Distribution of central corneal thickness and intraocular pressure in emmetropic eyes of healthy children of Palestine: a representative cross-sectional study

Distribution and associated factors of intraocular pressure in the older population: Tehran Geriatric Eye Study

AIM

To determine the distribution and associated factors of intraocular pressure (IOP) in an Iranian elderly population 60 years of age and above.

METHODS

The present report is part of the Tehran Geriatric Eye study (TGES), a population-based cross-sectional study that was conducted on the residents of Tehran 60 years of age and above. The sampling was performed using multistage stratified random cluster sampling methods from 22 districts of Tehran, Iran. Demographic and history information, blood samples, and blood pressure were collected from all participants. Ocular examinations included measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, and slit-lamp biomicroscopy. The IOP was measured using Goldmann applanation tonometry (GAT). Corneal imaging and ocular biometry were performed using Pentacam AXL.

RESULTS

The data of 3892 eyes of 2124 individuals were analyzed for this report. The mean age of the study participants was 66.49±5.31y (range: 60 to 95y). The mean IOP was 15.2 mm Hg (95%CI: 15.1 to 15.4), 15.3 mm Hg (95%CI: 15.1 to 15.5) and 15.1 mm Hg (95%CI: 15.0 to 15.3) in all participants, males, and females, respectively. Of the study participants, 1.3% had an IOP of ≥20 mm Hg. The mean IOP increased from 15.1 mm Hg in the age group 60-64y to 16.3 mm Hg in the age group ≥80y. According to the final multiple GEE model, the IOP was statistically significantly higher in men than in women. All the studied age groups, except for the 75-79-year-old age group, had significantly higher IOP compared to the 60-64-year-old age group. The IOP was significantly higher in underweight compared to other body mass index groups. Moreover, the IOP had a statistically significant direct relationship with the mean corneal power (mean CP), central corneal thickness (CCT), and systolic blood pressure.

CONCLUSION

The present study presents the distribution of IOP in an Iranian elderly population. A higher IOP (within the range 14 to 17 mm Hg) is significantly associated with older age, male sex, high systolic blood pressure, increased mean CP, and CCT. These factors should be considered in the clinical interpretation of IOP.

Normal intraocular pressure in Egyptian children and meta-analysis

OBJECTIVE

To determine the normal intraocular pressure in a sample of Egyptian children 0-12 years of age, and compare it to that recorded in previous studies.

METHODS

This is a prospective cross-sectional study, including 345 eyes. All children underwent complete history taking and ophthalmic examination. Any glaucomatous patients or glaucoma suspects were excluded. Intraocular pressure was measured using Haag Streit Perkins M2 handheld applanation tonometer under topical or general anaesthesia. Three readings were recorded for each eye and the average was calculated. Central corneal thickness was measured, using handheld pachymeter (Pachmate 2), whenever possible.

RESULTS

The study included 345 eyes of 187 children (101 males and 86 females), aged 2 months to 12 years (mean: 5.69 ± 3.42 years). The recorded IOP was 5-20 mm Hg (mean: 11.5 ± 2.34 mm Hg). Central corneal thickness was 469-742 μm (mean: 564.8 ± 42.72 μm). The mean recorded intraocular pressure showed positive correlation with increased age (p = 0.026) and increased central corneal thickness (p = 0.037), with a difference of 1 mm Hg for every 100-μm change in central corneal thickness. The mean IOP was significantly lower than that recorded by most previous studies. A detailed comparative analysis is presented comparing our findings with other studies including grouped analysis, by country, ethnicity and tonometers used.

CONCLUSIONS

The mean IOP in a group of normal Egyptian children was 11.5 ± 2.34 mm Hg, with positive correlation to age and central corneal thickness. This mean intraocular pressure was lower than that previously reported in any other population.

Distribution and analysis of intraocular pressure and its possible association with glaucoma in children

PURPOSE

To analyze intraocular pressure (IOP) and glaucoma-associated factors in children.

METHODS

A total of 4438 children aged 7-16 years (2321 boys and 2117 girls) were included in this study. Various ophthalmologic [IOP, central corneal thickness (CCT), etc.] and demographic (body mass index, etc.) parameters were evaluated.

RESULTS

IOP increased between the ages of 7 and 9 years, peaking at 9 years. IOP increased after reaching a trough at 11 years and subsequently stabilized after 14 years. Girls exhibited thinner CCT (534.28 ± 30.84 µm vs. 537.04 ± 31.33 µm, P = 0.003), thicker lens thickness (3.56 ± 0.21 mm vs. 3.54 ± 0.20 mm, P = 0.001), shorter axial length (22.91 ± 0.93 mm vs. 23.32 ± 0.89 mm, P < 0.001), shallower anterior chamber depth (2.92 ± 0.27 mm vs. 3.00 ± 0.26 mm, P < 0.001), higher refraction (- 0.57 ± 1.48 D vs. 0.16 ± 1.35 D, P < 0.001), and higher mean corneal curvature (43.77 ± 1.39 vs. 43.03 ± 1.35, P < 0.001). Multivariable analysis assessed the following IOP-associated factors: thicker CCT [standardized correlation coefficient (SRC) = 0.201, P < 0.001), deeper anterior chamber depth (SRC = 0.059, P = 0.009), shorter axial length (SRC =  - 0.086, P = 0.036), lower mean corneal curvature (SRC =  - 0.123, P < 0.001), higher refraction (SRC =  - 0.090, P < 0.001).

CONCLUSION

IOP fluctuated in children, and a trend toward a higher mean IOP between the ages of 9 and 11 years, which stabilized after 14 years, was observed. IOP was associated with CCT, anterior chamber depth, axial length, lens thickness, mean corneal curvature, spherical equivalent, and systolic blood pressure.