Impact of Axial Length and Preoperative Intraocular Pressure on Postoperative Intraocular Pressure Changes in Non-Glaucomatous Eyes Following Phacoemulsification Surgery in a University Hospital

Objectives: To evaluate the changes of Intraocular Pressure (IOP) in non-glaucomatous eyes following Phacoemulsification surgery among patient groups with different Axial Lengths (AL). Methodology: Within a retrospective cohort study design, medical records of cataract patients that underwent surgery between 2000 and 2010 at the Department of Ophthalmology, King Abdul-Aziz University Hospital (KAUH), Riyadh, Saudi Arabia were reviewed. Cases were identified as having an ocular AL >24 mm, <22mm, and a normal group of AL range; 22-24mm. The relationship between postoperative IOP changes and AL was evaluated for all patients fulfilling the inclusion criteria. Result: Among the Department of Ophthalmology, KAUH reviewers that underwent surgery during the period from 2000 to 2010, 252 eyes of 211 cataract patients were included in the current study. Patients were in the mean (±SD) age of 60.3 (±10.4), 110 (52.1%) male and 101 (47.9%) female. The average preoperative IOP for the whole study group significantly decreased from preoperative value of 14.5 (3.3) to 13.9 (3.4) mmHg (p=0.005). Within the normal axial length group, the mean IOP was significantly reduced from 14.1 (3.2) at baseline to 13.5 (2.9) post operatively (p=0.035). Similar reduction was noticed among the longer axial length group (AL >24 mm) while slight increase was recognized in the smaller AL group (AL <22mm). However, both changes were not statistically significant (p= 0.067 and 0.640 for the long and the short AL groups, respectively). In the univariate analysis, “having preoperative high IOP” was the only associated factor with the postoperative decrease in IOP (p=0.034). This factor has also persisted to be significant in the binary logistic regression analysis (p=0.029). Conclusion: Patients with relatively high preoperative IOP would have a considerable reduction in IOP posterior to Phacoemulsification procedure. Such anticipated reduction may be also applicable to eyes with moderate and long axial length. Phacoemulsification may also help reducing the need for postoperative anti-glaucoma medications among cases with ocular hypertension.