Evaluation of the Ocular Surface and Tear Film Quality in Post-keratoplasty Patients

Abstract Purpose To evaluate the ocular surface and tear film quality in post-penetrating keratoplasty patients in comparison with healthy individuals. Methods Slit lamp examination of lid parallel conjunctival folds (LIPCOF), tear osmolarity measurement, Schirmer I, fluorescein break-up time (FBUT) and corneal fluorescein staining tests were performed on 38 eyes of 34 patients underwent penetrating keratoplasty for different indications. In addition, 34 eyes of 18 healthy age-matched individuals served as normal controls. Results Average age was 55.86 ± 16.75 years in the post-keratoplasty group and 51.05 ± 18.85 years in the control group (p = 0.289). There were significant differences in LIPCOF (1.45 ± 0.76 vs. 1.03 ± 0.83; p = 0.035) and FBUT values (5.82 ± 4.48 s vs. 11.03 ± 6.72 s; p < 0.001) between the operated and control eyes. Schirmer I and tear osmolarity tests demonstrated no significant differences. The frequencies of corneal staining (p < 0.001), abnormal LIPCOF (p = 0.030) and artifical tear use (p < 0.001) were significantly higher in the post-keratoplasty group. However, proportions of abnormal FBUT and Schirmer I test were similar in the two groups. Tear osmolarity was slightly higher in the post-keratoplasty group (311.53 ± 23.75 mOsm/l vs. 308.12 ± 15.83 mOsm/l), but the difference was not significant (p = 0.524). There were no significant differences in the proportion of hyperosmolar ocular surfaces between the two groups using cut-off values either ≥ 308 mOsm/l (p = 0.635) or ≥ 316 mOsm/l (p = 0.805). Conclusions Abnormal dry eye tests are more prevalent in patients after penetrating keratoplasty. Reduced tear film stability, conspicuous corneal staining and lid parallel conjunctival folds represented further deterioration of the ocular surface homeostasis despite normal tear production and osmolarity. These findings highlight the importance of comprehensive ocular surface assessment and management in the postoperative care of keratoplasty patients.