Perbandingan ketebalan kornea dan morfologi sel endotel penderita miopia sedang pada pemakaian harian lensa kontak lunak hidrogel konvensional (nelfilcon a) terhadap silikon hidrogel (lotrafilcon b): penelitian pendahuluan = Comparison of corneal thickness and endothelial cell morphology in myopic patients with daily wear hydrogel (nelfilcon a) and silicon hydrogel (lotrafilcon b): contact lenses a pilot study