Aim: We aimed to investigate the morphometric development of the orbit and eyeball in the fetal p... more Aim: We aimed to investigate the morphometric development of the orbit and eyeball in the fetal period. Material and Methods: The present study was carried out on 136 fetal eyes (86 males, 50 females) obtained from 68 fetuses aged between 15-40 gestational weeks. In this study, the area, height, width, volume, depth, and circumference parameters of the orbit were measured, while the anteroposterior and transverse diameters, weight and volume parameters of the eyeball were measured. Also, the diameter at the place where the optic nerve enters the eyeball was measured. Results: It was determined that all parameters increased during the trimesters and there was a statistically significant difference between the trimesters in all parameters. There was no statistically significant difference in all parameters in terms of gender. In the comparison of the right and left sides, orbital area (p<0.011), orbital circumference (p<0.048) and orbital width (p<0.048) were higher on the ri...
Schwannomas, arising from the nerve sheath, are rare tumors of the orbit. They may present with v... more Schwannomas, arising from the nerve sheath, are rare tumors of the orbit. They may present with various clinical presentations depending on localization of tumors in the orbit and the nerve from which they arise. Therefore, they should be considered as differential diagnosis of orbital disease. In this study, the case of isolated orbital schwannoma is discussed in the light of the literature. A 41 year old female patient was referred to the hospital with a painless mass localized near the inferior part of the left orbit. Eye examination of the patient was normal except for the mass. Orbital computerized tomography showed a wellbordered, solid soft- tissue lesion measuring 15x10 mm in size, located in the extraconal space of the inferolateral orbit. As a result of the histopatholgical examination of the totally excised mass, the diagnosis was established as benign shwannoma. No complications were observed during the one-year follow-up of the patient
Frontal sinus and frontal recess anomalies are not very rare. These include bilateral or unilater... more Frontal sinus and frontal recess anomalies are not very rare. These include bilateral or unilateral aplasia or hypoplasia, absence of frontal sinus ostium, hyperpneumatization and frontal cells (extensive Agger nasi). We reported first case of frontal sinus draining to the contralateral nasal cavity, in a patient with bilateral frontal mucocele.
Purpose: To evaluate the efficiency of low dose intravitreal ranibizumab therapy in the treatment... more Purpose: To evaluate the efficiency of low dose intravitreal ranibizumab therapy in the treatment of aggressive posterior premature retinopathy (APROP).Methods: A total of 124 eyes of 62 patients who underwent intravitreal ranibizumab with APROP diagnosis between January 2015-January 2021 were evaluated retrospectively. After receiving family-approved informed consent, low-dose intravitreal ranibizumab was administered and regular follow-ups were performed.Results: Patients included in the study had a mean birth week of 26.6 (23-33 weeks), a mean birth weight of 905 (450-1970) grams, an average injection week post-natal 9.1 (4-19) weeks. The mean follow-up period was 63 (24-250) weeks. In all eyes, it was observed that ROP was regressed in the first week control after injection and no asymmetrical response was observed in the eyes of any baby. A 58 eyes recovered with a single dose of intravitreal injection therapy and peripheral retinal vascularization was completed. A second injec...
To evaluate the clinical findings of toxic keratopathy associated with abuse of topical anestheti... more To evaluate the clinical findings of toxic keratopathy associated with abuse of topical anesthetics and the treatment efficacy of amniotic membrane transplantation (AMT). Fifteen eyes of 10 patients with abuse of topical anesthetics were included in this study. The data collected included patients' demographic information, initial best corrected visual acuity (BCVA), clinical findings, time to AMT, duration of epithelization, additional treatments, posttreatment BCVA, and the results of psychiatric examination. All patients were male, with the mean age of 37.9±5.4y. The patients had received 0.5% proparacaine hydrochloride due to pain resulting from foreign bodies, such as welding flash burns and car battery explosions, for a mean of 18.2±12.4d. The mean initial BCVA of the patients was 0.069±0.100. All patients had persistent epithelial defects, stromal infiltration, ring ulcer, and corneal edema. Initially, medical treatment was attempted in all cases. Because of severe pain, ...
