Patient: 54 years of age, male; BCVA General medical history: empty. Ocular medical history: photophobia, and pain. Major complaint: sudden onset decrease in vision Methods: Colour Photography Anterior Segment, SL-OCT Findings: Colour Photography Anterior Segment, before intracameral air injection: massive stromal edema due to leakage of aqueous through a tear in descemet membrane. SL-OCT, before intracameral air injection: Descemet's membrane detachment with dilaceration of collagen lamellae with large fluid-filled intrastromal cavity. Colour Photography Anterior Segment , 15 days after intracameral air injection: no stromal edema, posterior displacement of the hyperreflective structures with increased epithelial thickening and stromal thinning. Discussion: Sandali et al. (1) proposed a Fourier-domain OCT classification containing 5 distinct keratoconus stages. Stage 1 demonstrates thinning of apparently normal epithelial and stromal layers at the conus. Stage 2 demonstrates hyperreflective anomalies occurring at the Bowman's layer level with epithelial thickening at the conus. Stage 3 demonstrates posterior displacement of the hyperreflective structures occurring at the Bowman's layer level with increased epithelial thickening and stromal thinning. Stage 4 demonstrates pan-stromal scar. Stage 5 demonstrates hydrops; 5a, acute onset: Descemet's membrane rupture and dilaceration of collagen lamellae with large fluid-filled intrastromal cysts; 5b, healing stage: pan-stromal scarring with a remaining aspect of Descemet's membrane rupture. Miyata et al. (2) found, that the intracameral air injection is a useful therapy to shorten the period of corneal edema in acute hydrops secondary to keratoconus. He reported that the average period of persistence of corneal edema was 20 days in the intracameral air injection group and 65 days in the control group. Literature: (1) Sandali O, El Sanharawi M, Temstet C, Hamiche T, Galan A, Ghouali W, Goemaere I, Basli E, Borderie V, Laroche L. Fourier-Domain Optical Coherence Tomography Imaging in Keratoconus: A Corneal Structural Classification. Ophthalmology. 2013 Aug 8. pii: S0161-6420(13)00483-1. (2) Miyata K, Tsuji H, Tanabe T, Mimura Y, Amano S, Oshika T. Intracameral air injection for acute hydrops in keratoconus. Am J Ophthalmol. 2002 Jun;133(6):750-2.