Intraoperative miosis was one of the most significant intraoperative problems and complications in the early use of femtosecond laser–assisted cataract surgery. Dr. Yeoh described the role of NSAID drops, which has almost been forgotten in recent years because of the quick and safe phacoemulsification technique.1 We have also known that during the early phase of femtosecond laser–assisted cataract surgery, intraoperative miosis was more common than during routine phacoemulsification. The possible causes are the mechanical effect of the patient interface and the role of bubble and gas formation within the anterior chamber and within the lens. We have known for some time that prostaglandins are strong bioregulatory substances with high potential within the eye and within the entire body. Prostaglandins are synthesized by the cyclooxygenase pathway, and the most important intraocular source is the nonpigmented epithelial layer of the ciliary body. Mechanical and thermal stimuli may increase the level of prostaglandins in the aqueous humor.2,3
Our working team has studied intraoperative miosis, as have other authors. Recently, Schultz et al.4 reported that the prostaglandin level is elevated in the aqueous following femtosecond laser pretreatment. The cause might be the mechanical effect of the patient interface and the bubble formation within the anterior chamber. Based on the experiences of femtosecond laser surgeons, it is strongly advised that preoperative NSAIDs be included in the dilation regimen. The personal experiences of Dr. Yeoh support this recommendation. Multicenter studies of the time to start NSAIDS and dilating drops are needed; ie, the previous day, 1 hour before surgery, or as in traditional phacoemulsification, adding only NSAID drops. I always warn surgeons not to wait too long between femtosecond laser pretreatment and starting phacoemulsification. In that case, the intraoperative dilation with epinephrine is more difficult than in traditional phacoemulsification cases.
We have a long journey before we can state that this new technology is safely established and surgeons can benefit from every step in its use without any compromise. Herewith, I would like to invite femtosecond laser users to establish the guidelines for preoperative pharmacology of femtosecond laser–assisted cataract surgery.
1. Gimbel HV. The effect of treatment with topical nonsteroidal anti-inflammatory drugs with and without intraoperative epinephrine on the maintenance of mydriasis during cataract surgery. Ophthalmology
2. Cole DF, Unger WG. Prostaglandins as mediators for the responses of the eye to trauma. Exp Eye Res
3. Maihöfner C, Schlötzer-Schrehardt U, Gühring H, Zeilhofer HU, Naumann GO, Pahl A, Mardin C, Tamm ER, Brune K. Expression of cyclooxygenase-1 and -2 in normal and glaucomatous human eyes. Invest Ophthalmol Vis Sci. 42, 2001, p. 2616-2624, Available at: http://www.iovs.org/content/42/11/2616.full.pdf
. Accessed February 8, 2014.
4. Schultz T, Joachim SC, Kuehn M, Dick HB. Changes in prostaglandin levels in patients undergoing femtosecond laser-assisted cataract surgery. J Refract Surg