Abstract Objective: To examine the pathological findings that occurred in the lens and cornea and... more Abstract Objective: To examine the pathological findings that occurred in the lens and cornea and biochemical findings in the lens of rats fed with corn syrup and the protective effects of alpha lipoic acid (ALA). Materials and methods: Twenty-four rats were randomly divided into three groups. Group I served as the control group. Group II was used as the study group; the rats were treated with 30% corn sugar solution for 10 weeks. Group III was the treatment group. Corn syrup was given by the oral route to the rats during the study, and ALA (100 mg/kg) was added to the treatment 4 weeks after the study began. At the end of the experiment, central corneal thickness (CCT) was measured in all rats with an ultrasonic pachymeter. Then the right eyes of the rats were enucleated for histopathological examination of the cornea and lens. The left lenses were homogenized for biochemical analyses. Results: The lenses of the rats treated with corn syrup revealed severe damage; many lens fibers appeared swollen and ruptured with large vacuoles near the lens epithelium. In addition, malondialdehyde (MDA) levels, a parameter of oxidative stress, increased but not significantly in Group II; however. ALA treatment decreased MDA levels significantly. Antioxidant enzyme and catalase (CAT) activities were significantly decreased in Group II, and ALA treatment increased these activities; however, the increase was not significant. Changes were observed in the cornea such as epithelial alterations, subepithelial vacuolizations, collagen fibers loss in the stromal layer, interruptions in the subepithelial basement membrane and central corneal thickening. Conclusions: Corn syrup can cause severe damage in rat lenses and corneas. However, ALA ameliorates the effect of corn syrup-related lesions on the cornea and lens.
ABSTRACT Purpose: To evaluate refractive errors in patients with migraine headache and to compare... more ABSTRACT Purpose: To evaluate refractive errors in patients with migraine headache and to compare with healthy subjects. Materials and Methods: This prospective case-control study includes patients with migraine and age- and sex-matched healthy subjects. Clinical and demographic characteristics of the patients were noted. Detailed ophthalmological examinations were performed containing spherical refractive error, astigmatic refractive error, spherical equivalent (SE), anisometropia, best-corrected visual acuity, intraocular pressure, slit lamp biomicroscopy, fundus examination, axial length, anterior chamber depth, and central corneal thickness. Spectacle use in migraine and control groups was compared. Also, the relationship between refractive components and migraine headache variables was investigated. Results: Seventy-seven migraine patients with mean age of 33.27 ± 8.84 years and 71 healthy subjects with mean age of 31.15 ± 10.45 years were enrolled (p = 0.18). The migraine patients had higher degrees of astigmatic refractive error, SE, and anisometropia when compared with the control subjects (p = 0.01, p = 0.03, p = 0.02, respectively). Conclusion: Migraine patients may have higher degrees of astigmatism, SE, and anisometropia. Therefore, they should have ophthalmological examinations regularly to ensure that their refractive errors are appropriately corrected.
Purpose: The purpose of this study was to document clinical findings and management of a patient ... more Purpose: The purpose of this study was to document clinical findings and management of a patient with bilateral globe luxation and optic nerve transection. Materials and Methods: A 25-year-old female patient was admitted to the emergency department with bilateral traumatic globe luxation following a motor vehicle accident. Results: Visual acuity testing showed no light perception. The right pupil was dilated and bilaterally did not react to light. The globes were bilaterally intact. A computed tomography scan revealed Le Fort type II fractures, bilateral optic nerve transection and disruption of all extraocular muscles. The globes of the patient were bilaterally reduced into the orbit. However, the patient developed phthisis bulbi in the right eye at month 3. Conclusion: Globe luxation presents a dramatic clinical picture, and may lead to the development of severe complications due to the concomitance of complete optic nerve dissection and multiple traumas. Even if the luxated globe...
Aims: To investigate the efficacy and safety of postoperative topical cyclosporine A 0.05% (tCsA)... more Aims: To investigate the efficacy and safety of postoperative topical cyclosporine A 0.05% (tCsA) (Restasis®, Allergan Pharmaceutical) eye drops in preventing the recurrence of pterygium. Methods: 31 patients with bilateral pterygium were examined between January 2006 and February 2007. During a 1-year follow-up, the right eyes of the patients assigned as the treatment group were treated by tCsA and the left eyes were considered as the control group. Results: The pterygium recurred in 4 (12.9%) of 31 right eyes in the treatment group and in 14 (45.2%) of 31 left eyes in the control group (p = 0.005). The mean follow-up ± SD was 9.39 ± 4.14 months (range, 1 to 12 months). The control group had a 7.37 times higher risk of recurrence in pterygium compared with the treatment group (OR = 0.1357, p = 0.0051). A statistically significant difference in recurrence-free probabilities was found for the treatment and control groups (log-rank test; p = 0.006). A multivariate Cox regression model...
