Phacoemulsification associated with loss of endothelial cells in cataract surgery: a systematic review of main surgical techniques

Abstract

Introduction: Phacoemulsification (PE) cataract surgery is the gold standard in ophthalmology, being effective in improving vision in more than 90.0% of patients. In this context, authors found that PE was associated with 16.67% of endothelial cell loss, which correlated with the degree of trauma during surgery. Endothelial changes are considered an important parameter for assessing trauma and for estimating the safety of a surgical technique. In this sense, more modern PE machines are capable of removing cataracts using optimized parameters such as high vacuum, aspiration flow, and low amount of ultrasonic energy. Objective: It was to present and discuss the main phacoemulsification techniques for optimizing the treatment of cataracts, in an attempt to reduce the loss of corneal endothelial cells. Methods: Experimental and clinical studies were included (case reports, retrospective, prospective, and randomized studies) with qualitative and/or quantitative analysis. Initially, the keywords were determined by searching the DeCS tool (Descriptors in Health Sciences, BIREME base) and later verified and validated by MeSH Terms. The search literature was carried out from January to April 2023 in Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. Results: A total of 122 articles involving phacoemulsification and endothelial cells were found. Initially, the existing title and duplications were excluded according to the interest described in this work. After this process, the abstracts were evaluated and a new exclusion was performed. A total of 80 articles were evaluated in full and 59 were included and discussed in this study. At the beginning of treatment with PE, without the endothelial protection of viscoelastic agents and the use of ultrasound in the anterior chamber, the endothelial loss was greater than in extracapsular cataract extraction. With the modernization of PE, the use of viscoelastic agents, the emergence of techniques for fracture of the nucleus within the capsular bag, and the use of ultrasound in the posterior chamber, the loss of endothelial cells reduced from 7 to 12% on average. Conclusion: Endothelial changes are considered an important parameter to assess trauma and estimate the safety of a surgical technique. Highlighted, the main predictors associated with the loss of corneal endothelial cells are the duration of the ultrasound used in the surgery, the turbulence of the liquid in the anterior chamber, and the mechanical trauma.