Dr.Ramanujan b odeyar, Dr.Ramanujan Odeyar
23 year old patient with refractive error of -1.25d -1.25 130 degree cylinder in OD and -5.5 d spher in OS and pachy of 531 and 535 came for LASIK. After taking flap and starting ablation ,laser beam was firing at a single point and digging a crater, within 4 seconds and just 12% of intended ablation, 62 microns were ablated.Ablation was stopped and flap re-positioned .Fluence test was repeated which was abnormal.Laser was switch offed and restarted fluence test repeated which was normal .Flap was reopened and 80% of intended ablation done. With timely intervention perforation was prevented. Patient achieved 6/9 and J/2 vision on 50th postoperative day. The cause of abnormal ablation was found to be failure of rotating mirror in Eximer laser.As refractive surgery is machine dependent procedure, we need to be very alert during surgery to prevent any complications arising from laser or microkeratome failure.