Comparison of macular thickness and inflammatory cytokine levels after microincision versus small incision coaxial cataract surgery

Abstract

ABSTRACT.Purpose: To compare the macular thickness and volume change, and inflammatory cytokine levels after cataract surgery performed using two different sizes of incision (microincision versus small incision). Methods: In this randomized, comparative clinical trial, 84 eyes with nuclear density from Grade 3-4 were randomly divided into two groups (microincision, 2.2 mm; and small incision, 2.75 mm). Forty-two patients underwent phacoemulsification with microincision coaxial cataract surgery and 42 patients underwent phacoemulsification with small incision coaxial cataract surgery. Clinical measurements included preoperative, 1-week, 1-month and 2-month postoperative best corrected visual acuity, central corneal thickness (CCT) and endothelial cell count. ELISA and RT-PCR were performed for IL-1b, IL-6, VEGF and PGE2 preoperatively and at 1 week postoperatively. Results: The percentage increase in CCT in the microincision group was significantly higher than that in the small incision group at 1 week after cataract surgery (p = 0.01). The increase in macular thickness in the microincision group was significantly higher than that in small incision group at 1 month after cataract operation (p = 0.04). Also, IL-1b, IL-6, VEGF and PGE2 concentrations and their expression ratio in the microincision group were significantly higher than those in the small incision group at 1 week after cataract surgery compared to the preoperative period (p < 0.05). Conclusions: Phacoemulsification with microincision coaxial cataract surgery may increase the macular thickness compared to phacoemulsification with small incision coaxial cataract surgery. Blood-aqueous barrier breakdown may occur more frequently after microincision cataract surgery than after small incision cataract surgery.

Different-sized incisions for phacoemulsification in age-related cataract

“…One trial was conducted in Bosnia and Herzegovina (Musanovic 2012), 13 trials in China (Hui 2016; Li 2016; Lin 2013; Luo 2012; Mao 2008; Shan 2016; Shi 2013; Wang 2009; Yao 2008; Yao 2011; Yu 2016; Zhang 2014; Zhu 2014), one trial in France (Febbraro 2015), one trial in India (Vasavada 2013a), one trial in Italy (Mastropasqua 2011), five trials in Korea (Hwang 2008; Hwang 2016; Jeong 2013; Li 2011; Moon 2011), two trials in Spain (Capella 2010; Morcillo-Laiz 2009), one trial in Switzerland (Dosso 2008), and one trial in Turkey (Can 2010). …”

“…Study investigators of Luo 2012 mentioned that only the technician and surgeon were masked during postoperative examinations, so we judged this trial to be at low risk of detection bias and unclear risk of performance bias. Hwang 2016 did not report whether the participants were masked, but the image examiner was masked, so we judged this trial to be at low risk of detection bias and unclear risk of performance bias.…”

“…Four studies were registered (Hwang 2016; Luo 2012; Vasavada 2013a; Yu 2016). The outcomes that were described in the registry search were consistent with those reported in the papers.…”

“…Fifteen trials reported outcomes for this comparison (Can 2010; Febbraro 2015; Hwang 2008; Hwang 2016; Jeong 2013; Li 2011; Li 2016; Lin 2013; Luo 2012; Moon 2011; Musanovic 2012; Shan 2016; Shi 2013; Wang 2009; Zhu 2014). Shi 2013 included both eyes of 34 of 98 participants (35%) in the study, but they did not report to which group the eyes were allocated and did not account for intraperson correlation in their analysis.…”

“…None of the included trials had assigned individual eyes of a participant to different interventions (standard phacoemulsification, C-MICS, or B-MICS). Sample sizes in some included trials suggested paired-eye trials because the number of eyes included was twice the number of participants (Capella 2010; Hwang 2016; Musanovic 2012; Zhu 2014). We referred to Chapter 16 of the Cochrane Handbook for Systematic Reviews of Interventions as a guide for intraperson correlation between eyes (Higgins 2011b).…”