Peripheral hypertrophic subepithelial corneal degeneration – clinical and histopathological features

Abstract

ABSTRACT.Purpose: To refine the diagnostic criteria for peripheral hypertrophic subepithelial corneal degeneration (PHSD) and characterize its clinical phenotype, histopathology and immunohistochemical features. Methods: Diagnostic criteria were refined on the basis of literature data. Fourteen patients (13 women and one man; median age 52 years, range 33-66) were identified based on these criteria. Keratectomy specimens were evaluated via routine and immunohistochemical stainings. The main outcome measures were symptoms, clinical phenotype, immunological status and histopathologic results. Results: We defined the diagnostic criteria of typical PHSD as elevated circumferential and perilimbal subepithelial fibrosis with focal superficial corneal neovascularization, which were supported by female sex (93%), bilaterality (86%), the centre being in the upper quadrants (81%) and irregular astigmatism of two dioptres or more. The typical symptoms were reduced vision (86%) and the symptoms of ocular surface disease (64%). Light microscopy showed fibrosis with abundant collagen deposition but no inflammation in all patients. An immunohistochemical analysis of nine patients showed uniform staining for vimentin in three distinct types of fibroblasts in variable proportions: keratocytelike cells that were positive for CD34, myofibroblasts that were positive for smooth muscle actin (SMA) and fibroblasts that were negative for CD34 and SMA. Small numbers of CD68-positive macrophages were also found. Conclusions: Peripheral hypertrophic subepithelial degeneration is characteristic of middle-aged women, in whom it is typically a bilateral idiopathic degeneration of the cornea associated with ocular surface disease and reduced vision. The fibrotic lesions probably undergo remodelling, inducing changes in corneal contour. A smouldering low-grade inflammation favouring low TGF-b1 concentrations is postulated as the primary pathological process leading to PHSD.

Re: Peripheral hypertrophic subepithelial corneal degeneration – clinical and histopathological features

“…In our data, female sex and corneal neovascularizations next to the nodules were associated with peripheral localization. This is in line with the refined PHSD criteria of Ja¨rventausta et al (2014) and supports the concept of a self-contained entity. Similar findings have also been reported by Schargus et al (2015).…”

“…W e very much appreciate the recent article from Ja¨rventausta et al (2014) on refined diagnostic criteria concerning the difference between peripheral hypertrophic subepithelial corneal degeneration (PHSD) and Salzmann's nodular degeneration (SND). The authors propose that PHSD lesions are located sectorally in the periphery or mid-periphery but never in the central cornea.…”

<p>Peripheral hypertrophic subepithelial corneal degeneration: clinical aspects related to in vivo confocal microscopy and optical coherence tomography</p>

“…Recently proposed diagnostic criteria for PHSD include perilimbal subepithelial fibrosis with thickening of the cornea, possible extension to the mid-periphery but no central cornea involvement 2,3. Superficial neovascularization up to the base of the fibrous tissue and two or more diopters of topographic astigmatism represent additional distinguishable features.…”

Corneal Dystrophies and Degenerations

“…It is a more recently recognized uncommon corneal degeneration, which is typically peri-limbal, slowly progressive, and bilateral. It tends to occur in white women with unknown etiology and, however, resembles Salzmann's nodular degeneration in appearance (Figure 16A and B) [62,63]. Ultraviolet radiation and limbal insufficiency have been proposed in the pathogenesis [64].…”

“…The fibrotic process has been linked to low-grade inflammation with low TGF F-B1 concentrations [62]. Surgical excision might be required for treatment of symptomatic cases, and the recurrence is not common [63].…”