Therapeutic efficacy of fibroblast growth factor 10 in a rabbit model of dry eye.

The aim of the present study was to investigate the therapeutic efficacy of fibroblast growth factor 10 (FGF10) in the promotion of healing, survival and expression of mucin in corneal epithelial cells in a rabbit dry eye model. A total of 12 healthy female New Zealand white rabbits were divided randomly into three groups. The lacrimal glands were injected with saline either alone (normal control group) or with concanavalin A (Con A), with either topical phosphate­buffered saline (PBS; PBS control group) or 25 µg/ml FGF10 (FGF10 treatment group). Lacrimal gland inflammation, tear function, corneal epithelial cell integrity, cell apoptosis and mucin expression were subsequently assessed. Lacrimal gland tissue biopsies were performed in conjunction with histology and electron microscopy observations. Tear meniscus height (TMH) and tear meniscus area (TMA) were measured using Fourier domain­optical coherence tomography. Tear membrane break­up time (TBUT) was also assessed and corneal fluorescein staining was performed. The percentages of apoptotic corneal and conjunctival (Cj) epithelial cells (ECs) were counted using a terminal deoxynucleotidyl transferase­mediated dUTP nick end labeling method. The mRNA expression levels of Muc1 were determined using reverse transcription­quantitative polymerase chain reaction analyses. The TMH and TMA values of the PBS and treatment groups were found to be significantly reduced, compared with those of the normal control group 3 days after Con A injection. However, the TMH and TMA of the FGF10 treatment group were higher, compared with those of the PBS group 3 and 7 days after treatment, respectively. Furthermore, the FGF10 treatment group exhibited prolonged TBUT, reduced corneal fluorescein staining and repaired epithelial cell ultrastructure7 days after treatment. The percentages of apoptotic corneal­ and Cj­ECs in the FGF10 treatment group were significantly reduced, compared with those in the PBS group. FGF10 significantly induced the mRNA expression of Muc1 in the corneal epithelial cells, compared with the normal control group, and induced higher mRNA expression levels of Muc1 in the Cj­ECs, compared with the PBS control group. In the present study, the rabbit dry eye model was successfully established 3 days after lacrimal gland Con A injection. FGF10 eye drops increased TMH and TMA, promoted corneal epithelial healing, reduced apoptosis of the corneal- and Cj-ECs and led to increased expression of Muc1.

Responses of the Ocular Anterior Segment and Refraction to 0.5% Tropicamide in Chinese School-Aged Children of Myopia, Emmetropia, and Hyperopia.

Purpose. To investigate the changes of anterior segment after cycloplegia and estimate the association of such changes with the changes of refraction in Chinese school-aged children of myopia, emmetropia, and hyperopia. Methods. 309 children were recruited and eligible subjects were assigned to three groups: hyperopia, emmetropia, or myopia. Cycloplegia was achieved with five cycles of 0.5% tropicamide. The Pentacam system was used to measure the parameters of interest before and after cycloplegia. Results. In the myopic group, the lenses were thinner and the lens position was significantly more posterior than that of the emmetropic and hyperopic groups in the cycloplegic status. The correlations between refraction and lens thickness (age adjusted; r = 0.26, P < 0.01), and lens position (age adjusted; r = -0.31, P < 0.01) were found. After cycloplegia, ACD and ACV significantly increased, while ACA significantly decreased. Changes in refraction, ACD, ACV, and ACA were significantly different among the three groups (P < 0.05, all). Changes of refraction were correlated with changes of ACD (r = 0.41, P < 0.01). Conclusions. Myopia presented thinner lenses and smaller changes of anterior segment and refraction after cycloplegia when compared to emmetropia and hyperopia. Changes of anterior chamber depth were correlated with refraction changes. This may contribute to a better understanding of the relationship between anterior segment and myopia.

Macular pigment optical density and its relationship with refractive status and foveal thickness in Chinese school-aged children.

PURPOSE: To investigate macular pigment optical density (MPOD) and its relationship with refractive status and foveal thickness in Chinese school-aged children. METHODS: Ninety-four healthy Chinese children, 6 to 12 years old, were recruited to the study. MPOD was measured with a heterochromatic flicker photometer (HFP), and foveal thickness, including both minimum and central foveal thicknesses (MFT and CFT, respectively), were measured by optical coherence tomography (OCT) with fast macular map scan. A noncontact tonometer was used to measure intraocular pressure (IOP) followed by determination of the refraction using an autorefractor after cycloplegia. Information on body mass index (BMI) was obtained. The correlation between MPOD values and foveal thickness, spherical equivalent (SE) refraction, IOP, BMI, sex, and age was statistically analyzed using SAS 8.2 statistical software. RESULTS: The MPOD in examined school-aged children was 0.56 ± 0.25, without any significant difference between boys and girls (p = 0.12). MPOD showed no significant association with age, BMI, IOP, SE, MFT, or CFT. In the myopia group, however, there was an inverse relationship between MPOD and MFT (R =-0.66, p = 0.028) and a positive relationship between MPOD and CFT (R = 0.67, p = 0.025). CONCLUSIONS: MPOD was inversely related to MFT and positively related to CFT in Chinese school-age children with low-to-moderate myopia. MPOD showed no significant association with age, BMI, IOP, SE or foveal thickness.

