Central Cornea Thickness Measures in Children With and Without Glaucoma

Abstract

Abstract: : Purpose:To assess central conreal thickness (CCT) in children with and without glaucoma. To study the relationship between CCT and intraocualr pressure (IOP) as well as patient demographics. Methods:Patients were recruited from the Departments of Glaucoma, Oncology and Pediatrics at Wills Eye Hosptial. Study eyes were derived from two groups: glaucomatous and non–glaucomatous. The glaucoma group consisted of congenital, infantile and juvenile glaucoma cases. The non–glaucoma group was composed of children without glaucoma who were either scheduled for strabismus surgery or for an exam to evaluate a posterior segment tumor. IOP in the non–glaucoma group was measured with the TONO–PEN^® until a 5% of standard deviation reading was achieved. The Perkins MK2 tonometer was used to measure the IOP of children with glaucoma or, when not under anesthesia, Goldmann applanation tonometry was used. All patients had three consecutive CCT readings with the Kerasonix KSX 1000 ultrasonic pachymeter and the average was used for analysis. The relationships between IOP, gender, race, age, diagnosis, previous surgery, and current ocular and systemic medications and CCT measurements were analyzed to determine what factors influence CCT readings. Linear regression was performed using SPSS 10.0. Results: 52 eyes of 29 patients were included in this study. 32 (61.5%) eyes were glaucomatous and 20 (38.5%) eyes were non–glaucomatous. The mean pachymetry readings were different between the glaucoma and non–glaucoma groups (627.22 SD 111.16 and 551.72 SD 49.31 (p=.002)), respectively. Although the glaucoma patients had higher CCT readings than the non– glaucoma group, the mean IOP readings were not significantly different (15.35 SD 5.40 and 17.94 SD 7.53 (p=.19)), respectively. The correlation between IOP and CCT was not significant (r=.07, p=.63). There was a significant correlation between CCT and corneal diameter (r=–.56, p=.008). The baseline characteristics race (p=.27) and sex (p=.73) were similar in both groups. However, the glaucoma group was older on average than the non–glaucoma control group (6.24 years vs. 2.88 years, p=.01). There was no difference in CCT among the various racial groups, sex groups and age was not correlated with CCT readings. Conclusions:Though the small sample size, counterintuitively children with glaucoma and no visible corneal edema had higher CCT on average than normal; and buphthalmos was not associated with thinner corneas. Possible reason for this are discussed.

Keywords: cornea: clinical science • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology • intraocular pressure