Abstract
Purpose: :
To evaluate whether eyelid specula commonly used in cataract surgery lead to changes in intraocular pressure (IOP). There are many aspects of cataract surgery that lead to intraocular pressure elevation, including supine positioning, the use of viscoelastics, and hydrostatic forces during phacoemulsification. One study in a pediatric population looking at 77 eyes of 45 children showed a 4mmHg elevation in IOP after the Alfonso newborn eyelid speculum placement. However there is no data looking at speculum use during cataract surgery and their effect on IOP in adults. This knowledge could help guide speculum choice in the future for high-risk patients during ophthalmic surgery.
Methods: :
31 patients undergoing routine cataract surgery under topical anesthesia were recruited for this prospective unmasked study. IOP measurements were performed before and after eyelid speculum placement with a Tono-Pen Avia. The first measurement took place once the patient had been lying on the surgical table for approximately 10 minutes, received a light benzodiazepine for comfort, and was ready to commence prepping in preparation for cataract surgery. The second measurement was performed approximately 5 minutes later, after the patient had been prepped and draped and the eyelid speculum had been inserted. 10 measurements were made and only measurements displayed with a 95% confidence were recorded. The three lid specula utilized included the Lieberman (24), Seibel 3D (6), and Kratz-Barraquer (1).
Results: :
The mean IOP prior to speculum placement was 24.03 (SD 6.24), and post-placement 20.97 (SD 6.45). The difference of 3.06 mmHg was found to be statistically significant at an alpha of 0.001 using a paired student t-test. Average preoperative clinic IOP was 15.87.
Keywords: intraocular pressure • cataract