Relationship between central corneal thickness and changes of optic nerve head topography and blood flow after intraocular pressure reduction in open-angle glaucoma and ocular hypertension.
OBJECTIVE
To investigate changes in optic nerve head topography and blood flow after therapeutic intraocular pressure reduction and to correlate them with central corneal thickness.


METHODS
Sixteen patients with open-angle glaucoma and 16 patients with ocular hypertension underwent Heidelberg retina tomography and scanning laser Doppler flowmetry in 1 eye before and at least 2 months after a mean 35% sustained therapeutic reduction in intraocular pressure. Patients were assigned to a thin or thick group based on their median central corneal thickness.


RESULTS
Compared with 16 patients with thick corneas (mean +/- SD central corneal thickness, 587 +/- 31 microm), the 16 patients with thin corneas (518 +/- 32 microm) had greater reductions in mean (36 +/- 32 vs 4 +/- 36 microm, P = .003) and in maximum cup depth (73 +/- 107 vs 4 +/- 89 microm, P = .02). These changes were not statistically significantly different between the patients with open-angle glaucoma and those with ocular hypertension. Smaller mean +/- SD improvements in neuroretinal rim blood flow were seen in patients with thinner corneas compared with those with thicker corneas (35 +/- 80 vs 110 +/- 111 arbitrary units, P = .04).


CONCLUSIONS
Patients with open-angle glaucoma and ocular hypertension with thinner corneas show significantly greater shallowing of the cup, a surrogate marker for lamina cribrosa displacement (compliance), and smaller improvements of neuroretinal rim blood flow after intraocular pressure reduction.
Lesk
Mark R
MR
Department of Ophthalmology, University of Montreal, Montreal, Quebec. lesk@videotron.ca
Hafez
Ali S
AS
Descovich
Denise
D
D000959:Antihypertensive Agents / Q000627:therapeutic use; D001783:Blood Flow Velocity / Q000502:physiology; D001837:Body Weights and Measures; D003315:Cornea / Q000000981:diagnostic imaging / Q000473:pathology*; D005902:Glaucoma, Open-Angle / Q000503:physiopathology* / Q000628:therapy; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D017078:Laser-Doppler Flowmetry; D008875:Middle Aged; D009798:Ocular Hypertension / Q000503:physiopathology / Q000628:therapy; D009898:Optic Disk / Q000098:blood supply* / Q000473:pathology*; D012039:Regional Blood Flow / Q000502:physiology; D014054:Tomography; D014065:Tonometry, Ocular; D014130:Trabeculectomy; D014463:Ultrasonography
D000959:Antihypertensive Agents