Nikolaos G Ziakas

Aristotle University of Thessaloniki, Saloníki, Central Macedonia, Greece

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Publications (24)39.98 Total impact

  • Clinical and Experimental Optometry 02/2015; 98(3). DOI:10.1111/cxo.12251 · 1.34 Impact Factor

  • Acta ophthalmologica 04/2014; 92(7). DOI:10.1111/aos.12430 · 2.84 Impact Factor

  • Archives of Disease in Childhood - Education and Practice 09/2013; 99(2). DOI:10.1136/archdischild-2012-303417 · 1.45 Impact Factor
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    ABSTRACT: Eye is the official journal of the Royal College of Ophthalmologists. It aims to provide the practising ophthalmologist with information on the latest clinical and laboratory-based research.
    Eye (London, England) 06/2013; 27(9). DOI:10.1038/eye.2013.138 · 2.08 Impact Factor
  • Nikolaos G Ziakas · Sokratis Kotsidis · Antonios Ziakas ·
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    ABSTRACT: We present a case of central retinal artery occlusion (CRAO) in a 59-year-old male suffering from infective endocarditis. The patient was receiving antibiotic treatment for the endocarditis for 5 days prior to the event and received conservative treatment for the CRAO without any improvement. A few days after the event, the patient underwent heart surgery with aortic and mitral valve replacement and eventually recovered without any other side-effects. CRAO is a rare but devastating embolic complication of infective endocarditis and can happen regardless of whether a patient is receiving systemic antibiotic treatment or not. These patients need close observation, because an immediate diagnosis and an urgent therapeutic procedure are mandatory, as the prognosis for vision is poor.
    International Ophthalmology 04/2013; 34(2). DOI:10.1007/s10792-013-9779-6 · 0.55 Impact Factor
  • N G Ziakas · A Chranioti · A Malamas · O Leliopoulou · A Mataftsi ·
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    ABSTRACT: Congenital ectropion uveae is a rare anomaly commonly associated with neurofibromatosis and occasionally with other ocular abnormalities. Glaucoma related with this condition may be present in infancy, or may develop later in life, and is thought to be due to an associated angle dysgenesis. Diagnosis is frequently delayed due to the subtle signs and the absence of symptoms and management is primarily surgical. We report an unusual case of unilateral congenital ectropion uveae in a 3-year-old child, with no evidence of neurofibromatosis, presenting as acute glaucoma, which was successfully managed by topical treatment only, avoiding surgical intervention.
    International Ophthalmology 02/2013; 34(1). DOI:10.1007/s10792-013-9735-5 · 0.55 Impact Factor
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    ABSTRACT: A 78-year-old female patient suffering from Fuchs endothelial dystrophy had uneventful Descemet stripping automated endothelial keratoplasty (DSAEK) on the right eye. One and a half months postoperatively, she underwent a corneal foreign body trauma and was referred to our clinic, complaining about vision deterioration. Slit-lamp examination revealed a severe and diffuse interface lamellar keratitis between the DSAEK graft and the recipient's cornea without any signs of graft dysfunction. Intensive treatment with local corticosteroids was applied immediately, resulting in prompt improvement of both visual acuity and clinical condition. A new clinical entity, described as interface lamellar keratitis after corneal trauma in a DSAEK patient, is presented. Early diagnosis and appropriate intensive treatment with local corticosteroids are essential to successfully address this uncommon post-DSAEK complication.
    Cornea 10/2012; 32(3). DOI:10.1097/ICO.0b013e3182656866 · 2.04 Impact Factor
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    ABSTRACT: Purpose: The aim of this study was to report the use of autologous serum eyedrops (ASEs) for resolution of a corneal ulcer secondary to bullous keratopathy. Methods: This is a case report. Results: A 66-year-old patient presented with an infected ulcer and hypopyon while using a bandage contact lens for bullous keratopathy. Staphylococcus warneri infection was treated with systemic and topical antibiotics, and ASEs were subsequently administered to enhance reepithelialization and to avoid the need for a bandage contact lens. The ASE treatment led to closure of the epithelium layer within 3 weeks, and it was subsequently tapered over the next 3 months. The clinical picture remained stable subjectively and objectively during the 7 months of follow-up. Discussion: To the best of our knowledge, this is the first report of successful use of ASEs in treating and preventing recurrence of ulcers in the context of bullous keratopathy.
