Year : 1976 | Volume
: 24 | Issue : 2 | Page : 16--18
Pinguecula and pterygium (a histopathological study)
IN Raizada, NK Bhatnagar
L.L.R.M., Medical College, Meerut, India
I N Raizada
L.L.R.M., Medical College, Meerut
|How to cite this article:|
Raizada I N, Bhatnagar N K. Pinguecula and pterygium (a histopathological study).Indian J Ophthalmol 1976;24:16-18
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Raizada I N, Bhatnagar N K. Pinguecula and pterygium (a histopathological study). Indian J Ophthalmol [serial online] 1976 [cited 2022 May 17 ];24:16-18
Available from: https://www.ijo.in/text.asp?1976/24/2/16/31527
The histopathology of pinguicula and pterygium was so very thoroughly studied by Fuchs that very little has been added to their basic knowledge since his da\s. He concluded that the histopathology of pinguecula is characterized by increased number of thickened elastic fibres, hyaline degeneration of the conjunctival tissue, concretions and epithelial changes and that similar changes also occur in pterygium along with characteristic corneal involvement
In an earlier study, Raizada et al reported on the histopathology of pterygium. The findings were grouped in three phases, i.e. a proliferative phase, a fibromatous phase and an atrophic sclerotic phase. The present study was undertaken to find out if the histopathology of pinguecula resembles in any way with any phase of pterygium, reported by us earlier.
Material and Methods
This histopathological study has been carried out in ten specimens of pinguecula obtained in a random way from patients who attended the outpatient departments at Medical Colleges in Kanpur and Meerut, India, for pterygium in one eye and pinguecula in the other. The specimens were blocked, sectioned and stained with haematoxylin and eosin stain, Modified Mayer's method (for amyloid degeneration) and Verhoeff's stain (for elastic fibres). The results were compared with the pterygium study published earlier.
(i) Epithelium was single layered or two or three layered thick acquiring stratified nature. [Figure 1]
(ii) Major portion of the section contained horizontally placed fibro-elastic tissue which had curly appearance. [Figure 2] Fibroblasts lined the walls of newly formed blood vessels. [Figure 5]
(iii) Areas of hyaline and amyloid degeneration scattered here and there. [Figure 3],[Figure 4].
(iv) Round cell infiltration though present was not a prominent feature.
The histopathology of pterygium has been grouped by Raizada et al in three phases i.e. proliferative phase, fibromatous phase and atrophic sclerotic phase. The fibromatous phase was observed in 52% of pterygia studied. The salient features of this phase were-flattening of the epithelial cells and nuclei showing a tendency to scar formation or having actually converted into a scar, fibroblastic activity and fibrous tissue formation, round cell infiltration, plasma cell sprinkling and neovascularization while on the other hand, atrophic sclerotic phase observed in 18% of the cases studied was characterized by pronounced atrophy and sclerosis of the epithelium, hyaline degeneration, amyloid degeneration, calcium deposits, fibroblastic activity and fibrous tissue formation. Similar views have been expressed by Kamel3 and Gerundo
From the observations, it is clear that the histopathology of pinguecula resembles in many respects the late fibrotic or early atrophic sclerotic phase of pterygium. That both pterygium and pinguecula occur in the interpalpebral zone (a zone of epithelial change) and that their histopathology is similar in many respects make us believe that they represent a kindred reaction to similar stimuli. Sugar believes that pinguecula is carried on to the cornea as the head of the pterygium and may leave no evidence of its original position.
But it must be mentioned that every pinguecula does not invariably become a pterygium. We believe that there is a potential limbal barrier which normally does not allow a pinguecula to advance over the cornea. When this potential limbal barrier is crossed, pinguecula advances over the cornea.
If one disregards the corneal changes then the histopathology of pinguecula and pterygium is identical in our series of cases. On this basis we can say that pinguecula is a precursor of pterygium, a view which has been disputed by Schoninger Friede, Almeida Reboucas and Forius and Erikson but supported by others. Evidence exists in literature that ultraviolet rays in solar radiations may produce corneal changes. Solar radiations supplemented in many cases by dry and dusty conditions, may help in breaking of the limbal barrier and the encroachment of the pinguecula over the cornea.
Ten pinguecula were subjected to histopathological study, using haematoxylin and eosin stain, Verhoeff's stain and modified Mayer's method for amyloid degeneration. The histopathology resembled the late fibrotic or early sclerotic please of pterygium. On the basis of the above study we conclude that pinguecula is a precursor of pterygium.
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