Evaluation of lamina cribrosa curvature index in different types of glaucoma.

OBJECTIVE: The aim of this study was to evaluate the lamina cribrosa curvature index in different types of glaucoma in comparison with clinical findings and conventional measurement methods. MATERIAL AND METHOD: Patients older than 18 years who were followed up in Glaucoma Unit of Department of Ophthalmology at Firat University Faculty of Medicine, whose disease had been under control at least for 1 year, who had at least three reliable visual fields, whose refractive error was between - 6 and + 5 diopter and who did not have any disease other than glaucoma that would affect the visual field, were included in the study. Clinical and demographic characteristics, visual field, optical coherence tomography and lamina cribrosa curvature index (LCCI) results were evaluated. The study patients were divided into six groups: early-stage primary open-angle glaucoma (POAG) as group 1 and intermediate-advanced stage POAG as group 2, pseudo-exfoliation glaucoma (PEXG) as group 3, normal tension glaucoma (NTG) as group 4, ocular hypertension patients whom subsequently developed POAG as group 5 and healthy control as group 6. RESULTS: A total of 189 eyes of 101 patients were included in our study. Forty-seven patients were male (46.5%) and 54 were female (53.5%). The mean age was 62.43 ± 1.49 years. LCCI, mean deviation (MD), visual field index (VFI), pattern standard deviation (PSD) and retinal nerve fiber layer thickness (RNFL) values were analyzed in all groups and Pearson correlation analysis showed statistically significant correlation between PSD and RNFL measurements with LCCI values in all groups. MD value was correlated with LCCI in groups 2, 3 and 4, while VFI value was correlated with LCCI in all groups except group 5. When the groups were compared with each other according to the Post-Hoc Tamhane test, LCCI measurement showed statistically significant results in accordance with MD, VFI, PSD and RNFL values. CONCLUSION: The LCCI assessment is mostly consistent with conventional tests. In this study, in which different types of glaucoma and healthy subjects were examined simultaneously, LCCI shows promise as a detailed and reliable assessment method.

Automated Diabetic Retinopathy Detection Using Horizontal and Vertical Patch Division-Based Pre-Trained DenseNET with Digital Fundus Images.

Diabetic retinopathy (DR) is a common complication of diabetes that can lead to progressive vision loss. Regular surveillance with fundal photography, early diagnosis, and prompt intervention are paramount to reducing the incidence of DR-induced vision loss. However, manual interpretation of fundal photographs is subject to human error. In this study, a new method based on horizontal and vertical patch division was proposed for the automated classification of DR images on fundal photographs. The novel sides of this study are given as follows. We proposed a new non-fixed-size patch division model to obtain high classification results and collected a new fundus image dataset. Moreover, two datasets are used to test the model: a newly collected three-class (normal, non-proliferative DR, and proliferative DR) dataset comprising 2355 DR images and the established open-access five-class Asia Pacific Tele-Ophthalmology Society (APTOS) 2019 dataset comprising 3662 images. Two analysis scenarios, Case 1 and Case 2, with three (normal, non-proliferative DR, and proliferative DR) and five classes (normal, mild DR, moderate DR, severe DR, and proliferative DR), respectively, were derived from the APTOS 2019 dataset. These datasets and these cases have been used to demonstrate the general classification performance of our proposal. By applying transfer learning, the last fully connected and global average pooling layers of the DenseNet201 architecture were used to extract deep features from input DR images and each of the eight subdivided horizontal and vertical patches. The most discriminative features are then selected using neighborhood component analysis. These were fed as input to a standard shallow cubic support vector machine for classification. Our new DR dataset obtained 94.06% and 91.55% accuracy values for three-class classification with 80:20 hold-out validation and 10-fold cross-validation, respectively. As can be seen from steps of the proposed model, a new patch-based deep-feature engineering model has been proposed. The proposed deep-feature engineering model is a cognitive model, since it uses efficient methods in each phase. Similar excellent results were seen for three-class classification with the Case 1 dataset. In addition, the model attained 87.43% and 84.90% five-class classification accuracy rates using 80:20 hold-out validation and 10-fold cross-validation, respectively, on the Case 2 dataset, which outperformed prior DR classification studies based on the five-class APTOS 2019 dataset. Our model attained about >2% classification results compared to others. These findings demonstrate the accuracy and robustness of the proposed model for classification of DR images.