    Eye & contact lens 07/2012; 39(4). DOI:10.1097/ICL.0b013e31825f6386 · 1.47 Impact Factor
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    ABSTRACT: Purpose. To investigate 24-hour variation in retinal thickness in patients with diabetic macular edema (DME) using optical coherence tomography (OCT). Methods. Fifty-three eyes of 53 diabetic patients with clinically significant macular edema and central subfield thickness (CST) >225 µm, 36 eyes of 36 healthy individuals (normal controls), and 22 eyes of 22 diabetic patients without macular pathology (diabetic controls) underwent 5 OCT measurements at 7 am, 10 am, 3 pm, 8 pm, and 1 am. Visual acuity, blood pressure, blood glucose, and body temperature were measured as well. Results. The CST (p<0.0005), total macular volume (p<0.0005), and visual acuity (p<0.0005) showed significant variation in patients. The CST (450 µm at 7 am) reached a minimum at 3 pm (absolute change of -49 µm, relative change of -17%) before increasing again. Thickening changes were higher in more thickened retinas (p<0.0005, p=0.024, absolute and relative change, respectively). Visual acuity was worse in the morning (0.38 logMAR) and improved to a maximum at 8 pm (0.30 logMAR) (p<0.0005). Blood pressure, blood glucose, and body temperature did not vary over time. Conclusions. The 24-hour variation of retinal thickness is observed in a large proportion of patients with DME, with a decrease from morning to afternoon. Time of examination should be taken into account when managing such patients.
    European journal of ophthalmology 01/2012; 22(5):785-91. DOI:10.5301/ejo.5000119 · 1.07 Impact Factor
  • N Ziakas · E Kanonidou · D Mikropoulos · N Georgiadis ·
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    ABSTRACT: To assess the visual function of patients with keratoconus who underwent penetrating keratoplasty with the use of the VF-14 questionnaire. Fourteen patients (9 male and 5 female) with a mean age of 38 years (SD 13.59) participated in the study. All patients had keratoconus, confirmed by corneal topography, and all had previously undergone penetrating keratoplasty in one eye. Their mean best-corrected visual acuity (BCVA) binocularly was 0.185 (SD 0.077) LogMAR. None of the grafted eyes had a BCVA < 0.300 LogMAR. Fourteen healthy volunteers, age- and sex-matched, also participated in the study as control subjects. The VF-14 questionnaire was used to evaluate the effect of the ocular status in the daily life activities of the patients. The mean VF-14 result for the grafted patients with keratoconus was 62.37% (SD 22.60) and for the control group it was 100% (P < 0.001). There was only a weak correlation between the VF-14 score and the binocular BCVA (r = -0.394, P = 0.163). The mean VF-14 result in grafted patients with keratoconus is indicative of low functional ability despite the satisfactory postoperative BCVA. The absence of a significant correlation between the VF-14 score and the mean BCVA indicates that the low functional visual ability in these patients is probably associated more with the 'perceived by themselves' difficulty due to their ophthalmological condition.
    International Ophthalmology 04/2011; 31(2):89-92. DOI:10.1007/s10792-010-9414-8 · 0.55 Impact Factor
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    E Lazaridou · C Fotiadou · N.G. Ziakas · C Giannopoulou · Z Apalla · D Ioannides ·
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    ABSTRACT: The prevalence of ophthalmic involvement in rosacea is probably higher than previously presumed and varies considerably among several studies. This study aimed to determine the incidence of ocular disease among a population of rosacea patients in Northern Greece, to objectively determine the presence of eye dryness in rosacea patients with and without clinical ophthalmic involvement and correlate the severity of ocular disease with the severity of cutaneous rosacea. One hundred patients with rosacea were assessed for the stage of their disease and examined for ocular symptoms and signs. In 24 of them the tear break up time (TBUT) and Schirmer test were performed in each eye, along with 24 controls. A total of 33 patients (33%) were positive for ophthalmic findings. The most frequent symptoms and signs were burning sensation and tearing, and conjunctivitis and blepharitis, respectively. Eleven patients with ophthalmic manifestations had mild to moderate erythematotelangiectatic rosacea, 17 had moderate papulopustular rosacea and four exhibited findings of phymatous rosacea. The total mean value of patients' Schirmer tests was significantly lower compared with the healthy controls (P < 0.0001). Mean TBUT was shorter in the rosacea group than that in the age-matched controls (P < 0.0001). Ocular involvement in rosacea is a common phenomenon with eye dryness being an early sign. Tear function tests, like Schirmer test and TBUT, although not specific, could contribute to the screening and early diagnosis of the disease, to prevent the potential development of sight-threatening conditions.
