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Öğe Analysis of Peripapillary Choroidal Thickness in Unilateral Amblyopia(Lippincott Williams & Wilkins, 2019) Bitirgen, Gulfidan; Mirza, Enver; Ozkagnici, Ahmet; Iyisoy, Mehmet SinanPurpose: To evaluate the peripapillary choroidal thickness (CT) in children with unilateral amblyopia using spectral-domain optical coherence tomography (SD-OCT). Methods: One hundred and six eyes of 53 children with unilateral amblyopia and 20 eyes of 20 children with normal vision were involved in this study. Of the 53 children with unilateral amblyopia, 29 (54.7%) had hyperopic anisometropic amblyopia and 24 (45.3%) had strabismic amblyopia. Peripapillary CT was measured from 6 mm length radial B-scans at the optic nerve head using the enhanced depth imaging program of an SD-OCT (Heidelberg Engineering, Germany). Age, sex, refractive error, and best-corrected visual acuity were also recorded. Results: The average peripapillary CT was greater in amblyopic eyes than in the fellow eyes of the children with amblyopia (P = 0.002), and control eyes (P < 0.001). There was no significant difference between the fellow eyes of children with amblyopia and the control eyes (P = 0.158). The average peripapillary CT was negatively correlated with axial length (AL) in amblyopic eyes (r = -0.381; P = 0.005) and fellow eyes (r = -0.392; P = 0.004) but not in control eyes (r = -0.232; P = 0.325). After adjustment for the possible effects of AL, the average peripapillary CT in amblyopic eyes was still greater than in fellow eyes (P = 0.014) and control eyes (P = 0.022). Conclusion: The peripapillary choroid of eyes with amblyopia was thicker than that of the fellow eyes and control eyes. No significant difference was observed between fellow eyes and control eyes.Öğe Assessment of Macula and Retinal Nerve Fiber Layer Thickness with Optical Coherence Tomography in Myopia(Ortadogu Ad Pres & Publ Co, 2012) Ozkagnici, Ahmet; Tokgoz, MineObjective: In the study, analysis of retina structure with optical coherence tomography (OCT) in emetropic and myopic cases was aimed. Material and Methods: The study group included a total of 224 cases (118 females, 106 males). Cases were divided into four groups: between 0.00/-0.75 D (first group=control group), between -1.00/-3.00 D (second group), between -3.25/-6.00 D (third group) and between -6.25/-12.00 D, according to their refractive error. Thickness of retinal nerve fiber layer (RNFL) and macula was measured using OCT. Results: While an increase was detected in foveal thickness and volume in the highly myopic group, a reduction was found in RNFL thickness of all areas except temporal area. Total macular volume, outer macular thickness and volume were also reduced. The highest thinning of RNFL in highly myopic cases was in 13.1% in superior and 18.6% in nasal thickness. There was a weak correlation between RNFL thickness, macular thickness and volume values and axial length/spheric equivalent. Conclusion: Assessment of especially nasal and superior quadrant thickness in RNFL is crucial in highly myopics. Distance between foveal pit and parafoveolar tip is inversely proportional with myopia, in other words, increase in degree of myopia causes macular area to become flatter.Öğe Characteristics of the cornea in patients with pseudoexfoliation syndrome(Consel Brasil Oftalmologia, 2015) Oltulu, Refik; Satirtav, Gunhal; Kayitmazbatir, Emine Tinkir; Bitirgen, Gulfidan; Ozkagnici, Ahmet; Karaibrahimoglu, AdnanPurpose: To quantify the morphological alterations in corneal nerve fibers and cells in patients with pseudoexfoliation syndrome (PEX) and their relationship with the presence of hyperreflective endothelial deposits observed using in vivo confocal microscopy. Methods: One eye each of 37 patients with PEX and 20 age-matched healthy control subjects was evaluated by in vivo corneal confocal microscopy. Patients with PEX were further classified into two groups: those with and without hyperreflective endothelial deposits. We evaluated the densities of basal epithelial cells, anterior and posterior stromal keratocytes, and endothelial cells and structure of sub-basal nerve fibers. Results: The mean anterior and posterior stromal keratocyte and endothelial cell densities and corneal sub-basal nerve plexus variables were significantly lower in patients with PEX compared with those in healthy control subjects. The mean basal epithelial cell density did not significantly differ. Conclusion: Eyes with PEX presented decreased corneal sub-basal nerve plexus variables and cell densities in all corneas, except for the mean basal epithelial cell density. Further, a trend of lower corneal sub-basal nerve plexus measurements in patients with hyperreflective endothelial deposits compared with those without endothelial deposits was observed.