Abstract
Abstract: :
Purpose: To compare the efficiacy of tetracain 1% Drops versus Gel for topical anesthesia in extracapsular cataract surgery Methods: A double blind randomized clinical trial was performed investigating 59 eyes of 58 patients. 23 eyes were anesthesized with tetracain gel (G), 36 eyes with tetracain drops (D). All eyes in the "gel-group"(GP) and 28 eyes in the "drop-group" (DP) underwent phacoemulsification (P) and 8 eyes hydrofragmentation-hydroexpression- technique (DH). Preoperative examination included: visual acuity, slit lamp examination, corneal endothelial cell count and intraocular pressure (IOP). Incision techniques were: clear cornea incision (CCI) for DP and GP or conjunctival incision, sclerocorneal tunnel and adaption of the conjunctiva at the end of surgery by electrocauterisation for DH. Intraoperative parameters were: time of P, duration of surgery, assessment of patient`s comfort or discomfort with the visual analog scale (VAS) and the the surgeon's opinion about the quality of anesthesia. Postoperative examinations were the same as preoperative and performed on day 1 and 40. An endothelial cell count was done at day 40. Results: Tetracain gel did not provide better analgesia than tetracain drops. Duration of surgery were: (min±SEM) DP: 15min± 1, GP: 16min±1, and DH 10min±1 (p<0.01). DH was associated with more discomfort (mean, 75% percentile) DP: 0, 5; GP: 0, 4; DH: 16, 30. IOP decreased in DP and GP at days 1 and 40. There was no change of IOP in DH and no difference between the 3 groups at postoperative day 40. There were no differences in patient`s discomfort and surgeon`s opinion about the quality of anesthesia. Endothelial cell loss was 13% in DP, 15% in GP and 12% in DH (p<0.01). Conclusions: Tetracain–gel does not provide better anesthesia than tetracain drops for CCI and P. Despite longer duration of surgery patients complain about less pain under CCI and P. Incision of conjunctiva, preparation of sclerocorneal tunnel and adaption by electrocauterisation seem to be less comfortable than CCI. IOP decreased in the postoperative period after P. The gel did not cause greater endothelial cell loss than the drops.
Keywords: cataract • pharmacology • cornea: endothelium