Minimally invasive strabismus surgery (MISS) employs keyhole incisions to expose muscles and perform surgery. MISS has been found to yield better cosmetic outcomes after surgery involving horizontal recti. To further these findings, our study compared MISS for inferior oblique (IO) recession with conventional approach, in terms of complications and functional outcomes.

Prospective Interventional study

Forty adult patients with inferior oblique overaction (IOOA) were randomly divided into two groups—those undergoing recession by MISS and those by conventional technique. MISS involved making a small radial cut over IO insertion, while in the conventional group recession was done via larger conjunctival incision. Main Outcome Measures included conjunctival injection, chemosis, periorbital edema and residual IOOA recorded during the first six postoperative weeks. Patients were followed up at postoperative day 1, day 7 and 6 weeks.

The mean age of patients was 21.17±3.43 years. The average recession performed was 9.5±0.98 mm (conventional: 9.4±1.14 mm; MISS: 9.6±0.82 mm; p>0.05). Conjunctival congestion (p<0.05) and periorbital edema (p<0.01) were significantly less in MISS than in the conventional group. There was also a significant difference in chemosis on postoperative days one and seven (p=0.00015 & 0.035 respectively). However, both groups had similar appearance at week six. No significant difference was found for final alignment and residual IOOA.

This study shows that the MISS technique is feasible for inferior oblique recessions. It seems to be particularly superior in the immediate postoperative period, due to fewer conjunctival and periorbital swelling complications. Long-term results did not differ between the two groups.