Optic disc tomography and perimetry in controls, glaucoma suspects, and early and established glaucomas.
OBJECTIVE
To analyze the priority of morphological and functional defects in glaucoma.


METHODS
Nine-hundred seventy-three eyes of 973 subjects were examined with Heidelberg retinal tomograph (HRT II) and Octopus 311 perimeter (TOP strategy). These included 72 controls (C), 659 early and suspect open angle glaucoma (ESG) with perimetric mean defect (MD) lower than 6 dB, and 242 confirmed moderate and advanced glaucomas (AG) with perimetric MD>or=6 dB.


RESULTS
I. (Control group): Age was significantly correlated with mean sensitivity (MS) (r=0.50, p<0.00001) and nasal cup shape measure (r=0.33, p=0.005). II. (C and ESG groups): For 95.8% specificity, the best sensitivity was obtained with square root of loss variance (sLV) (ROC area=69.7%, sensitivity=33.7%) and maximum contour elevation (ROC area=69.6%, sensitivity=29.0%). Maximum contour elevation and sLV coincided in diagnosis in 12.4% of cases. An equation using 64 HRT II indices predicted MS with a standard error of estimate (SEE) of 1.87 dB (r=0.67, p<0.00001) and MD (SEE=1.88 dB, r=0.47, p<0.00001). III. (All cases): RB discriminant function value was the best HRT II index to estimate MS values (SEE=5.4 dB, r=0.52, p<0.0001), MD (SEE=5.2 dB, r=0.50, p<0.0001), sLV (SEE=1.9 dB, r=0.41, p<0.0001) and Number of Pathological Points (NPP; SEE=21.3 dB, r=0.49, p<0.0001). Sector correlation of the optic nerve and visual field was high (maximum r=0.66) in cases with superior visual field defects and low in the rest of cases. More than 95% of cases with established glaucoma had abnormal sLV, but <60% had abnormal optic disc indices.


CONCLUSIONS
Perimetry reveals age-related defects slightly more than HRT II. HRT II indices correlated better with MS than with MD, probably because none of them was age corrected. Good correlation between anatomical and functional data in C and ESG, and sensitivity results indicated small differences in early development between both methods. Perimetry identifies defects more clearly than structural measures in established glaucoma.
de la Rosa
Manuel Gonzalez
MG
Department of Ophthalmology, University Hospital of the Canary Islands, University of La Laguna, Spain.
Gonzalez-Hernandez
Marta
M
Lozano-Lopez
Virginia
V
Mendez
Manuel Sanchez
MS
de la Vega
Ricardo Rodriguez
RR
D000293:Adolescent; D000328:Adult; D000368:Aged; D018450:Disease Progression; D005902:Glaucoma, Open-Angle / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology*; D011379:Prognosis; D012720:Severity of Illness Index; D013997:Time Factors; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*