Granular corneal dystrophy: slitlamp biomicroscopic appearances in three generations of patients

Vortex Pattern of Corneal Deposits in Granular Corneal Dystrophy Associated With the p.(Arg555Trp) Mutation in TGFBI

PURPOSE

To describe 2 unrelated families with multiple members demonstrating a less commonly recognized vortex pattern of corneal deposits confirmed to be granular corneal dystrophy type 1 (GCD1) after identification of the p.(Arg555Trp) mutation in the transforming growth factor β-induced gene (TGFBI).

METHODS

A slit-lamp examination was performed on individuals from 2 families, one of Mexican descent and a second of Italian descent. After DNA extraction from affected individuals and their unaffected relatives, TGFBI screening was performed.

RESULTS

Eight of 20 individuals in the Mexican family and 20 of 55 in the Italian family demonstrated corneal stromal opacities. Seven of the 8 affected individuals in the Mexican family and 4 of the 20 affected individuals in the Italian family demonstrated a phenotype characterized by a "sea fan" or vortex pattern of superficial stromal corneal deposits originating from the inferior aspect of the cornea. Screening of TGFBI in both families revealed a heterozygous missense mutation [p.(Arg555Trp)] in exon 12, confirming the diagnosis of GCD1.

CONCLUSIONS

Our findings demonstrate that GCD1 may present with a vortex pattern of anterior stromal deposits. Although this pattern of dystrophic deposits is not recognized by clinicians as a typical phenotype of GCD1, it is consistent with the production of the majority of the TGFBI protein by the corneal epithelium.

Confocal microscopy and optical coherence tomography imaging of hereditary granular dystrophy

OBJECTIVES

This case report examines the clinical characteristics of hereditary granular dystrophy through the use of slit lamp digital photography, confocal microscopy (CM) and optical coherence tomography (OCT). A review of the literature describing the histopathological and genetic associations of stromal dystrophies, suggest it may be possible to differentiate dystrophies based on their clinical manifestations, and appearances of CM and OCT images, with or without the use of genetic testing.

CASE REPORT

Two sisters, previously diagnosed with Granular (Groenouw I) Dystrophy, were examined. Examination included the use of digital slit lamp photography, CM and OCT imaging.

RESULTS

"Breadcrumb" opacities were visualized in the anterior two-thirds of the stroma with all three imaging techniques. Opacities were demonstrated in the posterior third of the stroma with the digital photography and OCT techniques.

CONCLUSIONS

The digital photography, CM and OCT images support the sister's diagnosis of Granular (Groenouw I) Dystrophy. Currently, genetic and histopathological testing are the only techniques available to determine exactly which corneal dystrophy and gene mutation are present. The results of this case report demonstrate that slit lamp digital photography, combined with CM and OCT may be capable of providing sufficient diagnostic information to diagnose corneal granular dystrophies in a clinical setting.

Deep anterior lamellar keratoplasty with melles technique for granular corneal dystrophy

PURPOSE

The purpose of this study was to evaluate the clinical results of deep anterior lamellar keratoplasty (DALK) using the Melles technique in granular corneal dystrophy.

METHODS

Seven eyes from 5 patients who underwent DALK using Melles technique for granular corneal dystrophy were included in this study. The parameters evaluated included patients' demographics, preoperative and postoperative best spectacle-corrected visual acuities (BSCVAs), and timing and pattern of recurrence.

RESULTS

The mean age of the patients was 37 +/- 9.4 years (range 29-46 years) at the time of surgery. The mean length of follow-up (DALK to last visit) was 38.4 +/- 18.6 months (range 10-63 months). The procedure was performed without any major complication in all eyes. Mean preoperative BSCVA was 20/220 (range 20/400 to 20/100), which improved to 20/27 (range 20/30 to 20/25) at 6 months after DALK. Mean BSCVA was 20/50 (range 20/400-20/20) at last follow-up. Simple recurrence occurred in 5 (71%) of 7 eyes. The mean time from surgery to recurrence was 15.6 +/- 1.8 months (range 13-16 months). Clinically significant recurrences occurred 34 +/- 2 months after the procedures in 3 (43%) of 7 eyes. Two (30%) of 7 eyes had no recurrence at all.

