New histopathologic and ultrastructural findings in Reis-Bücklers corneal dystrophy caused by the Arg124Leu mutation of TGFBI gene

Recurrence Characteristics on Optical Coherence Tomography and Treatments of Reis-Bücklers Corneal Dystrophy After Phototherapeutic Keratectomy or Penetrating Keratoplasty

PURPOSE

To evaluate the recurrence characteristics on optical coherence tomography and clinical outcomes after phototherapeutic keratectomy (PTK) or penetrating keratoplasty (PKP) in patients with Reis-Bücklers corneal dystrophy (RBCD).

DESIGN

Retrospective interventional case series.

METHODS

Seventeen patients with RBCD (31 eyes, including 6 surgery-naïve eyes and 25 surgical eyes) received 44 surgical interventions from 1996 through 2022. PTK or PKP was performed as the initial surgical procedure. Significant recurrence was determined when best spectacle-corrected visual acuity decreased at least 2 lines with increased opacity in the superficial cornea. Repeated PTK or PTK on the corneal graft (CG-PTK) was considered if patients could not endure poor vision due to significant recurrence. Recurrence depth and annual increase in thickness of the central cornea and subepithelial deposits were assessed by anterior segment optical coherence tomography.

RESULTS

The mean follow-up time was 12.8 ± 8.5 years (range, 2.0-25.5 years). The mean logMAR best spectacle-corrected visual acuity improved from 1.24 ± 0.48 preoperatively to 0.27 ± 0.09 postoperatively in the initial PTK group (13 eyes, P < .001), from 1.84 ± 0.69 to 0.40 ± 0.13 in the PKP group (12 eyes, P < .001), from 1.04 ± 0.46 to 0.30 ± 0.07 in the repeated PTK group (12 times in 7 eyes, P < .001), and from 1.29 ± 0.43 to 0.39 ± 0.11 in the CG-PTK group (7 times in 5 eyes, P = .001). The median significant recurrence time was 27 months (95% confidence interval 23.9-30.1), 96 months (84.1-107.9), 31 months (28.8-33.1), and 24 months (19.8-28.2), respectively (P < .001). The depth of superficial deposits located between the epithelium and the anterior stroma was approximately 115 µm (85-159 µm). The annual thickening of subepithelial deposits was 14 ± 2 µm after initial PTK, 7 ± 3 µm after PKP, 14 ± 3 µm after repeated PTK, and 30 ± 11 µm after CG-PTK, compared to 4 ± 2 µm in surgery-naïve eyes (P = .002, .515, .002, <.001). The thickness of the central cornea increased by 15 ± 2 µm, 7 ± 2 µm, 15 ± 3 µm, and 31 ± 10 µm per year in the 4 surgery groups, respectively, compared to 5 ± 2 µm in surgery-naïve eyes (P = .001, .469, .001, <.001).

CONCLUSIONS

Better visual acuity can be achieved after PTK than PKP for treatment of RBCD. The annual thickening of subepithelial deposits may approximate an increase in central corneal thickness. The superficial distribution of subepithelial deposits makes it feasible to perform repeated PTK, even on the corneal allograft, for recurrent RBCD.

Corneal epithelial development and homeostasis

The corneal epithelium (CE), the most anterior cellular structure of the eye, is a self-renewing stratified squamous tissue that protects the rest of the eye from external elements. Each cell in this exquisite three-dimensional structure needs to have proper polarity and positional awareness for the CE to serve as a transparent, refractive, and protective tissue. Recent studies have begun to elucidate the molecular and cellular events involved in the embryonic development, post-natal maturation, and homeostasis of the CE, and how they are regulated by a well-coordinated network of transcription factors. This review summarizes the status of related knowledge and aims to provide insight into the pathophysiology of disorders caused by disruption of CE development, and/or homeostasis.

The observation of anterior segment in children with an R124L mutation corneal dystrophy by anterior segment optical coherence tomography and in vivo confocal microscopy

Purpose

To evaluate the anterior segment in children with an R124L mutation corneal dystrophy (CD) using anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM).

Methods

We investigated a family with prevalent CD and an R124L mutation; 59 individuals (14 patients; 6 male and 8 female, aged 2–69 years, 6 children, 2:4 male: female ratio) from four generations were included. We observed corneal lesions through ophthalmologic examinations, AS-OCT, and IVCM. The mean follow-up was 4.60 ± 3.91 years.