Evaluation of aqueous humor and serum cortistatin levels in diabetic patients with and without diabetic retinopathy.

PURPOSE: To evaluate the aqueous humor and serum cortistatin levels in diabetic patients with and without diabetic retinopathy and its relationship with various metabolic markers that have been reported to be associated with diabetes mellitus. METHODS: The current study included 20 diabetes mellitus patients with diabetic retinopathy, 20 diabetes mellitus patients without diabetic retinopathy, and 20 healthy control subjects with the same sex and age characteristics. Aqueous humor and serum cortistatin, fasting blood glucose, hemoglobinA1c, 25-hydroxyvitamin D levels, blood lipid profiles, and body mass index were measured in all subjects. RESULTS: In diabetic patients with and without diabetic retinopathy and in healthy control subjects, the mean aqueous humor cortistatin levels were 25.55 ± 2.03, 27.71 ± 2.01, and 32.76 ± 3.43 ng/mL, respectively. Likewise, the mean serum cortistatin levels were 6.16 ± 1.08, 6.57 ± 1.00, and 7.56 ± 1.51 ng/mL, respectively. Aqueous humor cortistatin levels were decreased in diabetic patients with and without diabetic retinopathy when compared to healthy controls (p < 0.001). Although aqueous humor cortistatin levels tended to be reduced in diabetic patients with diabetic retinopathy, the difference was not statistically significant between diabetic patients with and without diabetic retinopathy (p = 0.147). Serum cortistatin levels were not statistically significant between diabetic patients with and without diabetic retinopathy and healthy control subjects (p = 0.166). Body mass index, fasting blood glucose, and hemoglobinA1c levels were significantly different between the groups (p < 0.05 for all parameters tested). CONCLUSION: Aqueous humor cortistatin levels were decreased in diabetic patients with and without diabetic retinopathy. The results suggest that a local decrease in the amount of cortistatin may play a role in the pathogenesis of diabetic retinopathy.

Clinical and Demographic Features of Pediatric-Onset Behçet's Disease and Evaluation of Optical Coherence Tomography Findings.

PURPOSE: To evaluate the clinical characteristics, including spectral domain optical coherence tomography (SD-OCT) findings, of pediatric-onset Behçet's disease (PBD) patients. METHODS: Medical records of 23 PBD (15 males and 8 females) and 24 (15 males and 9 females) healthy subjects were evaluated retrospectively. The main outcomes were compared between PBD patients, with and without ocular involvement, and healthy subjects. RESULTS: The mean age at onset was 12.00 ± 2.10 years. Mean follow-up period was 25.17 ± 15.36 months (range 6-48). Retinal vasculitis was the most common ocular finding (7 patients). Most of the complications of systemic treatment were associated with long term corticosteroid therapy. There was no significant difference between the mean retinal thickness of the PBD patients and healthy controls (p > 0.05). The mean choroidal thickness was significantly increased in all measured segments of PBD patients with ocular involvement (p < 0.01). CONCLUSION: Choroidal thickness of PBD patients with ocular involvement was significantly thicker compared to the PBD patients without ocular involvement and to healthy control subjects.

Association of Disease Activity with Serum and Tear IL-2 Levels in Behçet Disease.

PURPOSE: To investigate the association of Behçet disease activity with serum and tear interleukin-2 levels. METHODS: The study was designed as a prospective case control study. The study population consisted of 45 patients with Behçet disease and 24 age and sex-matched healthy participants. Behçet disease patients were classified as active (24 patients) or inactive (21 patients) according to disease activity. Serum and tear interleukin-2 levels were determined using the enzyme-linked immunosorbent assay method. RESULTS: The mean serum and tear interleukin-2 levels of the active disease, inactive disease, and control groups were 17.04 ± 5.02 and 32.61 ± 16.53 pg/mL; 15.20 ± 4.68 and 29.61 ± 8.30 pg/mL; and 14.22 ± 4.18 and 28.89 ± 8.73 pg/mL, respectively. There was no statistically significant difference between the groups with respect to all measured data. CONCLUSIONS: There was no significant difference in serum or tear IL-2 levels between Behçet patients and controls; there was no association of disease activity with serum and tear IL-2 levels.

