REDUCING EPITHELIAL INGROWTH

Michael O’Keefe FRCOphth

New surgical techniques and better understanding of risk factors should help reduce the incidence of epithelial ingrowth in the future, delegates attending the XXXVI UKISCRS Congress heard. Michael O’Keefe FRCOphth, Mater Private Hospital, Dublin, Ireland, spoke about how to treat epithelial ingrowth, which is one of the most common complications of LASIK with an incidence rate varying between .03 per cent to 9.1 per cent.

Key risk factors for epithelial ingrowth include trauma, flap dislocation, enhancements and intraoperative epithelial defects, he explained. Normal levels of epithelial ingrowth do not affect vision, and most cases are selflimiting and simply require monitoring. However, an excessive recurrence rate can cause serious problems including loss of vision, irregular astigmatism and flap melting so direct intervention is vital when this occurs, he told delegates.

Quoting a number of peer-reviewed journal articles on the topic, Dr O’Keefe said research has found that patients treated for hyperopia or patients who are hyperopic and have enhancements due to flap lifting are at an increased risk of developing endothelial ingrowth. “It has also been confirmed that there is an increased risk of epithelial ingrowth with a microkeratome assisted LASIK flap lift as it produces a tapered flap edge and the blade slides along the stromal surface,” he said.

Furthermore, research published this year in the US suggests that if surgeons use a less traumatic form of flap lift they can reduce the risks of epithelial ingrowth, he reported.

In the rapid flaporhexis technique, the flap edge is opened by one clock hour with a Sinskey hook and the flap is peeled back after the exposed edge is grasped with a forceps. When necessary, further blunt retraction of the flap is performed with a triangular polyvinyl acetate sponge. After ablation and before the flap is replaced, a triangular sponge is used to clear epithelial remnants from the interface. This method consistently produces a smooth epithelial dissection and decreases the risk of epithelial cells being retained beneath the flap and escalating to epithelial ingrowth, according to the researchers.

When severe epithelial ingrowth does occur, Dr O’Keefe said treatment options include surgical lifting-debridement, alcohol application, mitomycin C, fibrin glue, phototherapeutic keratectomy, suturing and amniotic membrane.

“The most common way to deal with severe cases of epithelial ingrowth is lifting, debridement – making sure that you scrape both the back of the flap and the stromal part of the cornea – and suturing. Leave in the sutures for about four weeks and then take them out and the outcome in these cases is quite good,” he told delegates. However, the recurrence rate can be quite high, varying between five per cent to 60 per cent.

“That said, you might not have to do anything further in the vast amount of these cases and it should be noted that in most cases of epithelial ingrowth the visual outcomes are quite good,” Dr O’Keefe concluded.