Results

The mean age for childhood CD onset was 0.90 ± 0.61 years. An Avelino DNA test revealed a heterozygous R124L mutation. Clinical manifestations included recurrent photophobia, tearing, and a foreign body sensation. Recurrence frequency decreased with age. Slit lamp microscopy revealed a rough corneal epithelium. The anterior matrix under the corneal epithelium and the anterior elastic layer were scattered with gray and white opacity. From onset to follow-up, the children’s visual acuity decreased from 0.34 ± 0.12 to 0.55 ± 0.17 LogMAR units. AS-OCT showed uneven corneal epithelial thickness. The Bowman’s layer was replaced by abnormal substances in the anterior segment. Corneal deposits became increasingly thicker; the average thickness at the last follow-up was 102.78 ± 10.13 μm. IVCM revealed uneven and reflective signals in the corneal upper cortex and subepithelium, with unclear boundaries and a loss of normal cell morphology.

Conclusion

We report an early age of onset in a family with prevalent CD due to R124L mutations. AS-OCT is a convenient, quick, and non-contact tool for screening and monitoring the pathological process of CD.

[Corneal dystrophies in optical coherence tomography]

BACKGROUND

Corneal optical coherence tomography (anterior segment OCT, AS-OCT) is described in the current IC3D classification of corneal dystrophies to be a method for improvement of clinical diagnostics and treatment.

OBJECTIVE

In this case series AS-OCT images of corneal dystrophies were analyzed with respect to morphological changes.

MATERIAL AND METHODS

This was a retrospective imaging and morphological case series with 38 eyes. For image acquisition the corneal module of the high-resolution spectral-domain OCT Zeiss Cirrus HD-5000 platform (Oberkochen, Germany) was employed. The following corneal dystrophies were analyzed: epithelial basement membrane dystrophy, Meesmann corneal dystrophy, Reis-Bücklers corneal dystrophy, granular corneal dystrophy type 1, granular corneal dystrophy type 2 and macular corneal dystrophy.

RESULTS

The AS-OCT images showed the typical changes of the dystrophies through hyperreflectivity and hyporeflectivity in the individual corneal layers. The findings in the AS-OCT images correlated well with the histological descriptions in the literature and provided additional information to the slit lamp examination, especially with respect to the exact location of the alterations.

CONCLUSION

Corneal AS-OCT imaging seems to be a helpful tool for determination of morphological changes in patients with corneal dystrophies and can facilitate both the diagnostics and surgical treatment decisions.

Identification of Prognostic Biomarkers by Combined mRNA and miRNA Expression Microarray Analysis in Pancreatic Cancer

Pancreatic cancer is the fourth leading cause for cancer-related death, and early diagnosis is one key to improve the survival rate of this disease. Molecular biomarkers are an important method for diagnostic use in pancreatic cancer. We used data from three mRNA microarray datasets and a microRNA dataset (GSE16515, GSE15471, GSE28735, and GSE41372) to identify potential key genes. Differentially expressed genes (DEGs) and microRNAs (DEMs) were identified. Functional, pathway enrichment, and protein-protein interaction analyses were performed on common DEGs across all datasets. The target genes of the DEMs were identified. DEMs targets that were also DEGs were further scrutinized using overall survival analysis. A total of 236 DEGs and 21 DEMs were identified. There were a total of four DEGs (ECT2, NR5A2, NRP2, and TGFBI), which were also predicted target genes of DEMs. Overall survival analysis showed that high expression levels of three of these genes (ECT2, NRP2, and TGFBI) were associated with poor overall survival for pancreatic cancer patients. The basic expression of DEGs in pancreas stood lower level in various organ tissues. The expression of ECT2 and NRP2 was higher in different pancreatic cancer cell lines than normal pancreas cell line. Knockout of ECT2 by Crispr Cas9 gene editing system decreased proliferation and migration ability in pancreatic cancer cell line MiaPaCa2. In conclusion, we think that data mining method can do well in biomarker screening, and ECT2 and NRP2 can play as potential biomarker or therapy target by Crispr Cas9 in pancreatic cancer.