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].

• Fishing

  Catanese M, Popovici C, Proust H, et al: Fluorescent in situ hybridization (FISH) on corneal impression cytology specimens (CICS): study of epithelial cell survival after keratoplasty. Invest Ophthalmol Vis Sci 2011;52:1009-1013. [karger.com]

  Adjuvant polyunsaturated fatty acids with high Omega-3 content before and after surgery improves sicca, foods containing PUFAs include flax and fish oil. [wikivisually.com]

• Gagging

  The GAG chains are able to form links with other GAG chains from adjacent fibrils. [wikivisually.com]

  Histopathology shows Glycosaminoglycans (GAGs) accumulation intra and extracellularly in corneal stroma, Descemet's membrane and endothelium. Guttae are often present at the Descemet membrane. [scielo.br]

• Piebaldism

  In RBCD, laminin and BPA were in a piebald mosaic distribution throughout the aberrant subepithelial fibrous tissue between the basal lamina and the buried Bowman's layer. [ncbi.nlm.nih.gov]

• Corneal Opacity

  A 50-year-old man (the proband) experienced recurring attacks of ocular irritation and had had bilateral ring-shaped anterior corneal opacity since adolescence. Corneal sensation was normal. [ncbi.nlm.nih.gov]

  This cloudiness, or opacity, causes the corneal epithelium to become elevated, which leads to corneal opacities. The corneal erosions may prompt attacks of redness and swelling in the eye (ocular hyperemia ), eye pain, and photophobia. [en.wikipedia.org]

  Definition A bilateral disorder of the cornea characterized by intermittent attacks of ocular irritation, recurrent painful corneal erosions starting in childhood, corneal opacities in a geographic pattern at the level of the Bowman layer, and a progressive [uniprot.org]

  The patient had a history of recurrent painful corneal erosion since childhood and showed geographic subepithelial corneal opacities. The following year, Munier et al. [ 3 ] reported on another family carrying the same mutation. [molvis.org]

  RBCD can be differentiated from TBCD clinically as the corneal opacities in RBCD are confluent and geographical, whereas they are honeycomb shaped in TBCD. [symptoma.com]

• Strabismus

  Strabismus MedGen UID: 21337 • Concept ID: C0038379 • Disease or Syndrome A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. [ncbi.nlm.nih.gov]

• Meningism

  This may occur as a manifestation of EYE DISEASES; MIGRAINE; SUBARACHNOID HEMORRHAGE; MENINGITIS; and other disorders. Photophobia may also occur in association with DEPRESSION and other MENTAL DISORDERS. [ncbi.nlm.nih.gov]

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
5. Dighiero P, Niel F, Ellies P et al. Histologic phenotype-genotype correlation of corneal dystrophies associated with eight distinct mutations in the TGFBI gene. Ophthalmology 2001;108818- 823
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
7. Dalton K, Schneider S, Sorbara L, Jones L. Confocal microscopy and optical coherence tomography imaging of hereditary granular dystrophy. Cont Lens Anterior Eye. 2010;33(1):33-40.
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