Corneal biomechanical properties in vernal keratoconjunctivitis and its subtypes: a preliminary study

Abstract

To explore the corneal biomechanical properties (CBPs) of patients with vernal keratoconjunctivitis (VKC) and the discrepancies among three subtypes of VKC including palpebral, limbal, and mixed forms. MethodsForty eyes of 20 VKC patients and twenty eyes of 10 non-VKC patients were included in this case-control study. Patients with VKC were further divided into three subtypes (6 patients in Palpebral form, 5 patients in limbal form, and 9 patients in mixed form). The CBPs of all patients were obtained from the Corneal Visualization Scheimp ug Technology (Corvis ST). ResultsFirst applanation (A1) length, Ambrosio relational thickness in horizontal (ARTh), and stiffness parameter at rst applanation (SP-A1) were signi cantly lower in the VKC group while A1 velocity was signi cantly higher in the VKC group (p < 0.05), compared to the non-VKC group. Furthermore, A1 velocity presented a positive correlation with disease course (p < 0.05). In addition, VKC patients of limbal form had lower central corneal thickness (CCT), SP-A1, and higher deformation amplitude ratio (DA ratio), compared to the other two subtypes (p < 0.05). Besides, patients in limbal form had higher A1 velocity, integrated radius, and corneal biomechanical index (CBI) compared with mixed form, and lower A1 length than palpebral form (p < 0.05). ConclusionsThe corneas of VKC patients were softer and more protruded compared with the control group, and the property of steepness was closely related to disease course. VKC patients in limbal form were more inclined to be keratoconus than the other two subtypes due to their CBPs` discrepancies. Key MessageVernal keratoconjunctivitis (VKC) is a chronic allergic ocular disease that mainly affects children and approximately a quarter of VKC patients have keratoconus, which leads to severe vision impairment.The corneas of VKC patients are different from those of non-VKC patients in some corneal biomechanical properties, including lower stiffness and steeper shape.VKC patients in limbal form have thinner, softer, more deformable corneas and are more likely to suffer from keratoconus, compared to palpebral and mixed forms.

Vernal Keratoconjunctivitis: A Systematic Review

“…Among these, perennial AC had the highest percentage of DED, followed by SAC and VKC High Thiagarajan et al [ 76 ] 2023 Malaysia 43 N/A To evaluate the corneal topographical changes in VKC subjects using OCULUS Pentacam Central corneal curvature and astigmatism were significantly higher in VKC subjects compared to the normal population ( p < 0.05). The minimal pachymetry was significantly lower with a longer duration of VKC ( p < 0.05) High Yilmaz et al [ 77 ] 2023 Turkey 80 13.1 To investigate changes in topometric corneal indices and proclivity toward corneal ectasia, keratometric indices, and anterior chamber dimensions in palpebral VKC Significantly higher mean topometric indices in VKC ( p = 0.001) indicate a proclivity for corneal ectasia, which could be attributed to general changes in the corneal ultrastructure caused by persistent itching-induced eye rubbing High Zhang et al [ 78 ] 2023 China 20 11.0 To explore the corneal biomechanical properties (CBPs) of patients with VKC The corneas of VKC patients were softer and more protruded compared with the control group. VKC patients in limbal form were more inclined to develop keratoconus High N/A non-available information …”

Vernal Keratoconjunctivitis: Immunopathological Insights and Therapeutic Applications of Immunomodulators

“…The incidence of ectasia development has been reported to be as high as 26.8%, with higher rates of incidence being associated with chronic disease and those of male gender [ 80 ]. Patients with the limbal form of the disease are reported to have an increased incidence of keratoconus compared to the other forms of the disease [ 81 ]. The bulbar conjunctival hyperemia and perilimbal chemosis observed during clinical evaluation of the ocular surface are clinical signs attributed to the action of mediators derived from mast cells and Th2 cells.…”