Abstract
Abstract: :
Purpose: To evaluate the association between optic morphologic parameters and retinal nerve fiber layer thickness evaluated with Heidelberg Retina Tomograph (HRT II) and functional parameters measured with standard automated perimetry (SAP) and short wavelenght automated perimetry (SWAP), in patients affected by ocular hypertension (OH) and primary open angle glaucoma (POAG). Methods:Controlled prospective study on 20 OH patients (20 eyes), 12 males and 8 females (mean age 62.3±7.6 years), 21 POAG patients (21 eyes), 11 males and 10 females (mean age 63.6±9.9 years), 22 normal subjects (22 eyes), 12 males and 10 females (mean age 59.4±10.4 years). HRT II optic disc morphometric analysis with evaluation of global stereometric parameters, SAP (Humphrey, prog. 30–2 SITA Standard) and SWAP (Humphrey, prog. 30–2 full threshold) were performed. Correlation between the parameters examined with the different methods (HRT II, SAP, SWAP) was evaluated with Pearson’s correlation coefficient (r) with a significance of p<0.05 and p<0.001. The significance of the differences between the three groups was evaluated with Student t–test. Results: In the entire cohort, a statiscally significative correlation between many HRT II parameters and SAP perimetric indexes was found (stronger correlation between Rim Area and MD r=0.45, p=0.000 and Cup/Disc Area Ratio and PSD r=0.45, p=0.000). The subgroup analysis showed, in the OH group, a moderate correlation between CSM and the SAP MD values (r=0.49) and a good correlation between the same parameters (r=0.61) with SWAP. In the POAG group, a moderate correlation between Cup Area, Rim/Disc Area Ratio, Mean RNFL Thickness, RNFL Cross Sectional Area and the SAP MD values (r=0.46, r=0.44, r=0.46, r=0.45 respectively) and between Cup Volume and Cup/Disc Area Ratio and the SAP PSD values (r=0.46 and r=0.44) was found. In normal subjects, a moderate correlation between Cup Area, CSM and the SAP MD values (r=0.48 and r=0.47 respectively) resulted. Conclusions:In the entire cohort, most of the HRT II parameters showed a significative correlation with SAP indexes. In the OH group a good correlation between CSM and the SWAP MD values, stronger than with SAP, emerged. In the present study most of the other HRT II parameters showed only a moderate correlation with perimetric indexes suggesting that the mere HRT II examination is not capable to reveal early optic disc damage. CR: None
Keywords: perimetry • imaging/image analysis: clinical • optic disc