Corneal histomorphology and electron microscopic observation of R124L mutated corneal dystrophy in a relapsed pedigree
Authors:   Department of Refractive Surgery Center, Weifang Eye Hospital, Weifang 261000, Shandong Province, China; State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China; National Clinical Research Center for Ocular Diseases, Eye Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China, Fu Meng-Jun , Duan Shan ,   Shanghai Research Center of Ophthalmology and Optometry, Shanghai 200000, China, Zhang Hao-Run ,   Department of Refractive Surgery Center, Weifang Eye Hospital, Weifang 261000, Shandong Province, China, Zhao Jing-Jing ,   Department of Refractive Surgery Center, Weifang Eye Hospital, Weifang 261000, Shandong Province, China, Zeng Li ,   Eye Institute and Department of Ophthalmology, Eye &amp; ENT Hospital, Fudan University, Shanghai 200031, China; NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai 200031, China, Wang Rui ,   Department of Refractive Surgery Center, Weifang Eye Hospital, Weifang 261000, Shandong Province, China, Zhou Xing-Tao ,   Eye Institute and Department of Ophthalmology, Eye &amp; ENT Hospital, Fudan University, Shanghai 200031, China; NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai 200031, China
Published: September 2022

AIM: To investigate the histological characteristics and ultrastructure of recurrent Chinese R124L mutated corneal dystrophy after keratoplasty.
METHODS: The subjects were enrolled from a Chinese family of corneal dystrophy with R124L heterozygous gene mutation and with a history of consanguineous marriage. Normal corneal samples were used as controls.
RESULTS: In this family, 2 patients (3 eyes) underwent penetrating keratoplasty (PKP) and 2 patients (4 eyes) underwent lamellar keratoplasty (LKP). They had recurrence at 33.5±3.0 (range 30-36)mo after keratoplasty. Among them, 1 patient (1 eye) underwent PKP again and 1 patient (2 eyes) underwent LKP again. In the R124L mutated recurrent corneal dystrophy, the corneal turbidity was mainly distributed from the upper corneal cortex to the anterior stroma; the corneal epithelium surface was rougher and more uneven; and, the corneal erosions were larger. Hematoxylin-eosin staining showed that the thickness of the corneal epithelium was uneven; the arrangement of the epithelial cells was disordered; and, some corneal epithelial cells were swollen. The results of Congo red staining, Masson’s trichrome staining and Periodic acid-Schiff staining were positive, while that of Alcian blue staining was negative. Under a transmission electron microscope, deposition of high electron density substances between epithelial and basal cells, and, apoptosis of basal cells were observed. Many high electron density depositions were observed in the sub-epithelial and anterior corneal matrix.
CONCLUSION: In the Chinese family of recurrent corneal dystrophy with R124L gene mutation, the corneal epithelia of the recurrent cases are rougher, and the corneal depositions are extracellular amyloid fibrin.