Öğe Corneal confocal microscopy detects corneal nerve damage and increased dendritic cells in Fabry disease(Nature Publishing Group, 2018) Bitirgen, Gulfidan; Turkmen, Kultigin; Malik, Rayaz A.; Ozkagnici, Ahmet; Zengin, NazmiFabry disease is characterised by neuropathic pain and accelerated vascular disease. This study evaluates the utility of corneal confocal microscopy (CCM) to non-invasively quantify corneal nerve and endothelial cell morphology and dendritic cell (DC) density in relation to disease severity in subjects with Fabry disease. Seventeen consecutive participants with Fabry disease and 17 healthy control subjects were included in this cross-sectional study. Fabry disease severity was measured using the Mainz Severity Score Index (MSSI). Central corneal sensitivity was assessed with a contact corneal esthesiometer. There was a significant reduction in the corneal sensitivity (5.75 [5.25-6.00] vs. 6.00 [6.00-6.00] cm, P = 0.014), nerve fiber density (NFD) (26.4 +/- 10.1 vs. 33.7 +/- 7.9 fibers/mm(2), P = 0.025) and nerve fiber length (NFL) (15.9 +/- 3.4 vs. 19.5 +/- 4.4 mm/mm(2), P = 0.012) and an increase in DC density (38.3 [17.5-97.3] vs. 13.5 [0-29.4] cells/mm(2), P = 0.004) in subjects with Fabry disease compared to the healthy control subjects. The total MSSI score correlated with NFD (rho = -0.686; P = 0.006), NFL (rho = -0.692; P = 0.006), endothelial cell density (rho = -0.511; P = 0.036), endothelial cell area (rho = 0.514; P = 0.036) and alpha-galactosidase A enzyme activity (rho = -0.723; P = 0.008). This study demonstrates reduced corneal sensitivity, corneal nerve fiber damage and increased DCs in subjects with Fabry disease.Öğe Corneal confocal microscopy identifies corneal nerve fibre loss and increased dendritic cells in patients with long COVID(Bmj Publishing Group, 2022) Bitirgen, Gulfidan; Korkmaz, Celalettin; Zamani, Adil; Ozkagnici, Ahmet; Zengin, Nazmi; Ponirakis, Georgios; Malik, Rayaz A.Background/Aims Long COVID is characterised by a range of potentially debilitating symptoms which develop in at least 10% of people who have recovered from acute SARS-CoV-2 infection. This study has quantified corneal sub-basal nerve plexus morphology and dendritic cell (DC) density in patients with and without long COVID. Methods Forty subjects who had recovered from COVID-19 and 30 control participants were included in this cross-sectional comparative study undertaken at a university hospital. All patients underwent assessment with the National Institute for Health and Care Excellence (NICE) long COVID, Douleur Neuropathique 4 (DN4) and Fibromyalgia questionnaires, and corneal confocal microscopy (CCM) to quantify corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD), corneal nerve fibre length (CNFL), and total, mature and immature DC density. Results The mean time after the diagnosis of COVID-19 was 3.7 +/- 1.5 months. Patients with neurological symptoms 4 weeks after acute COVID-19 had a lower CNFD (p=0.032), CNBD (p=0.020), and CNFL (p=0.012), and increased DC density (p=0.046) compared with controls, while patients without neurological symptoms had comparable corneal nerve parameters, but increased DC density (p=0.003). There were significant correlations between the total score on the NICE long COVID questionnaire at 4 and 12 weeks with CNFD (rho=-0.436; p=0.005, rho=-0.387; p=0.038, respectively) and CNFL (rho=-0.404; p=0.010, rho=-0.412; p=0.026, respectively). Conclusion Corneal confocal microscopy identifies corneal small nerve fibre loss and increased DCs in patients with long COVID, especially those with neurological symptoms. CCM could be used to objectively identify patients with long COVID.