George Kitsos | University of Ioannina/Greece (original) (raw)

Papers by George Kitsos

Research paper thumbnail of Prenatal detection of an inverted duplication deletion in the long arm of chromosome 1 in a fetus with increased nuchal translucency. Molecular cytogenetic analysis and review of the literature

Clinical Dysmorphology, 2012

Research paper thumbnail of Neurological manifestations of connective tissue diseases mimicking multiple sclerosis

Rheumatology International, 2007

The objective of the study was to analyze retrospectively the clinical, laboratory and imaging fi... more The objective of the study was to analyze retrospectively the clinical, laboratory and imaging findings of multiple sclerosis (MS), such as the manifestations in a cohort of 132 patients referred to the neurology in and outpatient clinic. The proposed clinical and laboratory diagnostic criteria for MS and connective tissue disorders were systematically assessed in 132 consecutive patients. Cerebrospinal fluid serology and brain or spinal cord MRI were studied in all cases. In patients suspected for connective tissue disorder, schirmer test, rose bengal staining and biopsy of minor salivary glands were performed. A total of 115 (87%) patients were diagnosed to have definite MS, while 17 (13%) were diagnosed to have connective tissue disorder. Positive neurological and MRI findings were observed in both groups. The majority of patients with connective tissue disorder demonstrated extra-neurological manifestations like Raynaud's phenomenon, arthritis, livedo reticularis, purpura and presence of multiple autoantibodies in their sera. All patients with MS should be screened systematically for connective tissue disorder. In the absence of pathognomonic clinical and laboratory findings, the diagnosis of MS is a diagnosis of exclusion.

Research paper thumbnail of Perimetric and peri-papillary nerve fibre layer thickness findings in multiple sclerosis

European Journal of Neurology, 2010

Several previous studies have employed optical coherence tomography (OCT) of the optic disc and &... more Several previous studies have employed optical coherence tomography (OCT) of the optic disc and 'white-on-white' automated perimetry to evaluate optic neuritis (ON) associated with multiple sclerosis (MS). This study employed OCT, white-on-white automated perimetry as well as 'blue-on-yellow' automated perimetry to evaluate MS patients with or without episodes of ON. The MS group consisted of 56 patients with MS (27 patients with no history of ON in both eyes and 29 patients with at least one ON attack in one or both eyes), whereas the control group consisted of 56 age- and sex-matched healthy subjects. All patients underwent a complete neurological and ophthalmological examination. Peri-papillary retinal nerve fibre layer thickness (RNFLT) was evaluated using OCT. The mean defect and pattern standard deviation for both white-on-white and blue-on-yellow perimetry were also recorded. RNFLT and perimetric scores were significantly lower in MS group without a history of ON and in the unaffected eyes of MS group with unilateral ON, compared with controls. MS group with more than one ON episodes had significantly compromised blue-on-yellow perimetric indices, compared with patients with one ON episode, whereas respective differences for white-on-white perimetry were not statistically significant. The significantly lower RNFLT and perimetric scores in MS group patients without ON, compared with control group, may possibly be attributed to sub-clinical episodes of ON or to retrograde degeneration of nerve cells from sub-clinical post-chiasmal lesions. Blue-on-yellow perimetry may be advantageous over white-on-white perimetry in evaluating MS-associated functional defects.

Research paper thumbnail of Periocular xanthogranuloma: A forgotten entity?

Clinical Ophthalmology, 2010

Research paper thumbnail of Conventional MRI and magnetisation transfer imaging of the brain and optic pathway in primary open-angle glaucoma

The British Journal of Radiology, 2009

Neuropathological studies in experimental and human glaucoma have shown degenerative changes in t... more Neuropathological studies in experimental and human glaucoma have shown degenerative changes in the optic pathway. The purpose of the study was to evaluate, with conventional MRI and magnetisation transfer imaging, the brain and the optic pathway of patients with primary open-angle glaucoma (POAG). 26 patients, aged 67.4¡8.6 years, and 26 control subjects were studied. The presence of white matter hyperintensities (WMH) was evaluated on fluid-attenuated inversion recovery images of the brain. The area of the optic nerves was assessed on coronal short tau inversion recovery images. Magnetisation transfer ratio (MTR) was measured in the chiasm and in the grey and white matter (CGM and CWM) of the calcarine fissure. More WMH were observed in patients (total 261, mean 10.8, standard deviation 12.7) than in control subjects (total 127, mean 4.7, standard deviation 5.7; p,0.001). The area (mm 2) of optic nerves (10.7¡5.7) and the MTR (%) of the chiasm (53.7¡8.4), the CWM (60.9¡4.2) and the CGM (53.6¡5.6) were all lower in patients than in control subjects (13.6¡4.3, 62.1¡6.2, 67.6¡8.6 and 57.0¡4.6, respectively; p,0.05). The area of optic nerves showed significant correlation with the MTR of the chiasm (R50.41), the MTR of the CGM (R50.33), the MTR of the CWM (R50.34) and the cup to disc ratio (R5 20.46). POAG leads to optic nerve atrophy and degeneration of the optic pathway. The finding of an increase in the number of WMH suggests that cerebrovascular disease may play a role in the pathogenesis of POAG.

