Comparison between Immunoglobulin G4-Related Eye Disease and Other Entities with Non-Immunoglobulin G4 Ocular Involvement.

Objective: Distinguishing immunoglobulin G4 (IgG4)-related disease ocular involvement (IgG4-ROD) from other non-IgG4 pathologies in the orbit and eyeball is often complex. The objective was to compare clinical, analytical, imaging, and anatomopathological features of IgG4-ROD with other inflammatory and/or autoimmune ocular diseases (non-IgG4-ROD).

Methods: An observational, descriptive, and retrospective study included 18 patients diagnosed with IgG4-ROD according to Umehara's 2011 and/or 2020 comprehensive criteria, from 3 centers. Additionally, 12 patients with non-IgG4-ROD between 2014 and 2022 were selected, forming 2 groups. Data collection involved visualizing medical records. Demographic profile, clinical manifestations, analytical, histopathological, and radiological findings were analyzed using SPSS Statistics 19. Categorical variables were presented as frequencies and percentages, and continuous variables as means with standard deviation or median with interquartile range. Proportions were compared using the chi-square test, and means and medians were compared using T-tests and nonparametric tests. A confidence level of α=.05 was selected.

Results: Thirty patients were analyzed: 18 with IgG4-ROD and 12 with non-IgG4-ROD. Among the latter, diagnoses included Histiocytosis (n=4), Amyloidosis (n=3), malignant secondary malignancy (n=2), and other conditions (n=3). Female sex predominated in IgG4-ROD (78% vs. 50%, P=.12). Mean age was 44 years, with no group difference (P=.26). Bilateral involvement was more common in non-IgG4 (92% vs. 72%, P=.21). Predominant symptoms in IgG4-ROD were proptosis, ocular pain, xerophthalmia, palpebral edema, and diplopia, while palpebral edema and ocular motility disturbance were more usual in other pathologies. Proptosis, xerophthalmia, and diplopia were significantly more frequent in IgG4-ROD (P=.042, P=.021, P=.021, respectively). Parotid involvement showed significant association in IgG4-ROD at 33% (P=.031). Statistically significant differences were observed in elevated serum IgG4 levels (67%, P=.002), IgG (P=.037), and IgG2 levels ≥ 5.3 g/L (56%, P=.023) in IgG4-ROD. There was also a significant difference between the association of eosinophilia and the non-IgG4 group (67% vs. 22%, P=.034), as did mean serum IgG value and the IgG4-ROD group (P=.037). Lacrimal gland involvement associated with IgG4-ROD (P=.032). Histopathologically, IgG4- ROD showed significant associations with lymphoplasmacytic infiltrate (100%, P=.004), storiform fibrosis (36%, P=.05), and presence of Eosinophils (64%, P=.003).

Conclusion: Immunoglobulin G4-related ophthalmic disease showed significant associations with xerophthalmia, proptosis, diplopia, and parotid involvement. Elevated serum IgG4, IgG, and IgG2 levels were also linked to this condition. Imaging studies revealed lacrimal gland involvement. Furthermore, lymphoplasmacytic infiltrate, storiform fibrosis, and eosinophil presence were significant in histopathological findings. Conversely, serum eosinophilia, bilateral involvement, and palpebral edema in imaging studies were statistically related to the non-IgG4 group.