Öğe Corneal Thickness During Corneal Collagen Cross-Linking with Isotonic Riboflavin Solution without Dextran(Turkish Ophthalmological Soc, 2014) Oltulu, Refik; Donbaloglu, Meryem; Satirtav, Gunhal; Zengin, Nazmi; Ozkagnici, AhmetObjectives: To monitor the corneal thickness change during the dextran-free isotonic riboflavin solution-aided corneal collagen cross-linking procedure in keratoconus patients. Materials and Methods: Corneal thickness measurements during the corneal collagen cross-linking (CXL) treatment for progressive keratoconus were evaluated. The corneal thickness measurements were obtained with ultrasonic pachymetry device at five different time points: 0, 15, and 30 minutes after epithelial removal and 15 and 30 minutes after the initiation of UVA irradiation. Results: Twenty-four eyes of 24 patients with progressive keratoconus were included in the study. The thinnest pachymetric values obtained at the 0, 15, and 30 minute measurements after corneal deepithelisation were 409.38 +/- 10.43 mu m (383-435 mu m), 434.56 +/- 17.68 mu m (400-485 mu m), and 457.44 +/- 21.78 mu m (428-516 mu m), respectively. Pachymetric values obtained at 15 and 30 minutes after UVA application to the cornea were 471.69 +/- 23.38 mu m (439-526 mu m) and 482.63 +/- 23.69 mu m (436-524 mu m), respectively. The gradual increase was found to be statistically significant when each measurement was compared with the previous values (p < 0.001). Conclusion: We found that the corneal thickness was not decreased during the CXL with dextran-free isotonic riboflavin solution; on the contrary, corneal thickness was increased regularly during the procedure.Öğe Effect of Eye Rubbing on Corneal Biomechanical Properties and Intraocular Pressure(Turkish Ophthalmological Soc, 2014) Oltulu, Refik; Donbaloglu, Meryem; Satirtav, Gunhal; Okka, Mehmet; Ozkagnici, AhmetObjectives: To determine whether corneal biomechanical properties and intraocular pressure (IOP) are affected by eye rubbing. Materials and Methods: Healthy individuals, aged between 15 and 50 years, without any ocular pathological signs were included. Corneal biomechanical parameters, Goldmann-equivalent intraocular pressure (IOPg), corneal-compensated intraocular pressure (IOPcc), corneal resistance factor (CRF), and corneal hysteresis (CH) values were measured using an ocular response analyzer (ORA). Measurements were taken at baseline and immediately after 30 seconds of eye rubbing. ORA parameters before and after eye rubbing were analyzed using student's t test. A p-value less than 0.05 was considered statistically significant. Results: We included eighty-one eyes of 53 individuals with a mean age of 32 +/- 10.11(15-50) years. Before eye rubbing, the mean measurement values were as follows: CH 10.93 +/- 1.69 mmHg, CRF 10.82 +/- 1.78 mmHg, IOPg 15.76 +/- 3.18 mmHg, and IOPcc 15.74 +/- 2.69 mmHg. The mean values after eye rubbing were: CH 11.11 +/- 1.52 mmHg, CRF 10.54 +/- 1.56 mmHg, IOPg 14.32 +/- 3.10 mmHg, and IOPcc 14.20 +/- 2.77 mmHg. The decrease in CRF, IOPg, and IOPcc was statistically significant, while the change in CH was found to be statistically insignificant. Conclusion: CRF, IOPg, and IOPcc decreased significantly after eye rubbing and this should be considered before taking any ORA measurements and interpreting the results.Öğe Effects of panretinal laser photocoagulation on the corneal nerve plexus and retinal nerve fiber layer in retinal vein occlusion(Wichtig Publishing, 2017) Bitirgen, Gulfidan; Belviranli, Selman; Malik, Rayaz A.; Kerimoglu, Hurkan; Ozkagnici, AhmetPurpose: To determine the effects of panretinal photocoagulation (PRP) on corneal sub-basal nerve plexus (SBNP) and peripapillary retinal nerve fiber layer (RNFL) thickness in patients with unilateral central retinal vein occlusion (CRVO) who had previously undergone PRP treatment. Methods: Sixty-four eyes of 32 patients (19 male, 13 female) with unilateral ischemic type CRVO who had undergone PRP treatment at least 6 months previously were included in this cross-sectional study. The laser scanning in vivo corneal confocal microscope was used to determine corneal SBNP parameters. The peripapillary RNFL thickness was assessed with spectral-domain optical coherence tomography. Data obtained from the PRP-treated eyes were compared with those of the fellow unaffected eyes. Results: The mean age of patients was 63.5 +/- 10.7 years (range 45-85 years). The mean nerve fiber density (NFD), nerve branch density, and nerve fiber length (NFL) were significantly lower in PRP-treated eyes compared with fellow eyes (p<0.001 for all). Average peripapillary RNFL thickness was significantly lower in PRP-treated eyes than in fellow eyes (p = 0.007). The NFD and NFL showed a modest but significant positive correlation with average peripapillary RNFL thickness (r = 0.310, p = 0.013 and r = 0.272, p = 0.030, respectively). conclusions: Significant reductions in corneal SBNP parameters and average peripapillary RNFL thickness were observed in the eyes of patients receiving PRP for the treatment of ischemic CRVO.