Goldmann tonometry and pachymetry measures in patients with and without topical medical treatment at a glaucoma clinic.
OBJECTIVE
To investigate, by audit, the intraocular pressure (IOP) and central corneal thickness (CCT) of patients attending a routine glaucoma clinic, in order to assess the potential effect of CCT on IOP measures.


METHODS
Data on current IOP (Goldmann), CCT (ultrasound) and glaucoma medications use were collected from 140 patients who presented for a follow-up visit over a 3-month period. Baseline IOP was retrieved from patient records.


RESULTS
The IOP was lower at follow-up, an expected effect of the use of IOP-lowering medications. However, the CCT was lower in medicated patients indicating, but not proving, that it changed in response to the lowering of IOP. Overall, the measured IOP was higher in patients with greater CCT values (p < 0.001) but this IOP-CCT relationship was most noticeable in patients with normal tension glaucoma and not obvious in those diagnosed with ocular hypertension. Overall, the slope of the IOP-CCT relationship was slightly steeper for those patients prescribed glaucoma medications.


CONCLUSIONS
In the routine assessment of glaucoma patients, corneal thickness can be shown to have an impact on applanation tonometry data. However, this effect may not be uniformly evident in patients with different types of glaucoma and may be different for patients under topical medical treatment.
Doughty
Michael J
MJ
Department of Vision Sciences, Glasgow-Caledonian University, Cowcaddens Road, Glasgow G4 OBA, UK. m.doughty@gcal.ac.uk
Gillis
Naiomi
N
MacGill
Jennifer
J
Montgomery
Donald M
DM
D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D003315:Cornea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D005901:Glaucoma / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D010865:Pilot Projects; D014065:Tonometry, Ocular / Q000379:methods; D014463:Ultrasonography
D000959:Antihypertensive Agents