The impact of octreotide in experimental proliferative vitreoretinopathy.

AIMS: This study aims to investigate the effects of intravitreal octreotide on the growth factors, which have significant roles in the pathogenesis of proliferative vitreoretinopathy (PVR). SETTINGS AND DESIGN: An experimental trial. MATERIALS AND METHODS: 21 guinea pigs were randomly assigned to form 3 groups each including 7 animals. In group 1 (the control group), 0.2 ml saline solution was applied intravitreally in a location of 1.5 mm behind the limbus. In group 2 (the sham group), 0.07 IU dispase in 0.1 ml and 0.1 ml saline solution were applied via the same route. The guinea pigs in group 3 (the treatment group) were applied 0.07 IU dispase in 0.1 ml and 1 mg octreotide in 0.1 ml via the same route. Octreotide injection was applied twice during the period of 10 weeks of the experiment. At the end of the 10 weeks, eyes were enucleated and retinal homogenates were prepared. The platelet derivated growth factor (PDGF), insulin-like growth factor (IGF 1) and transforming growth factor (TGF ß) levels in homogenized retina tissue were measured by Enzyme Linked-Immuno-Sorbent Assay (ELISA) method. STATISTICAL ANALYSIS USED: Kruskal-Wallis variance analysis and Mann-Whitney U test. RESULTS: In the treatment group, a significant decrease was observed in retinal PDGF levels (P < 0.01) while decreases in TGF ß and IGF 1 levels were not found to be significant (P > 0.05). CONCLUSIONS: Intravitreally applied octreotide at a dose of 1 mg has a highly strong effect on PDGF. This study suggests that intravitreal octreotide may suppress PVR development and that octreotide may merit investigation for PVR prophylaxis.

The impact of tacrolimus on growth factors in experimental proliferative vitreoretinopathy.

PURPOSE: To investigate the effect of intravitreal tacrolimus on an animal model of proliferative vitreoretinopathy (PVR) and on growth factors implicated in its pathogenesis. METHODS: Twenty-one guinea pigs were randomly assigned to one of three groups of seven animals each: no-PVR/saline group (no PVR/intravitreal saline-injected group), PVR/saline group (dispase-induced PVR group, treated with control injections of intravitreal saline), and PVR/tacrolimus group (treatment group, dispase-induced PVR group treated with intravitreal tacrolimus injections). At the end of the experiment, eyes were enucleated and the identification of the stages of PVR was carried out. While a halves of the enucleated globes were evaluated histopathologically for PVR formation, the retinas of the other halves of globes were used for the preparation of retinal homogenates. The transforming growth factor-ß, platelet-derived growth factor, and fibroblast growth factor levels in homogenized retina tissues were measured by the enzyme-linked immunosorbent assay method. RESULTS: When assessing the average PVR stages in terms of severe PVR rates, the PVR/tacrolimus group had significantly improved when compared with the PVR/saline group. The PVR/tacrolimus group demonstrated significantly decreased levels of transforming growth factor-ß, platelet-derived growth factor, and fibroblast growth factor when compared with the PVR/saline group and also demonstrated significant improvement in epiretinal membrane formation and retinal fold in the presence of histopathologic levels. The difference in degradation of photoreceptor cells between the PVR/tacrolimus and the PVR/saline groups was not statistically significant. CONCLUSION: This study suggests that intravitreal tacrolimus application may suppress PVR development and that tacrolimus may merit investigation for the prophylaxis of PVR.

A case of vogt-koyanagi-harada disease associated with polycystic ovary syndrome.