Corneal asphericity and its related factors in 1052 Chinese subjects.

PURPOSE: To observe and analyze corneal asphericity and its related factors in Chinese subjects. METHODS: The corneal asphericity of 1052 right eyes from a Chinese population was determined using the Wavelight-ALLEGRO Topographer. The corneal asphericity coefficient Q describes the rate of curvature variation of the cornea from its center to the periphery and specifies the type of conicoid that best represents its shape. All cases were grouped by age in years (A: ≤ 9; B: 10 to 19; C: 20 to 29; D: 30 to 39; E: 40 to 49; F: ≥50), and 223 myopic cases were grouped by magnitude in spherical equivalent (SE) refractive error (low myopia, > -3.0 diopters (D); moderate myopia, -6.0 D < SE ≤ -3.0 D; high myopia, -8.0 D < SE ≤ -6.0 D; and super high myopia, SE ≤ -8.0 D). In addition, corneal asphericity was analyzed by corneal quadrant (nasal, temporal, superior, and inferior) and two meridians (vertical and horizontal). RESULTS: The mean Q value of 1052 right eyes was -0.30 ± 0.12. Although statistical differences were found between some age groups, no statistical correlation between Q values and age was found in this study (r = -0.58, p = 0.06). Q values of the nasal and superior corneal quadrant were significantly more oblate than that of the temporal and inferior quadrants, respectively (both p < 0.0001). A trend toward more oblate Q values was found as the level of myopia increased (r = 0.166, p = 0.013). There was a negative relationship between Q value and central corneal radius in this entire study population (r = -0.09, p = 0.004). CONCLUSIONS: Corneal asphericity in this population is related more to corneal quadrant location than to age. The results from this study suggest that degree of myopia and central corneal radius both have a significant though weak association with corneal asphericity in Chinese eyes.

Macular measurements using optical coherence tomography in healthy Chinese school age children.

PURPOSE: To evaluate macular thickness/volume in a Chinese population of primary school children using optical coherence tomography (OCT), and assess its association with age, sex, spherical equivalent refraction (SE), body mass index (BMI), and intraocular pressure (IOP). METHODS: Healthy Chinese children (n = 806) from six randomly selected primary schools in Chongming County, Shanghai, China, were enrolled. Comprehensive standardized ophthalmic examinations included visual acuity, cycloplegic refraction, IOP, and fast macular scans using Stratus OCT. Mean values for the nine Early Treatment Diabetic Retinopathy Study (ETDRS) areas, foveal minimum thickness, and macular volume were calculated. RESULTS: OCT data from right eyes with high-quality scans were evaluated in 720 children (89.3% of total participants; 46.5% boys). Macular thickness and volume were normally distributed. The mean foveal minimum thickness was 140.0 ± 12.3 µm. There were significant differences between the boys and the girls in mean foveal volume (P = 0.023) and sectoral macular thickness in all the quadrants of the inner ring (P < 0.001 and P = 0.001) and temporal outer quadrant (P = 0.009). SE refraction correlated positively with inner and outer macular thickness and total macular volume (P < 0.001) and negatively with central macular volume (P = 0.012). BMI correlated significantly only with outer macular thickness (r = 0.074, P = 0.048). No age- and IOP-related differences were found in the macular parameters. CONCLUSIONS: OCT demonstrated that macular thickness/volume was normally distributed in this sample of Chinese children, with variations in sex and SE. The variables in macular thickness/volume should be considered when diagnosing and monitoring school-aged children with diseases that affect the macula.

Time course of Q value after myopic laser-assisted in situ keratomileusis.

OBJECTIVE: To assess the time course of Q value after myopic laser-assisted in situ keratomileusis (LASIK) and preliminarily evaluate the determinants of the difference of Q value between before and after LASIK. METHODS: We performed a retrospective, longitudinal investigation on patients undergoing wavefront optimized LASIK therapy for emmetropization. A total of 418 eyes from 222 cases were examined preoperatively, and partly followed up at one week (172 eyes), one month (134 eyes) and three months (51 eyes) after surgery. The horizontal, vertical and total Q values of cornea were calculated from eccentricity measured at the central 6-mm corneal zones respectively. Potential determinants of the change of Q value were analyzed using multiple linear regressions. RESULTS: The mean Q value was -0.17 +/- 0.13 preoperatively, and 0.99 +/- 0.70, 0.97 +/- 0.66, and 0.86 +/- 0.41 one week, one and three months postoperatively, respectively. One way analysis of variance (ANOVA) demonstrated significant differences between measurements made before surgery and at all postoperative times (at one week, one and three months; all P<0.0001, Bonferroni post hoc), but no significant differences were found among postoperative groups. Significant differences of Q values between horizontal and vertical meridians were found before surgery and at all postoperative times (all P<0.0001). Multiple regression analysis revealed that change of Q value significantly correlated with manifest refraction spherical equivalent (r=0.116, P<0.0001) and axial length (r=0.264, P<0.0001). CONCLUSIONS: Over the study period, the primary changes in Q value occur within 1 week after surgery, and then become slightly decreased and nearly stable. Manifest refraction spherical equivalent and axial length play a significant role in the change of postoperative Q value.