    Journal of the European Academy of Dermatology and Venereology 03/2011; 25(12):1428-31. DOI:10.1111/j.1468-3083.2011.03995.x · 2.83 Impact Factor
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    ABSTRACT: We report a new procedure for intra-operative toric intra-ocular lens (IOL) axis assessment in order to achieve optimal implantation. IOL implantation procedure was directly recorded. An assessor estimated the angle formed by the marked 0-180 axis and the toric IOL axis after implantation with the use of the appropriate software. If IOL implantation was assessed to be inaccurate, the surgeon was advised to correct IOL positioning by rotating the IOL clockwise. The assessment procedure was repeated until accurate IOL positioning was achieved.
    Indian Journal of Ophthalmology 01/2011; 59(1):60-2. DOI:10.4103/0301-4738.73726 · 0.90 Impact Factor
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    ABSTRACT: Purpose To compare the mean homocysteine concentration in aqueous humor and plasma in patients with exfoliation syndrome (XFS), exfoliative glaucoma (XFG), primary open-angle glaucoma (POAG) and normal controls and to evaluate the role of this biochemical index in the management of glaucomaMethods Aqueous and blood samples were collected from 30 subjects with XFS, 30 subjects with XFG 30 subjects with POAG and 48 individuals with senile cataract who underwent routine phacoemulsification surgery. The mean homocysteine concentration was determined with the enzyme immunoassay method Axis® FHCY 100Results The mean concentration of homocysteine was significantly higher in XFG patients in both aqueous (2,89±0,82 μmol/l) and plasma samples (17,51±6,08 μmol/l) compared with normal controls (1,87±0,47 μmol/l in the aqueous and 13,04±3,37 μmol/l in the plasma respectively). Patients with POAG exhibited higher mean homocysteine concentration both in aqueous (2,29±0,43μmol/l) and plasma samples (19,17±2,80 μmol/l) compared with normal controls. No significant differences were detected in homocysteine levels between XFS subjects and normal controls in the aqueous (1,98±0,48 μmol/l), or plasma (14,52±5,47 μmol/l). However, a significantly higher level of homocysteine was detected in the aqueous and plasma of those with XFG compared with the XFS group (<0.05). Hypehomocystenemia was present in 93,3% (28/30) of POAG samples, in 70% (21/30) of XFG samples, in 40% (12/30) of XFS samples, and in 27,1% (13/48) of normal control samples.Conclusion The study confirms a significantly higher homocysteine level in XFG and POAG, which may represent a modifiable risk factor in the future.
    Acta ophthalmologica 09/2010; 88(s246). DOI:10.1111/j.1755-3768.2010.374.x · 2.84 Impact Factor
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    ABSTRACT: The aim of the study was to evaluate long-term results of autologous serum treatment for recurrent corneal erosions. In this prospective single-centre study, 33 eyes of 33 patients (21 male and 12 female) were treated with autologous serum eye drops for recurrent corneal erosions. Mean age of the patients was 49.3 ± 9.8 standard deviation (range 24-73) years. All subjects had failed to respond to other treatments. Autologous serum drops were administered for a 6-month period: six times daily for the first 3 months and four times daily for the remaining 3 months. Detailed informed consent was obtained from the entire patient group before the study. The mean follow-up period was 30 ± 6.3 standard deviation (range 12-48) months. None of the patients experienced a recurrence while under treatment. Twenty-eight patients (85%) had complete healing of erosions with no relapses of the disease over the whole follow-up period. Five patients (15%) presented a single recurrence 3-12 months after the end of the treatment. No sight-threatening complications were reported over the follow up. There was no statistically significant difference in the best spectacle-corrected visual acuity values (t(stat) = 2.1, F = 0.096, degree of freedom = 40,166, P < 0.41) or in the intraocular pressure measurements (P < 0.38) between the pre- and post-treatment patient groups. Autologous serum drops proved to be a safe and efficient treatment modality for patients with recurrent corneal erosion syndrome as observed through a long-term follow up.
