Association of unilateral lattice corneal dystrophy on slit lamp and bilateral confocal microscopy features with H572R mutation in the TGFBI gene

Unilateral lattice corneal dystrophy with c.1501C>A (p.P501T) and c.1733T>C (p.L578P) variants in the transforming growth factor-beta induced gene: a case report

BACKGROUND

Corneal dystrophies (CDs) significantly affect quality of life. However, their progression and characteristics remain unclear. This study aimed to report a case of a unilateral variant of lattice corneal dystrophy (LCD) with c.1501C>A (p.P501T) and c.1733T>C (p.L578P) variants in the transforming growth factor-beta-induced (TGFBI) gene.

CASE PRESENTATION

A 39-year-old Japanese woman presented with ocular pain and decreased visual acuity in the left eye. A slit-lamp examination of her left cornea revealed recurrent corneal erosion complicated by contact lens-associated infectious keratitis, fine lattice lines, and central corneal haze in the anterior stroma, with no opacities in the right cornea. In vivo confocal microscopic examination of the right eye showed highly reflective branching filaments in the corneal stroma, whereas the left cornea was unremarkable. Based on these clinical findings, we diagnosed the patient with unilateral LCD. The molecular genetic analysis revealed the TGFBI: a c.1501C>A (p.P501T) variant in exon 11 and the c.1733T>C (p.L578P) variant in exon 13.

CONCLUSION

A 39-year-old female patient with LCD with c.1501C>A (p.P501T) and c.1733T>C (p.L578P) TGFBI variants exhibited unilateral corneal findings, including recurrent corneal erosion, fine lattice lines, and central corneal haze in the anterior stroma. The study's findings could benefit CD treatment.

Unilateral Granular Type 2 Corneal Dystrophy With Exacerbation After LASIK

PURPOSE

The aim of this study was to report a case of unilateral granular corneal dystrophy type 2 (GCD2) with exacerbation after bilateral laser in situ keratomileusis (LASIK).

METHODS

Clinical evaluation, Scheimpflug imaging, anterior segment optical coherence tomography (AS-OCT), cytology, and genetic testing were used to confirm the diagnosis of unilateral GCD2 with exacerbation after bilateral LASIK. Detailed literature review for possible unilateral GCD2 presentations was performed.

RESULTS

A 54-year-old White woman presented with blurred vision in her left eye and a history of bilateral LASIK performed 8 years before. Examination revealed dense opacities in the left cornea only, which were confirmed to be confined to the LASIK interface and adjacent corneal stromal tissue, as determined by AS-OCT. The patient underwent flap lift, interface debris removal, and stromal bed phototherapeutic keratectomy. Cytological analysis showed eosinophilic corneal stromal deposits that stained with trichrome stain and were congophilic on Congo red stain. Genetic testing was positive for heterozygous GCD2 transforming growth factor β-induced gene ( TGFBI ), c.371G>A, p.R124H mutation. There were no opacities identifiable in the right eye on serial slit-lamp examination, Scheimpflug imaging, or OCT imaging at 4 or 8 years after bilateral LASIK. Literature review failed to identify any previous reports of unilateral GCD2.

CONCLUSIONS

This is the first known reported case of unilateral granular corneal dystrophy type 2. LASIK is contraindicated in eyes with corneal stromal dystrophies related to mutations in TGFBI as both flap creation and laser ablation can exacerbate visually significant opacity formation. Scheimpflug and AS-OCT imaging are useful to identify opacities in GCD2.

Confirmation of association of TGFBI p.Ser591Phe mutation with variant lattice corneal dystrophy

PURPOSE

To provide the initial confirmation of the c.1772C>T (p.Ser591Phe) mutation in the transforming growth factor-β-induced (TGFBI) gene as being associated with variant lattice corneal dystrophy (LCD).

METHODS

Ophthalmologic examination of the proband was performed with slit lamp biomicroscopy. Saliva was collected as a source of DNA for screening all 17 exons of TGFBI, after which three family members were selectively screened for variants in exon 13. Rosetta-based structure prediction was used to calculate changes in TGFBI protein (TGFBIp) stability secondary to the c.1772C>T (p.Ser591Phe) missense mutation.

RESULTS

Slit lamp examination of the 38-year-old proband revealed a clear cornea right eye and unilateral, discrete, and branching lattice lines in the anterior and mid-stroma of the central cornea left eye. Screening of TGFBI in the proband revealed a heterozygous missense mutation in exon 13 (c.1772C>T (p.Ser591Phe)) that was also identified in her affected mother but not in her brother or maternal grandmother. Calculated energy change in Rosetta (ΔΔG) for the TGFBIp variant p.Ser591Phe was 23.5, indicating a thermodynamic destabilization resulting from energetic frustration.

CONCLUSIONS

The p.Ser591Phe mutation in TGFBI is associated with an unilateral variant of LCD. Rosetta-predicted stability changes indicate that the p.Ser591Phe variant is destabilizing, which is consistent with other observations for LCD-causing mutations.

In vivo confocal microscopy qualitative investigation of the relationships between lattice corneal dystrophy deposition and corneal nerves

Background

To investigate the corneal neurotropic phenomenon in patients with lattice corneal dystrophy (LCD) with in vivo laser scanning confocal microscopy (IVCM).

Methods

IVCM was performed on a total of 15 patients (28 eyes) with LCD annually at a follow-up. A collection of the data was acquired to be analyzed.

Results

As indicated by the analysis, the LCD patients’ normal corneal stromal nerves (Grade 0) presented a decline with the prolongation of the follow-ups, corresponding to a gradual increase in grade I and II involving amyloid-wrapped nerve fibers, which demonstrated that the growing amount of amyloid deposit due to the corneal nerve invasion increased slowly over time.

Conclusions

The neurotropic phenomenon could increase with its severity in the corneal lesion of the patients with LCD, and also reflect the distribution of the corneal nerves, to some extent. IVCM provides a rapid, noninvasive way to observe the corneal nerves, which can be an efficient means of better understanding the development of LCD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02149-1.