The impact of systemic isotretinoin treatment on the tear film, meibomian glands, and corneal endothelium.

PURPOSE: The study aims to investigate changes in tear function, meibomian glands and corneal endothelium in patients receiving systemic isotretinoin therapy. MATERIALS AND METHODS: This prospective study included 38 eyes from 38 patients (23 females and 15 males) treated with systemic isotretinoin (0.5-1 mg/kg/day) following the diagnosis of acne vulgaris. All patients underwent a comprehensive ophthalmologic examination at baseline, 1st month, and third month of treatment. Subjective complaints were assessed using the Ocular Surface Disease Index (OSDI). Tear functions were evaluated through non-invasive tear break up time (NIBUT) and Schirmer I test. Meibomian gland (MG) changes were examined using meibography. Corneal parameters, including endothelial cell density (ECD), coefficient of variation (CV), the number of cells with a hexagonal shape (6A), average cell area (AVG), and central corneal thickness (CCT) were assessed using non-contact specular microscopy. RESULTS: The mean age of the patients was 19.29 ± 2.83 years. Ocular surface-related discomfort, measured with OSDI scores, significantly worsened at the third month measurements compared to the pre-treatment values (p < 0.001). In the 1st month of treatment, there was a significant decrease in NIBUT (p < 0.05). No statistically significant difference was found in the Schirmer test results at each visit. According to the 1st and third-month analysis, there was a significant increase in MG loss compared to the pre-treatment period (p < 0.001). ECD, CV, 6 A, AVG measurements at the first and third months showed a significant change compared to the pre-treatment values (p < 0.001). No significant difference was observed in the CCT measurements during the treatment. CONCLUSION: Systemic isotretinoin disrupted tear stability, caused MG loss, deterioration in corneal endothelium, and led to symptomatic complaints in patients.

Protective Effect of Vaccinium myrtillus Extract on X-ray Irradiation-Induced Retinal Toxicity via eNOS and 8-OHdGexpression.

Every year, hundreds of thousands of cancer patients receive radiotherapy treatment. Oxidative stress is observed in healthy tissues due to irradiation exposure. The present study is the first to address the effects of Vaccinium myrtillus (whortleberry, WB) against the effects of x-ray irradiation on retinal tissue. Twenty-four Sprague-Dawley rats were randomly allocated into 4 groups: (1) control group: rats without any treatment, (2) x-ray irradiation group: 8 Gray (Gy) RT for 2 days, (3) 100 mg WB extract + x-ray irradiation group: 8 Gy irradiation for 2 days and followed by intraperitoneal (IP) WB extract (100 mg/kg) supplementation for 10 days, (4) 200 mg WB extract + x-ray irradiation group: 8 Gy irradiation for 2 days and followed by intraperitoneal (IP) WB extract (200 mg/kg) supplementation for 10 days. Eyes were enucleated on the 10th day after RT for histopathological, immunohistochemical (8-hydroxy deoxyguanosine (8-OHdG), endothelial nitric oxide synthase (eNOS), and biochemical analyses (glutathione peroxidase (GSH), and malondialdehyde (MDA). The GSH levels significantly decreased and MDA levels and 8-OHdG staining increased after x-ray irradiation compared to the control group. Combined x-ray irradiation +WB treatment significantly increased GSH levels and significantly decreased MDA production and 8-OHdG staining. However, eNOS staining was not affected in any of the groups. Besides, x-ray irradiation significantly increased cell losses and edematous areas. The WB significantly reversed the cellular damage in ganglion cells, inner nuclear, and outer nuclear layers in quantitative analyses. The x-ray irradiation caused significant retinal impairment, and additional WB therapy provided protective effects against radiation-induced retinopathy. These results may suggest WB extract as an adjuvant therapy to reverse retinal impairments after x-ray irradiation.

The impact of hybrid contact lenses on keratoconus progression after accelerated transepithelial corneal cross-linking.

