Relationship between matrix metalloproteinase-9 level and anophthalmic socket contracture grading: a cross-sectional study

BACKGROUND: High recurrence levels of orbital socket contractures result in the requirement for repeated reconstructive surgeries. The specific tissue responsible for the clinical abnormality of socket contractures has not been identified; however, overexpression of matrix metalloproteinase-9 may lead to prolonged wound healing and inflammation. This study aimed to establish the correlation between matrix metalloproteinase-9 level and anophthalmic socket contracture degree.METHODS: This cross-sectional study analyzed patients diagnosed with anophthalmic sockets who were at least six weeks post-evisceration or post-enucleation. The Gopal Krishnan criteria were used for socket grading. Tear samples were collected and matrix metalloproteinase-9 levels were measured using the Schirmer Test. The Mann-Whitney Test, Kruskal-Wallis Test or unpaired t-test were used and the test results were considered significant at P<0.05.RESULTS: The study included one eye from each of 30 patients. The majority of the socket grades (15 patients, 50%) were normal (Grade 0). All groups exhibited a noticeable increase in matrix metalloproteinase-9 level when compared to the normal levels found in tears (P<0.05). However, no statistically significant link was observed between socket grading and matrix metalloproteinase-9 level (P>0.05). Furthermore, no significant difference in matrix metalloproteinase-9 level occurred between normal sockets and contracture sockets across the different gradings (P>0.05).CONCLUSIONS: Although matrix metalloproteinase-9 levels were notably higher in contracted anophthalmic sockets compared to normal sockets, no significant statistical link was observed between matrix metalloproteinase-9 level and anophthalmic socket contracture severity across the different grades.