Analysis of pathohistological characteristics of pterygium

Abstract

Pterygium internum (external eye layer) shows great recurrence tendency after surgical removal. Its etiology is still unclear and represents a significant problem. The main goal of our study was to explore the interrelationships of pathohistological characteristics of pterygium, namely presence of inflammation, vascularisation degree and fibrinoid changes and on the basis of their analysis to test the possibility of predicting its evolution and recurrence. The analysis was performed on the material taken from 55 patients surgically treated by the technique of Arlt. The specimens were stained using the classical histochemical methods: hematoxylin-eosin (HE), Masson's trichrome, Gomori's reticulin stain and PAS technique. Pterygium is mostly covered by conjunctival epithelium, while in the cap region shows morphology of modified stratified squamous epithelium of the cornea. Structural basis of the epithelium is composed of continuous basal lamina and continuous connective fibers underneath. This connective basis shows fibrinoid changes in the form of oval islets of different size, parallel to convexity of pterygium, or is in the form of unified focus. The number, caliber and the type of blood vessels showed excessive variability. Pathohistological analysis of morphological characteristics of pterygium is adequate basis for prediction of recurrences; as they present the biggest concern in treatment of this widely spread disease.

CHART 1

Intensity of pathohistological changes of the pterygia

FIGURE 1

Abundant pterygium stroma mostly covered by conjunctival epithelium (HE, 10x).

FIGURE 2

Vascular stalk of the pterygium neck and its branching towards the progressing part of pterygium (HE, 10x).

FIGURE 3

Appearance of an edematous tissue with fibrinoid change elements in the progressive part of pterygium (HE, 20x).

FIGURE 4

Subepithelial connective tissue with focal fibrinoid change (HE, 40x).

FIGURE 5

Fibrinoid change of subepitheli-al connective tissue with confluent patches (HE, 40x).

FIGURE 6

Collagen connective tissues disorder, as well as their fibrinoid transformation of granular protein mass appearance (HE, 40x).

FIGURE 7

Edo-matous stroma of the pterygium with delicate capillary network and poorly expressed fibrinoid change in the pterygium of shorter evolution (HE, 20x).

FIGURE 8

Richly branched capillaries with wide lumen in the pterygia of longer evolution (HE, 20x).

CHART 2

Comparative analysis: Recurrence of the Fuchs’ spot

CHART 3

Comparative analysis: Pathohistological changes - Fuchs’ spots

CHART 4

Comparative analysis: Recurrence of the Pathohistological changes