PURPOSE: To investigate the effect of hybrid contact lenses (HCLs) on keratoconus (KCN) progression after accelerated transepithelial cross-linking (A-TE CXL). METHODS: Thirty-five eyes of 26 patients who preferred Ultrahealth HCLs for an optical correction after A-TE CXL formed the study group, and 45 eyes of 34 patients who preferred spectacle correction were age- and sex-matched to form the control group. Corrected distance visual acuity (CDVA), maximum keratometry, mean keratometry, apical posterior keratometry, cylindrical power, minimum corneal thickness, keratoconus vertex indices and curvature asymmetry indices obtained by Scheimpflug corneal topography were compared before, 6 and 12 months after the procedure. Anterior segment optic coherence tomography (AS-OCT) was performed to measure the apical corneal clearance of HCL-wearing patients. RESULTS: The median pre-CXL CDVA value of the patients in the HCL group was logMAR 0.30 (0.20-1.0), and it was logMAR 0.30 (0.10-1.0) in the spectacle-corrected group. There was a significant increase in CDVA 6 and 12 months after CXL procedure in both groups (p < 0.001, 0.003, respectively). The median front curve asymmetry index (FCAsym) significantly improved after A-TE CXL in the HCL group. The pre-CXL and 12th-month topographic comparisons of the spectacle-corrected group revealed no significant difference. In addition, no significant difference was observed between topographic alterations of two groups (p > 0.05). CONCLUSION: The CDVA significantly improved, and KCN progression was halted in patients wearing HCL 12 months after A-TE CXL. Besides, FCAsym indices can be considered for follow-up of the HCL-wearing patients as an assistive parameter to AS-OCT measurements.

Pupillometry measurement and its relationship to retinal structural changes in children with attention deficit hyperactivity disorder.

PURPOSE: This study aims to assess the pupillometry measurements of the attention deficit hyperactivity disorder (ADHD) patients and to investigate their correlations with macular and RNFL thickness parameters by comparing the values with a healthy control group. METHODS: Newly diagnosed ADHD patients in a child and adolescent clinic of a tertiary hospital were consulted in an ophthalmology clinic. All participants had undergone a standard ophthalmological examination including refractometry, best corrected visual acuity, color vision, anterior segment biomicroscopy, fundoscopy, pupillometry, and OCT. All results were compared with a healthy control group at the same age. RESULTS: The study group consisted of 32 patients and there were 43 children in the control group. Mean pupillary velocities of ADHD patients and control group were 0.60 ± 0.11 mm/s and 0.63 ± 0.11 mm/s, and 0.49 ± 0.12 mm/s and 0.50 ± 0.10 mm/s, for right and left eyes, respectively. The difference was statistically significant for both eyes (p < 0.05). Mean RNFL thickness measurements of the study group were 90.69 ± 8.58 µm and 89.63 ± 8.14 µm for right and left eyes, respectively and those were 87.35 ± 7.67 µm and 88.77 ± 7.44 µm, respectively in the healthy group. Correlation between right pupillary velocity and RNFL thickness was statistically significant (r = 0.339, p = 0.003). CONCLUSION: Higher pupillary velocity values were observed in both eyes of children with ADHD and that was positively correlated with RNFL measurements of their right eyes.

The effect of endothelin receptor antagonists in the endotoxin-induced uveitis rabbit model.

PURPOSE: To investigate the effect of Bosentan (non-selective endothelin receptor antagonist) and BQ123 (ETA receptor antagonist) on intraocular inflammation in an endotoxin-induced uveitis (EIU) rabbit model. METHODS: Uveitis was induced by intravitreal injection of lipopolysaccharide (LPS). The animals were divided into 7 groups and there were six rabbits in each group (saline, saline and ethanol, bosentan, BQ123, lipopolysaccharide (LPS), bosentan and LPS, BQ123 and LPS-injected groups). Bosentan and BQ123 were applied before LPS injection. Aqueous humour was collected at 24th hour post-injections and enucleation was performed for the evaluation of histopathological changes. RESULTS: BQ123 decreased clinical score, cell counts and protein amount more than bosentan and it was significant for cell counts (p = 0.018). Bosentan significantly diminished inflammatory reactions more than BQ123 as shown in histopathological specimens (p = 0.002). CONCLUSIONS: ETA receptor blockage is effective on uveitis treatment by its protective effect on blood aqueous barrier.

