[Value of ocular hypotony as a predictor of open-globe injury in patients with ocular trauma]

Ocular hypotony is an indirect open-globe injury sign that can be evaluated during primary care. A study was performed to ascertain the chances of a patient with ocular trauma and hypotony during initial evaluation of having open-globe injury compared with another patient without hypotony, and to estimate the value of hypotony as a predictor of open-globe injury.

Patients with ocular trauma evaluated between 1995 and 2003 with intraocular pressure records were included; patients with other causes of hypotony were excluded. Patients with hypotony were assigned to group 1 and those without hypotony to group 2. Rate of open-globe injury was compared between groups with chi2, odds ratio (OR), and 95% confidence intervals (95% CI).

Three hundred sixty one patients (aged 1-90 years average age 26.3 years) were evaluated; 329 patients had closed-globe (91.1%) and 32, open-globe injury (8.9%). Thirty six were assigned to group 1 (10%) and 325 (90%) to group 2. Twenty three patients in group 1 had open-globe injury (63.9%) while nine in group 2 had open-globe injury (2.8%, p <0.001, OR 62.12, 95% CI 21.81-183.6). There was hypotony in 71.9% of eyes with open-globe injury and in 4% of eyes with closed-globe injury.

Although hypotony was not present in every open-globe injury, the chance of finding the latter when there was hypotony was 62 times greater than without it. Absence of hypotony might be a useful tool to rule out open-globe injury. It would be convenient to validate ocular hypotony as a diagnostic test of open-globe injury by means of a prospective study.