CONCLUSIONS

Although granular corneal dystrophy is likely to recur after DALK, this technique can restore and preserve useful visual function for a significant period in these patients.

The extracellular matrix protein TGFBI promotes myofibril bundling and muscle fibre growth in the zebrafish embryo

The extracellular matrix protein Tgfbi has been shown to localise to myotendinous junctions in mouse and postulated to interact with the transmembrane protein Integrin alpha7beta1, which, in parallel with the Dystrophin-associated protein complex, is critical for linkage between the extracellular matrix and the cytoskeleton of muscle fibres. Here we use a GFP-tagged form of Tgfbi to analyse its distribution in the developing skeletal muscle of the zebrafish embryos and antisense morpholino oligonucleotides to investigate the function of the endogenous protein. We find that although tagged Tgfbi accumulates at the myosepta, the attachment of muscle fibres to the myosepta is established and maintained normally in morphant embryos; however, the fibres show a marked reduction in their growth and a disruption of their myofibril bundles.

Automated Lamellar Keratoplasty for Recurrent Granular Corneal Dystrophy After Phototherapeutic Keratectomy

PURPOSE

To evaluate the safety and efficacy of automated lamellar keratoplasty for the treatment of recurrent granular corneal dystrophy after phototherapeutic keratectomy (PTK).

METHODS

We performed a prospective interventional noncomparative case study of nine eyes (seven patients) with severe recurrent granular corneal dystrophy after PTK. An automated microkeratome was used to cut partial-thickness sections through the anterior surface of the donor and host corneas. The donor disc was placed on the recipient bed with four or eight interrupted sutures. The sutures were removed between 4 and 6 weeks postoperatively. Visual acuity, corneal clarity, corneal thickness, and corneal topography were assessed before and at different time points after surgery.

RESULTS

During a mean follow-up period of 18.9 +/- 4.1 months, all grafts were transparent without visible opacity at the interface, and no serious complications occurred. In all cases, the visual acuity improved: seven eyes had best spectacle-corrected visual acuity of > or = 20/40; two eyes reached 20/25. At last follow-up > 12 months postoperatively, the mean corneal refractive power had significantly increased by 2.34 +/- 0.93 diopters (D) (P<.001), and the corneal astigmatism significantly decreased by 0.91 +/- 0.98 D (P<.05). The mean corneal thickness was 477.4 +/- 26.9 microm preoperatively and 507.8 +/- 23.4 microm at last follow-up (P<.001).

CONCLUSIONS

Our findings suggest that automated lamellar keratoplasty for the treatment of recurrent granular corneal dystrophy is a safe and effective method of improving visual acuity, but recurrence remains a risk.

Atypical vortex pattern of corneal deposits in granular corneal dystrophy

PURPOSE

To report the appearance of an unusual vortex pattern of corneal deposits in two patients with the R555W mutation in the transforming growth factor beta-induced gene (TGFB1) associated with granular corneal dystrophy.

METHODS

DNA from affected patients and unaffected relatives was isolated from buccal swabs, and TGFB1 mutation screening was performed.

RESULTS

The proband and an affected daughter demonstrated rays of deposits emanating from a point in the inferior cornea of each eye in a "sea fan" or vortex pattern. Screening all 17 exons of TGFB1 in the proband identified a single missense mutation (C1710T) in exon 12, consistent with the diagnosis of granular corneal dystrophy. The identical mutation was identified in the affected daughter.

CONCLUSIONS

In spite of the strict phenotype-genotype correlation reported for the TGFB1-associated corneal dystrophies, atypical clinical findings may be produced by previously identified, conserved mutations.