Serum 25-Hydroxy Vitamin D, Vitamin B12, and Folic Acid Levels in Progressive and Nonprogressive Keratoconus.

PURPOSE: To evaluate the serum 25-hydroxy vitamin D, vitamin B12, and folic acid (FA) levels in progressive and nonprogressive patients with keratoconus (KCN). METHODS: Fifty-five patients with KCN (28 progressive and 27 nonprogressive) who were followed up for at least 12 months were recruited and separated into 2 groups according to corneal topographic progression criteria. Age- and sex-matched 30 healthy individuals formed the control group. Serum vitamin D, B12, FA, and Ca levels were compared among control, nonprogressive, and progressive groups. The effect of gender, age, vitamin D, B12, and FA parameters on KCN progression was investigated. RESULTS: Serum vitamin D levels were 12.77 ± 5.52, 11.78 ± 4.32, and 17.40 ± 5.12 ng/mL in nonprogressive, progressive, and control groups, respectively. The serum vitamin D levels in KCN groups (nonprogressive and progressive) were significantly lower than the control group (P = 0.002 and P < 0.001, respectively). There was no significant difference between all groups in serum vitamin B12, FA, and Ca levels (P > 0.05). Decreased vitamin D levels significantly increased nonprogressive KCN probability 1.23 times and progressive KCN probability 1.29 times more than the control group (P = 0.002, 95% confidence interval, 0.708-0.925; P < 0.001, 95% confidence interval, 0.668-0.888, respectively). CONCLUSIONS: Serum vitamin D levels were significantly decreased in both KCN groups. However, serum vitamin B12, FA, and Ca levels were similar in all groups. Serum vitamin D evaluation of patients with KCN at onset and follow-up examinations may help to predict the course of the disease.

The acute effects of single cup of coffee on ocular biometric parameters in healthy subjects.

PURPOSE: To evaluate ocular biometric changes in healthy subjects after caffeine consumption from a cup of coffee. METHODS: A total of 36 subjects were included in this prospective observational study. Axial length (AL) and anterior segment parameters including aqueous depth (AD), anterior chamber depth (ACD), lens thickness (LT), and central corneal thickness (CCT) were measured with optic biometry, Lenstar LS 900 (Haag-Streit, Inc., Koeniz, Switzerland) before and 1 and 4 h after ingesting a cup of coffee (60 mg caffeine/100 mL). RESULTS: Mean age of the participants was 30.05 ± 7.43 years (range, 19-45). At baseline, 1st, and 4th hour, AL values were 23.9 ± 1.04 mm, 23.91 ± 1.04 mm, and 23.89 ± 1.04 mm, respectively, and no significant difference was observed (P>0.05). At baseline, 1st, and 4th hour, AD values were 3.06 ± 0.3 mm, 3.11 ± 0.3 mm, and 3.09 ± 0.3 mm, and ACD values were 3.6 ± 0.32, 3.66 ± 0.31, and 3.64 ± 0.31, respectively. AD and ACD values were significantly greater than baseline at 1st and 4th hours following coffee ingestion. Coffee intake caused a significant reduction in LT, compared with baseline and at the 1st and 4th hours which were 3.76 ± 0.28 mm, 3.69 ± 0.32 mm, and 3.72 ± 0.27 mm, respectively. No statistically significant difference was determined in between the 3 measurements in terms of CCT (P>0.05). CONCLUSION: Caffeine causes a significant increase in AD and ACD and a significant decrease in LT following oral intake, for at least 4 h.

Retinal nerve fiber layer thickness in children with ß-thalassemia major.

