Abstract
Purpose: :
To study the anatomical relationships between central corneal thickness and lamina cribrosa, peripapillary sclera, the intraocular pressure space, and the retrobulbar cerebrospinal fluid space in normal eyes of Chinese.
Methods: :
The histomorphometric study included 55non-glaucomatous globes (55 patients; mean age: 41.6 ±13.6 years;range:15-72 years) enucleated due to a malignant choroidal melanoma. Anterior-posterior histological sections through the pupil and the optic disc were morphometrically evaluated. Thickness of the cornea, lamina cribrosa and parapapillary sclera and the shortest distance between the intraocular space and the cerebrospinal fluid space were measured. Axial length ranged between 22 and 27mm.
Results: :
Mean central corneal thickness (mean ± S.D.: 499.8 ± 67.6 µm) and mean central lamina cribrosa thickness (206.6 ± 60.2 µm) were statistically independent of each other (p=0.09; correlation coefficient r=0.27). In a similar manner, lamina cribrosa thickness at the optic disc border was statistically independent of central corneal thickness (p=0.06; r=0.30). In a parallel way, peripapillary scleral thickness just outside of the optic nerve meninges (p=0.40) and the thinnest part of peripapillary sclera close to the optic nerve scleral canal (p=0.18) and the shortest distance between the prelaminar space and cerebrospinal fluid space (p=0.41) were statistically independent of central corneal thickness.
Conclusions: :
In non-glaucomatous human globes, central corneal thickness may not significantly be correlated with lamina cribrosa thickness, parapapillary scleral thickness and shortest distance between intraocular space and cerebrospinal fluid space. One must consider that histological artifact and sectioning methods could partially account for the lack of an association. The study results may suggest clinically that an assumed relationship between central corneal thickness and glaucoma susceptibility may not be explained by a corresponding anatomy between corneal thickness and histomorphometry of the optic nerve head.
Keywords: cornea: basic science • sclera • lamina cribrosa