Rare stromal corneal dystrophic diseases in Oman: A clinical and histopathological analysis for accurate diagnosis

INTRODUCTION: Corneal dystrophy (CD) encirclements a heterogeneous group of genetically determined corneal diseases. Many features still remain unknown. AIM: The purpose of this study was to highlight the clinical and the histopathological aspects of rare stromal CDs and to assess the clinical and the histopathological roles in their diagnosis. PATIENTS AND METHODS: This study incorporated 10 eyes of six patients, clinically diagnosed as follows: four patients with bilateral lattice stromal CD (8 eyes) and two patients, each one eye, one with macular and the other with granular-type CD. Histopathological examination with applications of many special stains was done in four eyes (4 patients) after penetrating keratoplasty. RESULTS: The histopathological examination was in concordance with the clinical diagnosis of three examined corneas and revealed first eye with lattice dystrophy, second eye with macular dystrophy, and third eye with granular dystrophy. The fourth examined cornea was not that in concordance with the clinical diagnosis of lattice CD as it showed mixed stromal CD patterns of granular, macular, and lattice types. CONCLUSION: Histopathological assessment of corneal dystrophy cases, subjected to keratoplasty is recommended to avoid missing cases with mixed stromal corneal dystrophy. Also, using low magnification slit lamp alone in the clinical assessment of the corneal opacity appeared to be limited mode and thus, the imaging corneal methods such confocal microscopy and high-definition optical coherence tomography are recommended for future cases especially in cases with unclassic query diagnosis.