Confronto tra lo spessore coroideale peripapillare e il danno dello strato delle fibre nervose retiniche (RNFL) in soggetti sani, con ipertensione oculare e glaucoma ad angolo aperto Maraone G, De Rosa V, Salomone M, Cutini A, Valente S. Università degli studi di Roma “La Sapienza”- Polo Pontino, Ospedale “A.Fiorini” Terracina
Purpose: To evaluate the role of the choroid thickness at different stages of the damage of the retinal nerve fiber layer ( RNFL ) in patients with ocular hypertension (OH) and primary open-angle glaucoma ( POAG ) Methods: We examined 117 eyes of 117 patients with primary open-angle glaucoma or ocular hypertension ( 66.8 ± 12.8 years ) and 50 healthy subjects ( 63.09 ± 21.42 years ) . The patients were divided into 2 groups according to the RNFL classification: 54 eyes within normal limits ( WNL ) and 48 eyes outside normal limits ( ONL ) . Eyes borderline ( n = 15 ) were excluded from the study. The thickness of the peripapillary RNFL was obtained by spectral domain optical coherence tomography (SD -OCT , Heidelberg Engineering) . The thickness choroidal peripapillary (CT ) was measured from the outer edge of the retinal pigment epithelium to the interface chorio - scleral , using EDI mode (enhanced depth imaging for imaging of the deep layers ) . The maps of the choroidal thickness and the RNFL were compared between the groups for the dials global (G) inferior- temporal (IT) , inferior- nasal (IN) , superior- temporal (ST) , superior- nasal (SN) , nasal (N) and temporal (T ). Statistical analysis was performed using the Mann -Whitney U test ( non-normal distribution , Shapiro- Wilk test p < 0.05) or with the independent Student's t test ( normal distribution ) . To compare we calculated the correlation coefficient Spearman rank . Results: The overall average choroidal thickness was 129.23 ± 49.93 mM in the eyes suffering from POAG or OH and 143.71 ± 40.0 mM in healthy subjects ( p = 0,04 ) . It was observed a negative correlation between choroidal thickness and age in the eyes suffering from POAG or OH (r = -0.48 , p < 0.0001) and in healthy subjects ( r = -0.63 , p < 0.0001). In the eyes with POAG or OH , the average peripapillary choroidal thickness in the lower quadrants was significantly lower than the other quadrants ( p < 0.001). In addition, the peripapillary CT WNL group , compared to healthy subjects was significantly thinner in quadrants NS , NI and TI (p = 0.03 , p = 0.01 and p = 0.05). In the group ONL dials NS , NI , TI, T and G were significantly less. Than in healthy subjects (p = 0.05, p = 0.02 , p = 0.02 , p = 0.05 and p = 0.04 , respectively). Conclusions: In subjects with POAG or OH, choroidal thickness in quadrants NS , NI and TI was compromised compared this parameter in healthy subjects , although the thickness of the RNFL appeared within normal limits ( WNL ) . This suggests that the thinning of the choroid may precede the morphological glaucomatous damage . Furthermore, in the eyes of the group ONL the thickness T and choroidal overall were significantly thinner than in healthy subjects . This could be correlated with the progression of morphological damage associated with the tendency of the eye with a thinner choroid to develop a more advanced glaucomatous damage .