Reis-Bucklers Corneal Dystrophy

Reis-Bucklers corneal dystrophy (RBCD) primarily involves the Bowman’s layer of the cornea and was first described by Reis in 1917 [1], followed in 1949 by Bucklers [2]. It is also known as granular corneal dystrophy (GCD) type III, a superficial variant of GCD, and corneal dystrophy of Bowman layer type I. It should be distinguished from Thiel-Behnke corneal dystrophy (TBCD) which also involves Bowman's layer but differs clinically, genetically, and prognostically. Both of these dystrophies are transmitted in an autosomal dominant pattern [1] [2] [3] [4].

Patients with RBCD are usually asymptomatic until they start to suffer from an exacerbation of recurrent corneal erosions which is characterized by severe ocular pain and hyperemia. This typically occurs around the age of 5 years and is accompanied by foreign body sensation and photophobia. The corneal erosions decrease with age but the visual acuity progressively worsens by the age of 20 years with the development of an irregular surface of the cornea.

RBCD can be differentiated from TBCD clinically as the corneal opacities in RBCD are confluent and geographical [1] [2] [5], whereas they are honeycomb shaped in TBCD [3] [6]. Genetically, RBCD is caused by an R124L mutation while TBCD is due to an R555Q mutation in the transforming growth factor β–induced (TGFBI) gene on chromosome 5q31 [6].

The workup includes a detailed history followed by a thorough ophthalmological examination. A positive family history is usually indicative of the diagnosis. The ophthalmologist will perform visual acuity testing, slit lamp examination, and anterior segment optical coherence tomography which is useful in the assessment of the disorder [6] [7] [8] [9]. Clinically, RBCD is characterized by confluent geographic opacities whereas TBCD by honeycomb-shaped opacities. Laboratory tests are not performed as part of the workup as they are not helpful.

A corneal biopsy is not routinely performed but can be considered after a corneal transplant procedure. On histological examination, RBCD is associated with "rod-shaped bodies" while "curly fibers" are found in TBCD.

Besides histopathological analyses, genetic studies in affected individuals are used to detect transforming growth factor β–induced (TGFBI) gene mutations on chromosome 5q31. Studies have reported that an R124L mutation is associated with RBCD while an R555Q mutation is associated with TBCD [10] [11] [12]. These studies help in clear distinguishing between the two types of corneal dystrophies whose prognosis is also different [12].

1. Reis W. Fämiliare, fleckige Hornhautetartung. Dtsch Med Wochenschr.1917;43575
2. Bücklers M. Über eine weitere familiare Hornhautdystrophie (Reis). Klin Monatsbl Augenheilkd.1949;114386- 397
3. Küchle M, Green WR, Völcker HE, Barraquer J. Reevaluation of corneal dystrophies of Bowman’s layer and the anterior stroma (Reis-Bücklers and Thiel-Behnke types): a light and electron microscopic study of eight corneas and a review of the literature. Cornea. 1995;14:333–354.
4. Thiel HJ, Behnke H. Ein bisher unbekannte subepitheliale hereditare Hornhautdystrophie. Klin Monatsbl Augenheilkd 1967;150862- 874
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6. Qiu WY, Zheng L-B, Pan F, et al. New histopathologic and ultrastructural findings in Reis-Bücklers corneal dystrophy caused by the Arg124Leu mutation of TGFBI gene. BMC Ophthalmol. 2016;16(1):158
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8. Ashar JN, Latha M, Vaddavalli PK. Phototherapeutic keratectomy versus alcohol epitheliectomy with mechanical debridement for superficial variant of granular dystrophy: A paired eye comparison. Cont Lens Anterior Eye. 2012;35(5):236-239.
9. Jung SH, Han KE, Stulting RD, et al. Phototherapeutic Keratectomy in Diffuse Stromal Haze in Granular Corneal Dystrophy Type 2. Cornea. 2013;32(3):296-300.
10. Mashima Y, Nakamura Y, Noda K, et al. A novel mutation at codon 124 (R124L) in the BIGH3 gene is associated with a superficial variant of granular corneal dystrophy. Arch Ophthalmol 1999;11790-93
11. Dighiero P, Valleix S, D'Hermies F, et al. Clinical, histologic, and ultrastructural features of the corneal dystrophy caused by the R124L mutation of the BIGH3 gene. Ophthalmology 2000;1071353-1357
12. Ellies P, Renard G, Valleix S, Boelle PY, Dighiero P. Clinical outcome of eight BIGH3-linked corneal dystrophies. Ophthalmology 2002;109:793-797