Sir,

Intraoperative floppy iris syndrome (IFIS) associated with hypersensitivity reaction to adrenaline and without other known risk factors for IFIS is described. This may suggest that hypersensitivity reaction to adrenaline is an important preoperative warning sign of IFIS. IFIS is characterized by subnormal preoperative pupil dilation, repeated intraoperative prolapse of a billowing, floppy iris, and progressive intraoperative miosis.1 IFIS may occur with or without α-blockers and has been proposed as a form of iris dystonia.2 It can occur in either sex with variable susceptibility and severity.3

A 64-year-old myopic lady (OD −7.00/−5.00 @ 20, OS −10.50/−1.00 @ 175, preoperative visual acuity (VA) with glasses 6/6 OD, 6/12 OS) was referred for cataract surgery due to myopic shift. Despite Cyclopentolate 1% and Tropicamide 1% drops the patient did not dilate well (Actual pupil size was not recorded). There was no history of previous eye disease and no evidence of pseudoexfoliation syndrome. The patient's regular medication included: Premarin, Lomotil, Seroxat, and Ibuprofen. There had been no prior α-blocker usage. When questioned about allergies, the patient reported severe shaking and palpitations with adrenaline (given by her dentist). There was no prior history of cardiac problems.

During left cataract surgery under subtenons local anaesthesia, the pupil became progressively smaller; the iris billowed and prolapsed. Intraocular lens insertion was difficult due to iris catching on the injector device. Subsequent right cataract surgery was undertaken using iris hooks and low-flow settings. This prevented iris prolapse although the iris was floppy. Each operation was performed by a different experienced consultant. The patient was satisfied with a final VA of 6/6 OD and 6/9 OS unaided.

This patient's hypersensitivity to adrenaline may be as a result of a phenomenon similar to that seen in denervation hypersensitivity in Horner's syndrome. Perhaps downregulation of α1 adrenoreceptors, due to whatever cause, leads to iris dilator tone loss and disuse atrophy. A single case proves nothing and we cannot prove the patient definitely was hypersensitive to adrenaline, but feel that the reported symptoms may be an important preoperative warning sign of possible IFIS.