Abstract
Purpose:
<br /> To describe and propose an new classification of posterior vitreous detachment measured by optic coherence tomography, and to describe the correlation between the proposed types of PVD and diabetic macular edema.
Methods:
A prospective study of 122 eyes of 61 consecutive patients of a diabetes clinic were examined. Patients had the diagnosis of diabetes and OCT was performed with a spectral-domain OCT. The imaging of the macula was assessed by a 300 OCT image crossing the center of the fovea. According the posterior vitreous status 8 types were described. 0 - Attached; 1 - Mild detachment; 2 - Perifoveal detachment with hyaloidal central adhesión in “U” shape; 3 - Perifoveal detachment with hyaloidal central adhesión in “inverted-U” shape; 4 - Perifoveal detachment with central adhesión, asymetric detachment, higher on one side of the fovea, both in “U”shape; 5 - Perifoveal detachment with central adhesión, asymetric detachment, higher on one side of the fovea, one in “U”shape and one in “inverted-U” shape; 6 - Perifoveal detachment with central adhesión, asymetric detachment, higher on one side of the fovea, both in “inverted-U”shape; 7 - Detached; 8 - No classifiable. Macular edema was classified according to the international classification in mild, moderate and sever. Statistical analysis was performed using a Fisher exact test.
Results:
Frequencies in the whole population of the different types of PVD are the following: Type 1: 27%, 2: 17%, 3: 11%, 4: 16%, 5:0%, 6:5%, 7: 20%, 8: 2%. Particularly, type 3 PVD was statistically associated with eyes presenting moderate and severe macular edema with an Odds ratio of 4.038 (IC95% 1.34-12.17, P=0.013). Patients with moderate and severe edema had a frequency of 36.8% of type 3 PVD, while patients without edema had a frequency of 13%. Such association was not found with mild and none macular edema.
Conclusions:
In this novel classification, patients with moderate/severe macular edema had 4 times more possibilities of having type 3 PVD (Inverted “U” perifoveal) when compared with patients with mild or no edema. Type 3 PVD is statistially associated with moderate and severe stages of diabetic macular edema. This provides another proven factor to the multifactorial pathogenesis of this diabetic macular edema.