Journal of Receptors and Signal Transduction, 2014
Despite the importance of oxidative stress and apoptosis through mitochondrial depolarization in ... more Despite the importance of oxidative stress and apoptosis through mitochondrial depolarization in neurodegenerative diseases, their roles in etiology of glaucoma are poorly understood. We aimed to investigate whether oxidative stress and apoptosis formation are altered in rat pheochromocytoma-derived cell line-12 (PC12) neuronal cell cultures exposed to elevated different hydrostatic pressures as a cell culture model of glaucoma. Cultured PC12 cells were subjected to 0, 15 and 70 mmHg hydrostatic pressure for 1 and 24 h. Then, the following values were analyzed: (a) cell viability; (b) lipid peroxidation and intracellular reactive oxygen species production; (c) mitochondrial membrane depolarization; (d) cell apoptosis; (e) caspase-3 and caspase-9 activities; (f) reduced glutathione (GSH) and glutathione peroxidase (GSH-Px). The hydrostatic pressures (15 and 70 mmHg) increased oxidative cell damage through a decrease of GSH and GSH-Px values, and increasing mitochondrial membrane potential. Additionally, 70 mmHg hydrostatic pressure for 24 h indicated highest apoptotic effects, as demonstrated by plate reader analyses of apoptosis, caspase-3 and -9 values. The present data indicated oxidative stress, apoptosis and mitochondrial changes in PC12 cell line during different hydrostatic pressure as a cell culture model of glaucoma. This findings support the view that mitochondrial oxidative injury contributes early to glaucomatous optic neuropathy.
Aim: We aimed to investigate the morphometric development of the orbit and eyeball in the fetal p... more Aim: We aimed to investigate the morphometric development of the orbit and eyeball in the fetal period. Material and Methods: The present study was carried out on 136 fetal eyes (86 males, 50 females) obtained from 68 fetuses aged between 15-40 gestational weeks. In this study, the area, height, width, volume, depth, and circumference parameters of the orbit were measured, while the anteroposterior and transverse diameters, weight and volume parameters of the eyeball were measured. Also, the diameter at the place where the optic nerve enters the eyeball was measured. Results: It was determined that all parameters increased during the trimesters and there was a statistically significant difference between the trimesters in all parameters. There was no statistically significant difference in all parameters in terms of gender. In the comparison of the right and left sides, orbital area (p<0.011), orbital circumference (p<0.048) and orbital width (p<0.048) were higher on the ri...
Schwannomas, arising from the nerve sheath, are rare tumors of the orbit. They may present with v... more Schwannomas, arising from the nerve sheath, are rare tumors of the orbit. They may present with various clinical presentations depending on localization of tumors in the orbit and the nerve from which they arise. Therefore, they should be considered as differential diagnosis of orbital disease. In this study, the case of isolated orbital schwannoma is discussed in the light of the literature. A 41 year old female patient was referred to the hospital with a painless mass localized near the inferior part of the left orbit. Eye examination of the patient was normal except for the mass. Orbital computerized tomography showed a wellbordered, solid soft- tissue lesion measuring 15x10 mm in size, located in the extraconal space of the inferolateral orbit. As a result of the histopatholgical examination of the totally excised mass, the diagnosis was established as benign shwannoma. No complications were observed during the one-year follow-up of the patient
Frontal sinus and frontal recess anomalies are not very rare. These include bilateral or unilater... more Frontal sinus and frontal recess anomalies are not very rare. These include bilateral or unilateral aplasia or hypoplasia, absence of frontal sinus ostium, hyperpneumatization and frontal cells (extensive Agger nasi). We reported first case of frontal sinus draining to the contralateral nasal cavity, in a patient with bilateral frontal mucocele.
