).

Setting

Department of Ophthalmology, Royal Berkshire Hospital, Reading, United Kingdom.

Methods

Clear corneal incisions in adult eyes were examined using a Visante AS-OCT imaging system within 1 hour of surgery. Half the CCIs had stromal hydration with a balanced salt solution and half did not. Incisions were made with a 2.75 mm steel keratome. Intraocular pressure (IOP) was measured within 90 minutes after surgery. The CCI length and corneal thickness at the CCI site were measured using software built into the AS-OCT system.

Results

Thirty CCIs were evaluated. Stromal hydration significantly increased the measured CCI length (P<.05, t test); this was the result of a trend toward increased corneal thickness at the CCI site with hydration (P<.1, t test). The mean CCI length was 1.69 mm ± 0.27 (SD) (range 1.31 to 2.32 mm) with hydration and 1.51 ± 0.23 mm (range 1.30 to 1.95 mm) without hydration. The mean IOP was 20.9 ± 8.18 mm Hg and 15.8 ± 8.20 mm Hg, respectively. The IOP tended to be higher with hydration (P<.1, t test). Local detachment of Descemet membrane was more likely with stromal hydration (63%) than without (25%).

Conclusion

Stromal hydration significantly increased CCI length and tended to leave the eye with a higher early postoperative IOP, showing the importance of taking stromal hydration into account when designing similar OCT studies of CCI architecture.