UNLABELLED: We report a female patient diagnosed as Vogt-Koyanagi-Harada (VKH) and polycystic ovary syndrome (PCOS). She has diagnosed as VKH with diminished vision, bilateral serous retinal detachment, the signs of fundus fluorescein angiography and the findings of optical coherence tomography. The patient was referred to the gynecology clinic for her complaints as weight gain, hirsutismus and amenorrhea. She has also been diagnosed with PCOS. With oral steroid treatment, visual acuity has improved and the detachments have resolved within a month. VKH disease may be associated with polycystic ovary syndrome. The two conditions may have a common autoimmune pathogenesis. KEYWORDS: Autoimmune pathogenesis; Polycystic ovary syndrome; Vogt-Koyanagi-Harada.

Retinal nitric oxide and malonyldialdehyde levels following photodynamic therapy.

BACKGROUND: To determine the retinal nitric oxide (NO) and malonyldialdehyde (MDA) levels following photodynamic therapy (PDT). MATERIALS AND METHODS: Seven Dutch-belted rabbits received dextrose, while seven others received 2 mg/kg verteporfin infusion over a period of 15 minutes in a dim-lit room. Irradiation to a 1.5 mm diameter intact chorioretinal area in the right eye of verteporfin-infused rabbits, was started 5 minutes after the end of infusion. Three groups were control (dextrose infusion), infusion with verteporfin (left eyes were not irradiated), and irradiation after verteporfin injection (right eyes were irradiated). On the fifth day of the experiment, the eyes were enucleated. The retinas were subsequently frozen and homogenized. Nitrite, a stable end-product of NO and MDA, was measured using the spectrophotometer. Protein concentrations were measured by the Lowry method. Tissue NO and MDA levels were expressed as µmol/gprt and nmol/mgprt, respectively. RESULTS: The mean retinal NO and MDA levels of the control, infusion, and irradiation groups were 24.67 ± 6.66, 0.11 ± 0.02; 45.90 ± 15.52, 0.21 ± 0.09; and 84.43 ± 14.96 µmol/gprt, 0.58 ± 0.14 nmol/mgprt, respectively. The mean retinal NO levels were significantly elevated in the infusion and irradiation groups compared with the control group ( p :0.004; p :0.001). The mean retinal MDA levels were significantly elevated in the infusion and irradiation groups compared to the control one ( p :0.026; p :0.001). Also the mean retinal NO and MDA levels in the irradiation group were found to be significantly higher than the infusion group ( p :0.018; p :0.018). CONCLUSION: Not only PDT, but also verteporfin infusion alone resulted in NO and MDA level increments in the retina, which might be toxic.

The impact of tacrolimus on vascular endothelial growth factor in experimental corneal neovascularization.

PURPOSE: To investigate the impact of tacrolimus on vascular endothelial growth factor (VEGF) in experimental corneal neovascularization (NV) immunohistochemically. MATERIAL AND METHODS: Five groups of seven Wistar albino rats were formed. A silver nitrate cauterization technique was used to induce corneal NV in the study groups, excluding Group 1 (Control Group). Rats in group 1 did not receive any treatment. Rats in group 2 (sham 1) were administered 1 ml of saline intraperitoneally once a day and those in group 3 (sham 2) received one drop of saline four times a day. Rats in group 4 were administered 0.3 mg/kg tacrolimus intraperitoneally once a day. For group 5, 0.3 mg/ml tacrolimus was installed four times a day. Digital photography for each cornea was performed and the percentage area of the NV on the total corneal surface was calculated. The intensity of VEGF immunostaining in the epithelial, the stromal, and endothelial layers was performed in a semi quantitative fashion. RESULTS: The mean percentages of the neovascularized areas of intraperitoneally and topically tacrolimus-treated groups were lesser than those of the sham groups (p = 0.002, p = 0.038, respectively). The mean intensity of the epithelial VEGF immunostaining of the intraperitoneally tacrolimus-treated group was less than that of its sham group (p = 0.002), while the mean intensity of the stromal VEGF staining of the topically tacrolimus-treated group was lesser than that of its sham group (p = 0.042). The intensities of the endothelial VEGF immunostaining of the intraperitoneally and topically tacrolimus-treated groups were less than those of the sham groups (p = 0.038, p = 0.032). CONCLUSION: Systemic and topical administration of tacrolimus may be beneficial in the prevention of corneal NV because of its effect on VEGF.

Comparison of serum glycosylated hemoglobin levels in patients with diabetic cystoid macular edema with and without serous macular detachment.

