Subconjunctival Hemorrhage

Excerpt

Red eyes are a common complaint in emergency departments and outpatient clinics. One frequent cause is subconjunctival hemorrhage (SCH), which is generally benign but potentially indicative of serious underlying disease if persistent or recurrent. This ocular condition is generally painless but presents as a sharply demarcated red patch that may appear diffusely hyperemic (see Image. Subconjunctival Hemorrhage). Physicians, advanced practice providers, and ophthalmologists frequently encounter SCH in clinical practice.

The conjunctiva is divided into 2 sections: the bulbar conjunctiva, which covers the sclera, and the tarsal conjunctiva, which covers the inside of the eyelids. This thin, transparent, vascular membrane consists of stratified epithelial and stromal layers supported by a dense capillary network.

SCH arises from rupture of small superficial conjunctival vessels overlying the sclera rather than from deeper intraocular structures. Blood accumulates in the potential space between the bulbar conjunctiva and the Tenon capsule, producing a localized, well-defined red area. Superficial location and limited structural support render these vessels vulnerable to rupture. Thus, minor venous pressure elevations or mechanical strain can trigger hemorrhage. Older adults with hypertension or diabetes face the greatest risk, whereas younger patients more often experience traumatic or spontaneous causes.

SCH usually does not require specific treatment. The condition follows a benign, self-limiting course, with most cases resolving within 1 to 2 weeks. The rate of blood resorption depends on the size of the hemorrhage, patient age, systemic comorbidities, and local factors such as conjunctival lymphatic drainage. Discoloration progresses in a predictable sequence. The patch initially appears bright red, darkens to a deeper red, and eventually takes on a yellow-green hue as hemoglobin is metabolized into biliverdin and bilirubin.

SCH does not cause pain, photophobia, reduced visual acuity, or pupillary abnormalities. These absent features help differentiate the condition from more serious ocular disorders. The benign presentation often reassures clinicians and patients, although its dramatic appearance can prompt urgent evaluation. Cases with recurrence or accompanying symptoms require further investigation to exclude systemic disease or structural abnormalities.