Altered corneal biomechanical properties in patients with chronic ocular graft vs host disease

Session Details

Session Title: Cornea & Miscellaneous
Session Date/Time: Friday 15/02/2019 | 10:30-12:30
Paper Time: 11:24
Venue: Room MC3

First Author: M.Pellegrini ITALY
Co Author(s): G. Giannaccare  L. Taroni  F. Bernabei  E. Campos        

Abstract Details

Purpose:

Ocular graft versus-host disease (oGVHD) is the most frequent complication occurring after allogeneic hematopoietic stem cells transplantation (HSCT). Dry eye disease is the hallmark of oGVHD, and is caused by the progressive immune-mediate damage of each component of the ocular surface system. The purpose of this study was to investigate the corneal biomechanical properties, including corneal hysteresis (CH) and corneal resistance factor (CRF), in patients with oGVHD and healthy subjects. The correlations of corneal biomechanics with hematological and ocular surface characteristics were also evaluated.

Setting:

Ocular Surface Center of S.Orsola-Malpighi University Hospital, Bologna, Italy.

Methods:

Twenty-eight hematological patients with oGVHD and 28 healthy matched subjects were enrolled in this prospective case-control study. Ophthalmological examination included Schirmer test type 1, break-up time (BUT), slit lamp examination with corneal staining (Oxford score) and conjunctival staining (van Bijsterveld score), central corneal thickness (CCT) measurement (ultrasound pachymetry, Tomey SP-3000, Tomey Ltd, Japan). Commercially available InflammaDry® (Rapid Pathogen Screening, Inc, Sarasota, FL) kits were used to determine the presence of matrix metalloproteinase 9 (MMP-9) in the tear film. Corneal biomechanics were assessed by using ocular response analyzer (ORA, Reichert Instruments, Depew, New York, USA) and included CH and CRF values.

Results:

Patients with oGVHD showed significantly lower values of CH, CRF and CCT compared to controls (respectively, 10.0±1.3 mmHg vs 11.4±1.8, p=0.009; 9.7±1.2 mmHg vs 12.1±1.3, p<0.001; 515.3±26.7 µm vs 537.1±5.6, p<0.001). MMP-9 assays were positive in a significantly higher percentage of oGVHD patients than in controls (p<0.001). In patients with oGVHD, CH was significantly correlated with corneal staining (Rs=-0.415, p=0.028), conjunctival staining (Rs=-0.518, p=0.007), Schirmer test (Rs=0.403, p=0.041), BUT (Rs=0.455, p=0.015) and CCT (Rs=0.447, p=0.002); CRF was correlated with corneal staining (Rs=-0.554, p=0.002) and CCT (Rs=0.441, p=0.003).

Conclusions:

The two corneal biomechanical parameters CH and CRF as well as CCT value are reduced in patients with oGVHD compared to matched controls. The increasing severity of ocular surface impairment is associated with a greater alteration of corneal biomechanical properties. These changes may be caused by the increased tear levels of MMP-9 in patients with oGVHD, that may lead to collagen and elastin degradation in the corneal stroma. Corneal biomechanics may represent novel non-invasive biomarkers of disease severity in oGVHD.

Financial Disclosure:

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