TJ-CEO
2008 , Vol 3 , Num 3
Evaluation of the Relationship Between Retinal Nerve Fiber Layer Thickness Measured By Optical Coherence Tomography and Central Corneal Thickness in Normal Tension and Primary Open Angle Glaucoma
1Maya Göz Merkezi, Ankara, Uzm. Dr.2Yeditepe Üniversitesi Göz Hastalıkları A.D., İstanbul, Dr.
3Gazi Üniversitesi Tıp Fakültesi Göz Hastalıkları A.D., Ankara, Prof. Dr. Purpose: To evaluate the relationship between central corneal thickness (CCT) and retinal nerve fiber layer (RNFL) thickness measured with optic coherence tomography (OCT) in patients with normal tension glaucoma (NTG) and primary open angle glaucoma (POAG).
Materials and Methods: Records of total one hundred and eighty eight eyes of 188 patients with NTG, POAG and healthy controls were included in the study. Complete ophthalmologic examination, intraocular pressure (IOP) measurement with Goldman applanation tonometry, CCT measurement, RNFL analysis and automated perimetry were performed in all patients. Patient’s age, refraction, IOP, CCT, RNFL thickness, mean deviation (MD) and pattern standart deviation (PSD) values were recorded.
Results: Pattern of RNFL loss was mostly found to be diffuse in both NTG and POAG groups. CCT of NTG patients was significantly lower than that of healthy controls (p=0.001). Correlation between CCT and RNFL thickness was significant at 8, 11, 2 o’clock in POAG group whereas it was significant only at 7 o’clock in NTG group (p= 0.045, p=0.048, p=0.030 and p=0.017; respectively).
Conclusion: Distribution of RNFL loss is similar in NTG and POAG. CCT significantly correlates with RNFL thickness measured by OCT in NTG and POAG patients. This correlation seems to be localized in NTG patients whereas more diffuse in POAG patients. Keywords : Central corneal thickness, retinal nerve fiber layer thickness, normal tension glaucoma, primary open angle glaucoma, optic coherence tomography