Ocular dimensions of the Chinese adolescents with keratoconus

Abstract

BackgroundAdolescent KC is a special segment of the general KC population because an adolescents’s eyes are still susceptible to blurred vision and optical defocus during the sensitive period of ocular and visual development. In the present study, we evaluated the ocular dimensions of 53 KC adolescents.MethodsOne hundred and six KC eyes of 53 (42 boys and 11 girls) KC adolescents (age 15.5 ± 1.7 years, range 11 to 18) were involved in this retrospective study. The eye with more severe KC (Severe Group) of each patient was compared with their less affected eye (Mild Group). Optical axial length (OAL) was measured by optical coherence biometry (IOL-master). Central corneal thickness, anterior chamber depth (ACD), flat keratometry value, steep keratometry value, and maximum keratometry value were assessed with an anterior segment analyzer (Pentacam HR). Anterior segment length (ASL) was manually measured from the 25 scheimpflug images captured by the Pentacam HR with the mean value recorded. The posterior segment length (PSL) was calculated with the formula “PSL = OAL-ASL”.ResultsThe mean ACD, OAL, ASL, and PSL values of the Severe Group were 3.51 ± 0.32 mm, 24.76 ± 1.24 mm, 4.01 ± 0.30 mm and 20.76 ± 1.15 mm.While those of the Mild Group were 3.36 ± 0.29 mm, 24.97 ± 1.40 mm, 3.94 ± 0.35 mm and 21.03 ± 1.31 mm. The Severe Group has significantly higher ACD (t = 4.539, P < 0.001) value but lower OAL (t = − 3.120, P = 0.003) and PSL (t = − 4.537, P < 0.001) values when compared with those of the Mild Group. For the Severe Group, the Kmax values were significantly correlated with the SE values (R = − 0.385, P = 0.004), the ACD values (R = 0.375, P = 0.006), the ASL values (R = 0.308, P = 0.025) and the PSL values (R = − 0.317, P = 0.021), but not with the OAL values (R = − 0.220, P = 0.114). In the Mild Group, the Kmax values were negatively correlated with the SE (R = − 0.577, P < 0.001), OAL(R = − 0.533, P < 0.001), and PSL (R = − 0.523, P < 0.001) values, but not with ACD (R = − 0.110, P = 0.434) or ASL (R = − 0.182, P = 0.192) values.ConclusionsFor adolescent KC, the more keratoconic eyes may be characterized by deeper ACD but shorter OAL and PSL, when compared with the less affected ones.

Keratoconus in pediatric age: Clinical-refractive characteristics and evolution. Donum foundation medical specialties center. Cuenca. Ecuador. 2015-2018

“…It usually appears in the second decade of life, although cases at a younger age [15][16][17][18] have been reported. Therefore, the interest of the current study in highlighting the presence of the disease since childhood and our results agree with those that study KC cases with a presentation in the pediatric age [19][20][21][22][23] . In the case of our study, they are patients who usually came to the office for different reasons: ophthalmological examination as a requisite to enroll in school, renewal of optical correction, family history of the disease, and parents request for corneal topography, among others.…”

“…Regarding sex, there is no consensus in the literature regarding whether the disease is more frequent in one or the other; different series report the disease in both sexes, without statistically significant differences between them 12,19,20 . The disease is hereditary and there are families where both male and female children inherit the disease [22][23][24] .…”

A hospital-based study on clinical data, demographic data and visual function of keratoconus patients in Central China

“…Patients usually visit the hospital when they are unable to obtain adequate care at optometry clinics. The rural population in Henan Province is relatively larger, and the per capita disposable income in Henan Province is lower than those in Beijing (northern China) and Shanghai (eastern China) 16 , 17 . The percentage of patients with KC in the capital district is much higher because the diagnosis is not covered by health insurance.…”

“…However, the disease was defined based on only corneal refractive power, and the corneal topography that could detect minor forms of KC was not included in the study design. Jian et al 17 evaluated the ocular dimensions of KC eyes from Shanghai, eastern China, and found that KC eyes were characterized by deeper anterior chamber depths but shorter optical axial lengths and posterior segment lengths in adolescents (11–18 years). The demographic data, VF questionnaire data and corneal biomechanics of KC patients were not evaluated.…”

Distribution of Ocular Anterior and Posterior Segment Lengths Among a Cataract Surgical Population in Shanghai

“…Ocular biometric characteristics, such as AL, anterior chamber depth (ACD), white-to-white (WTW) distance, central corneal thickness (CCT), keratometric power (K), and corneal astigmatism (CA) have been described previously ( 1 – 7 ). However, few studies have been focused on the overall anterior and posterior segment dimensions of the eyes ( 8 , 9 ). Nowadays, modern optical biometry devices can measure different axial biometric parameters of the eyes, including ACD and AL ( 10 ).…”