ESCRS - PP02.02 - Histopathological Changes In Corneas Of Patients With Mucopolysaccharidosis Type Vi That Underwent Penetrating Keratoplasty

Histopathological Changes In Corneas Of Patients With Mucopolysaccharidosis Type Vi That Underwent Penetrating Keratoplasty

Published 2022 - 40th Congress of the ESCRS

Reference: PP02.02 | Type: ESCRS 2022 - Posters | DOI: 10.82333/d88r-7s97

Authors: Ana Faria Pereira* 1 , Sofia Pedrosa 2 , Augusto Magalhães 1 , Raul Moreira 1 , João Costa 1 , Elisa Leão-Teles 3 , Fernando Falcão-Reis 1

1Department of Ophthalmology,Centro Hospitalar e Universitário de São João,Porto,Portugal, 2Department of Pathology,Centro Hospitalar e Universitário de São João,Porto,Portugal, 3Department of Pediatrics, Reference Centre of Inherited Metabolic Diseases,Centro Hospitalar e Universitário de São João,Porto,Portugal

Purpose

Mucopolysaccharidosis (MPS) are a group of diseases caused by accumulation of undegraded glycosaminoglycans (GAGs). MPS VI is a rare autosomal recessive disease caused by deficiency in N-acetylgalactosamine-4-sulfatase. Ocular manifestations are frequent and include corneal opacity, caused by accumulation of GAGs in corneal layers, inducing light scattering. In these cases, the only current treatment is corneal transplantation, usually penetrating keratoplasty (PK) or deep anterior lamellar keratoplasty (DALK).The main purpose of this study is to identify the histopathological characteristics of corneas of patients with MPSVI and based on these characteristics, determine the most suitable surgical approach in corneal surgery in these cases.

Setting

Centro Hospitalar e Universitário de São João, Oporto, Portugal.


Methods

This study includes the corneas of four MPS VI patients which have been submitted to PK for corneal clouding.  Specimens of primitive corneas were examined using hematoxylin/eosin, special trichrome, colloidal iron and periodic acid-Schiff stains. 


Results

Studied corneas showed hyperparakeratosis of epithelium with enlarged cytoplasm, large intra and extracellular vacuoles and subepithelial deposits of mucopolissacharides, subepithelial vacuolization with Bowman disruption, presence of elongated clefts in the stroma and deposits of acid mucopolissacharides in the anterior and posterior stroma, Descemet and endothelium. However, in some specimens, continuous Descemet, without alterations and endothelium with vacuolization and fine granular deposit were also found.

Conclusions

Descemet membrane and endothelium can remain unaffected until later stages of disease progression. In such cases the surgical treatment should consist of DALK. However our study revealed the presence of deposits in all corneal layers in most cases suggesting that older patients with more severe forms of disease must be treated with PK. MPSVI is a disabling disease in which historically palliative care was the only option. Fortunately, the current therapeutic modalities, including hematopoietic stem cell transplantation and enzyme replacement therapy have increased life span and life quality in affected patients. Currently, these patients require differentiated multidisciplinary care, which includes ophthalmic surgery in specialized centers.