BY WILLIAM L. MILLER, OD, MS, PHD, FAAO
A complication that may occur subsequent to ocular trauma is the formation of a hyphema. Its manifestation may range from a few blood cells in the anterior chamber (microhyphema) to more aggressive bleeds, typically referred to as 8-ball hyphemas (Grade 4). The blood results from a compromise, in this case concussive or contusive, to the iris or angle blood vessels. In rare cases, a hyphema can result from systemic causes, such as blood disorders including von Willebrand disease, hemophilia, or systemic pharmacologic agents (e.g., aspirin, warfarin). Sickle cell disease should also be ruled out as a causative or complicating factor.
The presence of a hyphema mandates a careful history, review of systems, and comprehensive evaluation to determine a course of action. Ruling out penetrating injuries or other intraocular sequelae (retinal detachment) is necessary before initiating therapy. If you are unable to adequately assess the intraocular contents behind the hyphema, then attempt or order imaging such as ultrasonography. An X-ray or a computerized tomography (CT) scan may be required if you suspect a fracture or foreign body penetration.
Hyphema management includes providing an environment for blood cell evacuation through the trabecular meshwork and protection against future re-bleeds. An ocular shield can help protect against further trauma. A mydriatic (atropine 1% q.d.) is required to prevent mechanical excursion by the iris that would exacerbate conditions for a re-bleed. The incidence of a secondary hemorrhage or a re-bleed ranges between 3 percent and 38 percent (Lai et al, 2001).
Figure 1. Traumatic hyphema.
Treat secondary anterior chamber inflammation (anterior uveitis) with topical steroids (prednisolone acetate 1% q.i.d. or t.i.d.). Increased intraocular pressure (IOP) is frequently managed with beta blockers. Do not use prostaglandin analogues because they may exacerbate the inflammation, and don’t use carbonic anhydrase inhibitors in patients who have sickle cell traits/disease to avoid creating an acidic aqueous humor. You can also suggest bed rest with patients’ heads elevated 30 degrees to 45 degrees.
Hospital admission is possible in cases of noncompliance or severe complications. A hyphema should clear within three to four days. Monitor visual acuity, IOP, and size of the hyphema daily until it resolves. For hyphemas lasting five to six days (risk of corneal blood staining), cases of intractable IOP elevation, or in children (amblyopia risk), surgical intervention may be warranted.
Systemic use of antifibrinolytic agents (aminocaproic acid, 50mg/ kg every four hours or tranexamic acid, 25mg/kg t.i.d. for five days), although controversial, may also be necessary to prevent secondary hemorrhages (Walton et al, 2002; Albiani et al, 2008). Their effect on preventing a re-bleed is greater compared to topical steroids, but less than or equal to oral steroids; however, the literature is equivocal on this. Oral aminocaproic acid has side effects that include nausea and vomiting, with tranexamic acid demonstrating fewer gastric issues.
A more thorough and comprehensive look at the evidence-based medicine approach to managing a hyphema is available in the Cochrane Collaboration Report (Savage et al, 2011). CLS
For references, please visit www.clspectrum.com/references.asp and click on document #216.
Dr. Miller is an associate professor and chair of the Clinical Sciences Department at the University of Houston College of Optometry. He is a consultant or advisor to Alcon and Vistakon and has received research funding from Alcon and CooperVision and lecture or authorship honoraria from Alcon and B+L. You can reach him at firstname.lastname@example.org.