Öğe Evaluation of Contact Lens-Induced Changes in Keratoconic Corneas Using In Vivo Confocal Microscopy(Assoc Research Vision Ophthalmology Inc, 2013) Bitirgen, Gulfidan; Ozkagnici, Ahmet; Malik, Rayaz A.; Oltulu, RefikPURPOSE. To quantitatively analyze laser scanning in vivo confocal microscopy (IVCM) images of all corneal layers in contact lens-wearing and noncontact lens-wearing keratoconus patients. METHODS. The study population included rigid gas permeable (RGP) contact lens-wearing keratoconus patients (group 1; N = 29), keratoconus patients who did not wear contact lenses (group 2; N = 30), and subjects who neither had keratoconus nor wore contact lenses (group 3; N = 30), with groups 2 and 3 matched to group 1 by age and sex. The central cornea was examined with IVCM in all subjects. The mean duration of contact lens wear was 5.50 +/- 3.68 years (range, 2-15 years). RESULTS. Eyes with keratoconus showed significantly lower basal epithelial cell and anterior and posterior stromal keratocyte densities, as well as subbasal nerve fiber density, nerve branch density, and nerve fiber length compared with healthy control subjects. Furthermore, compared with group 2, group 1 had significantly lower basal epithelial cell density (4920 +/- 476 cells/mm(2) vs. 4503 +/- 461 cells/mm(2), P = 0.001) and anterior stromal keratocyte density (561 6 91 cells/mm2 vs. 464 6 55 cells/mm2, P < 0.001), but there was no significant difference for posterior stromal keratocyte density (P = 0.808), endothelial cell density (P = 0.699), or subbasal nerve fiber density (P = 0.142), nerve branch density (P = 0.614), and nerve fiber length (P = 0.850). CONCLUSIONS. Significant corneal microstructural abnormalities were observed in eyes with keratoconus. RGP contact lens wear was associated with a further reduction in the basal epithelial cell and anterior stromal keratocyte densities, but with no effect on posterior stromal keratocyte density, endothelial cell density, or corneal nerve morphology.Öğe Evaluation of Pupillary Light Reflex in Amblyopic Eyes Using Dynamic Pupillometry(Turkish Ophthalmological Soc, 2019) Bitirgen, Gulfidan; Daraghma, Mohammed; Ozkagnici, AhmetObjectives: To evaluate the pupillary light reflex responses in patients with unilateral strabismic and anisometropic amblyopia using dynamic pupillometry. Materials and Methods: A total of 102 eyes of 51 patients with unilateral amblyopia were included in this cross-sectional study. Of the 51 patients, 37 (72.5%) had strabismic amblyopia and 14 (27.5%) had anisometropic amblyopia. All patients underwent complete ophthalmological examination, and pupillary light reflex responses were measured using a computerized dynamic pupillometry system (MonPack One; Metrovision, France). Initial pupil diameter; the amplitude, latency, duration, and velocity of pupil contraction; and the latency, duration, and velocity of pupil dilation were recorded. Results obtained from the patients' amblyopic and normal fellow eyes were compared using paired-samples t-test and Wilcoxon signed rank test. Results: The mean age of the patients was 11.9 +/- 6.0 years. Amblyopic eyes had longer contraction latency (p=0.009), shorter contraction duration (p=0.002), and higher dilation velocity (p=0.033) compared to fellow eyes, while other parameters did not show significant differences. In subgroup analysis, eyes with strabismic amblyopia had longer contraction latency (p=0.006) and shorter contraction duration (p=0.017), while eyes with anisometropic amblyopia had shorter contraction duration (p=0.030) when compared with fellow eyes. Conclusion: In this study, the objective records obtained by dynamic pupillometry showed that pupillary light reflex responses are affected in amblyopic eyes. This finding may shed light on unclear aspects of the pathophysiology of amblyopia.