Abstract
Purpose :
To assessed the contrast sensitivity function (CSF) of post-keratoplasty patients following keratoplasty with the quick CSF method and evaluated the relationship between CSF and visual quality of the patients.
Methods :
27 patients (12 cases of keratoconus, 7 corneal stromal dystrophy, 5 limbal dermoid, 2 herpes simplex keratitis and 1 mooren’s ulcer; mean age: 24.6 ± 14.1 yrs; mean spherical and cylindrical correction: -2.66 ± 3.05 D and 2.56 ± 0.84 D) were included in this study. All patients underwent a routine ophthalmic examination and monocular visual acuity and quick CSF tests under full optical correction in the post-surgery eye. In addition, 13 patients performed a binocular quick CSF test and filled out the 9-SF visual quality questionnaire. The normal group consisted of 15 normal subjects (mean age: 25.83 ± 1.67 yrs; mean spherical and cylindrical correction: -5.35 ± 3.01 D and 0.17 ± 0.24D) whose visual acuities were reduced to the corresponding degree to match the patients by using the positive spherical lens of 1.0D to 6.0D. Subjects in the normal group participated in a monocular quick CSF test. Two summary metrics, the cutoff spatial frequency (cutoff SF) and the area under log CSF (AULCSF) in CSF were derived from the quick CSF tests.
Results :
The cutoff SF of the keratoplasty group (7.09 ± 2.65 cpd) was significantly lower than that of the normal group (mean ± SD, 8.64 ± 4.12cpd) (P < 0.001). The AULCSF of the keratoplasty group (0.56 ± 0.18) was significantly lower than that of the normal group (0.69 ± 0.34) (P < 0.001). For the keratoplasty patients, the monocular AULCSF and cutoff SF both correlated negatively with the degree of astigmatism of the surgical eye (r = -0.591, P = 0.020; r = -0.618, P = 0.014); the AULCSF but not the cutoff SF correlated negatively with the LogMAR BCVA (r = -0.407, P = 0.048; r = -0.150, P = 0.485). The results suggest that post-keratoplasty astigmatism significantly contributed to CSF deficits. For the 13 patients who performed the binocular quick CSF test, both AULCSF and cutoff SF correlated positively with the 9-SF scores (r = 0.831, P < 0.0001; r = 0.856, P < 0.0001).
Conclusions :
Patients following keratoplasty exhibited CSF deficits above and beyond their visual acuity deficits. As CSF is highly correlated with visual quality, it is an important clinical management tool for assessing visual quality of patients with keratoplasty.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.