Structural And Biomechanical Changes In The Anterior Segment After Uneventful Phacoemulsification

To evaluate structural and biomechanical changes in the anterior ocular segment one month after uncomplicated cataract surgery by phacoemulsification using combined assessment with Pentacam (Scheimpflug tomography) and Corvis ST (dynamic corneal biomechanical analysis). The study examines corneal stability, ectasia-related indices, anterior chamber parameters, and biomechanical responses in the early postoperative period to assess clinical significance and potential implications for glaucoma risk and detection of subclinical ectatic changes.

The study was conducted between November 2025 and February 2026 at the University Specialized Hospital for Active Treatment of Eye Diseases - Varna. All interventions were performed using a standardized phacoemulsification technique with posterior chamber IOL implantation. The cohort included 10 patients: three with glaucoma (two with primary open-angle and one with primary angle-closure glaucoma) and seven without.

This study included patients undergoing uneventful phacoemulsification with posterior chamber IOL implantation. Anterior segment parameters assessed with Pentacam comprised anterior chamber depth (ACD), volume (ACV), angle (ACA), central corneal thickness (CCT), keratometry (K1, K2), corneal astigmatism, and the Belin/Ambrosio Enhanced Ectasia Display total deviation index (BAD-D). Corneal biomechanical parameters measured with Corvis ST included biomechanically corrected intraocular pressure (bIOP), stress–strain index (SSI), stiffness at first applanation (SP-A1), deformation amplitude (DA), and Corvis Biomechanical Index (CBI). Measurements were obtained preoperatively and one month postoperatively under standardized conditions.

Pentacam analysis demonstrated significant anterior segment remodeling after surgery, with increased anterior chamber depth (1.54 mm), volume (45.0 mm³), and angle width (19.9°). Central corneal thickness changed minimally (−2 µm). Keratometric values and ectasia-related indices (BAD-D) remained stable. Corvis ST assessment showed stable corneal biomechanics. Changes in biomechanically corrected IOP (+0.34 ± 4.80 mmHg), stress–strain index (+0.06 ± 0.19), and stiffness at first applanation (−1.01 ± 22.01) were minimal. Deformation parameters (DA: −0.23 ± 0.45; integrated radius: −0.38 ± 0.75) showed no signs of biomechanical weakening. Corvis-derived CCT increased (+11.3 ± 17.3 µm). No parameters indicated increased ectasia risk.

Uncomplicated phacoemulsification results in significant anterior segment remodeling one month postoperatively, characterized by increased anterior chamber depth and angle width. Corneal tomographic and biomechanical parameters remain stable, indicating preserved corneal structural and functional integrity. Combined structural and biomechanical assessment provides clinically relevant information on postoperative ocular stability and supports individualized monitoring, particularly in patients with borderline corneal characteristics or elevated glaucoma risk.