Corneal 'dellen' as a complication of strabismus surgery

PURPOSE: This paper presents results of an analysis on patients operated on for strabismus in order to evaluate frequency and clinical characteristics of corneal alterations. In our experience, this kind of complication occurs more frequently after reoperation and/or after surgery for esotropia in sixth nerve palsy using transposition procedures. METHODS: A retrospective analysis was made of 655 consecutive patients operated on for strabismus on the recti muscles with a limbal approach from January 2001 to July 2003 (30 months). RESULTS: We found 30 corneal dellen out of the 184 eyes (16.30%) reoperated on medial rectus muscles, 7 corneal dellen out of the 37 eyes (18.92%) operated on using transposition procedures, 4 corneal dellen out of the 101 eyes (3.96%) operated of lateral rectus muscle recession combined with medial rectus muscle resection and no corneal dellen in the other 976 eyes operated of using different surgical procedures on the recti muscles. All patients had been operated on using a conjunctival limbal approach. All corneal dellen disappeared in about 10-15 days, using topical antibiotics and a firm bandage applied to the eye at night, leaving permanent alterations in corneal homogeneity in 8 eyes (19.51%). CONCLUSION: This study showed that this kind of complication is relatively frequent after reoperations and/or transposition procedures, thus indicating that it is possible to identify surgical procedures which might play a role in the development of corneal dellen. Therefore, the post-operative monitoring of patients at risk should not be delayed for more than one week, in order to avoid possible corneal perforation.