Purpose: To evaluate the efficiency of low dose intravitreal ranibizumab therapy in the treatment... more Purpose: To evaluate the efficiency of low dose intravitreal ranibizumab therapy in the treatment of aggressive posterior premature retinopathy (APROP).Methods: A total of 124 eyes of 62 patients who underwent intravitreal ranibizumab with APROP diagnosis between January 2015-January 2021 were evaluated retrospectively. After receiving family-approved informed consent, low-dose intravitreal ranibizumab was administered and regular follow-ups were performed.Results: Patients included in the study had a mean birth week of 26.6 (23-33 weeks), a mean birth weight of 905 (450-1970) grams, an average injection week post-natal 9.1 (4-19) weeks. The mean follow-up period was 63 (24-250) weeks. In all eyes, it was observed that ROP was regressed in the first week control after injection and no asymmetrical response was observed in the eyes of any baby. A 58 eyes recovered with a single dose of intravitreal injection therapy and peripheral retinal vascularization was completed. A second injec...
To evaluate the clinical findings of toxic keratopathy associated with abuse of topical anestheti... more To evaluate the clinical findings of toxic keratopathy associated with abuse of topical anesthetics and the treatment efficacy of amniotic membrane transplantation (AMT). Fifteen eyes of 10 patients with abuse of topical anesthetics were included in this study. The data collected included patients' demographic information, initial best corrected visual acuity (BCVA), clinical findings, time to AMT, duration of epithelization, additional treatments, posttreatment BCVA, and the results of psychiatric examination. All patients were male, with the mean age of 37.9±5.4y. The patients had received 0.5% proparacaine hydrochloride due to pain resulting from foreign bodies, such as welding flash burns and car battery explosions, for a mean of 18.2±12.4d. The mean initial BCVA of the patients was 0.069±0.100. All patients had persistent epithelial defects, stromal infiltration, ring ulcer, and corneal edema. Initially, medical treatment was attempted in all cases. Because of severe pain, ...
Abstract Objective: To examine the pathological findings that occurred in the lens and cornea and... more Abstract Objective: To examine the pathological findings that occurred in the lens and cornea and biochemical findings in the lens of rats fed with corn syrup and the protective effects of alpha lipoic acid (ALA). Materials and methods: Twenty-four rats were randomly divided into three groups. Group I served as the control group. Group II was used as the study group; the rats were treated with 30% corn sugar solution for 10 weeks. Group III was the treatment group. Corn syrup was given by the oral route to the rats during the study, and ALA (100 mg/kg) was added to the treatment 4 weeks after the study began. At the end of the experiment, central corneal thickness (CCT) was measured in all rats with an ultrasonic pachymeter. Then the right eyes of the rats were enucleated for histopathological examination of the cornea and lens. The left lenses were homogenized for biochemical analyses. Results: The lenses of the rats treated with corn syrup revealed severe damage; many lens fibers appeared swollen and ruptured with large vacuoles near the lens epithelium. In addition, malondialdehyde (MDA) levels, a parameter of oxidative stress, increased but not significantly in Group II; however. ALA treatment decreased MDA levels significantly. Antioxidant enzyme and catalase (CAT) activities were significantly decreased in Group II, and ALA treatment increased these activities; however, the increase was not significant. Changes were observed in the cornea such as epithelial alterations, subepithelial vacuolizations, collagen fibers loss in the stromal layer, interruptions in the subepithelial basement membrane and central corneal thickening. Conclusions: Corn syrup can cause severe damage in rat lenses and corneas. However, ALA ameliorates the effect of corn syrup-related lesions on the cornea and lens.
