Effect of Capsular Tension Ring on Refractive and Morphological Outcomes in Pseudoexfoliative Eyes
Bruna Cunha1, Pedro Gil1, Nuno Rodrigues Alves1
1Ophthalmology Department, ULS São José, Lisboa, Portugal.
Purpose:
To evaluate the effect on anterior chamber depth (ACD) and postoperative refractive prediction error (PE) of capsular tension ring (CTR) implantation during phacoemulsification in pseudoexfoliative (PEX) eyes.
Methods:
Prospective case-control study of eyes submitted to uneventful cataract surgery, divided into three study groups: Group 1 - controls; Group 2 - PEX eyes without CTR implantation; Group 3 - PEX eyes with CTR implantation. Biometric data including ACD were measured preoperatively and 1-month postoperatively, using swept-source anterior segment optical coherence tomography (ANTERION®, Heidelberg Engineering), and endothelial cell density (ECD) with specular microscopy. Postoperative refractive PE was calculated using an optimized A-constant and the Kane formula.
Results:
A total of 25 eyes were included in each group. Anterior chamber increased significantly in all groups (p<0.001), with the change being significantly greater in Group 2 compared to Group 1 (p=0.014). No significant differences in ACD changes were observed between Group 3 and the other groups (p>0.05). In Group 2, a significant hyperopic shift (p=0.035) and 12% of eyes with a prediction error above 1D was observed, which were not seen in Groups 1 or 3. The percentage of eyes with a PE within ±0.25D was significantly lower in Group 2 (p=0.013). IOP and ECD decreased similarly across all groups (p>0.05).
Conclusion:
Routine CTR implantation during uneventful phacoemulsification in PEX eyes appears to prevent the pseudoexfoliative hyperopic shift previously reported, likely due to more even zonular tension distribution. If CTR is not used, a slightly myopic target should be considered.