    Clinical and Experimental Ophthalmology 04/2010; 38(7):683-7. DOI:10.1111/j.1442-9071.2010.02304.x · 2.35 Impact Factor
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    ABSTRACT: To present clinical results of toric intraocular lens (IOL) implantation for preexisting astigmatism correction and determine the time of any postoperative rotation. Twenty-nine eyes of 19 patients underwent uncomplicated phacoemulsification and were implanted with an Acrysof ((c)) toric IOL. Uncorrected visual acuity, residual astigmatism, and postoperative rotation of the IOL were estimated one and six months after the operation. Uncorrected visual acuity was >/=0.5 in 26 of 29 eyes (89.7%) and >/=0.8 in 19 of 29 patients (65.5%). The mean toric IOL axis rotation was 2.2 +/- 1.5 degrees (range 0.6-7.8 degrees ) one month postoperation and 2.7 +/- 1.5 degrees (range 0.9-8.4 degrees ) six months postoperation. Implantation of one-piece hydrophobic acrylic toric IOLs appears to have acceptable stability, which encourages visual outcome and emerges as an attractive alternative for correction of refractive astigmatism.
    Clinical Ophthalmology 03/2010; 4(1):137-42. · 0.76 Impact Factor
  • E Lazaridou · Z Apalla · S Sotiraki · N G Ziakas · C Fotiadou · D Ioannides ·
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    ABSTRACT: Numerous factors have been implicated in the pathogenesis of rosacea, which remains obscure. To examine the epidemiological characteristics of rosacea patients, the histopathological alterations, the prevalence of gastric Helicobacter pylori infection and the role of ultraviolet radiation, to detect the presence of Demodex folliculorum on affected skin and to elucidate the immunological nature of this disorder. The study included 100 patients with rosacea. Each patient was assessed with a clinical, haematological, biochemical and histological examination; serology test for the detection of antibodies against H. pylori; direct immunofluorescence on perilesional, sun exposed skin and indirect immunofluorescence with monkey oesophagus as a substrate; antinuclear antibody titre and a skin surface biopsy to search for Demodex folliculorum. Women were more frequently affected. Half of our patients were 51-70 years old. About two-thirds were photo-types I and II and 73% complained of worsening of conditions after sun exposure. An almost permanent histopathological feature was solar elastosis. Higher prevalence of H. pylori was not established. Prevalence and mean density of Demodex folliculorum were significantly increased in rosacea patients. Direct and indirect immunofluorescence tests were positive in 6.4% and 6.7% respectively. Antinuclear antibody titres were found in 21.1%. Our results suggest the pivotal role of chronic sun exposure in the pathogenesis of rosacea. Demodex folliculorum represents a significant cofactor that may contribute to the transition of the disease from a vascular to an inflammatory stage. The low positive results of direct and indirect immunofluorescence do not support a potential autoimmune role in the development of rosacea.
    Journal of the European Academy of Dermatology and Venereology 10/2009; 24(4):410-4. DOI:10.1111/j.1468-3083.2009.03424.x · 2.83 Impact Factor
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    ABSTRACT: The purpose of the study was to evaluate the effect of trypan blue on intraocular pressure (IOP) after small-incision cataract surgery. Prospective, randomized study. Fifteen patients (30 eyes) with bilateral, dense, age-related cataracts. Patients with glaucoma, ocular hypertension, exfoliation, pigment dispersion syndrome, history of uveitis, recent use of topical or systemic steroids, and previous ocular surgery were excluded. The patients were randomly assigned to receive trypan blue during cataract surgery for enhancing capsulorrhexis in 1 of their eyes, while in the other eye, trypan blue was not used. Cataract surgery was performed in an identical fashion in both eyes, with a sutureless posterior limbal incision, phacoemulsification, and implantation of a foldable intraocular lens. The same viscoelastic (sodium hyaluronate) was used in all cases and was thoroughly aspirated at the end of the procedure. All patients received a single dose of 250 mg acetazolamide 8 hours after surgery. No other antiglaucomatous agent was used during surgery or postoperatively. The intraocular pressure (IOP) was measured preoperatively and at 24 hours, 1 week, 1 month, and 3 months postoperatively. IOP values were similar in both groups at all 4 postoperative measurements. There was no statistically significant difference in postoperative IOP values between the eyes in which trypan blue was used and the control eyes. The use of trypan blue during small-incision cataract surgery does not have any effect on IOP during the immediate and early postoperative period.
    Canadian Journal of Ophthalmology 07/2009; 44(3):293-6. DOI:10.3129/i09-055 · 1.33 Impact Factor
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    ABSTRACT: Exfoliation syndrome (XFS) was first described in 1917 by the Finnish ophthalmologist John Lindberg1 and currently affects 60–70 million people worldwide.2–4 Of these, 15–17 million have increased intraocular pressure (IOP) and 5–6 million are estimated to suffer from exfoliative glaucoma (XFG), a form of secondary open-angle glaucoma that develops as a consequence of XFS and is considered the most common identifiable cause of open-angle glaucoma worldwide.2 Its aggressive course and worldwide prevalence makes it critical for ophthalmologists to be familiar with the full clinical spectrum of the disease.