ABSTRACT Purpose: To evaluate refractive errors in patients with migraine headache and to compare... more ABSTRACT Purpose: To evaluate refractive errors in patients with migraine headache and to compare with healthy subjects. Materials and Methods: This prospective case-control study includes patients with migraine and age- and sex-matched healthy subjects. Clinical and demographic characteristics of the patients were noted. Detailed ophthalmological examinations were performed containing spherical refractive error, astigmatic refractive error, spherical equivalent (SE), anisometropia, best-corrected visual acuity, intraocular pressure, slit lamp biomicroscopy, fundus examination, axial length, anterior chamber depth, and central corneal thickness. Spectacle use in migraine and control groups was compared. Also, the relationship between refractive components and migraine headache variables was investigated. Results: Seventy-seven migraine patients with mean age of 33.27 ± 8.84 years and 71 healthy subjects with mean age of 31.15 ± 10.45 years were enrolled (p = 0.18). The migraine patients had higher degrees of astigmatic refractive error, SE, and anisometropia when compared with the control subjects (p = 0.01, p = 0.03, p = 0.02, respectively). Conclusion: Migraine patients may have higher degrees of astigmatism, SE, and anisometropia. Therefore, they should have ophthalmological examinations regularly to ensure that their refractive errors are appropriately corrected.
Purpose: The purpose of this study was to document clinical findings and management of a patient ... more Purpose: The purpose of this study was to document clinical findings and management of a patient with bilateral globe luxation and optic nerve transection. Materials and Methods: A 25-year-old female patient was admitted to the emergency department with bilateral traumatic globe luxation following a motor vehicle accident. Results: Visual acuity testing showed no light perception. The right pupil was dilated and bilaterally did not react to light. The globes were bilaterally intact. A computed tomography scan revealed Le Fort type II fractures, bilateral optic nerve transection and disruption of all extraocular muscles. The globes of the patient were bilaterally reduced into the orbit. However, the patient developed phthisis bulbi in the right eye at month 3. Conclusion: Globe luxation presents a dramatic clinical picture, and may lead to the development of severe complications due to the concomitance of complete optic nerve dissection and multiple traumas. Even if the luxated globe...
Aims: To investigate the efficacy and safety of postoperative topical cyclosporine A 0.05% (tCsA)... more Aims: To investigate the efficacy and safety of postoperative topical cyclosporine A 0.05% (tCsA) (Restasis®, Allergan Pharmaceutical) eye drops in preventing the recurrence of pterygium. Methods: 31 patients with bilateral pterygium were examined between January 2006 and February 2007. During a 1-year follow-up, the right eyes of the patients assigned as the treatment group were treated by tCsA and the left eyes were considered as the control group. Results: The pterygium recurred in 4 (12.9%) of 31 right eyes in the treatment group and in 14 (45.2%) of 31 left eyes in the control group (p = 0.005). The mean follow-up ± SD was 9.39 ± 4.14 months (range, 1 to 12 months). The control group had a 7.37 times higher risk of recurrence in pterygium compared with the treatment group (OR = 0.1357, p = 0.0051). A statistically significant difference in recurrence-free probabilities was found for the treatment and control groups (log-rank test; p = 0.006). A multivariate Cox regression model...
Journal of Receptors and Signal Transduction, 2014
Despite the importance of oxidative stress and apoptosis through mitochondrial depolarization in ... more Despite the importance of oxidative stress and apoptosis through mitochondrial depolarization in neurodegenerative diseases, their roles in etiology of glaucoma are poorly understood. We aimed to investigate whether oxidative stress and apoptosis formation are altered in rat pheochromocytoma-derived cell line-12 (PC12) neuronal cell cultures exposed to elevated different hydrostatic pressures as a cell culture model of glaucoma. Cultured PC12 cells were subjected to 0, 15 and 70 mmHg hydrostatic pressure for 1 and 24 h. Then, the following values were analyzed: (a) cell viability; (b) lipid peroxidation and intracellular reactive oxygen species production; (c) mitochondrial membrane depolarization; (d) cell apoptosis; (e) caspase-3 and caspase-9 activities; (f) reduced glutathione (GSH) and glutathione peroxidase (GSH-Px). The hydrostatic pressures (15 and 70 mmHg) increased oxidative cell damage through a decrease of GSH and GSH-Px values, and increasing mitochondrial membrane potential. Additionally, 70 mmHg hydrostatic pressure for 24 h indicated highest apoptotic effects, as demonstrated by plate reader analyses of apoptosis, caspase-3 and -9 values. The present data indicated oxidative stress, apoptosis and mitochondrial changes in PC12 cell line during different hydrostatic pressure as a cell culture model of glaucoma. This findings support the view that mitochondrial oxidative injury contributes early to glaucomatous optic neuropathy.
Uploads
Papers by Özlem Tök