Öğe Evaluation of Retinal Nerve Fiber Layer Thickness in Patients With Anisometropic and Strabismic Amblyopia Using Optical Coherence Tomography(Slack Inc, 2013) Ersan, Ismail; Zengin, Nazmi; Bozkurt, Banu; Ozkagnici, AhmetPurpose: To evaluate the retinal nerve fiber layer (RNFL) thickness of eyes with amblyopia using optical coherence tomography (OCT). Methods: RNFL thickness measurements obtained by time-domain OCT of amblyopic eyes of patients with strabismus (35 patients) and patients with anisometropia (30 patients) were compared with their fellow eyes and age-and gender-matched healthy eyes (40 participants). RNFL thickness values of the groups were also compared and the correlation between RNFL thickness and refraction was evaluated. Results: In the strabismic and anisometropic groups, there were no statistically significant differences in average RNFL thickness between amblyopic eyes and their fellow eyes (P > .05). Temporal RNFL quadrant in the hypermetropic anisometropic group, and superior RNFL quadrant in the myopic anisometropic group were significantly thinner in amblyopic eyes compared to their fellow eyes (P < .05). RNFL thickness did not differ between strabismic amblyopic, anisometropic amblyopic, and control eyes (P > .05). In the anisometropic group, a significant correlation was found between mean RNFL thickness and refraction (P < .05). Conclusion: Amblyopia is not associated with a decrease in RNFL thickness in strabismic or anisometropic amblyopia. In the anisometropic group, the inter-eye differences in RNFL thickness parameters seemed to be related to the refraction differences between the amblyopic eyes and their fellow eyes. [J Pediatr Ophthalmol Strabismus 2013;50:113-117.]Öğe The Frequency and Causes of Blindness in a Rural Region of Central Anatolia of Turkey(Aves, 2019) Mirza, Enver; Mirza, Gunsu Deniz; Oltulu, Refik; Okka, Mehmet; Ozkagnici, AhmetObjective: This study aimed to evaluate the frequency and primary causes of blindness in adults aged 18 years and more in Sarikaya rural region of Yozgat, Turkey, to contribute to the epidemiologic information about blindness in our country. Materials and Methods: Patients who were examined between October 2016 and March 2017 in Sarikaya State Hospital, Clinic of Ophthalmology, were prospectively investigated. Demographic and ophthalmic examination data, presented visual acuities (VA), primary causes of blindness, and monocular blindness were recorded. Blindness was defined as presented visual acuities (VA) definition of World Health Organization criteria. Results: A total of 3423 participants, aged 18-96 years, were examined. Among them, 1887 participants (55%) were female and 1536 (45%) were male. The frequency of blindness was 15% (95% CI: 1.1%-2.0(%); and cataract was the primary cause of blindness (42%). Age-related macular degeneration (21%) and uncorrected refractive error (13%) were the next main causes of blindness. The frequency of monocular blindness was 4% (95% CI: 3.8%-5.2%), and cataract (27%) followed by phthisis bulbi/evisceration (13%) and glaucoma (12%) were the leading causes of monocular blindness. Conclusion: In this rural region of Central Anatolia, the primary cause of blindness and monocular blindness was an unoperated cataract. The patterns of age-specific causes of blindness are variable, but most of them are avoidable or treatable. Thus, awareness should be increased in societies, and people should be prevented from blindness with health-care programs in rural regions of developing countries.Öğe In Vivo confocal Microscopic evaluation of corneal nerve Fibers and Dendritic cells in Patients With Behcet's Disease(Frontiers Media Sa, 2018) Bitirgen, Gulfidan; Kayitmazbatir, Emine Tinkir; Satirtav, Gunhal; Malik, Rayaz A.; Ozkagnici, AhmetCentral and peripheral nervous system involvement may occur during the course of Behcet's disease (BD). In vivo corneal confocal microscopy (CCM) can detect corneal small fiber damage and immune cell density. The aim of this study was to assess central corneal sensitivity, corneal subepithelial nerve plexus morphology and dendritic cell (DC) density in patients with BD. Forty-nine consecutive patients with BD and 30 healthy control subjects were included in this cross-sectional study conducted at a tertiary referral university hospital. Central corneal sensitivity was measured using the contact corneal esthesiometer (Cochet-Bonnet; Luneau, France). The laser scanning CCM (Heidelberg, Germany) was used to quantify corneal nerve fiber density (NFD), nerve branch density (NBD), nerve fiber length (NFL), and DC density. There was a significant reduction in NFD (P = 0.001) and NFL (P = 0.031) and an increase in DC density (P = 0.038) in patients with BD compared to healthy controls, whereas corneal sensitivity (P = 0.066) and NBD (P = 0.067) did not differ significantly. There was no difference in corneal sensitivity, corneal nerve parameters, or DC density between BD patients with [n = 18 (36.7%)] and without a previous history of uveitis (P > 0.05 for all). Disease duration [median (IQR), 6.5 (4.0-14.5) years] correlated with corneal sensitivity (rho = -0.463; P = 0.001) and NFD (rho = -0.304; P = 0.034) and corneal sensitivity correlated with NFD (rho = 0.411; P = 0.003) and NFL (rho = 0.295; P = 0.039) in patients with BD. CCM demonstrates corneal sub-basal nerve fiber loss and increased DC density, providing a non-invasive ophthalmic means to identify peripheral neuropathy and inflammation in patients with BD.