The effect of uncomplicated cataract surgery on intraocular pressure: A retrospective review

Purpose: To determine the effect of three different techniques of cataract surgery on intraocular pressure (IOP) and identify those groups of patients in which a significant sustained reduction in IOP occurred. Methods: A retrospective, nonrandomized, comparative review was performed on 119 patients (143 eyes) who underwent cataract surgery by eight third-year residents at Parkland Memorial Hospital between January and December, 1997. Three groups of patients - normal, ocular hypertensives (OUT), and primary open-angle glaucoma patients (POAG) - who underwent cataract extraction with posterior chamber intraocular lens (PCIOL) implantation by either extracapsular cataract extraction with manual expression (ECCE), scleral tunnel phacoemulsification (STP), or clear corneal phacoemulsification (CCP) were studied. Change in IOP at final exam (115 eyes available six months post-operatively) was measured and analyzed with respect to patient group, surgical technique performed, and preoperative axial length. Results: IOP was significantly lower at final exam in patients undergoing CCP and ECCE (17.9% and 16.3% drop from baseline, respectively). OUT patients experienced the greatest drop in IOP (22.1%) followed by POAG patients (16.7%) and normal patients (4.2%). Shorter eyes (<23.0 mm) were much more likely to experience a clinically significant (>20% from baseline) drop in IOP than longer eyes (61% vs 39%). Conclusion: Cataract extraction with PC-IOL implantation produces a sustained significant drop in IOP. The effect is most pronounced in OHT patients, patients with POAG, patients with shorter eyes, and those undergoing CCP.