Palpebral lobe of the human lacrimal gland: morphometric analysis in normal versus dry eyes

Abstract

Aim: To study the morphological features of the palpebral lobe of the main lacrimal gland in normal and dry eyes.

Methods: This cross-sectional study included 25 healthy subjects and 83 patients with dry eye disease (DED). The aetiological groups of DED were cicatrising conjunctivitis (CC, n=35), evaporative dry eyes (EDE, n=25) and Sjogren's syndrome (SS, n=23). The palpebral lobes in both eyes were evaluated using slit-lamp biomicroscopy and photography for size (exposed area in mm²), shape (convex or flat), presence of cicatrisation (scarring and/or symblepharon) and appearance of the overlying conjunctival vessels.

Results: The palpebral lobes in the normal and EDE group were similar in terms of size (41.5±15.6 mm² vs 39±12.2 mm², p=0.203), convex shape (100%) and absence of cicatrisation or vascular engorgement (0%). However, as compared to normal controls, the size of the palpebral lobe was markedly reduced in the SS (27.9±12.3, p<0.0001) and CC (18.1±13.7, p<0.0001) groups. The size of the lobes was asymmetric in the CC group (p<0.0001) and differed significantly from the SS group (p=0.0003). Flat contour (79% vs 50%, p=0.0028), subepithelial scarring with or without symblepharon (52% vs 13%, p<0.0001) and engorged conjunctival vessels (96% vs 63%, p=0.00011) were seen in a significantly higher proportion of lobes in the CC as compared to the SS group.

Conclusion: The morphological features of the palpebral lobe of the main lacrimal gland are significantly distorted in aqueous deficient dry eyes due to CC and SS; however, the lobes in patients with EDE are similar to normal eyes.

Keywords: Anatomy; Conjunctiva; Lacrimal gland; Ocular surface; Tears.