PURPOSE: To measure the retinal nerve fiber layer thickness (RNFLT) in children with ß-thalassemia major and to compare with healthy controls. METHODS: A total of 47 patients with ß-thalassemia major and 51 healthy controls were included. Each subject underwent a standard ophthalmological examination. RNFLT measurements were performed using optical coherence tomography. RESULTS: Mean age of the patient group and healthy controls were 13.7 ± 2.1 and 14.3 ± 2.2 years, respectively. Mean peripapillary RNFL thickness was 94 µm in the patient group, and 100 µm in the control group (p < 0.01). In patients with ß-thalassemia major, RNFL was thinner in all quadrants than control subjects. Within the ß-thalassemia major group neither average RNFLT nor each four quadrant RNFLT were correlated with the age, serum ferritin or serum hemoglobin levels (p > 0.05). CONCLUSION: In this study, we observed RNFL was thinner in patients with ß-thalassemia major. Thinning of RNFL did not correlate with hemoglobin or ferritin levels.

Choroidal Thickness in Turkish Children with Anisometric Amblyopia.

PURPOSE: To assess macular choroidal thickness (CT) and axial length measurements in children with anisometropic amblyopia and to compare the measurements with that of fellow non-amblyopic eyes and age-sex matched controls. METHODS: Forty patients with anisometropic amblyopia and 40 age-/sex-matched controls were evaluated in this study. Eyes were classified into three groups as follows: amblyopic eyes (n = 40), fellow non-amblyopic eyes, and healthy eyes (n = 40). All subjects underwent complete ophthalmic examination and macular choroidal thickness measurements by enhanced depth imaging method of the Spectralis optical coherence tomography system. CT was measured at the fovea and at 1000-µm intervals from the foveal center in both temporal and nasal directions. The statistical assessment was performed with the assistance of one-way analysis of variance (ANOVA) and Pearson's correlation test. RESULTS: The mean subfoveal CT was 389.35, 349.07, and 315.8 µm in the amblyopic, fellow non-amblyopic and healthy eyes, respectively. Choroid was thickest in subfoveal and thinnest in nasal regions among all groups. Both amblyopic and fellow non-amblopic eyes were more hyperopic than healthy eyes. While the subfoveal and nasal CT in amblyopic eyes and fellow eyes were significantly higher than healthy eyes, the temporal CT in amblyopic eyes was significantly higher than in healthy eyes. There was a significant positive correlation between the CT of the subfoveal, nasal, and temporal regions and the refractive state (r = 0.432 p = 0.001; r = 0.324 p = 0.001; r = 0.215 p = 0.01, respectively). CONCLUSION: The macular choroidal thickness-not only in amblyopic eyes but also in non-amblyopic fellow eyes-was significantly thicker than in the healthy subjects. The thick choroid in amblyopic and non-amblyopic fellow eyes may indicate bilateral delay of emmetropization, which probably means amblyopia affecting the visual feedback of both eyes.

Surgical management of traumatic nasolacrimal duct obstruction.

PURPOSE: To evaluate etiologies, demographics, and surgical outcomes in cases of traumatic nasolacrimal duct obstruction (NLDO). METHODS: Charts of 35 patients with the diagnosis of traumatic NLDO were reviewed retrospectively. Patient demographics, type of trauma, previous lacrimal surgery history, surgical treatment, follow-up time, and anatomical and functional outcomes were evaluated. RESULTS: Forty eyes of 35 patients were included in this study over 12 years. Twenty-four patients were male (68.5%) and the mean age of the patients was 31.52 ± 14.58 years (range 9-68). The most common etiology was motor vehicle accidents (52.5%), followed by high velocity blunt injury (27.5%), accidental fall (7.5%), occupational trauma (5%), iatrogenic surgical trauma (5%), and animal bite (2.5%). A total of 21 eyes (52.5%) were treated with external dacryocystorhinostomy (DCR), 30% with conjunctival DCR, 15% with endoscopic DCR, and 2.5% with diode laser-assisted DCR. Mean follow-up time was 23.02 ± 13.53 months. Functional and anatomical success was recorded in 37 out of 40 eyes (92.5%). CONCLUSIONS: Naso-orbitoethmoidal fracture is the main etiology of traumatic NLDO. The majority of the injuries occurred in male participants from motor vehicle accidents and high-velocity blunt injury. Dacryocystorhinostomy provides anatomical and functional success in 92.5% of cases of traumatic NLDO.

