Comparative Study of Anterior Eye Segment Measurements with Spectral Swept-Source and Time-Domain Optical Coherence Tomography in Eyes with Corneal Dystrophies.

PURPOSE: To compare anterior eye segment measurements and morphology obtained with two optical coherence tomography systems (TD OCT, SS OCT) in eyes with corneal dystrophies (CDs). METHODS: Fifty healthy volunteers (50 eyes) and 54 patients (96 eyes) diagnosed with CD (epithelial basement membrane dystrophy, EBMD = 12 eyes; Thiel-Behnke CD = 6 eyes; lattice CD TGFBI type = 15 eyes; granular CD type 1 = 7 eyes, granular CD type 2 = 2 eyes; macular CD = 23 eyes; and Fuchs endothelial CD = 31 eyes) were recruited for the study. Automated and manual central corneal thickness (aCCT, mCCT), anterior chamber depth (ACD), and nasal and temporal trabecular iris angle (nTIA, tTIA) were measured and compared with Bland-Altman plots. RESULTS: Good agreement between the TD and SS OCT measurements was demonstrated for mCCT and aCCT in normal individuals and for mCCT in the CDs group. The ACD, nTIA, and tTIA measurements differed significantly in both groups. TBCD, LCD, and FECD caused increased CCT. MCD caused significant corneal thinning. FECD affected all analyzed parameters. CONCLUSIONS: Better agreement between SS OCT and TD OCT measurements was demonstrated in normal individuals compared to the CDs group. OCT provides comprehensive corneal deposits analysis and demonstrates the association of CD with CCT, ACD, and TIA measurements.

Phenotype and genotype analysis in patients with macular corneal dystrophy.

AIM: The aim of this study was to analyse corneal morphological organisation and identify mutations in the carbohydrate sulfotransferase 6 gene (CHST6) in patients with macular corneal dystrophy originating in a Polish population. METHODS: Macular corneal dystrophy was diagnosed in 24 patients based on the slit-lamp exam, confocal microscopy, 1310 nm time domain and 840 nm spectral domain optical coherence tomography. 10 corneal buttons obtained from penetrating keratoplasty were processed for light microscopy. Genetic analysis of the CHST6 gene was performed, followed by a study of the sequencing results. RESULTS: Highly reflective, diffuse corneal deposits and a general increase in reflectivity were revealed with optical coherence tomography and confocal microscopy. The deposits extended from the Bowman layer to the Descemet membrane and correlated with the Alcian blue-positive granular-filamentous material into and around the stromal keratocytes confirmed by structural analysis of the corneal buttons. The genetic analysis of the blood samples identified the following mutations and single nucleotide polymorphisms: novel P64L (heterozygous), Y110C (homozygous), R162G and L200R, and M1L (heterozygous and homozygous). CONCLUSIONS: Genetic mutation heterogeneity was revealed. No phenotype heterogeneity was revealed among patients with in vivo corneal morphology assessment or histological analysis.

Phenotype-genotype correlation in patients with Schnyder corneal dystrophy.

PURPOSE: The aim of this study was to analyze the corneal morphology features and define mutations in the UbiA prenyltransferase domain-containing 1 (UBIAD1) gene in patients with Schnyder corneal dystrophy from a Polish population. METHODS: Five affected and 15 unaffected members originating from 3 families with Schnyder corneal dystrophy were included in the study. Phenotype analysis consisted of visual acuity, slit-lamp biomicroscopy with photography, time domain optical coherence tomography, spectral domain optical coherence tomography, and confocal microscopy. Three patients underwent a penetrating keratoplasty. Corneal buttons obtained from the penetrating keratoplasty were processed for light microscopy. RESULTS: A novel mutation I245N of the UBIAD1 gene was revealed in 1 proband and associated with the phenotype without central corneal opacities. The analysis of the other patients showed the N102S mutation. In vivo corneal morphology analysis using optical coherence tomography and confocal microscopy confirmed the presence of multiple crystalline corneal deposits in all affected corneas. The histological examination revealed multiple empty widenings of the corneal lamellae that could represent lipids removed from the specimen. CONCLUSIONS: N102S may also be a mutation hotspot in the Polish population, as in other previously reported populations. Corneal crystals formed a characteristic pattern on optical coherence tomography scans.

