The palpebral lobe of the main lacrimal gland may exhibit significant differences in patients with aqueous-deficient dry eye disease (DED) compared with those with evaporative DED, a study in the British Journal of Ophthalmology suggests.

Researchers from India found the structure of the palpebral lobe of the main lacrimal gland was significantly distorted in aqueous-deficient DED due to cicatrising conjunctivitis and Sjögren’s syndrome, while the lobes in patients with evaporative dry eye were similar to normal eyes.

The cross-sectional study enrolled 25 healthy subjects and 83 patients with DED. The dry eye group included cicatrizing conjunctivitis (n=35), evaporative DED (n=25) and Sjögren’s syndrome (n=23). The investigators evaluated the palpebral lobes in both eyes using slit-lamp biomicroscopy and photography for size (exposed area in mm2), shape (convex or flat), presence of cicatrization (scarring and/or symblepharon) and appearance of the overlying conjunctival vessels.

The researchers found the palpebral lobes in the normal and evaporative DED groups were similar in terms of size (41.5±15.6mm2 vs. 39±12.2mm2), convex shape (100%) and absence of cicatrization or vascular engorgement. However, compared with normal controls, the size of the palpebral lobe was markedly reduced in the Sjögren’s syndrome (27.9±12.3mm2) and cicatrizing conjunctivitis (18.1±13.7mm2) groups.

Additionally, the investigators noted the size of the lobes was asymmetric in the cicatrizing conjunctivitis group and differed significantly from the Sjögren’s group. The study also found significant differences in flat contour (79% vs. 50%), subepithelial scarring with or without symblepharon (52% vs. 13%) and engorged conjunctival vessels (96% vs. 63%) between cicatrizing conjunctivitis patients and Sjögren’s group.

Singh S, Shanbhag SS, Basu S. Palpebral lobe of the human lacrimal gland: morphometric analysis in normal versus dry eyes. British Journal of Ophthalmology. September 12, 2020. [Epub ahead of print].