Neutrophil-to-Lymphocyte Ratio Increases in Patients With Dry Eye.

PURPOSE: To assess the neutrophil-to-lymphocyte ratio (NLR) as an indicator of inflammation in patients with non-Sjögren dry eye disease. METHODS: Serum NLR and C-reactive protein values were determined in 33 patients with dry eye and in 32 controls. The NLR was calculated by dividing the neutrophil count by the lymphocyte count. RESULTS: Characteristics of the dry eye and control groups were similar. The mean NLR value was 2.8 ± 1.4 (range: 1.1-6.1) in the dry eye group and 1.6 ± 0.7 (range: 0.8-2.8) in the control group (P = 0.002, t test). The mean C-reactive protein value was 0.6 ± 0.7 mg/dL (range: 0-2.3 mg/dL) in the dry eye group and 0.5 ± 0.6 mg/dL (range: 0-1.9 mg/dL) in the control group (P = 0.307, t test). CONCLUSIONS: The NLR values were found to be higher in patients with non-Sjögren dry eye than in controls. This result suggests that non-Sjögren dry eye disease may be associated with systemic inflammation or the NLR values may increase in local inflammatory ocular diseases.

Evaluation of Ocular Surface Health in Patients with Obstructive Sleep Apnea Syndrome.

OBJECTIVES: To evaluate ocular surface health in obstructive sleep apnea syndrome (OSAS) and to investigate the tendency of these patients toward dry eyes. MATERIALS AND METHODS: Fifty patients who underwent polysomnography and were diagnosed with OSAS and 50 normal control subjects were compared with respect to ocular surface disease index (OSDI), Schirmer I test and tear film break-up time (TBUT) values. RESULTS: Patients were grouped as mild (n=15, 30%), moderate (n=15, 30%) and severe (n=20, 40%) according to apnea-hypopnea index values. The right eyes of patients were included in both groups. OSDI values were as follows: control group, 18.7±8.5; mild OSAS group, 40.2±2.8; moderate OSAS group, 48.5±2.2 and severe OSAS group, 62.7±2.3 (p<0.001). TBUT values were as follows: control group, 12.3±4.9; mild OSAS group, 8.2±4.7; moderate OSAS group, 5.8±2.1 and severe OSAS group, 4.2±3.7 (p<0.001). Schirmer values were as follows: control group, 18±6.1 mm; mild OSAS group, 12.9±6.7 mm; moderate OSAS group, 8.5±5.2 mm and severe OSAS group, 7.9±4.7 mm (p<0.001). CONCLUSION: Patients with OSAS seem to have a tendency toward dry eyes. Clinicians should be aware of dry eye development in these patients.

Evaluation of Anterior Segment Parameters in Obesity.

PURPOSE: To investigate anterior segment parameters in obese patients in comparison to healthy individuals. METHODS: Thirty-four obese subjects and 34 age-sex-matched healthy subjects were enrolled in this prospective cross-sectional study. Ophthalmological examinations including intraocular pressure (IOP), central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), and axial length (AL) measurements were performed on each subject. Height and weight of all subjects were recorded and body mass index (BMI) was calculated. RESULTS: IOP was significantly higher in the obese group (p = 0.003). The mean ACD in obese subjects was significantly lower than that in control subjects (p = 0.036). AL, ACV, ACA and CCT were not significantly different between the groups. There was a positive correlation between BMI and IOP (r = 0.404, p < 0.001). ACD and ACA were negatively correlated with BMI. CONCLUSIONS: IOP was significantly higher and ACD was significantly lower in obese subjects. AL, ACV, ACA and CCT were not significantly different between the groups. The impact of obesity on anterior chamber parameters should be further investigated.