Attila Vajas

Assessment and reproducibility of anterior chamber depth measurement with anterior segment optical coherence tomography compared with immersion ultrasonography

PURPOSE: To measure anterior chamber depth (ACD) with an anterior segment optical coherence tomography (AS‐OCT) and a standard ultrasonic (US) axial scan (A‐scan) device using an immersion technique and to assess repeatability, reproducibility, and correlations of the measurements. SETTING: Department of Ophthalmology, Medical Health and Science Center, University of Debrecen, Debrecen, Hungary. METHODS: Sixty healthy eyes of 41 patients were enrolled in a study. The central ACD was measured 5 times with AS‐OCT (Visante, Carl Zeiss Meditec) using its chamber tool and 5 times with a US A‐scan device (UltraScan Imaging System, Alcon Laboratories) using an immersion method. The measurements were performed consecutively by 2 independent observers. RESULTS: The mean ACD measured with AS‐OCT was 3.12 mm ± 0.33 (SD) by observer 1 and 3.11 ± 0.33 mm by observer 2 (P = .78). The repeatability was 0.8% ± 0.4% and 1.9% ± 1.4%, respectively. The reproducibility was 0.23%. The reliability coefficient with AS‐OCT was 99.6%. The mean ACD measured with immersion US A‐scan was 2.98 ± 0.33 mm by observer 1 and 2.95 ± 0.34 mm by observer 2 (P = .68). The repeatability was 6.4% ± 3.8% by observer 1 and 8.5% ± 4.9% by observer 2. The reproducibility was 0.88%. The reliability coefficient was 87.1% for US A‐scan measurements. The difference between ACD values with AS‐OCT and values with US A‐scan was statistically significant (P = .02). The correlation (r) between AS‐OCT and US A‐scan was 0.732 (P<.0001) by observer 1 and 0.802 (P<.0001) by observer 2. CONCLUSIONS: Anterior chamber measurements were significantly deeper with AS‐OCT than with US immersion A‐scan. Repeatability of ACD measurements was better with AS‐OCT than with immersion US, and reproducibility was equal with the 2 methods.

Anterior chamber depth measurements in phakic and pseudophakic eyes: Pentacam versus ultrasound device.

PURPOSE: To compare anterior chamber depth (ACD) measurements with a new optical device with those taken with a standard ultrasound (US) device in emmetropic phakic and pseudophakic eyes. SETTING: Department of Ophthalmology, Medical Health and Science Center, University of Debrecen, Debrecen, Hungary. METHODS: Forty‐two phakic and 42 pseudophakic patients with normal axial lengths (mean 22.91 mm ± 1.21 [SD]) were enrolled in the study. The ACD was measured 3 times with Scheimpflug‐based Pentacam (Oculus) and then 3 times with a standard A‐scan US device (AL‐2000, Tomey). The data were then analyzed. RESULTS: In the phakic group, the mean ACD was 2.87 ± 0.4 mm with the Pentacam and 2.89 ± 0.49 mm with ultrasound A‐scan (US) (P = .84). In the pseudophakic group, the mean ACD was 3.41 ± 0.28 mm and 3.97 ± 0.45 mm, respectively (P<.001). The correlation between measurements was significant in both the phakic and pseudophakic groups (r = .547/P<.001 and r = .404/P = .01, respectively). CONCLUSIONS: In phakic eyes, ACD measured with the Pentacam and with US was the same. However, in pseudophakic eyes, the difference was significantly lower when the ACD was measured with the Pentacam. Therefore, in pseudophakic patients, further evaluation of ACD data with the Scheimpflug‐based system is necessary.

Comparison of central corneal thickness measurements with a new optical device and a standard ultrasonic pachymeter

PURPOSE: To compare central corneal thickness (CCT) values obtained with ultrasonic pachymetry and a new optical method using partial coherence interferometry (PCI). SETTING: Department of Ophthalmology, Medical Health and Science Center, University of Debrecen, Debrecen, Hungary. METHODS: The study comprised 136 eyes of 70 patients whose spherical refractive error was not greater than ±6.0 diopters (D) and whose keratometric astigmatism was not greater than 2.0 D. Central corneal thickness was measured 5 times with a new optical device (ACMaster, Zeiss) and with an ultrasonic pachymeter (AL‐2000, Tomey). All measurements were obtained by the same investigator. RESULTS: Mean CCT was 531.2 μm ± 3.9 (SD) with PCI and 547.8 ± 36.0 μm with the ultrasonic device. The difference between groups was significant (P = .001). There was no difference between CCT values measured in right and left eyes (P = .55) with ultrasonography and PCI (P = .67). The coefficient variation was 0.73% for PCI and 6.5% for ultrasonography. Correlation between the CCT measurements with both devices was strong and statistically significant (Spearman correlation = .91, P = .001). CONCLUSIONS: Mean CCT values measured by the PCI method were significantly smaller than those measured by the ultrasonic device. Central corneal thickness measured with PCI is more reproducible and seems to be more reliable than that measured by ultrasonography.

Analysis of complement factor H Y402H, LOC387715, HTRA1 polymorphisms and ApoE alleles with susceptibility to age‐related macular degeneration in Hungarian patients

Purpose:  Recent studies strongly support the role of genetic factors in the aetiology of age‐related macular degeneration (AMD). We investigated the frequency of Tyr402His polymorphism of the complement factor H (CFH) gene, Ser69Ala polymorphism at LOC387715, rs11200638 polymorphism of the HTRA1 gene and different apolipoprotein E (ApoE) alleles in Hungarian patients with AMD in order to determine the disease risk conferred by these factors.