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    ABSTRACT: Oxidative stress plays an important role in the pathobiology of exfoliation syndrome (XFS) and exfoliative glaucoma (XFG). We investigated the prooxidant-antioxidant balance (PAB) in aqueous humour and serum samples of 20 consecutive cases of XFS, 20 of XFG, and 20 age-matched controls, employing a recently described novel assay. The activity of catalase and the levels of (hydrogen) peroxide were also measured in these samples. There was no significant difference between the PAB in the aqueous humour of the XFS group (82.5 +/- 10 AU) and age-matched control patients (78.9 +/- 13.4 AU; p > 0.05). A significant shift of the PAB balance in favour of oxidants was detected in the XFG group (90.2 +/- 7.6 AU) compared with controls (p < 0.001). In the serum of patients with XFS (138.8 +/- 13.2 AU) and XFG (124.08 +/- 13.50 AU), PAB was significantly altered in favour of oxidants as compared to age-matched controls (114.9 +/- 9.91 AU); p < 0.001). Catalase activity in the aqueous from XFS (10.1 +/- 4.5 U/ml) and XFG (12.2 +/- 6 U/ml) patients was significantly lower than that measured in the normal aqueous (14.6 +/- 1.9 U/ml). Similarly, a significantly lower catalase activity was found in XFS (103 +/- 21.4 U/ml) and XFG (116 +/- 38 U/ml) serum samples compared with controls (189.6 +/- 84.3 U/ml). Finally, (hydrogen) peroxide concentration in aqueous and serum samples from patients with XFS (aqueous: 26.9 +/- 6.6 microM; serum: 41 +/- 10 microM) and XFG (aqueous: 21.7 +/- 7 microM; serum: 32 +/- 4 microM) were significantly higher than that of the controls (aqueous: 9.6 +/- 5.8 microM; serum: 24 +/- 9 microM; p < 0.001). These findings suggest that in XFS oxidative stress is counterbalanced in the aqueous, whereas the development of XFG is accompanied by a disruption of this balance in favour of oxidants.
    Albrecht von Graæes Archiv für Ophthalmologie 08/2008; 246(10):1477-83. DOI:10.1007/s00417-008-0871-y · 1.91 Impact Factor
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    ABSTRACT: To determine the long term intraocular pressure (IOP) response to phacoemulsification in patients with and without exfoliation syndrome (XFS). Prospective, multicentre, cohort study with the following inclusion criteria: age over 50 years, open iridocorneal angle, and cataract. Two groups were enrolled: those with XFS and those without. The main outcome was mean IOP reduction 2 years after phacoemulsification cataract extraction (PCE). Univariate and multivariate analyses were performed. 183 patients were enrolled, 71 with and 112 without XFS. There were 29 patients with glaucoma in both groups. Mean baseline IOP was higher in XFS compared to control eyes (17.60 (SD 3.23) mm Hg v 16.08 (3.18) mm Hg, p = 0.002). Overall IOP reduction was significantly greater in the XFS group at the 2 year time point (-1.85 mm Hg v -0.62 mm Hg in the controls (p = 0.0037)). Multivariate analysis demonstrated that the IOP lowering effect in the XFS group may be related to irrigation volume at the time of surgery. In the subgroup analyses IOP lowering was significantly greater in the XFS and XFG patients than in controls without glaucoma, and POAG controls, respectively. The percentage of patients with a postoperative IOP spike was similar and relatively high in both XFS and control groups (34% v 25%; p = 0.54). IOP decreases more in patients with XFS following PCE compared to control eyes without XFS. This effect is more pronounced in glaucoma patients and persists for at least 2 years.
    British Journal of Ophthalmology 09/2006; 90(8):1014-8. DOI:10.1136/bjo.2006.091447 · 2.98 Impact Factor

Publication Stats

209 Citations
39.98 Total Impact Points


  • 2009-2015
    • Aristotle University of Thessaloniki
      • Department of Ophthalmology II
      Saloníki, Central Macedonia, Greece
  • 2008-2012
    • AHEPA University Hospital
      Saloníki, Central Macedonia, Greece
  • 2006
    • University of Ottawa
      Ottawa, Ontario, Canada
  • 2004
    • Wolfe Eye Clinic
      Spencer, Iowa, United States