The Key Role of VEGF in the Cross Talk between Pterygium and Dry Eye and Its Clinical Significance

Abstract

Purpose: To examine whether dry eye severity is a risk factor for pterygium activity and whether vascular endothelial growth factor (VEGF) is crucial in the cross talk between pterygium and dry eye. Methods: A total of 103 patients with primary pterygium (Pteg) were included in the study group; they were divided into 2 groups according to the complication of dry eye (DE) (Pteg + DE group, Pteg -DE group). Further, 60 patients with just dry eye (DE group) and 60 normal individuals (normal) were included as 2 control groups. DE severity and pterygium activity were measured, and unstimulated tear samples and pterygium tissues were collected for cytokine detection. Results: (1) Tear detection: VEGF expression increased in the Pteg + DE group compared to the Pteg -DE, DE, and normal control groups; VEGF was especially increased in the active Pteg + DE group. VEGF concentration was positively correlated with pterygium activity. (2) Tissue detection: the mRNA expression of VEGF was upregulated in the active pterygium group. Conclusions: Inflammation played an important role in the development of dry eye and pterygium. VEGF was the core molecule in the cross talk, which might explain the high incidence of the coexistence of these 2 diseases.

Exploring the Molecular Mechanisms of Pterygium by Constructing lncRNA–miRNA–mRNA Regulatory Network

“…1,2 It comprises a wing-shaped progressively growing fibrovascular tissue usually located on the nasal side, and could lead to visual impairment, astigmatism, and dry eye. 3 Over the years, various medical measures, such as anti-inflammatory eye drops and chemotherapeutic agents have been used in the treatment of pterygium. Surgical removal can be performed if the patient desires symptomatic or cosmetic improvement, but recurrence remains the main complication.…”

Lack of HPV in pterygium with no evidence of autoinoculation and the role of cytokines in pterygium with dry eye

“…Moreover, VEGF concentrations did not significantly differ between the primary and recurrent groups. Many studies have reported that VEGF is involved in causing pterygia 13 , 17 , 30 . However, few studies have compared VEGF concentrations between primary and recurrent pterygium groups 30 .…”

“…These mechanisms could expand the inflammatory reactions in pterygium tissue and the ocular surface 33 . Liu et al described that VEGF and MMP-9, which are upregulated by VEGF through the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) signaling pathway, play important roles in the crosstalk between pterygia and DE 15 , 17 , 33 . In this study, we also found significantly higher VEGF levels in the pterygium group, which were 1.97, 3.41, and 5.20 times those of the HC group regardless of DE status, in pterygium patients with DE compared with HCs with DE and in pterygium patients with DE compared with pterygium patients without DE, respectively.…”

“…However, the exact mechanism of IL-18 in DE remains unclear. Moreover, many studies have reported the coexistence of pterygia and DE [17][18][19]32 . Theories of DE development in pterygium patients include that the same aggravating factor that causes pterygium development may also induce ocular surface inflammation, including ultraviolet radiation or the pterygium itself causing ocular surface irregularity and consequently a loss of tear film stability.…”

“…Inflammatory factors in DED include increased secretion of inflammatory cytokines, such as IL-1α, IL-1β, IL-6 and VEGF, leading to tear hyperosmolarity and conjunctival goblet cell loss, which, in turn, produces more proinflammatory cytokines, creating a vicious cycle 15,16 . Many studies have shown that pterygia and DED are strongly associated and have reported a possible overlap of relevant inflammatory cytokines [17][18][19] .…”