Abstract
Abstract: :
Purpose: To evaluate the ability of OCT to detect structural damage in ocular hypertensive (OHT), early and moderate glaucoma eyes. Methods: Nineteen normal eyes, thirty ocular hypertensive eyes (OHT) and 33 eyes diagnosed of open angle glaucoma (OAG) were examined with 24–2–SITA standard (SAP), N–30 test of FDT and ocular coherence tomography (OCT Stratus). Normal eyes had IOP under 21 mmHg, normal optic disk and normal fields (SAP, Humphrey 24–2), OHT had IOP > 21 mmHg and normal disks and fields (SAP), and OAG presented IOP > 21 mmHg, glaucomatous disks and repeatable glaucomatous fields (SAP) with mean defect under or equal to 15 dB. Main outcome measures were rim area, rim width, and global and regional RNFL thickness for OCT; mean defect and pattern standard deviation for SAP and mean defect, pattern standard deviation and number of locations outside 95% normal limits for FDT. FDT was considered abnormal if three locations were outside 95% normal limits. Eyes were classified as normal or abnormal with OCT according to the percentiles of our normative database (n: 38) and the best cut–points calculated from an independent sample selected with the same criteria (38 normals and 52 glaucomas). The percentage of abnormal OCT and FDT results were calculated. The correlation between functional indices and OCT parameters was evaluated with Pearson's correlation coefficient. Results: Average thickness (OCT) significantly correlated with mean defect and pattern standard deviation of SAP and FDT (r²: 0.09–0.17, p: 0.02). The following table shows the percentage of cases classified as outside normal limits for FDT and some OCT parameters: TABLE Conclusions: RNFL thickness evaluated with OCT correlates with visual field indices from SAP and FDT. Our classification methods for OCT identify abnormality in 21 to 42 % of early and moderate glaucoma eyes and 10 to 27 % of OHT. These results are currently being compared with the recently released OCT normative database.
Keywords: nerve fiber layer • optic disc • visual fields