Introduction: Groenouw type 1 granular corneal dystrophy is an autosomal dominant disease, with complete penetrance, following a mutation in transforming growth factor beta-induced protein H3 gene. It is a rare corneal condition. Often responsible for pain, photophobia, and gradual decline in visual acuity. We describe the epidemiological, clinical, tomographic, genetic, and therapeutic aspects of this condition in a family of two children from a consanguineous marriage, whose parents are also affected.
Observation: The first patient was a 6-year-old boy, with no personal history, who had consulted for lowering progressive bilateral visual acuity evolving since birth with photophobia. Parents are linked by third-degree consanguinity.
The examination of the child found a bilateral visual acuity without correction reduced to 5/10, not improvable with optical correction. The biomicroscopic examination revealed several small, superficial, central, whitish, confluent, snowflake-shaped, bilateral and symmetrical corneal lesions located on Bowman's layer and sparing the limb, suggestive of granular corneal dystrophy type 1 with organic amblyopia.
Optical coherence tomography of the anterior segment revealed well-defined hyperreflective deposits at Bowman's layer, anterior and middle stroma. The orthoptic treatment instituted was considered insufficient, and the child had been programmed for a therapeutic photokeratectomy. Examination of the family found similar lesions to varying degrees.
Conclusion: Type 1 granular corneal dystrophy is a hereditary condition that appears in the first two decades and affects both sexes. It can manifest itself severely in childhood and cause amblyopia, especially in homozygous individuals. The OCT of the anterior segment confirms the diagnosis, helps in the choice of the therapeutic technique and intraoperatively it refines the treatment. In severe cases, PKT is the technique of choice, and may in the long term, in case of recurrence, be supplemented by transfixing keratoplasty, a more invasive technique that does not guarantee the absence of recurrences.
Key words: Groenouws corneal dystrophy, consanguinity, OCT SA, Therapeutic photokeratectomy