BACKGROUND: To report an unusual case of salzmann nodular degeneration (SND) in posterior keratoconus (PKC) after a corneal penetrating injury.
METHODS: A 56-year-old woman presented with a history of recurrent light sensitivity, foreign body sensation, and tears after a corneal penetrating injury 20 years ago. The patient was diagnosed with SND accompanying with PKC by slit-lamp microscope, anterior segment optical coherence tomography (OCT), and corneal tomography. A combined therapy of medication (0.1% sodium hyaluronate eye drops, recombinant bovine basic fibroblast growth factor eye drops, and 0.1% fluorometholone eye drops) and bandage contact lens could not relieve the latest episode. A phototherapeutic keratectomy (PTK) treatment (laser ablation depth: 15 μm; treatment zone: 7.5 mm) was performed to remove nodules and smooth the surface. The best spectacle-corrected visual acuity improved from 20/63 preoperatively to 20/40 postoperatively. No SND relapse and corneal ectasia were recorded at follow-up 12 months later.
CONCLUSIONS: This is the first known, reported case of SND accompanying with PKC after corneal trauma. The PTK is a safe and effective option for SND with PKC.

Posterior keratoconus is a rare corneal anomaly which is part of the ectatic corneal disorders. We report a clinical presentation of a unilateral posterior keratoconus in a 42-year-old man. At the time of presentation, corrected distance visual acuity (CDVA) was 20/20 with a correction of +2.50 +2.50 × 90° in the right eye and 20/40 with +1 +3.00 × 105° in the left eye. Slit lamp microscopy showed in the left eye an evidence of corneal thinning with a mild anterior protrusion and a remarkable posterior excavation. The intraocular pressure was 19 mmHg in right eye and 16 mmHg in left eye. Ultrasound pachymetry showed a minimum corneal thickness of 556 μ in right eye and 289 μ in left eye. The anterior segment optical coherence tomography (AS-OCT) revealed central corneal thinning and showed a reduced epithelial thickness. Videokeratography showed an increase of the corneal curvature in a defined area with central steepening in the area of the posterior corneal depression with gradual paracentral flattening. The description of this case underlines the importance of this instruments such us AS-OCT and corneal topography in diagnosis of posterior keratoconus. It can also be observed that in the contralateral eye there are no signs of ectasia as in the rare condition of unilateral keratoconus.