Pathologically, both the hyaline deposits typical of granular dystrophy and the amyloid deposits typical of lattice dystrophy are seen. These lesions extend from the basal epithelium to the deep corneal stroma. Individual opacities stain with the Masson trichrome or Congo red stain. The deposits appear as rod-shaped bodies on electron microscopy; randomly aligned fibrils of amyloid are also seen. Findings on confocal microscopy are a combination of those seen in GCD1 and LCD.
Affected patients have a granular dystrophy both histologically and clinically, with shorter, whiter lattice lesions in addition to the granular lesions. Clinical findings in GCD2 differ from those in GCD1. Stellate-shaped, snowflake-like, and icicle-like opacities appear between the superficial stroma and midstroma (Fig 7-12). Lattice lines are also seen deeper than the snowflake opacities. Older patients have anterior stromal haze between deposits, which reduces vision. Pain may occur with mild corneal erosions.
Figure 7-12 Granular corneal dystrophy type 2. Stellate-shaped opacities with intervening clear spaces can be seen in direct illumination (left) and in retroillumination (right).
(Reproduced with permission from Weiss JS, Møller HU, Aldave AJ, et al. IC3D classification of corneal dystrophies—edition 2. Cornea. 2015;34(2):141.)
Lamellar or penetrating keratoplasty may be useful, depending on the depth of the deposits. PTK may be considered as an alternative to reduce surface irregularity and increase corneal clarity. Laser in situ keratomileusis (LASIK) and PRK are contraindicated.
Aldave AJ, Vo RC, de Sousa LB, Mannis MJ. The stromal dystrophies. In: Mannis MJ, Holland EJ, eds. Cornea. Vol 1. 4th ed. Philadelphia: Elsevier; 2017:781–799.
Holland EJ, Daya SM, Stone EM, et al. Avellino corneal dystrophy. Clinical manifestations and natural history. Ophthalmology. 1992;99(10):1564–1568.
Kim TI, Hong JP, Ha BJ, Stulting RD, Kim EK. Determination of treatment strategies for granular corneal dystrophy type 2 using Fourier-domain optical coherence tomography. Br J Ophthalmol. 2010;94(3):341–345.
Weiss JS, Møller HU, Aldave AJ, et al. IC3D classification of corneal dystrophies—edition 2. Cornea. 2015;34(2):117–159.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.