Medical interventions for traumatic hyphema.

BACKGROUND

Traumatic hyphema is the entry of blood into the anterior chamber (the space between the cornea and iris) subsequent to a blow or a projectile striking the eye. Hyphema uncommonly causes permanent loss of vision. Associated trauma (e.g., corneal staining, traumatic cataract, angle recession glaucoma, optic atrophy, etc.) may seriously affect vision. Such complications may lead to permanent impairment of vision. Patients with sickle cell trait/disease may be particularly susceptible to increases of elevated intraocular pressure. If rebleeding occurs, the rates and severity of complications increase.

OBJECTIVE

The objective of this review was to assess the effectiveness of various medical interventions in the management of traumatic hyphema.

METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2010, Issue 6), MEDLINE (January 1950 to June 2010), EMBASE (January 1980 to June 2010), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (http://clinicaltrials.gov). We searched the reference lists of identified trial reports to find additional trials. We also searched the ISI Web of Science Social Sciences Citation Index (SSCI) to find studies that cited the identified trials. There were no language or date restrictions in the search for trials. The electronic databases were last searched on 25 June 2010.

METHODS

Two authors independently assessed the titles and abstracts of all reports identified by the electronic and manual searches. In this review, we included randomized and quasi-randomized trials that compared various medical interventions to other medical interventions or control groups for the treatment of traumatic hyphema following closed globe trauma. There were no restrictions regarding age, gender, severity of the closed globe trauma or level of visual acuity at the time of enrollment.

METHODS

Two authors independently extracted the data for the primary and secondary outcomes. We entered and analyzed data using Review Manager (RevMan) 5. We performed meta-analyses using a fixed-effect model and reported dichotomous outcomes as odds ratios and continuous outcomes as mean differences.

RESULTS

Nineteen randomized and seven quasi-randomized studies with 2,560 participants were included in this review. Interventions included antifibrinolytic agents (oral and systemic aminocaproic acid, tranexamic acid, and aminomethylbenzoic acid), corticosteroids (systemic and topical), cycloplegics, miotics, aspirin, conjugated estrogens, monocular versus bilateral patching, elevation of the head, and bed rest. No intervention had a significant effect on visual acuity whether measured at two weeks or less after the trauma or at longer time periods. The number of days for the primary hyphema to resolve appeared to be longer with the use of aminocaproic acid compared to no use, but was not altered by any other intervention.Systemic aminocaproic acid reduced the rate of recurrent hemorrhage (odds ratio (OR) 0.25, 95% confidence interval (CI) 0.11 to 0.5), but a sensitivity analysis omitting studies not using an intention-to-treat (ITT) analysis reduced the strength of the evidence (OR 0.41, 95% CI 0.16 to 1.09). We obtained similar results for topical aminocaproic acid (OR 0.42, 95% CI 0.16 to 1.10). We found tranexamic acid had a significant effect in reducing the rate of secondary hemorrhage (OR 0.25, 95% CI 0.13 to 0.49), as did aminomethylbenzoic acid as reported in a single study (OR 0.07, 95% CI 0.01 to 0.32). The evidence to support an associated reduction in the risk of complications from secondary hemorrhage (i.e., corneal blood staining, peripheral anterior synechiae, elevated intraocular pressure, and development of optic atrophy) by antifibrinolytics was limited by the small number of these events. Use of aminocaproic acid was associated with increased nausea, vomiting, and other adverse events compares with placebo. We found no difference in the number of adverse events with the use of systemic versus topical aminocaproic acid or with standard versus lower drug dose. The available evidence on usage of corticosteroids, cycloplegics or aspirin in traumatic hyphema was limited due to the small numbers of participants and events in the trials.We found no difference in effect between a single versus binocular patch nor ambulation versus complete bed rest on the risk of secondary hemorrhage or time to rebleed.

CONCLUSIONS

Traumatic hyphema in the absence of other intraocular injuries, uncommonly leads to permanent loss of vision. Complications resulting from secondary hemorrhage could lead to permanent impairment of vision, especially in patients with sickle cell trait/disease. We found no evidence to show an effect on visual acuity by any of the interventions evaluated in this review. Although evidence is limited, it appears that patients with traumatic hyphema who receive aminocaproic acid or tranexamic acid are less likely to experience secondary hemorrhaging. However, hyphema in patients on aminocaproic acid take longer to clear.Other than the possible benefits of antifibrinolytic usage to reduce the rate of secondary hemorrhage, the decision to use corticosteroids, cycloplegics, or non-drug interventions (such as binocular patching, bed rest, or head elevation) should remain individualized because no solid scientific evidence supports a benefit. As these multiple interventions are rarely used in isolation, further research to assess the additive effect of these interventions might be of value.