A 41 year old Caucasian female consulted me for a routine examination. Her chief complaint was photophobia and poor vision. My examination revealed the following.
IOP right and left was 16mmHg and lenses were clear. Fundoscopy revealed no retinal or posterior segment pathology. Slit lamp examination revealed bilateral inferior sub-epithelial, fairly symmetrical, vascularised hypertrophic corneal opacification (Figure 1). Pentacam scan showed changes in the inferior cornea extending well into the stroma (Figure 2). OCT confirmed the stromal invasion in both eyes.
A diagnosis of Peripheral Hypertrophic Sub-epithelial Corneal Degeneration was made. PHSCD was first described in 2003 by Maust and Raber , and involves bilateral, symmetrical, peripheral, hypertrophic, sub-epithelial corneal opacification. Adjacent limbal vascularisation is not uncommon, but chronic ocular surface inflammation is usually absent . An increase in hyperopic astigmatism as a result of the disease may cause blurred vision, which with ocular irritation is the most common presenting symptoms . The disease affects mostly young Caucasian females with light-coloured eyes and must be differentiated from corneal intraepithelial neoplasia, bullous keratopathy, climatic droplet keratopathy, corneal amyloidosis, corneal keloid, hereditary hypertrophic scarring, pseudo-pterygia and Salzmann’s nodular degeneration [2, 4]. Salzmann’s nodular degeneration is often asymptomatic, unilateral, mid-peripheral and associated with chronic ocular surface inflammation . Underlying causes of Salzmann’s degeneration include phlyctenular keratitis, meibomian gland dysfunction, contact lens wear, peripheral neovascularisation, pterygium, keratoconjunctivitis sicca and exposure keratoconjunctivitis .
Histologic findings of PHSCD show a conjunctival component similar to that of pterygium and a corneal component with hypocellular fibrous tissue similar to that seen in Salzmann’s nodular degeneration – in other words the disease can be described as pterygium-like with a corneal component .
Most patients require no therapeutic intervention other than frequent use of lubricants. In those patients with significant discomfort and where the visual axis is threatened, superficial keratectomy with pterygium excision and conjunctival autograft can be carried out .
The patient described in the case report was referred for surgical opinion, but due to lack of visual involvement the surgeon agreed that conservative therapy with lubrication was the best course of action providing that she has regular follow-up to monitor progression.
- Maust HA, Raber IM. Peripheral hypertrophic subepithelial corneal degeneration. Eye & contact lens. 2003;29:266-9.
- Gore DM, Iovieno A, Connell BJ, Alexander R, Meligonis G, Dart JK. Peripheral hypertrophic subepithelial corneal degeneration: nomenclature, phenotypes, and long-term outcomes. Ophthalmology. 2013;120:892-8.
- Jeng BH, Millstein ME. Reduction of hyperopia and astigmatism after superficial keratectomy of peripheral hypertrophic subepithelial corneal degeneration. Eye & contact lens. 2006;32:153-6.
- Das S, Link B, Seitz B. Salzmann’s Nodular Degeneration of the Cornea: A Review and Case Series. Cornea. 2005;24:772-7.
- Maharana PK, Sharma N, Das S, Agarwal T, Sen S, Prakash G, et al. Salzmann’s Nodular Degeneration. Ocul Surf. 2016;14:20-30.
- Farjo AA, Halperin GI, Syed N, Sutphin JE, Wagoner MD. Salzmann’s nodular corneal degeneration clinical characteristics and surgical outcomes. Cornea. 2006;25:11-5.