Alpha-adrenergic antagonists and iris dynamics: Challenges and solutions in cataract surgery

BMC Ophthalmol. 2024 Oct 3;24(1):431. doi: 10.1186/s12886-024-03705-1.

Abstract

Background: Alpha-1 adrenergic receptor antagonists (α1-ARAs) are frequently used in treatment of Hypertension and symptomatic benign prostatic hypertrophy (BPH). Numerous studies have demonstrated the association between α1-ARAs like Tamsulosin and increased surgical risks for patients undergoing cataract surgery. This study aims to identify and study the effects of α1-ARAs on iris parameters and the subsequent operative challenges encountered during cataract surgery.

Methods: A cross-sectional, prospective study involving 30 patients on α1-ARAs planned for cataract surgery and equal number of age and sex matched controls were subjected to evaluation of changes on iris parameters and subsequent challenges in cataract surgery.

Results: The study group had statistically significant lesser pupil diameter. Iris thickness at sphincter muscle region (SMR) was similar between groups (P = 0.53). Significantly lower values of iris thickness at dilator muscle region (DMR) found in treated subjects (P = < 0.001). There was statistically significant difference between DMR/SMR ratio of two groups (P < 0.001). Multiple regression analysis revealed longer duration of α1-ARAs treatment correlated with reduced DMR/SMR ratio (P = 0.001; r = 0.47).

Conclusion: α1-ARAs have implications for pupil size regulation and surgical procedures involving the eye. Tamsulosin is more potent than alfuzosin in inducing IFIS. Systemic α1-ARAs lower values of DMR thickness, DMR/SMR ratio and reduces pupillary diameter. Therefore, ophthalmologists, primary care physicians, urologists, and patients should be aware of the potential difficulties that these drugs pose for cataract surgery.

Keywords: Alpha adrenergic antagonists; Intraoperative floppy iris syndrome (IFIS); Pupillary diameter; Tamsulosin.

MeSH terms

  • Adrenergic alpha-1 Receptor Antagonists* / pharmacology
  • Adrenergic alpha-1 Receptor Antagonists* / therapeutic use
  • Aged
  • Cataract Extraction*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Iris* / drug effects
  • Male
  • Middle Aged
  • Prospective Studies
  • Prostatic Hyperplasia / drug therapy
  • Pupil / drug effects
  • Tamsulosin* / therapeutic use

Substances

  • Adrenergic alpha-1 Receptor Antagonists
  • Tamsulosin