Meta-analysis on the recurrence rates after bare sclera resection with and without mitomycin C use and conjunctival autograft placement in surgery for primary pterygium

Abstract

Background/aims: Bare sclera resection with and without use of mitomycin C and conjunctival autograft placement are three surgical techniques currently in use for the treatment of primary pterygium. The purpose of this study was to determine through a meta-analysis the risk for postoperative pterygium recurrence comparing the three surgical treatment modalities.

Methods: A search through Medline for randomised controlled clinical trials comparing at least two of the three surgical techniques in the treatment of primary pterygium, along with a hand search of all references in relevant papers, was conducted. All eligible clinical trials were graded for quality utilising the Detsky score; those studies with a score of 0.5 or greater were included. The main outcome measurements were the pooled odds ratios and 95% confidence intervals for the risk of pterygium recurrence. These were calculated utilising the Mantel-Haenszel method.

Results: Five eligible studies with an adequate quality score were retrieved, three comparing bare sclera resection with and without mitomycin C use, one comparing bare sclera resection with conjunctival autograft placement, and one comparing both. The pooled odds ratio for pterygium recurrence in patients who had only bare sclera resection was 6.1 (95% confidence intervals, 1.8 to 18.8) compared with the patients who had conjunctival autograft placement and 25.4 (9.0 to 66.7) compared with the patients who received mitomycin C.

Conclusions: The odds for pterygium recurrence following surgical treatment of primary pterygium are close to six and 25 times higher if no conjunctival autograft placement is performed or if no intra/postoperative mitomycin C is used, respectively. Surgeons and clinical triallists should not be encouraged in the use of bare sclera resection as a surgical technique for primary pterygium.

Figure 1

Individual study and pooled odds ratios and 95% confidence intervals calculated from data provided by original studies comparing bare sclera resection with postoperative mitomycin C versus placebo. Singh et al ²³ OR: 109.33 (12.18-980.34), Frucht-Pery et al ²⁴ OR: 25.38 (4.68-136.4), Cano-Parra et al ¹⁵ OR: 18.45 (2.24-150.27), Chen et al ¹¹ OR: 12.5 (0.81-192.92). (OR = individual study odds ratio, 95% confidence intervals for individual studies are in parenthesis.) Cumulative odds ratio: 25.4 (95% cumulative confidence intervals 9.02 to 66.69)

Figure 2

Individual study and pooled odds ratios and 95% confidence intervals calculated from data provided by original studies comparing bare sclera resection versus conjunctival autograft placement. Lewallen et al ¹⁴ OR: 3.11 (0.17-55.21), Chen et al ¹¹ OR:11.67 (2.14-64.04). (OR = individual study odds ratio, 95% confidence intervals for individual studies are in parenthesis.) Cumulative odds ratio: 6.1 (95% cumulative confidence intervals 1.82-18.75).