Relationship between Dry Eye Parameters and Anterior Corneal Higher-Order Aberrations Measured by Two Different Instruments

PURPOSE: To compare the corneal first surface higher-order aberrations (HOAs) of normal subjects and patients with dry eye using KR-1W(R) (Topcon Corp., Tokyo, Japan) and Pentacam(R) HR (Oculus Inc., Dutenhofen, Germany). We analyzed the relationship between the aberrations and the diagnostic parameters of dry eye. METHODS: We evaluated anterior corneal HOAs in 71 normal eyes and 71 dry eyes using KR-1W(R) and Pentacam(R). Dry eye patients were examined for fluorescein staining, tear break-up time (TBUT), and Schirmer I test. Ocular Surface Disease Index (OSDI) was used for assessment of subjective symptoms in dry eye patients. RESULTS: HOAs measured by both instruments were greater in the dry eye group than in the control group, although HOAs using KR-1W(R) only achieved statistical significance. The anterior corneal HOAs measured by the 2 instruments were significantly correlated with superficial punctate keratitis. Moreover, TBUT and the Shirmer I test negatively correlated, and OSDI positively correlated, with anterior corneal HOAs. CONCLUSIONS: The HOAs in patients with dry eye were significantly different from controls and tended to increase with disease severity. KR-1W(R) might be more useful than Pentacam(R) to detect tear film instabilities.

Measurement of Precorneal Tear Film Using Scheimpflug Camera and Relationship with Parameters for Dry Eye

PURPOSE: To compare the anterior segment parameters including precorneal tear film thickness (PTFT) using Pentacam(R) (Oculus, Wetzlar, Germany) between normal control and dry eye groups and to examine the relationships between the PTFT and other parameters for dry eye. METHODS: The present study included 23 normal controls (31 eyes) and 25 patients with dry eyes (31 eyes). We compared measurements including PTFT, corneal thickness and astigmatism using Pentacam(R) and analyzed the correlations among the PTFT and fluorescein tear break-up time (FBUT), Schirmer I test (without anesthesia), and ocular surface disease index (OSDI). RESULTS: The mean PTFT in dry eyes (21.1 +/- 2.0 microm) was significantly thinner than in normal eyes (37.6 +/- 2.0 microm; p < 0.01). In the dry eye group, the corneal thickness was thicker than in the normal eye group but there were no clinically significant differences. The dry eye group experienced more frequent and severe corneal astigmatism compared with the normal group. OSDI scores showed a weak negative correlation with objective clinical measures of dry eye (FBUT, Schirmer I test) but was not statistically significant. However, OSDI was statistically significantly negatively correlated with PTFT (r = -0.46, p < 0.01). The PTFT showed a weak positive correlation with FBUT and Schirmer I test without statistical significance. CONCLUSIONS: The mean PTFT using Pentacam(R) in the dry eye group was thinner than in the normal group. Additionally, the PTFT was correlated with subjective symptoms. Therefore, the PTFT measurement using Pentacam(R) could be considered a useful method for diagnosis and treatment of dry eye.

Comparison of Corneal Higher-Order Aberrations Measured with Two Instruments Using Scheimpflug Camera System

PURPOSE: To compare the corneal higher-order aberrations (HOAs) of normal young subjects using Galilei(TM) G4 (Zeimer, Port, Switzerland) and Pentacam(R) (Oculus Inc., Wetzlar, Germany). METHODS: Corneal HOAs were measured using Galilei(TM) G4 and Pentacam(R) in 41 healthy individuals (41 eyes). Intraclass correlation coefficients (ICCs) were obtained to evaluate the repeatability of the 2 devices. Differences in HOAs between the 2 instruments were analyzed with a paired t-test and correlations evaluated. RESULTS: All ICCs measured using Galilei(TM) G4 and Pentacam(R) showed more than moderate repeatability (>0.81) except trefoil, tetrafoil, 4th and 5th HOAs. When comparing the measurements obtained with Galilei(TM) G4 and Pentacam(R), total HOAs, spherical aberration (SA), secondary astigmatism and 5th total HOAs were statistically significantly different between the 2 device (all p < or = 0.001). In addition, Galilei(TM) G4 and Pentacam(R) showed discrepancy among all corneal HOAs items. Although the total corneal HOAs and the SA were significantly correlated, other HOA measurements generally exhibited a low correlation. CONCLUSIONS: Corneal HOAs obtained by the 2 instruments cannot be used interchangeably due to their differences and discrepancy although corneal HOAs measured using Galilei(TM) G4 and Pentacam(R) showed relatively high repeatability.

The Measurements of Macular Thickness and Volume with SD-OCT in Normal Eyes

PURPOSE: We investigated reproducibility and repeatability of average macular thickness and volume measurements in normal eyes with Cirrus HD OCT (optical coherence tomography). METHODS: Fifty normal eyes from twenty-five subjects without medical and ocular histories were included. Macular cube 512 x 128 combination scanning using the Cirrus HD OCT was performed for a total of three times on the same visit by an experienced technician. Then other two technicians performed one more macular scanning respectively. Within-results, the intraclass correlation coefficient (ICC) was calculated for each parameter studied to evaluate repeatability and reproducibility. The correlation between macular measurements and demographic variables (age, gender, and spherical equivalent) were also investigated. RESULTS: The ICCs for intraoperator reproducibility were 0.99 on the average macular thickness and 0.96 on the macular volume. And the ICCs for interoperator repeatability were found to be 0.98 and 0.96, respectively. The ICCs for measurements of nine regional retinal thickness also were higher than 0.90. The retinal thickness was correlated with age, gender and refractive error. However, neither age nor refractive error affected to reproducibility and repeatability. CONCLUSIONS: The retinal thickness and macular volume measurements using Cirrus HD OCT in healthy volunteers showed excellent reproducibility and repeatability. Therefore, Cirrus HD OCT has been recognized as an useful tool for diagnosis and mornitoring of variable maculopathies.

Horner's Syndrome with Abducens Nerve Palsy

A 68-year-old male patient presented with a week of sudden diplopia. He had been diagnosed with nasopharyngeal cancer 8 months prior and had undergone chemotherapy with radiotherapy. Eight-prism diopter right esotropia in the primary position and a remarkable limitation in abduction in his right eye were observed. Other pupillary disorders and lid drooping were not found. After three weeks, the marginal reflex distance 1 was 3 mm in the right eye and 5 mm in the left eye. The pupil diameter was 2.5 mm in the right eye, and 3 mm in the left eye under room illumination. Under darkened conditions, the pupil diameter was 3.5 mm in the right eye, and 5 mm in the left eye. After topical application of 0.5% apraclonidine, improvement in the right ptosis and reversal pupillary dilatation were observed. On brain magnetic resonance imaging, enhanced lesions on the right cavernous sinus, both sphenoidal sinuses, and skull base suggested the invasion of nasopharyngeal cancer. Lesions on the cavernous sinus need to be considered in cases of abducens nerve palsy and ipsilateral Horner's syndrome.