Research paper thumbnail of Systematic review of the association between Alzheimer’s disease and chronic glaucoma

Clinical Ophthalmology, 2014

A potential association between Alzheimer's disease (AD) and chronic glaucoma has been suggested ... more A potential association between Alzheimer's disease (AD) and chronic glaucoma has been suggested but results of epidemiological studies have been inconsistent. Therefore, we performed a systematic review and critical appraisal of this literature. We searched systematically in PubMed from December 1964 to September 2013 and identified 239 articles potentially relevant for abstract and full-text review. Statistical heterogeneity (variability) across studies was evaluated using the Cochran Q test and the I 2 statistic, and the Newcastle-Ottawa score was used to assess study quality. Ten studies were finally selected. Compared to non-demented participants, patients with AD had a statistically significant decreased risk of glaucoma but the results were very heterogeneous, and thus summary estimates were not reported (I 2 , 89%; P heterogeneity , 0.001). The study results ranged from large positive relative risks identified in small and poorly-conducted studies to weak inverse associations or null estimates observed in some cohort and record-linkage studies, but the summary estimates were essentially driven by a large retrospective cohort using medical claims that may be afflicted by underdiagnosis bias. There was also evidence for substantial publication bias (Egger's P#0.01). The association of AD and glaucoma is heterogeneous and most studies are small and inadequately designed. Large prospective studies with long follow-ups are warranted to clarify this association.

Research paper thumbnail of Assessment of hydroxychloroquine maculopathy after cessation of treatment: an optical coherence tomography and multifocal electroretinography study

Drug Design, Development and Therapy, 2015

Objective: This study was conducted to evaluate the macular status of patients treated with hydro... more Objective: This study was conducted to evaluate the macular status of patients treated with hydroxychloroquine before and after cessation of treatment. Methods: Forty-two patients with systemic lupus erythematosus underwent ocular examination based on visual acuity evaluation, optical coherence tomography retinal thickness measurements, and multifocal electroretinography (mfERG) records at first visit. The tests were repeated 6 months after treatment withdrawal and compared to the findings at their first visit. Results: Mean visual acuity (measured in log minimum angle of resolution) of both eyes was statistically increased after hydroxychloroquine discontinuation (difference in means: 0.06 [P0.0001] and 0.01 [P=0.003] for the right and left eyes, respectively). Retinal response amplitudes of central and peripheral areas were significantly improved for both eyes. The following values were observed for central responses: the difference in means was-19.9 (P0.0001) and-13.6 (P0.0001) for the right eye and the left eye, respectively; for peripheral responses, difference in means was-10.3 (P0.0001) and-9.5 (P0.0001) for right eye and left eye, respectively, after the 6-month examination. There were no statistically significant differences in the retinal thickness of patients after cessation of treatment. The visual acuity of the patients was correlated to central and peripheral mfERG responses (r=-0.53 [P0.0001] and r=-0.53 [P0.0001], for the right eye and the left eye, respectively). Conclusion: The visual acuity of patients receiving hydroxychloroquine improves along with the amplitudes of the mfERG responses 6 months after discontinuation of the drug, but no difference in retinal thickness is identified.

Research paper thumbnail of Pseudoexfoliation syndrome: Gray matter volume and microstructural changes revealed by histogram and brain surface analysis

Purpose: White matter (WM) abnormalities may occur in patients with pseudoexfoliation syndrome (P... more Purpose: White matter (WM) abnormalities may occur in patients with pseudoexfoliation syndrome (PXS). The presence of gray matter (GM) abnormalities in patients with PXS without glaucoma was evaluated, applying histogram and brain surface analysis of MRI data. Material and Methods: Brain MRI was conducted on 20 patients newly diagnosed with PXS without glaucoma, (mean age 68.7 ± 8.6 years) and 14 control subjects (mean age 63.3 ± 6.6 years). The histogram scalars of mean diffusivity (MD) and fractional anisotropy (FA) of GM and WM were evaluated. Brain surface analysis was performed on 3D T1-weighted images. Results: The MD value of the WM showed higher mean, standard deviation, median and 75 th percentile in the patients than in the control subjects. The FA values of GM showed higher mean, standard deviation, median and 75 th percentile, and lower kurtosis and skewness in the patients than in the control subjects. Greater GM volume was observed in the patients in Brodmann areas 25 ...