Öğe In vivo corneal confocal microscopic analysis in patients with keratoconus(Ijo Press, 2015) Bitirgen, Gulfidan; Ozkagnici, Ahmet; Bozkurt, Banu; Malik, Rayaz A.AIM: To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in patients with keratoconus and control subjects. METHODS: Unscarred corneas of 78 keratoconic subjects without a history of contact lens use and 36 age-matched control subjects were evaluated with slit-lamp examination (SLE), corneal topography and laser scanning IVCM. One eye was randomly chosen for analysis. Anterior and posterior stromal keratocyte, endothelial cell and basal epithelial cell densities and sub-basal nerve structure were evaluated. RESULTS: IVCM qualitatively demonstrated enlarged basal epithelial cells, structural changes in sub -basal and stromal nerve fibers, abnormal stromal keratocytes and keratocyte nuclei, and pleomorphism and enlargement of endothelial cells. Compared with control subjects, significant reductions in basal epithelial cell density (5817 +/- 306 cells/mm(2) vs 4802 +/- 508 cells/mm(2), P<0.001), anterior stromal keratocyte density (800 +/- 111 cells/mm(2) vs 555 +/- 115 cells/mm(2), P<0.001), posterior stromal keratocyte density (333 +/- 34 cells/mm(2) vs 270 +/- 47 cells/mm(2), P<0.001), endothelial cell density (2875 +/- 223 cells/mm(2) vs 2686 +/- 265 cells/mm(2), P<0.001), sub-basal nerve fiber density (31.2 +/- 8.4 nerves/mm(2) vs 18.1 +/- 19.2 nerves/mm(2), P<0.001), sub -basal nerve fiber length (21.4 +/- 3.4 mm/mm(2) vs16.1 +/- 5.1 mm/mm(2), P<0.001), and sub-basal nerve branch density (median 50.0 (first quartile 31.2 - third quartile 68.7) nerve branches/mm(2) vs median 25.0 (first quartile 6.2 - third quartile 45.3) nerve branches/mm(2), P<0.001) were observed in patients with keratocon us. CONCLUSION: Significant microstructural abnormalities were identified in all corneal layers in the eyes of subjects with keratoconus using IVCM. This non invasive in vivo technique provides an important means to define and follow progress of microstructural changes in patients with keratoconus.Öğe Influence of Cyclopentolate Hydrochloride on Corneal Biomechanical Properties in Healthy Individuals(Lippincott Williams & Wilkins, 2014) Oltulu, Refik; Satirtav, Gunhal; Kerimoglu, Hurkan; Zengin, Nazmi; Ozkagnici, Ahmet; Okka, MehmetObjective: This observational study aims to investigate the effects of cyclopentolate hydrochloride (1%) on corneal biomechanical properties, with the ocular response analyzer (ORA), in healthy individuals. Methods: Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc) measurements of 36 (15 female and 21 male) healthy individuals, before and after 45 min of 1% cyclopentolate hydrochloride instillation, were performed by the ORA. Results: The mean CH and IOPcc measurements of the eyes were 10.63 +/- 1.17 mm Hg and 15.15 +/- 2.69 mm Hg, precycloplegia, and 11.09 +/- 1.32 mm Hg and 14.16 +/- 2.77 mm Hg, postcycloplegia, respectively. The differences between the precycloplegia and postcycloplegia in both measurements were statistically significant (P=0.031, P=0.016, respectively; paired t test). The mean CRF and mean IOPg measurements of the eyes were 10.40 +/- 1.16 mm Hg and 14.83 +/- 2.56 mm Hg, precycloplegia, and 10.61 +/- 1.33 mm Hg and 14.25 +/- 2.65 mm Hg, postcycloplegia, respectively. The differences between the precycloplegia and postcycloplegia measurements of the eyes were insignificant (P=0.264 and P=0.100, respectively; paired t test). Conclusions: A 1% cyclopentolate hydrochloride instillation leads to significant changes in the CH values and IOPcc measurements. This should be taken into account during the evaluation of refractive surgery candidates and in clinical conditions where ORA measurements are considered in the diagnosis and follow-up.