Pseudoexfoliation Dry Eye With Unilateral Symptoms May Actually Be Bilateral

Dry eye disease (DED) was once categorized as either stemming from aqueous deficiency or too much tear evaporation. Now, researchers believe it is prompted by multifactorial causes, extending to ocular surface damage, neurosensory malfunction, or pseudoexfoliation (PEX) syndrome.

Notably, DED is also more common in individuals with PEX, and studies show patients with this disorder display both reduced tear quantity and tear film break-up time (TBUT). In a new report, researchers demonstrated that a cohort of patients with unilateral PEX have similar Schirmer’s test results and meibomian gland dropout in both their symptomatic and asymptomatic eyes, offering evidence for parallel progression, according to the data published in Journal Français d’Ophtalmologie.

To date, research on PEX has centered more on tear secretion, hyperosmolarity, and tear film stability, but until now few have included meibography. The current prospective investigation evaluates meibomian gland loss for 32 patients with unilateral PEX, and 30 control individuals. Assessments also included Schirmer’s test, TBUT, and ocular surface disease index (OSDI). Mean age in the patient group was 68±6.83 years, with 19 women and 13 men, and the control set was 65.9±3.19 years, with 20 women and 10 men. The analysis was conducted at a university research hospital in Turkey.

Although meibomian gland loss in eyes presenting clinical PEX was significantly greater than for control individuals in the upper lid (P =.001) and lower lid (P =.009), dropout was only slightly different between symptomatic and asymptomatic eyes in the patient group (upper lid P =.956, lower lid P =.553). Differences also appeared when comparing meiboscores of PEX-affected eyes with control eyes for upper lid (P =.028), and lower lid (P <.001). Bilaterally, case eyes more closely matched each other’s meiboscores in upper lid (P =.485) and lower lid (P =.694).

The investigators suggest some of the extracellular buildup with PEX may occur in both eyes; potentially seen microscopically. ”There are many studies in the literature stating that in cases where PEX syndrome is clinically seen unilaterally, both eyes are actually affected, but the accumulation of pseudoexfoliative material is asymmetrical,” the researchers added.

Schirmer’s test revealed tear quantity was comparable bilaterally in the case group; 10.438±4.47 mm for eyes with clinical PEX, compared with 11.563±4.35 mm for patient eyes that showed no symptoms. Both were less than control eyes at 15.967±9.75 mm. Patterns were similar regarding TBUT — eyes with symptoms were gauged at 6.188±2.66 seconds, those without DED measured 6.250±1.87 seconds, and control individuals at 8.233±2.66 seconds.

Subjective OSDI scores were not considerably different between the cohorts (P =.233). 

Relatively small cohort limits this study, as well as no assessment of plugged outlets for meibum, or irregular lid margins. Strengths involve grading by 2 masked, experienced physicians, and being the first investigation to apply meibography in unilateral PEX. “Evaluation of meibomian glands might be useful in the diagnosis and treatment of ocular surface disease in PEX patients,” according to the analysis.

Reference

Atik SS, Ekin MA. The role of meibomian glands on the development of dry eye disease in patients with unilateral pseudoexfoliation. J Fr Ophtalmol. Published online June 11, 2022. doi:10.1016/j.jfo.2022.03.004