Research paper thumbnail of Results of a modified non-penetrating deep sclerectomy in the treatment of open angle glaucoma with or without cataract

Research paper thumbnail of A modified deep sclerectomy with or without external trabeculectomy: a comparative study

Clinical Ophthalmology

To determine whether the removal of the inner wall of Schlemm's canal (external trabeculectom... more To determine whether the removal of the inner wall of Schlemm's canal (external trabeculectomy) improves the effectiveness of a modified method of deep sclerectomy (DS), which we will call "reversed" deep sclerectomy (RDS). We conducted a prospective study of two groups of patients. Group A included 22 eyes of 18 patients with open angle glaucoma (OAG) under maximum medical treatment, which underwent RDS - a modified method of performing DS - with the removal of the inner wall of Schlemm's canal (external trabeculectomy) and without using any implant. Group B included 20 eyes of 17 patients which had undergone RDS alone. Demographic and tonometric data of patients of Group A revealed no significant difference from data of patients in Group B. A mean follow up period for Group A was 22.8 months and for Group B was 23.4 months. The outcome of the operations was termed a total success when intraocular pressure (IOP) was <21 mmHg postoperatively, without additional ...

Research paper thumbnail of Linkage studies in primary open angle glaucoma

American Journal of Human Genetics, 1994

Glaucoma is a leading cause of blindness worldwide. The majority of glaucoma is associated with a... more Glaucoma is a leading cause of blindness worldwide. The majority of glaucoma is associated with an open, normal appearing anterior chamber angle and is termed primary open angle glaucoma (POAG, MIM 137760). It is characterized by elevated intraocular pressure and onset in middle age or later. A subset of POAG with juvenile onset has recently been linked to chromosome 1q

Research paper thumbnail of Oxidative stress in dry age-related macular degeneration and exfoliation syndrome

Critical reviews in clinical laboratory sciences, 2015

Oxidative stress refers to cellular or molecular damage caused by reactive oxygen species, which ... more Oxidative stress refers to cellular or molecular damage caused by reactive oxygen species, which especially occurs in age-related conditions as a result of an imbalance between the production of reactive oxygen species and the antioxidant defense response. Dry age-related macular degeneration (AMD) and exfoliation syndrome (XFS) are two common and complex age-related conditions that can cause irreversible vision loss. Two subtypes of AMD, which is the leading cause of blindness in the Western world, exist: the most prevalent dry type and the most severe wet type. Early dry AMD is characterized by formation of drusen, which are sub-retinal deposits, in the macular area and may progress to geographic atrophy with more dramatic manifestation. XFS is a systemic disorder of the extracellular matrix characterized by the accumulation of elastic fibrils that leads, in most cases, to glaucoma development with progressive and irreversible vision loss. Due to the aging population, the prevalen...

Research paper thumbnail of Investigation of founder effects for the Thr377Met Myocilin mutation in glaucoma families from differing ethnic backgrounds

Molecular vision, 2007

The aim of this study was to determine if there is a common founder for the Thr377Met myocilin mu... more The aim of this study was to determine if there is a common founder for the Thr377Met myocilin mutation in primary open angle glaucoma (POAG) families with various ethnic backgrounds. Genomic DNA of 24 POAG-affected individuals from nine pedigrees with the Thr377Met mutation and 104 unaffected family members was genotyped with six microsatellite markers and four single nucleotide polymorphisms. The families were from Greece, India, Finland, the USA, and Australia. To assess the degree of linkage disequilibrium across MYOC in the general population we also investigated data generated from the HapMap consortium. Three distinct haplotypes associated with the Thr377Met myocilin mutation were identified. The families from the USA and Greece, as well as the three Australian families originating from Greece and the former Yugoslavian Republic of Macedonia had one common haplotype. Interestingly, however, HapMap data suggest that linkage disequilibrium across MYOC was not strong. The Thr377...

