Delhi Journal of Ophthalmology

Granular Corneal Dystrophy Type II

Siddharth Madan, Sarita Beri
Department of Ophthalmology, Lady Hardinge Medical College and Associated S.S.K.H & K.S.C. Hospital, University of Delhi, India

Corresponding Author:

Siddharth Madan
M.B.B.S, M.S, D.N.B (Ophthalmology), F.I.C.O
Affiliation: Assistant Professor, Department of Ophthalmology, Lady Hardinge Medical College and Associated S.S.K.H & K.S.C. Hospital, University of Delhi, New Delhi
Email: drsiddharthmadan@gmail.com

Received: 12-APR-2020

Accepted: 21-MAY-2020

Published Online: 20-DEC-2020

DOI:http://dx.doi.org/10.7869/djo.605

Abstract
A paradigm shift has been observed in the classification of Granular corneal dystrophies (GCD). GCD is a bilateral, progressive, genetically determined and non-inflammatory disease limited to the cornea that has an autosomal dominant mode of inheritance. A 28 year old young male presented to us without any visual complaints. The examination of his cornea revealed the presence of diffuse linear, multiple round to granular, bread crumb like and stellate opacities extending from the sub-epithelium migrating down till the deep stroma, the classical clinical features of a heterozygous phenotypic variant of GCD type II.It progresses slowly and majority of the affected patients maintain a stable vision. Since this patient was asymptomatic therefore a complete ophthalmic examination in routine cases presenting to the oupatient clinics is indispensible. Various management options exist but a definitive treatment option is lacking.

Keywords :Granular Corneal Dystrophy Type II, Corneal Dystrophy

A paradigm shift has been observed in the classification of Granular corneal dystrophies (GCD) which can be attributed to the 2005 creation of The International Committee on the Classification of Corneal Dystrophies (Table 1 and 2).1,2,3 GCD is a bilateral, progressive, genetically determined and non-inflammatory disease limited to the cornea that has an autosomal dominant mode of inheritance. Transforming growth factor beta-induced (TGFßI) gene located on chromosome 5q31 codes for keratoepithelin, a type of corneal stromal protein secreted by corneal epithelium. Recent research has suggested that excessive accumulation of the C-terminal of the mutant TGFB-I p (TGFB-I protein) as a result of mutation in this gene results in crystalloid accumulation in GCD corneas which plays a principal role in the pathobiology of GCD.4,5 A 28 year old male tailor by occupation presented to us for his ophthalmic examination for applying for a driving license. He apparently had no visual complaints. On examination his unaided visual acuity (VA) in both eyes (BE) was 6/9. Bilateral cornea revealed the presence of diffuse linear, multiple round to granular, bread crumb like and stellate opacities extending from the sub-epithelium migrating down till the deep stroma (Figure 1 and 2). There was no significant refractive error on cycloplegic refraction, intraocular pressure was 12 and 14 mm Hg in the right eye and left eye respectively Bilateral fundus examination was unremarkable and so was the ocular examination in all other aspects. Although immunohistochemical testing to demonstrate a positive reaction with antibodies to microfibrillary protein, immunoglobulin G in the kappa and lambda light chains and light microscopy to stain hyaline and amyloid deposits with Masson trichome/Congo red was not performed nor was any genetic testing done on the patient, yet the clinical appearance was highly suggestive of a heterozygous phenotypic variant of GCD  type II. GCD type II mostly starts in the second decade of life, visual acuity is rarely worse than 6/24 and these patients infrequently demonstrate recurrent corneal erosion (RCE) symptoms.The corneal opacities in heterozygous patient progress slow and majority maintain a stable VA.6  Significant visual disabilities occur only later due to the natural history of the disease. Therefore our patient was instructed for a reexamination six months later and was educated on the possibility of development of RCE symptoms. GCD type II is observed globally now with a prevalence of 11.5 affected persons per 10,000 population as per a Korean study and the term Avellino addressing this dystrophy is now obsolete. Broadly, GCD usually requires no treatment.1 Pressure patching, bandage contact lenses, artificial tear and hyperosmotic sodium chloride drops are first line options in RCE cases. Topical treatment in the form of steroids, immunomodulators, autologous serum and topical and oral macrolides are second line agents. Surgical intervention is the final treatment option that aims to reduce the frequency of RCE symptoms and improve VA. Anterior stromal puncture and phototherapeutic keratectomy provides a less invasive alternative to penetrating keratoplasty (PK) in GCD patients to control RCE symptoms. Femtosecond Deep anterior lamellar keratoplasty (FDALK) and femtosecond laser-assisted keratoplasty (FLAK) enhance treatment outcomes.






Figure 1: A-D: Slit lamp examination of the cornea of the right eye (Figure.1A) and the left eye (Figure.1C) reveal the presence of diffuse linear, multiple round to granular, bread crumb like and stellate opacities extending from the sub-epithelium migrating down till the deep stroma. Torch light examination of the right eye (Figure.1B) and the left eye (Figure.1D) show multiple dot like corneal opacities.


Figure 2: A-B: Rings or stellate-shaped snowflake stromal opacities between the superficial stroma and the mid stroma along-with lattice lines in deeper cornea are seen in the right eye on indirect retroillumination (2A) and also in the left eye (2B).

References
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  2. Weiss JS, Møller HU, Lisch W, Kinoshita S, Aldave AJ, Belin MW, et al. The IC3D classification of the corneal dystrophies. Cornea. 2008 Dec;27 Suppl 2:S1-83.
  3. Weiss JS, Møller HU, Aldave AJ, Seitz B, Bredrup C, Kivelä T, et al. IC3D classification of corneal dystrophies--edition 2. Cornea. 2015 Feb;34(2):117–59. 
  4. Folberg R, Alfonso E, Croxatto JO, Driezen NG, Panjwani N, Laibson PR, et al. Clinically atypical granular corneal dystrophy with pathologic features of lattice-like amyloid deposits. A study of these families. Ophthalmology. 1988 Jan;95(1):46–51. 
  5. Lee EJ, Kim KJ, Kim HN, Bok J, Jung SC, Kim EK, et al. Genome-wide scan of granular corneal dystrophy, type II: confirmation of chromosome 5q31 and identification of new co-segregated loci on chromosome 3q26.3. Exp Mol Med. 2011 Jul 30;43(7):393–400. 
  6. Han KE, Kim T, Chung WS, Choi S, Kim B, Kim EK. Clinical findings and treatments of granular corneal dystrophy type 2 (Avellino corneal dystrophy): a review of the literature. Eye Contact Lens. 2010 Sep; 36(5):296–9.

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Madan S, Beri SGranular Corneal Dystrophy Type II.DJO 2020;31:99-102

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Madan S, Beri SGranular Corneal Dystrophy Type II.DJO [serial online] 2020[cited 2021 Jan 26];31:99-102. Available from: http://www.djo.org.in/articles/31/2/Granular-Corneal-Dystrophy.html