Öğe Intraocular lens explantation or exchange: indications, postoperative interventions, and outcomes(Consel Brasil Oftalmologia, 2015) Oltulu, Refik; Ersan, Ismail; Satirtav, Gunhal; Donbaloglu, Meryem; Kerimoglu, Hurkan; Ozkagnici, AhmetPurpose: To analyze the indications for explantation or exchange of intraocular lenses (IOLs), which were originally implanted for the correction of aphakia during cataract extraction. Methods: All cases that involved intraocular lens explantation or exchange in one institution between January 2008 and December 2014 were analyzed retrospectively. Results: In total, 93 eyes of 93 patients were analyzed. The median time interval between implantation and explantation of the anterior chamber intraocular lenses (AC IOL) and posterior chamber intraocular lenses (PC IOL) was 83.40 +/- 83.14 months (range: 1-276 months) and 55.14 +/- 39.25 months (range: 1-168 months), respectively. Pseudophakic bullous keratopathy (17 eyes, 38.6%) and persistent iritis (12 eyes, 27.8%) in the AC IOL group and dislocation or decentration (30 eyes, 61.2%) and incorrect IOL power (nine eyes, 18.4%) in the PC IOL group were the most common indications for explantation of IOLs. The mean logMAR best corrected visual acuity (BCVA) improved significantly from 1.30 preoperatively to 0.62 postoperatively in the PC IOL group (p<0.001) but did not improve significantly in the AC IOL group (p=0.186). Conclusions: The primary indication for IOL explantation or exchange was pseudophakic bullous keratopathy in the AC IOL group and was dislocation or decentration in the PC IOL group. PC IOL explantation or exchange is safe and improves visual acuity.Öğe Intraoperative Corneal Thickness Monitoring During Corneal Collagen Cross-Linking With Isotonic Riboflavin Solution With and Without Dextran(Lippincott Williams & Wilkins, 2014) Oltulu, Refik; Satirtav, Gunhal; Donbaloglu, Meryem; Kerimoglu, Hurkan; Ozkagnici, Ahmet; Karaibrahimoglu, AdnanPurpose: The aim of this study was to analyze and compare corneal thickness changes during corneal collagen cross-linking procedures performed with isoosmolar riboflavin solution with 20% dextran and without dextran in corneal ectatic diseases. Methods: The patients in this study were analyzed in 2 groups: group 1 receiving riboflavin solution containing 20% dextran and group 2 receiving dextran-free riboflavin solution. Corneal thickness measurements were obtained with ultrasonic pachymetry at 6 different time points: preoperatively and at 0, 15, 30, 45, and 60 minutes after epithelial removal and initiation of ultraviolet A irradiation. Results: Twenty-seven eyes of 27 patients with progressive keratoconus were included in the study. In group 1 (n = 13), the mean preoperative thinnest pachymetric readings were 469.3 +/- 8.5 mu m, which decreased to 423.8 +/- 8.9 mu m after deepithelization and further decreased to 385.9 +/- 10.9 mm at 15 minutes. The corneal thickness assumed a steady course at the 30-, 45-, and 60-minute measurements (378.9 +/- 9.8 mu m, 384.5 +/- 10.5 mu m, and 396.7 +/- 9.4 mu m, respectively). The initial change was statistically significant (P < 0.01). In group 2 (n = 14), the corneal thickness decreased from 459.4 +/- 3.8 mu m to 414.7 +/- 2.6 mu m with deepithelization, after which it increased steadily with the initiation of the dextran-free riboflavin solution. The final measurement in group 2 was 474.1 +/- 9.4 mu mm; the increase at each time point was statistically significant when compared with the previous measurement (P < 0.01). Conclusions: Using isoosmolar riboflavin solution without dextran causes a steady increase in the corneal thickness during the cross-linking procedure, as opposed to riboflavin with dextran. This result might be beneficial in broadening the spectrum of cross-linking indications in patients with thin corneas.Öğe Monocyte/HDL Ratio and Lymphocyte/Monocyte Ratio in Patients with Pseudoexfoliation Syndrome(Taylor & Francis Inc, 2020) Mirza, Enver; Oltulu, Refik; Katipoglu, Zeynep; Mirza, Guensu Deniz; Ozkagnici, AhmetPurpose: To evaluate the association between monocyte count/high-density lipoprotein (HDL) ratio (MHR) and lymphocyte count/monocyte count ratio (LMR) with pseudoexfoliation syndrome (PEXS) and pseudoexfoliation glaucoma (PEXG). Materials and Methods: A total of 63 participants included in the study. Participants were divided into three groups. Twenty-one patients with PEXS regarded as group 1, 21 patients with PEXG regarded as group 2 and 21 participants without PEXS or PEXG regarded as the control group. Blood parameters were accessed from file records and database retrospectively. Results: The mean MHRs were significantly higher in group 1 and group 2 (p = 0.003, p = 0.036) than the control group, whereas there was no difference between group 1 and group 2 (p = 0.686). The mean LMRs were lower in group 1 and group 2 than the control group but the difference was insignificant (p = 0.232). Conclusion: We found that there is an association between higher MHR and lower LMR with PEXS.