Research paper thumbnail of The situation of alcohol use and abuse in Greece

Trastornos Adictivos, 2005

Objetivo: Este artículo analiza los datos del recientemente creado Sistema Nacional Griego de Vig... more Objetivo: Este artículo analiza los datos del recientemente creado Sistema Nacional Griego de Vigilancia del Alcohol, desarrollado por el Punto Focal Griego, instituto de salud mental. El objetivo de este artículo es presentar una revisión y visión de conjunto de la situación del alcohol en Grecia.

Research paper thumbnail of A novel locus on 19q13 associated with autosomal-dominant macular dystrophy in a large Greek family

Journal of Medical Genetics, 2006

Research paper thumbnail of Exclusion of one pedigree affected by adult onset primary open angle glaucoma from linkage to the juvenile glaucoma locus on chromosome 1q21-q31

Journal of Medical Genetics, 1996

A locus for autosomal dominant juvenile onset primary open angle glaucoma (POAG) was recently ass... more A locus for autosomal dominant juvenile onset primary open angle glaucoma (POAG) was recently assigned to chromosome region lq21-q31. In the present study, a large Greek family with autosomal dominant adult onset POAG was investigated using microsatellite markers. Exclusion of linkage of the adult onset POAG gene to the region DlS194-DlS191 was obtained in this pedigree. Therefore, the data provide evidence that juvenile and adult onset POAG are genetically distinct disease entities.

Research paper thumbnail of Results of a modified non-penetrating deep sclerectomy in the treatment of open angle glaucoma with or without cataract

Clinical Ophthalmology, 2010

Research paper thumbnail of Primary open angle glaucoma due to T377M MYOC: Population mapping of a Greek founder mutation in Northwestern Greece

Clinical Ophthalmology, 2010

Background: Mutations in the MYOC gene have been shown to explain 5% of unrelated primary open an... more Background: Mutations in the MYOC gene have been shown to explain 5% of unrelated primary open angle glaucoma (POAG) in different populations. In particular, the T377M MYOC mutation has arisen at least three separate times in history, in Great Britain, India, and Greece. The purpose of this study is to investigate the distribution of the mutation among different population groups in the northwestern region of Greece.

Research paper thumbnail of Refining the primary open-angle glaucoma GLC1C region on chromosome 3 by haplotype analysis

Clinical Genetics, 2003

The GLC1C locus for primary open-angle glaucoma (POAG) is inherited as an autosomal dominant trai... more The GLC1C locus for primary open-angle glaucoma (POAG) is inherited as an autosomal dominant trait. This region on chromosome 3 is 11 cM long. DNA samples from members of a Greek and an American GLC1C family were obtained to determine whether additional typing of microsatellite markers in family members might narrow the region. GLC1C family members were evaluated clinically for POAG on the basis of open angles, intraocular pressures, cupping of discs, and visual fields. DNA samples from the Greek and Oregon GLC1C families were used to further refine the GLC1C region using microsatellite markers. A total of 22 affected members were identified in the two families. Common alleles for D3S3637 and D3S3612 were present in the disease haplotype from both families, suggesting that they may have a common founder. A newly diagnosed patient in the American family had a recombination in the distal portion of the GLC1C haplotype. This recombination narrows the GLC1C region from 11 to 4 cM.

Research paper thumbnail of Partial trisomy 17q22-qter and partial monosomy Xq27-qter in a girl with a de novo unbalanced translocation due to a postzygotic error: Case report and review of the literature on partial trisomy 17qter

American Journal of Medical Genetics, 1997

Partial trisomy 17q22-qter is a rare but well-recognized clinical entity. We present a case of pa... more Partial trisomy 17q22-qter is a rare but well-recognized clinical entity. We present a case of partial trisomy for the long arm of chromosome 17, which was detected in a female infant with severe psychomotor and somatic retardation, Stargardt disease, short limbs, and numerous minor anomalies. Differential chromosomal staining demonstrated an excess of genetic material on the long arm of the late replicating X chromosome. FISH and DNA polymorphism analysis showed that the extra material belonged to the distal part of the long arm of chromosome 17 and that there was a partial monosomy of the distal part of the long arm of the derivative X chromosome. The breakpoint regions of this translocation were identified by molecular analysis using polymorphic microsatellite markers on human chromosomes 17 and X. The origin of the abnormal X chromosome was found to be paternal, whereas the origin of the duplicated part of chromosome 17 was maternal. The unbalanced translocation between the paternal X and the maternal chromosome 17 is, therefore, suggested to be due to a postzygotic error.

