Morphological and clinical characteristics of myopic posterior staphyloma in Caucasians

We aimed to study the morphological characteristics of myopic posterior staphyloma in Caucasians and to evaluate the correlation between posterior staphyloma, myopic macular lesions and visual acuity. Ninety eyes of 67 consecutive patients affected by high myopia associated with posterior staphyloma were recruited between January 2012 and December 2013. Posterior staphyloma was classified according to Curtin's criteria. Every patient underwent fundoscopic examination and best corrected visual acuity measurement (BCVA). A and B-scan ultrasound (US), high-resolution, three-dimensional magnetic resonance image (MRI), optical coherence tomography (OCT), fundus autofluorescence (FAF), red free (RF) and color fundus photography studies were performed. The mean age was 64.4 +/- 9.48 years (range: 41-82). The mean BCVA was 0.7 +/- 0.5 logMAR (range: 0-2). The mean axial length was 29.92 +/- 2.39 millimeters (range: 24.25-36.53). The authors found four types of posterior staphyloma according to Curtin's classification: I, II, IV and IX. Significant prevalence of posterior staphyloma in female sex was observed (p = 0.0235). Significant correlation between the depth and the diameters of posterior staphyloma was demonstrated (p < 0.0001). Significant association between posterior staphyloma type and tomographic foveal patterns (p = 0.0230) was highlighted. Posterior staphyloma type I was more frequently associated with peripapillary atrophy and less with macular atrophy compared to type II and IX (p = 0.0169). The prevalence of macular atrophy was more than double in posterior staphyloma type II (33.3 %) in comparison to posterior staphyloma type I (12.5 %). This study confirms that the type I and II are the most common types of posterior staphyloma, as already highlighted in the literature. A significant association between the type of posterior staphyloma and the MRI ocular shape pattern, the OCT patterns of macular profile and the location of chorioretinal atrophy was highlighted. The correlation between the depth and the width of posterior staphyloma has demonstrated that the deeper the staphyloma, the wider it was. The deepest area of the posterior staphyloma was characterized by a greater thinning of the sclera and by a higher prevalence of chorioretinal atrophy compared to the other parts of the eye. More studies are necessary to support our findings and to add more information on the natural evolution of posterior staphyloma and on its associated complications.