Eye signs in SLE-PAH linked to treatment response, prognosis
Changes to conjunctiva’s microcirculation may help predict severe disease risk
A slit lamp exam of the eyes may detect signs that could help doctors predict how well treatment will work in people with pulmonary arterial hypertension (PAH) associated with systemic lupus erythematosus (SLE), an autoimmune disease, a small study suggests.
Specific eye signs can also help evaluate PAH progression and its prognosis. The study, “Eye signs as a novel risk predictor in pulmonary arterial hypertension associated with systemic lupus erythematosus,” was published in Advances in Rheumatology by a research team in China.
While it’s relatively uncommon, some people with SLE, the most common form of lupus, have pulmonary hypertension due to the blood vessels that supply the lungs narrowing, which limits blood flow and increases blood pressure.
Changes to the conjunctiva’s microcirculation, which refers to blood flow through the smallest blood vessels, may help predict the risk of severe SLE-PAH. However, detecting eye signs is simpler than a conjunctival microcirculation examination since they can be observed with a “conventional slit lamp or even with the naked eye,” the researchers wrote. The conjunctiva is a membrane that covers the front part of the eyes. A slit lamp is a microscope that shines a bright light into the eyes so eye care specialists can look at the different eye structures. A slit lamp exam is usually part of a routine eye exam.
Here, researchers reviewed how eye signs caught on a slit lamp exam were linked to outcomes in 29 people with SLE-PAH. Eye signs included twisted or dilated (widened) blood vessels, areas lacking blood supply (ischemic areas), bleeding, abnormal structures, and wound spots.
Eyeing PAH progression, prognosis
Twelve patients showed a PAH improvement over six months, which was defined as dropping at least one grade on the European Society of Cardiology (ESC)/European Respiratory Society (ERS) strata of low, intermediate, and high risk. Seventeen patients didn’t improve.
Those who improved had higher blood vessel density and better microvascular flow index in their eyes than those who didn’t. Blood vessel density and microvascular flow index were linked to how well the heart and lungs were working.
Both parameters correlated negatively with disease severity according to the World Health Organization (WHO) functional classification, meaning lower blood vessel density and microvascular flow index were linked to worse PAH symptoms.
They also correlated negatively with the levels of N-terminal prohormone of brain natriuretic peptide (NT-proBNP). Higher NT-proBNP levels indicate the heart may be working harder to push blood into the lungs, which may cause it to fail.
But blood vessel density and microvascular flow index correlated positively with the distance patients could walk in six minutes, indicating better functional capacity. Patients who improved could walk a median 60 meters, or about 196 feet, farther than those who didn’t.
Blood vessel density, microvascular flow index, NT-proBNP levels, and six-minute walking distance were important for predicting how well patients would do over time. All these parameters could differentiate patients who improved from those who didn’t.
Blood vessel density and microvascular flow index were more sensitive than the two other parameters, however, meaning they were better at predicting improvements in those who did improve. These two factors had excellent specificity, meaning that all the patients who failed to improve in PAH were identified as indeed not having improved.
“SLE-PAH can lead to various conjunctival microvascular manifestations,” the researchers wrote. “Vascular density and microvascular flow index can be used to assess cardiopulmonary function and predict therapeutic efficacy and prognosis in SLE-PAH patients.” The researchers called a conjunctival microcirculation assessment both convenient and feasible for clinical use, but said more clinical trials are needed to “refine parameter calculations and achieve standardization.”
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