Research paper thumbnail of Prenatal detection of an inverted duplication deletion in the long arm of chromosome 1 in a fetus with increased nuchal translucency. Molecular cytogenetic analysis and review of the literature

Clinical Dysmorphology, 2012

Research paper thumbnail of Neurological manifestations of connective tissue diseases mimicking multiple sclerosis

Rheumatology International, 2007

The objective of the study was to analyze retrospectively the clinical, laboratory and imaging fi... more The objective of the study was to analyze retrospectively the clinical, laboratory and imaging findings of multiple sclerosis (MS), such as the manifestations in a cohort of 132 patients referred to the neurology in and outpatient clinic. The proposed clinical and laboratory diagnostic criteria for MS and connective tissue disorders were systematically assessed in 132 consecutive patients. Cerebrospinal fluid serology and brain or spinal cord MRI were studied in all cases. In patients suspected for connective tissue disorder, schirmer test, rose bengal staining and biopsy of minor salivary glands were performed. A total of 115 (87%) patients were diagnosed to have definite MS, while 17 (13%) were diagnosed to have connective tissue disorder. Positive neurological and MRI findings were observed in both groups. The majority of patients with connective tissue disorder demonstrated extra-neurological manifestations like Raynaud&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s phenomenon, arthritis, livedo reticularis, purpura and presence of multiple autoantibodies in their sera. All patients with MS should be screened systematically for connective tissue disorder. In the absence of pathognomonic clinical and laboratory findings, the diagnosis of MS is a diagnosis of exclusion.

Research paper thumbnail of Perimetric and peri-papillary nerve fibre layer thickness findings in multiple sclerosis

European Journal of Neurology, 2010

Several previous studies have employed optical coherence tomography (OCT) of the optic disc and &... more Several previous studies have employed optical coherence tomography (OCT) of the optic disc and &#39;white-on-white&#39; automated perimetry to evaluate optic neuritis (ON) associated with multiple sclerosis (MS). This study employed OCT, white-on-white automated perimetry as well as &#39;blue-on-yellow&#39; automated perimetry to evaluate MS patients with or without episodes of ON. The MS group consisted of 56 patients with MS (27 patients with no history of ON in both eyes and 29 patients with at least one ON attack in one or both eyes), whereas the control group consisted of 56 age- and sex-matched healthy subjects. All patients underwent a complete neurological and ophthalmological examination. Peri-papillary retinal nerve fibre layer thickness (RNFLT) was evaluated using OCT. The mean defect and pattern standard deviation for both white-on-white and blue-on-yellow perimetry were also recorded. RNFLT and perimetric scores were significantly lower in MS group without a history of ON and in the unaffected eyes of MS group with unilateral ON, compared with controls. MS group with more than one ON episodes had significantly compromised blue-on-yellow perimetric indices, compared with patients with one ON episode, whereas respective differences for white-on-white perimetry were not statistically significant. The significantly lower RNFLT and perimetric scores in MS group patients without ON, compared with control group, may possibly be attributed to sub-clinical episodes of ON or to retrograde degeneration of nerve cells from sub-clinical post-chiasmal lesions. Blue-on-yellow perimetry may be advantageous over white-on-white perimetry in evaluating MS-associated functional defects.

Research paper thumbnail of Periocular xanthogranuloma: A forgotten entity?

Clinical Ophthalmology, 2010

Research paper thumbnail of Conventional MRI and magnetisation transfer imaging of the brain and optic pathway in primary open-angle glaucoma

The British Journal of Radiology, 2009

Neuropathological studies in experimental and human glaucoma have shown degenerative changes in t... more Neuropathological studies in experimental and human glaucoma have shown degenerative changes in the optic pathway. The purpose of the study was to evaluate, with conventional MRI and magnetisation transfer imaging, the brain and the optic pathway of patients with primary open-angle glaucoma (POAG). 26 patients, aged 67.4¡8.6 years, and 26 control subjects were studied. The presence of white matter hyperintensities (WMH) was evaluated on fluid-attenuated inversion recovery images of the brain. The area of the optic nerves was assessed on coronal short tau inversion recovery images. Magnetisation transfer ratio (MTR) was measured in the chiasm and in the grey and white matter (CGM and CWM) of the calcarine fissure. More WMH were observed in patients (total 261, mean 10.8, standard deviation 12.7) than in control subjects (total 127, mean 4.7, standard deviation 5.7; p,0.001). The area (mm 2) of optic nerves (10.7¡5.7) and the MTR (%) of the chiasm (53.7¡8.4), the CWM (60.9¡4.2) and the CGM (53.6¡5.6) were all lower in patients than in control subjects (13.6¡4.3, 62.1¡6.2, 67.6¡8.6 and 57.0¡4.6, respectively; p,0.05). The area of optic nerves showed significant correlation with the MTR of the chiasm (R50.41), the MTR of the CGM (R50.33), the MTR of the CWM (R50.34) and the cup to disc ratio (R5 20.46). POAG leads to optic nerve atrophy and degeneration of the optic pathway. The finding of an increase in the number of WMH suggests that cerebrovascular disease may play a role in the pathogenesis of POAG.

