ANTERIOR CHAMBER MORPHOLOGICAL CHANGES AND REFRACTIVE OUTCOMES FOLLOWING PHACOEMULSIFICATION IN PSEUDOEXFOLIATIVE EYES: A CASE-CONTROL STUDY

To compare the changes in angle morphological parameters and anterior chamber depth (ACD), intraocular pressure (IOP), endothelial cell density (ECD) and postoperative refractive prediction error (PE) after uneventful phacoemulsification between pseudoexfoliative (PEX) and non-PEX eyes.

Central Lisbon Universitary Hospital Centre, Lisbon, Portugal

Prospective case-control study of eyes submitted to uneventful cataract surgery with implantation of a single intraocular lens model (AU00T0). Biometric data and angle parameters including Anterior Chamber Angle (ACA), Angle Opening Distance (AOD), Scleral Spur Angles (SSA) and Trabecular Iris Space Area (TISA) at 500 and 750 µm were measured preoperatively and 1-month postoperatively, through swept-source anterior segment optical coherence tomography (ANTERION®, Heidelberg Engineering); ECD with specular microscopy. Postoperative refractive prediction error (PE) was calculated using an optimized A-constant and the Kane formula.

A total of 60 eyes (30 PEX and 30 non-PEX) of 60 patients were included. Preoperative angle analysis revealed a lower ACA, AOD, SSA and TISA in PEX group (p<0.05), without differences between groups regarding biometric data (AL and mean keratometry, both p>0,05). Angle parameters increased significantly postoperatively in both groups (p<0.001). Despite the observed tendency for a higher magnitude of morphometric angle changes in PEX eyes, only SSA at 500µm (0º) and TISA at 750µm (0º) showed a significantly superior percentile of increase (p=0.030 and p=0.041, respectively). The anterior chamber deepened significantly in both groups (PEX 3.09 ± 0.48mm to 4.82 ± 0.37mm, p<0.001; non-PEX 3.06 ± 0.41mm to 4.55 ± 0.21mm, p=0.01), with arithmetic and percentile change being significantly higher in PEX group (p=0.017 and p=0.047, respectively). IOP and ECD decreased after surgery, without differences between groups. There was no significant difference in arithmetic and absolute PE between PEX and non-PEX eyes (p=0.105 and p=0.68, respectively). However, a significant PE hyperopic shift was observed (p=0.035) in PEX group.

Pseudoexfoliative eyes with cataract have narrower angles, revealing a tendency for higher angle opening after surgery, along with an increased ACD deepening compared to non-PEX eyes, which may be explained by PEX-associated zonular laxity. Moreover, a significant hyperopic shift was observed in PEX eyes, a relevant fact to take into consideration when selecting intraocular lens power.