Öğe Ophthalmic manifestations in recently diagnosed childhood leukemia(Sage Publications Ltd, 2016) Bitirgen, Gulfidan; Belviranli, Selman; Caliskan, Umran; Tokgoz, Huseyin; Ozkagnici, Ahmet; Zengin, NazmiPurpose: To determine the prevalence and the pattern of ocular involvement in children with leukemia at the time of diagnosis. Methods: The data of patients with leukemia who underwent complete ophthalmic examination at the time of diagnosis between January 2005 and December 2014 were retrospectively reviewed. Demographic data, type of leukemia, ocular findings, blood parameters, and duration of follow-up were analyzed. Results: A total of 185 patients (111 male and 74 female) were included in the study, with a median age of 6.0 years (range 0.5-18.0 years) and a median follow-up time of 36.0 months (range 0.5-108.0 months). Ocular signs were present in 24.3% of the patients at the time of diagnosis and 37.8% of them were symptomatic. The prevalence of ocular involvement was 20.4% in patients with acute lymphocytic leukemia (ALL) and 36.4% in patients with acute myelocytic leukemia (AML) (p = 0.051). Fatality rate was significantly higher in subjects with AML compared with ALL (p = 0.019), but was not significantly different between patients with and without ocular involvement (p = 0.166). There were no significant differences in hemoglobin levels, white blood cell counts, or platelet counts between patients with ALL and AML. Platelet counts were significantly lower in patients with ocular signs compared with subjects without ocular involvement (p = 0.012), while hemoglobin levels and white blood cell counts did not differ significantly. Conclusions: Various ocular signs may be present at the time of diagnosis in childhood leukemia, even in patients without any symptoms. Routine ophthalmic examination should be performed in recently diagnosed children with leukemia.Öğe Progressive Loss of Corneal and Retinal Nerve Fibers in Patients With Multiple Sclerosis: A 2-Year Follow-up Study(Assoc Research Vision Ophthalmology Inc, 2020) Bitirgen, Gulfidan; Akpinar, Zehra; Uca, Ali Ulvi; Ozkagnici, Ahmet; Petropoulos, Ioannis N.; Malik, Rayaz A.Purpose: To determine longitudinal alterations in corneal nerve fiber morphology, dendritic cell (DC) density, and retinal nerve fiber layer (RNFL) thickness over 2 years in patients with multiple sclerosis (MS). Methods: Thirty-one consecutive patients with relapsing-remitting MS (RRMS) underwent assessment of the Kurtzke Expanded Disability Status Scale (EDSS), Multiple Sclerosis Severity Score (MSSS), corneal confocal microscopy to quantify corneal subbasal nerve morphology and DC density, and spectral-domain optical coherence tomography to quantify RNFL thickness at baseline and after 2 years. Results: There was a significant reduction in corneal nerve fiber area (CNFA) (P = 0.003), nerve fiber width (CNFW) (P = 0.005), and RNFL thickness (P = 0.004) with an increase in EDSS (P = 0.01) over 2 years. The change in corneal nerve fiber density (CNFD) correlated with the change in EDSS (rho = -0.468; P = 0.008), MSSS (rho = -0.442; P = 0.01), DC density (rho = -0.550; P = 0.001), and RNFL (rho = 0.472; P = 0.007). The change in corneal nerve fiber length (CNFL) correlated with the change in EDSS (rho = -0.445; P = 0.01) and MSSS (rho = -0.490; P = 0.005). Furthermore, there was a significant decrease in CNFL (P < 0.001), CNFA (P = 0.02), CNFW (P = 0.04), corneal total branch density (P = 0.01), and RNFL thickness (P = 0.02) and a significant increase in DC density (P = 0.04) in patients with worsening EDSS (n = 15). Conclusions: Corneal confocal microscopy can be used to detect progressive corneal nerve fiber loss that relates to a progression of disability in patients with RRMS. Translational Relevance: Corneal confocal microscopy acts as a sensitive imaging biomarker for progressive nerve degeneration in patients with MS.