Research paper thumbnail of Systematic review of the association between Alzheimer’s disease and chronic glaucoma

Clinical Ophthalmology, 2014

A potential association between Alzheimer's disease (AD) and chronic glaucoma has been suggested ... more A potential association between Alzheimer's disease (AD) and chronic glaucoma has been suggested but results of epidemiological studies have been inconsistent. Therefore, we performed a systematic review and critical appraisal of this literature. We searched systematically in PubMed from December 1964 to September 2013 and identified 239 articles potentially relevant for abstract and full-text review. Statistical heterogeneity (variability) across studies was evaluated using the Cochran Q test and the I 2 statistic, and the Newcastle-Ottawa score was used to assess study quality. Ten studies were finally selected. Compared to non-demented participants, patients with AD had a statistically significant decreased risk of glaucoma but the results were very heterogeneous, and thus summary estimates were not reported (I 2 , 89%; P heterogeneity , 0.001). The study results ranged from large positive relative risks identified in small and poorly-conducted studies to weak inverse associations or null estimates observed in some cohort and record-linkage studies, but the summary estimates were essentially driven by a large retrospective cohort using medical claims that may be afflicted by underdiagnosis bias. There was also evidence for substantial publication bias (Egger's P#0.01). The association of AD and glaucoma is heterogeneous and most studies are small and inadequately designed. Large prospective studies with long follow-ups are warranted to clarify this association.

Research paper thumbnail of Assessment of hydroxychloroquine maculopathy after cessation of treatment: an optical coherence tomography and multifocal electroretinography study

Drug Design, Development and Therapy, 2015

Objective: This study was conducted to evaluate the macular status of patients treated with hydro... more Objective: This study was conducted to evaluate the macular status of patients treated with hydroxychloroquine before and after cessation of treatment. Methods: Forty-two patients with systemic lupus erythematosus underwent ocular examination based on visual acuity evaluation, optical coherence tomography retinal thickness measurements, and multifocal electroretinography (mfERG) records at first visit. The tests were repeated 6 months after treatment withdrawal and compared to the findings at their first visit. Results: Mean visual acuity (measured in log minimum angle of resolution) of both eyes was statistically increased after hydroxychloroquine discontinuation (difference in means: 0.06 [P0.0001] and 0.01 [P=0.003] for the right and left eyes, respectively). Retinal response amplitudes of central and peripheral areas were significantly improved for both eyes. The following values were observed for central responses: the difference in means was-19.9 (P0.0001) and-13.6 (P0.0001) for the right eye and the left eye, respectively; for peripheral responses, difference in means was-10.3 (P0.0001) and-9.5 (P0.0001) for right eye and left eye, respectively, after the 6-month examination. There were no statistically significant differences in the retinal thickness of patients after cessation of treatment. The visual acuity of the patients was correlated to central and peripheral mfERG responses (r=-0.53 [P0.0001] and r=-0.53 [P0.0001], for the right eye and the left eye, respectively). Conclusion: The visual acuity of patients receiving hydroxychloroquine improves along with the amplitudes of the mfERG responses 6 months after discontinuation of the drug, but no difference in retinal thickness is identified.

Research paper thumbnail of Pseudoexfoliation syndrome: Gray matter volume and microstructural changes revealed by histogram and brain surface analysis

Purpose: White matter (WM) abnormalities may occur in patients with pseudoexfoliation syndrome (P... more Purpose: White matter (WM) abnormalities may occur in patients with pseudoexfoliation syndrome (PXS). The presence of gray matter (GM) abnormalities in patients with PXS without glaucoma was evaluated, applying histogram and brain surface analysis of MRI data. Material and Methods: Brain MRI was conducted on 20 patients newly diagnosed with PXS without glaucoma, (mean age 68.7 ± 8.6 years) and 14 control subjects (mean age 63.3 ± 6.6 years). The histogram scalars of mean diffusivity (MD) and fractional anisotropy (FA) of GM and WM were evaluated. Brain surface analysis was performed on 3D T1-weighted images. Results: The MD value of the WM showed higher mean, standard deviation, median and 75 th percentile in the patients than in the control subjects. The FA values of GM showed higher mean, standard deviation, median and 75 th percentile, and lower kurtosis and skewness in the patients than in the control subjects. Greater GM volume was observed in the patients in Brodmann areas 25 ...