Donor disc attachment assessment with intraoperative spectral optical coherence tomography during descemet stripping automated endothelial keratoplasty.

Optical coherence tomography has already been proven to be useful for pre- and post-surgical anterior eye segment assessment, especially in lamellar keratoplasty procedures. There is no evidence for intraoperative usefulness of optical coherence tomography (OCT). We present a case report of the intraoperative donor disc attachment assessment with spectral-domain optical coherence tomography in case of Descemet stripping automated endothelial keratoplasty (DSAEK) surgery combined with corneal incisions. The effectiveness of the performed corneal stab incisions was visualized directly by OCT scan analysis. OCT assisted DSAEK allows the assessment of the accuracy of the Descemet stripping and donor disc attachment.

Genotype-phenotype correlation of TGFBI corneal dystrophies in Polish patients.

PURPOSE: To analyze genotype-phenotype correlation in patients originating from Polish population with the transforming growth factor beta induced (TGFBI) corneal dystrophies. METHODS: Sixty affected and 31 unaffected individuals from 15 unrelated Polish families were included in the study. The clinical diagnosis was based on the slit-lamp exam, 1310 nm time domain and 1310 nm swept source spectral domain optical coherence tomography (OCT). Histopathologic analysis was performed on 10 available corneal buttons. Exons of the TGFBI gene were screened for mutations with polymerase chain reaction (PCR) and direct DNA sequencing. RESULTS: We found the lattice phenotype dominant compared to the granular one in the Polish population (41:16 patients; lattice:granular). We identified five distinct mutations responsible for TGFBI corneal dystrophies (R124R, R124H, R555W, R555Q, and H626R). There was a strong genotype-phenotype correlation in the case of R124R and R555W mutations, while there was a distinct phenotypic heterogeneity in the case of the H626R mutation. OCT analysis revealed that the reflectivity, location and pattern of the corneal deposits were different among the TGFBI corneal dystrophies. The advantage of spectral swept source OCT over time-domain OCT scans is a more distinct visualization of the Bowman's layer area and deposits located under the epithelium. CONCLUSIONS: This study underlines the role of comprehensive phenotype-genotype analysis in TGFBI corneal dystrophies, describes for the first time the TGFBI mutation spectrum in a Polish population and reveals phenotypic heterogeneity in the case of the H626R mutation.

Anterior segment imaging: Fourier-domain optical coherence tomography versus time-domain optical coherence tomography.

PURPOSE: To compare anterior segment measurements and morphology of 2 optical coherence tomography (OCT) systems. SETTING: Department of Ophthalmology, District Railway Hospital, and the Nursing Department and Social Medical Issues, Health Care Division, Silesian Medical University, Katowice, Poland. METHODS: In normal eyes and in eyes with corneal and trabecular-iris angle disorders, the central corneal thickness (CCT), trabecular-iris angle, and angle-opening distance at the nasal and temporal angles were measured 3 times during 1 visit using the Visante time-domain OCT system and the RTVue-100 Fourier-domain corneal anterior module OCT system. Anterior segment morphology was assessed and compared. RESULTS: Fifty-four eyes were evaluated. The mean values (+/-SD) by time-domain OCT and Fourier-domain OCT were, respectively, automatic CCT, 535 +/- 33.07 microm and 538 +/- 31.82 microm; manual CCT, 545 +/- 30.91 microm and 542 +/- 30.57 microm; nasal trabecular-iris angle, 34.7 +/- 9.5 degrees and 35.2 +/- 8.9 degrees; temporal trabecular-iris angle, 35.3 +/- 8.5 degrees and 35.5 +/- 9 degrees; nasal angle-opening distance, 435 +/- 95 microm and 444 +/- 98 microm; and temporal angle-opening distance, 443 +/- 103 microm and 452 +/- 99 microm. There was no significant difference between mean values, and they were highly correlated. On morphologic analysis, time-domain OCT had lower resolution; however, all anterior chamber structures were visible on 1 image. Fourier-domain OCT provided precise information about small areas of the anterior chamber. CONCLUSION: Fourier-domain OCT provided accurate anterior eye segment measurements that agreed with those obtained with time-domain OCT.