Perioperative time and economic impact of an intracameral combination of mydriatics and anaesthetics in routine cataract surgery

Intracameral Anaesthetic Mydriatic Versus Topical Mydriasis in Pediatric Cataract Surgery: A Randomized Control Study

PURPOSE

To compare pupil dynamics after using premixed intracameral anesthetic mydriatic combination (ICAM) of phenylephrine (0.31%), tropicamide (0.02%), and lidocaine (1%) versus topical mydriatic (TM) drops consisting of tropicamide 0.8%, phenylephrine 5%, and cyclopentolate 0.5% in pediatric cataract surgery.

DESIGN

Randomized, masked, fellow eye-controlled trial.

SETTING

Tertiary eye care facility.

STUDY POPULATION

Children ≤12 years of age with bilateral cataracts planned for surgery. One eye was randomized to receive ICAM and the other eye (control) TM drops.

INTERVENTION

Commercially available ICAM that was injected at the beginning of surgery or TM 3 times at an interval of 30 minutes, 1 hour before the scheduled time of surgery. The other treatment was administered for the second eye cataract surgery.

MAIN OUTCOME MEASURE

Pupil dynamics at various points of surgery were studied by a masked observer.

RESULTS

Sixty-three patients (126 eyes) were randomized to receive ICAM in 1 eye (group 1) or TM drops (group 2). The mean age of the children in the study was 15.7 ± 24.3 months (range 3 months to 5 years). Adequate mydriasis with a single injection was achieved in 93.5% of patients in group 1 and 88.8% of patients in group 2 without additional pharmacotherapy or intervention. The mean pupillary diameter increased from 1.78 mm to 5.1 mm after injection of 1 unit of ICAM and from 1.75 mm to 6.06 mm with TM drops (P < .0001). The maximum pupillary dilation achieved was 6.06 ± 1.17 mm in group 1 and 6.75 ± 1.07 mm in group 2 (P = .004). The average change in pupillary size from injection of drug until the end of surgery was positive in group 1 (0.75 ± 0.98 mm) and negative in group 2 (-0.3348 ± 2.57 mm), ie, there was a relative miosis in group 2 toward the end of surgery (P = .001).

CONCLUSIONS

Topical drugs achieved a larger maximum pupil size compared with ICAM. However, ICAM provided adequate and stable mydriasis without the need for augmentation compared with topical drops in children undergoing cataract surgery.

Intracameral phenylephrine for surgical mydriasis and intraoperative floppy-iris syndrome: systemic adverse effects and optimal dose

Phenylephrine, a potent sympathomimetic, induces mydriasis via iris dilator muscle contraction. Intracameral (IC) phenylephrine has been successfully used in cataract surgery for initial mydriasis, maintaining mydriasis, and management of intraoperative floppy-iris syndrome. Serious systemic adverse events (mainly cardiovascular) have been described with topical phenylephrine drops, but we found very little evidence of such adverse events associated with IC phenylephrine use. However, we suspect under-reporting of such adverse events, as they may instead be ascribed to anxiety, positioning, anesthesia, etc. Optimal dosage/concentrations for IC phenylephrine use in different purposes have not been fully studied. In the absence of robust evidence, we suggest that lower but effective IC phenylephrine concentrations are used: a lower concentration (0.31%), in conjunction with an anticholinergic and lidocaine, may be used for initial mydriasis. For management of intraoperative floppy-iris syndrome, 0.31% may be effective, though a higher concentration (1% to 1.25%) may be required.