Research paper thumbnail of Results of a modified non-penetrating deep sclerectomy in the treatment of open angle glaucoma with or without cataract

Research paper thumbnail of A modified deep sclerectomy with or without external trabeculectomy: a comparative study

Clinical Ophthalmology

To determine whether the removal of the inner wall of Schlemm's canal (external trabeculectom... more To determine whether the removal of the inner wall of Schlemm's canal (external trabeculectomy) improves the effectiveness of a modified method of deep sclerectomy (DS), which we will call "reversed" deep sclerectomy (RDS). We conducted a prospective study of two groups of patients. Group A included 22 eyes of 18 patients with open angle glaucoma (OAG) under maximum medical treatment, which underwent RDS - a modified method of performing DS - with the removal of the inner wall of Schlemm's canal (external trabeculectomy) and without using any implant. Group B included 20 eyes of 17 patients which had undergone RDS alone. Demographic and tonometric data of patients of Group A revealed no significant difference from data of patients in Group B. A mean follow up period for Group A was 22.8 months and for Group B was 23.4 months. The outcome of the operations was termed a total success when intraocular pressure (IOP) was <21 mmHg postoperatively, without additional ...

Research paper thumbnail of Linkage studies in primary open angle glaucoma

American Journal of Human Genetics, 1994

Glaucoma is a leading cause of blindness worldwide. The majority of glaucoma is associated with a... more Glaucoma is a leading cause of blindness worldwide. The majority of glaucoma is associated with an open, normal appearing anterior chamber angle and is termed primary open angle glaucoma (POAG, MIM 137760). It is characterized by elevated intraocular pressure and onset in middle age or later. A subset of POAG with juvenile onset has recently been linked to chromosome 1q

Research paper thumbnail of Oxidative stress in dry age-related macular degeneration and exfoliation syndrome

Critical reviews in clinical laboratory sciences, 2015

Oxidative stress refers to cellular or molecular damage caused by reactive oxygen species, which ... more Oxidative stress refers to cellular or molecular damage caused by reactive oxygen species, which especially occurs in age-related conditions as a result of an imbalance between the production of reactive oxygen species and the antioxidant defense response. Dry age-related macular degeneration (AMD) and exfoliation syndrome (XFS) are two common and complex age-related conditions that can cause irreversible vision loss. Two subtypes of AMD, which is the leading cause of blindness in the Western world, exist: the most prevalent dry type and the most severe wet type. Early dry AMD is characterized by formation of drusen, which are sub-retinal deposits, in the macular area and may progress to geographic atrophy with more dramatic manifestation. XFS is a systemic disorder of the extracellular matrix characterized by the accumulation of elastic fibrils that leads, in most cases, to glaucoma development with progressive and irreversible vision loss. Due to the aging population, the prevalen...

Research paper thumbnail of Investigation of founder effects for the Thr377Met Myocilin mutation in glaucoma families from differing ethnic backgrounds

Molecular vision, 2007

The aim of this study was to determine if there is a common founder for the Thr377Met myocilin mu... more The aim of this study was to determine if there is a common founder for the Thr377Met myocilin mutation in primary open angle glaucoma (POAG) families with various ethnic backgrounds. Genomic DNA of 24 POAG-affected individuals from nine pedigrees with the Thr377Met mutation and 104 unaffected family members was genotyped with six microsatellite markers and four single nucleotide polymorphisms. The families were from Greece, India, Finland, the USA, and Australia. To assess the degree of linkage disequilibrium across MYOC in the general population we also investigated data generated from the HapMap consortium. Three distinct haplotypes associated with the Thr377Met myocilin mutation were identified. The families from the USA and Greece, as well as the three Australian families originating from Greece and the former Yugoslavian Republic of Macedonia had one common haplotype. Interestingly, however, HapMap data suggest that linkage disequilibrium across MYOC was not strong. The Thr377...