AIM: A clinical comparative trial was conducted to compare the levels of glycosylated hemoglobin (HbA1c) in patients with diabetic cystoid macular edema (CME) with and without serous macula detachment (SMD). MATERIALS AND METHODS: Thirty patients (group 1) with diabetic CME in both eyes, but without SMD, and 30 patients (group 2) with diabetic CME and SMD in both eyes documented by optical coherence tomography (OCT) and fundus fluorescein angiography (FFA), were included in the study. In addition to the measurement of central macular thickness by OCT and visual acuity (VA) (as logMAR) using the the early treatment diabetic retinopathy study (ETDRS) chart, the concentrations of HbA1c were measured by high performance liquid chromatography (HPLC). Statistical analysis was done by independent samples t test. RESULTS: The mean logMAR VA was 0.8 +/- 0.22 (1.0-0.5) in group 1 and 0.7 +/- 0.16 (1.0-0.6) in group 2. The mean central macular thickness, as determined by OCT, was 468.70 +/- 70.44 microm (344-602 microm) in group 1 and 477.80 +/- 73.34 microm (354-612 microm) in group 2. The difference between the groups was not statistically significant (P = 0.626). The mean HbA1c levels were 8.16 +/- 0.99% in group 1 and 10.05 +/- 1.66% in group 2. The difference between the groups was statistically significant (P < 0.001). CONCLUSIONS: The presence of SMD and high HbA1c levels in the patients with diabetic CME may be indirectly suggestive of retinal pigment epithelium dysfunction.

Mycoplasma pneumoniae and Chlamydia pneumoniae seropositivity in patients with age-related macular degeneration.

BACKGROUND: To determine a possible relation between Mycoplasma pneumoniae (MP) or Chlamidia pneumoniae (CP) seropositivity and age-related macular degeneration (AMD). METHODS: Sixty patients (20 wet AMD, 20 dry AMD and 20 non-AMD controls) were included in the study. Serum samples were collected for analysis of IgM and IgG antibody seropositivity for CP and MP by enzyme-linked immunosorbent assay (ELISA). Comparison of the distribution of seropositivity of these antibodies among patients with wet and dry AMD, and controls was performed. A prospective comparative clinical trial was applied. RESULTS: There was no major difference in the distribution of IgM and IgG seropositivity to CP and MP in patients with wet and dry AMD, and in controls (p > 0.05). CONCLUSIONS: We found no significant association between MP as well as CP antibody titers and AMD. It seems that MP or CP infection is not a risk factor for AMD. KEYWORDS: Mycoplasma pneumoniae; Chlamydia pneumoniae; Age-related macular degeneration; Serology.

The evaluation of vestibular functions in patients with pseudoexfoliation syndrome.

The main objective of the study is to evaluate vestibular system of the inner ear with postural tests in the patients with pseudoexfoliation syndrome (PEX). It is clinical case-control study. The study group included 34 patients with PEX and 40 controls without PEX. The patients and controls underwent complete ophthalmic and otorhinolaryngologic examinations. Vestibular functions were done by Fitzgerald and Dix-Hallpike, caloric tests, Romberg test, tandem Gait test, Quiks test in both control and study groups. Pur-tone and high-frequency audiography were also performed in all cases. The mean patient age was 63 years (+/-11.80) (range 47-74 years) in the PEX group and 65 years (+/-8.70) (range 61-68 years) in the control group with no differences among the two groups (P > 0.05). Although none of the 34 patients with PEX had clinical history of balance disturbance, 21 (61.76%) had significant pathologic sign in vestibular function tests (P < or = 0.05), while only 3 (7.5%) of 40 cases in the control group had pathologic sign in vestibular function tests. The scales from pure tone and high-frequency audiogram in the PEX group were similar to those of the control group. In conclusion, the patients with PEX, there may be a vestibular involvement in the pathological level in the inner ear. Larger clinical studies, experimental animal studies, and post mortem studies in humans are needed to disclose the pathology in the vestibulocochlear system in the patients with PEX.

Serum erythropoietin levels in patients with central serous chorioretinopathy.

