Intraoperative miosis in femtosecond laser–assisted cataract surgery
2014; Lippincott Williams & Wilkins; Volume: 40; Issue: 5 Linguagem: Inglês
10.1016/j.jcrs.2014.02.026
ISSN1873-4502
Autores Tópico(s)Corneal surgery and disorders
ResumoIn their comprehensive review, Nagy et al.1 described the various complications encountered during their first 100 cases of femtosecond laser–assisted cataract surgery. In particular, I wish to comment on the occurrence and prevention of intraoperative miosis after the femtosecond laser step just prior to commencing phacoemulsification. In my first 50 cases of femtosecond laser–assisted cataract surgery using the Lensx system, I too encountered a 25% incidence of miosis after the femtosecond laser procedure. The miosis ranged from moderate, with 3.0 to 4.0 mm diameter pupils, to severe, resulting in pupils of only 2.0 mm, with tenting of the edge of the free anterior capsule flap by the pupil in some cases (Figure 1).Figure 1: Severe miosis after the femtosecond laser step.My preoperative dilating regimen for these first 50 cases was a drop of tropicamide 1.0% (parasympatholytic) every 15 minutes 1 hour preoperatively and 1 application only of phenylephrine 2.5% (sympathomimetic) 1 hour preoperatively. It is unclear from Nagy et al.’s paper whether the pupillary dilation used was “1 drop of tropicamide 0.5% every 15 minutes for 3 times” (page 21) or “mainly a combination of parasympatholytics and sympathomimetics and application of nonsteroidal antiinflammatory drops” (page 26). Significant pupillary constriction obviously renders removal of the anterior capsule flap problematic as the completeness of the femtosecond laser-created capsulorhexis is hard to determine and subsequent removal of the fragmented nucleus is also compromised. Having experienced significant pupillary constriction in such a high proportion of cases, I decided to add a topical nonsteroidal antiinflammatory drug (NSAID) to my existing dilating regimen based on the knowledge that NSAIDs are known to prevent pupillary constriction during cataract surgery.2,3 I used nepafenac ophthalmic suspension 0.5% and applied 2 drops 1 hour preoperatively. In my subsequent 50 cases of femtosecond laser–assisted cataract surgery using the same femtosecond laser platform with this new regimen, I saw only 1 case of post-femtosecond laser–induced miosis. The maintenance of pupillary dilation by the simple expedient of applying 2 drops of NSAID 1 hour preoperatively with the start of the dilating drops was remarkable. Interestingly, the 1 patient who had moderate miosis had not been given the NSAID preoperatively due to suspected allergy to NSAIDs. The topical application of the NSAID an hour preoperatively seems to have successfully eradicated the commonly observed femtosecond laser–induced miosis. Although the use of NSAIDs to prevent intraoperative miosis has long been recognized in cataract surgery, phacoemulsification has become so quick and efficient that there was little need for its continued use. However, the increasing popularity of femtosecond laser–assisted cataract surgery with its tendency to cause prostaglandin-mediated intraoperative miosis after the femtosecond laser step suggests that we should revisit the use of topical NSAIDs as part of the preoperative dilating regimen.
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