Central corneal thickness and thickness of the lamina cribrosa in human eyes

PURPOSE. Since central corneal thickness may inversely influence the amount and rate of progression of glaucomatous optic nerve damage and because lamina cribrosa thickness may be of importance in susceptibility to glaucoma, it was the purpose of the present study to evaluate whether central corneal thickness is related to lamina cribrosa thickness. METHODS. The histomorphometric study included 111 enucleated nonglaucomatous eyes of 111 white subjects. On anterior - posterior histologic sections through the pupil and the central optic disc region, the thickness of the cornea, lamina cribrosa, and peripapillary sclera and the shortest distance between the intraocular space and the cerebrospinal fluid space were measured. Axial length ranged between 20 and 32 mm. RESULTS. Mean central corneal thickness ( mean +/- SD: 616.6 +/- 108.3 mu m) and mean central lamina cribrosa thickness ( 378.1 +/- 117.8 mu m) were statistically independent of each other ( P = 0.15; correlation coefficient, r = 0.14). In a similar manner, lamina cribrosa thickness at the optic disc border was statistically independent of central corneal thickness ( P = 0.51; r = 0.06) and peripheral corneal thickness ( P = 0.34; r = 0.09). In a parallel way, peripapillary scleral thickness ( P = 0.84) and the shortest distance between the prelaminar space and cerebrospinal fluid space ( P = 0.10) were statistically independent of central corneal thickness. CONCLUSIONS. In nonglaucomatous human globes, central corneal thickness may not correlate significantly with lamina cribrosa thickness, peripapillary scleral thickness, and shortest distance between intraocular space and cerebrospinal fluid space. Histologic 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 susceptibility to glaucoma cannot be explained by an anatomic correspondence between corneal thickness and histomorphometry of the optic nerve head.