OBJECTIVE: To evaluate the levels of erythropoietin (EPO) in the serum in patients with central serous chorioretinopathy (CSC). METHODS: An institutional comperative clinical study. The serum EPO levels were measured with the enzyme-linked immunosorbent assay (ELISA) method, of 15 patients with active CSC (Group 1), 15 patients with inactive CSC (Group 2) and 15 healthy volunteers (Group 3). Kruskal-Wallis variance analysis and Mann-Whitney U test were used for statistical analysis. RESULTS: The patient and control groups were matched for age and sex. There was no statistically significant variation with regard to age and gender among the groups (P > 0.05). The mean serum EPO concentrations in patients with active CSC (Group 1), inactive CSC (Group 2) and in healthy controls (Group 3) were 11.39 ± 3.01 mlU/mL, 11.79 ± 3.78 mlU/mL and 11.95 ± 3.27 mlU/mL, respectively. There was no significant variation among the serum EPO concentrations of the study groups (P > 0.05). CONCLUSION: These findings suggest no role of serum EPO in pathogenesis of CSC.

Spontaneous corneal perforation in a patient with lamellar ichthyosis and dry eye.

We report spontaneous corneal perforation in a patient with lamellar ichthyosis. The patient presented with complaints of pain, redness, diminished vision, and discharge in her right eye for 15 days. Visual acuities were light perception in the right and 20/400 in the left eye. Cicatricial ectropion in both lower eyelids and 2 mm perforation site in the center of the right cornea were observed. Lamellar ichthyosis was suspected because of scaling and excessive dryness of entire body skin and was confirmed by skin biopsy. Amniotic membrane transplantation and transient tarsorraphy was performed and systemic anti-ichthyosis therapy was started. The follow-up visits were not possible because of patient inconsistency. In patients with cicatricial ectropion secondary to ichthyosis, corneal health should be closely monitored because of the perforation risk.

The protective role of Visudyne eyeglass against VEGF synthesis after photodynamic therapy with verteporfin.

PURPOSE: We aimed to determine the extent of protection provided by Visudyne eyeglass against vascular endothelial growth factor (VEGF) synthesis following photodynamic therapy (PDT). METHODS: Three groups with 14 rabbits in each were established. These consisted of a control (dextrose infusion) group, an infusion (verteporfin infusion) group and an irradiation (verteporfin infusion + irradiation) group. One eye in each animal was closed with Visudyne eyeglass and the other by eyelid sutures. The rabbits were exposed to daylight for 30 mins at 2 and 48 hours after the infusion was administered. Half the animals in each group were killed on day 5. The remaining animals were killed on day 10. Levels of VEGF in homogenized retina and choroids were analysed with an ELISA (enzyme-linked immunosorbent assay). RESULTS: Mean VEGF levels, in pg/mg protein, on days 5 and 10 in the control + glass, control + suture, infusion + glass, infusion + suture, irradiation + glass and irradiation + suture subgroups were, respectively: 1.69 +/- 0.67, 1.91 +/- 0.44; 1.75 +/- 0.69, 1.93 +/- 0.53; 2.30 +/- 0.77, 3.47 +/- 2.02; 1.90 +/- 1.00, 2.93 +/- 0.16; 4.39 +/- 2.74, 13.63 +/- 5.25; 3.38 +/- 1.05, 7.37 +/- 2.12. On day 10, VEGF levels were significantly higher in the infusion and irradiation groups compared with the control group (p < 0.05). There were no statistically significant differences between glass and suture samples on days 5 and 10 in the infusion group, or on day 5 in the irradiation group. However, on day 10, the mean VEGF level in eyes closed with Visudyne eyeglass in the irradiation group was significantly higher than in sutured eyes (p = 0.011). CONCLUSIONS: Visudyne eyeglass offers full protection against VEGF increases caused by verteporfin infusion but is only partially protective in eyes exposed to sensitizing light.

The effects of injection site on the reflux following intravitreal injections.