Research paper thumbnail of The situation of alcohol use and abuse in Greece

Trastornos Adictivos, 2005

Objetivo: Este artículo analiza los datos del recientemente creado Sistema Nacional Griego de Vig... more Objetivo: Este artículo analiza los datos del recientemente creado Sistema Nacional Griego de Vigilancia del Alcohol, desarrollado por el Punto Focal Griego, instituto de salud mental. El objetivo de este artículo es presentar una revisión y visión de conjunto de la situación del alcohol en Grecia.

Research paper thumbnail of A novel locus on 19q13 associated with autosomal-dominant macular dystrophy in a large Greek family

Journal of Medical Genetics, 2006

Research paper thumbnail of Exclusion of one pedigree affected by adult onset primary open angle glaucoma from linkage to the juvenile glaucoma locus on chromosome 1q21-q31

Journal of Medical Genetics, 1996

A locus for autosomal dominant juvenile onset primary open angle glaucoma (POAG) was recently ass... more A locus for autosomal dominant juvenile onset primary open angle glaucoma (POAG) was recently assigned to chromosome region lq21-q31. In the present study, a large Greek family with autosomal dominant adult onset POAG was investigated using microsatellite markers. Exclusion of linkage of the adult onset POAG gene to the region DlS194-DlS191 was obtained in this pedigree. Therefore, the data provide evidence that juvenile and adult onset POAG are genetically distinct disease entities.

Research paper thumbnail of Results of a modified non-penetrating deep sclerectomy in the treatment of open angle glaucoma with or without cataract

Clinical Ophthalmology, 2010

Research paper thumbnail of Primary open angle glaucoma due to T377M MYOC: Population mapping of a Greek founder mutation in Northwestern Greece

Clinical Ophthalmology, 2010

Background: Mutations in the MYOC gene have been shown to explain 5% of unrelated primary open an... more Background: Mutations in the MYOC gene have been shown to explain 5% of unrelated primary open angle glaucoma (POAG) in different populations. In particular, the T377M MYOC mutation has arisen at least three separate times in history, in Great Britain, India, and Greece. The purpose of this study is to investigate the distribution of the mutation among different population groups in the northwestern region of Greece.

Research paper thumbnail of Refining the primary open-angle glaucoma GLC1C region on chromosome 3 by haplotype analysis

Clinical Genetics, 2003

The GLC1C locus for primary open-angle glaucoma (POAG) is inherited as an autosomal dominant trai... more The GLC1C locus for primary open-angle glaucoma (POAG) is inherited as an autosomal dominant trait. This region on chromosome 3 is 11 cM long. DNA samples from members of a Greek and an American GLC1C family were obtained to determine whether additional typing of microsatellite markers in family members might narrow the region. GLC1C family members were evaluated clinically for POAG on the basis of open angles, intraocular pressures, cupping of discs, and visual fields. DNA samples from the Greek and Oregon GLC1C families were used to further refine the GLC1C region using microsatellite markers. A total of 22 affected members were identified in the two families. Common alleles for D3S3637 and D3S3612 were present in the disease haplotype from both families, suggesting that they may have a common founder. A newly diagnosed patient in the American family had a recombination in the distal portion of the GLC1C haplotype. This recombination narrows the GLC1C region from 11 to 4 cM.

Research paper thumbnail of Partial trisomy 17q22-qter and partial monosomy Xq27-qter in a girl with a de novo unbalanced translocation due to a postzygotic error: Case report and review of the literature on partial trisomy 17qter

American Journal of Medical Genetics, 1997

Partial trisomy 17q22-qter is a rare but well-recognized clinical entity. We present a case of pa... more Partial trisomy 17q22-qter is a rare but well-recognized clinical entity. We present a case of partial trisomy for the long arm of chromosome 17, which was detected in a female infant with severe psychomotor and somatic retardation, Stargardt disease, short limbs, and numerous minor anomalies. Differential chromosomal staining demonstrated an excess of genetic material on the long arm of the late replicating X chromosome. FISH and DNA polymorphism analysis showed that the extra material belonged to the distal part of the long arm of chromosome 17 and that there was a partial monosomy of the distal part of the long arm of the derivative X chromosome. The breakpoint regions of this translocation were identified by molecular analysis using polymorphic microsatellite markers on human chromosomes 17 and X. The origin of the abnormal X chromosome was found to be paternal, whereas the origin of the duplicated part of chromosome 17 was maternal. The unbalanced translocation between the paternal X and the maternal chromosome 17 is, therefore, suggested to be due to a postzygotic error.