İnvestigations of the effects of central corneal thickness and axial length on intraocular pressure in different glaucoma subgroups

ABSTRACTINVEST GAT ON OF THE EFFECTS OF CENTRAL CORNEAL TH CKNESS ANDAX AL LENGTH ON NTRAOCULAR PRESSURE N D FFERENT GLAUCOMASUBGROUPSDr. Aysun Taşdemir ARIResidency thesis, Department of OphthalmologySupervisor: Necdet A. BEK R, M.D. ProfessorDecember 2006,52 pagesGlaucoma is a pressure sensitive optic neuropathy. Intraocular pressure (IOP) measurewas used for the diagnosis, prognosis, and the response to treatment of glaucoma.We included 162 glaucoma patients and 162 healthy control subjects in this studyadmitted to department of ophthalmology, medical faculty, Gaziantep University through theperiod between 2005 January and 2006 October. The patients were compared according tomean central corneal thickness (CCT), axial length (ALX), IOP, and refraction error values.We performed best-corrected visual acuity, slit-lamp examination in all patients. Intraocularpressure measurement with Goldmann applanation tonometry, CCT values with ultrasonicpachimetry, and ALX measurement with a-scan ultrasonography were done.Mean CCT values were determined in primary open angle glaucoma group (POAG)553.70 ± 40.84 µm, primary narrow angle glaucoma group (PNAG) 548.79 ± 34.10 µm,pseudoexfoliation glaucoma group (PEG) 534.50± 10.67 µm, normotensive glaucoma group(NTG) 510.00 ± 16.46 µm, ocular hypertension group (OHT) 556.67 ± 21.55 µm, juvenilglaucoma group (JG) 545.14 ± 34.03 µm, and control group 539.46 ± 21.59 µm. When thegroups among themselves and with control group were compared, mean CCT values inPOAG group was statistically significant according to control group (p < 0.05). Mean CCTvalues in OHT group was higher than other groups and control group. On other hand, meanCCT values in NTG group was lower than other groups and control group. But thedifferences were not statistically significant (p > 0.05).Mean ALX values were determined in POAG group 23.65 ± 1.47 mm, PNAG 23.16 ±0.75, PEG 22.40 ± 0.42 mm, NTG group 22.88 ± 0.46 mm, OHT group 22.28 ± 0.41 mm,JG group 22.86 ± 0.42 mm, and control group 23.27 ± 0.94 mm.Mean ALX values in PEG group was lower than control group as statisticallysignificant. Although mean ALX values in POAG group was determined higher than PNAGgroup (p > 0.05).In the light of these data, the incidence of myopia was more higher, the measurements ofALX was more longer that we observed. The eyes with PNAG is more tendency to behypermetropia and these eyes with PNAG had more shorter ALX than POG and controlgroup.Keywords: Glaucoma, Intraocular pressure, Axial length, Central corneal thickness.