Keratometry evaluations with the Pentacam high resolution in comparison with the automated keratometry and conventional corneal topography

Purpose: To determine the reliability and repeatability of keratometry (K) measurements obtained with the Pentacam high resolution (HR), automated keratometry, and corneal topography systems. Methods: The right eyes of 46 healthy subjects were examined prospectively. Keratometry measurements in the flat (Kf) and steep (Ks) meridians were taken by 2 independent investigators with the Pentacam HR (Oculus, Wetzlar, Germany) followed by automated keratorefractometry (KR-8100; Topcon, Tokyo, Japan), and corneal topography (TMS-4; Tomey, Erlangen, Germany). Results: The mean K readings of the Pentacam HR, automated keratometry, and corneal topography were 43.40/43.34 diopter (D), 43.99/43.98 D, and 43.80/43.83 D, respectively. The difference between the values was statistically significant (P < 0.0001, repeated measures analysis of variance). Strong significant correlation was observed between the Pentacam HR and keratometry (Kf: r = 0.952/0.954; Ks: r = 0.845, Spearman rank test), and Pentacam HR and corneal topography (Kf: r = 0.933/0.930; Ks: r = 0.838/0.829) (P < 0.0001). No significant difference was presented between the 2 investigators for any of the instruments (P = 0.215–0.983). Moreover, high correlation was found between the K readings of the observers (interoperator intraclass correlation coefficients ranged from 0.95 to 0.99). Conclusions: The Pentacam HR provided reliable K measurements in clinical practice in comparison with an automated keratometer and a corneal topographer. Based on the results, for patient follow-up, one keratometry device is recommended.

Clearance of dying ARPE-19 cells by professional and nonprofessional phagocytes in vitro– implications for age-related macular degeneration (AMD)

Acta Ophthalmol. 2011: 89: e30–e34

Effect of the Gas6 c.834+7G>A Polymorphism and the Interaction of Known Risk Factors on AMD Pathogenesis in Hungarian Patients

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly in the developed world. Numerous genetic factors contribute to the development of the multifactorial disease. We performed a case-control study to assess the risk conferred by known and candidate genetic polymorphisms on the development of AMD. We searched for genetic interactions and for differences in dry and wet AMD etiology. We enrolled 213 patients with exudative, 67 patients with dry AMD and 106 age and ethnically matched controls. Altogether 12 polymorphisms in Apolipoprotein E, complement factor H, complement factor I, complement component 3, blood coagulation factor XIII, HTRA1, LOC387715, Gas6 and MerTK genes were tested. No association was found between either the exudative or the dry form and the polymorphisms in the Apolipoprotein E, complement factor I, FXIII and MerTK genes. Gas6 c.834+7G>A polymorphism was found to be significantly protective irrespective of other genotypes, reducing the odds of wet type AMD by a half (OR = 0.50, 95%CI: 0.26–0.97, p = 0.04). Multiple regression models revealed an interesting genetic interaction in the dry AMD subgroup. In the absence of C3 risk allele, mutant genotypes of both CFH and HTRA1 behaved as strongly significant risk factors (OR = 7.96, 95%CI: 2.39 = 26.50, p = 0.0007, and OR = 36.02, 95%CI: 3.30–393.02, p = 0.0033, respectively), but reduced to neutrality otherwise. The risk allele of C3 was observed to carry a significant risk in the simultaneous absence of homozygous CFH and HTRA1 polymorphisms only, in which case it was associated with a near-five-fold relative increase in the odds of dry type AMD (OR = 4.93, 95%CI: 1.98–12.25, p = 0.0006). Our results suggest a protective role of Gas6 c.834+7G>A polymorphism in exudative AMD development. In addition, novel genetic interactions were revealed between CFH, HTRA1 and C3 polymorphisms that might contribute to the pathogenesis of dry AMD.

Myopia and Late-Onset Progressive Cone Dystrophy Associate to LVAVA/MVAVA Exon 3 Interchange Haplotypes of Opsin Genes on Chromosome X

Purpose Rare interchange haplotypes in exon 3 of the OPN1LW and OPN1MW opsin genes cause X-linked myopia, color vision defect, and cone dysfunction. The severity of the disease varies on a broad scale from nonsyndromic high myopia to blue cone monochromatism. Here, we describe a new genotype-phenotype correlation attributed to rare exon 3 interchange haplotypes simultaneously present in the long- and middle-wavelength sensitive opsin genes (L- and M-opsin genes). Methods A multigenerational family with X-linked high myopia and cone dystrophy was investigated. Results Affected male patients had infantile onset myopia with normal visual acuity and color vision until their forties. Visual acuity decreased thereafter, along with the development of severe protan and deutan color vision defects. A mild decrease in electroretinography response of cone photoreceptors was detected in childhood, which further deteriorated in middle-aged patients. Rods were also affected, however, to a lesser extent than cones. Clinical exome sequencing identified the LVAVA and MVAVA toxic haplotypes in the OPN1LW and OPN1MW opsin genes, respectively. Conclusion Here, we show that LVAVA haplotype of the OPN1LW gene and MVAVA haplotype of the OPN1MW gene cause apparently nonsyndromic high myopia in young patients but lead to progressive cone-rod dystrophy with deuteranopia and protanopia in middle-aged patients corresponding to a previously unknown disease course. To the best of our knowledge, this is the first report on the joint effect of these toxic haplotypes in the two opsin genes on chromosome X.

The effect of a Gas6 c.834+7G>a polymorphism and the interaction of known risk factors on AMD pathogenesis in Hungarian patients

Purpose We performed a case‐control study to search for genetic interactions and for differences in dry and wet age‐related macular degeneration (AMD) pathogenesis.