BACKGROUND: This study aimed to investigate the effects of injection site on the reflux after intravitreal injection. METHODS: One hundred and eighty eyes undergoing intravitreal injection including 0.1 ml of triamcinolone acetonide or bevacizumab or pegaptanib were divided to six groups (30 patients in each group) to compare the vitreal reflux after injection using superotemporal versus inferotemporal quadrant. The amount of intraoperative reflux was estimated by measuring the width of the subconjunctival bleb. An interventional, prospective, comparative clinical trial was applied. RESULTS: The mean bleb width as the reflux amount after injection of three drugs was statistically less after the inferotemporal injection (1.50 ± 0.94 mm for triamcinolone acetonide, p < 0.001; 1.60 ± 1.07 mm for bevacizumab, p < 0.001; and 1.77 ± 0.94 mm for pegaptanib, p = 0.001) than those in eyes undergoing the superotemporal injection (3.20 ± 1.63 mm for triamcinolone acetonide; 3.07 ± 1.53 mm for bevacizumab; and 2.80 ± 1.32 mm for pegaptanib). CONCLUSIONS: The injection through inferotemporal quadrant provides statistically significant less vitreal reflux for intravitreal drug injection. KEYWORDS: Intravitreal injection; Injection site; Reflux.

Plasma and vitreous homocysteine concentrations in patients with proliferative diabetic retinopathy.

PURPOSE: An increase in plasma concentrations of homocysteine (Hcy) in proliferative diabetic retinopathy (PDR) has been described. The aim of this study was to investigate vitreous Hcy levels in patients with PDR. METHODS: Plasma and vitreous samples were obtained simultaneously at the time of vitreoretinal surgery from 20 patients with PDR and 12 nondiabetic patients with nonproliferative ocular diseases. Hcy levels were determined by high-performance liquid chromatography. RESULTS: The mean vitreous and plasma Hcy concentrations for the diabetic group were 3.64 +/- 0.65 micromol/L and 16.04 +/- 2.75 micromol/L, respectively. The mean intravitreal and plasma Hcy concentrations for the control group were 1.08 +/- 0.45 micromol/L and 9.18 +/- 3.91 micromol/L, respectively. Both plasma and vitreous Hcy concentrations for the diabetic group were significantly higher than those for the control group (P < 0.001). A statistically significant correlation between vitreous and plasma Hcy concentrations was present only for the diabetic group (r = 0.525; P = 0.017). CONCLUSION: Vitreous Hcy concentrations were elevated in patients with PDR probably due to breakdown of the blood-retina barrier.

The effect of photodynamic therapy on retrobulbar blood flow parameters.

PURPOSE: To investigate the effect of photodynamic therapy (PDT) on retrobulbar blood flow parameters. METHODS: Twenty-four patients with choroidal neovascular membrane of at least four MPS disc area in one eye due to age-related macular degeneration scheduled for PDT were recruited. Peak systolic and end diastolic velocity of ophthalmic, central retinal and posterior ciliary artery of both eyes were measured with colour Doppler imaging and resistivity index were computed before, at the first and fourth weeks following PDT. RESULTS: Following PDT, the mean peak systolic velocity of posterior ciliary artery increased significantly to a value of 31.90 +/- 13.44 at the first (P = 0001), then returned to an insignificant value of 29.95 +/- 13.03 at the fourth week (P = 0.360), when compared with pre-PDT mean measurement (30.16 +/- 13.15). Resistivity index of posterior ciliary artery also increased significantly to a value of 0.740 +/- 0.77 at the first (P = 0.046), then returned to an insignificant value of 0.666 +/- 0.14 at the fourth week (P = 0.407), when compared with pre-PDT mean measurement (0.709 +/- 0.90). All the other measured data (peak systolic velocity, end diastolic velocity, resistivity index of ophthalmic and central retinal artery; end diastolic velocity of posterior ciliary artery of the treated eyes; all colour Doppler imaging measurements of untreated eyes) did not show any significant change at the first and fourth week following PDT, when compared with the pre-PDT values. CONCLUSION: The peak systolic velocity and resistivity index of the posterior ciliary artery appear to increase in the first week and return to their baseline values at the fourth week following PDT.

The effect of thalidomide on vascular endothelial growth factor and tumor necrosis factor-alpha levels in retinal ischemia/reperfusion injury.

BACKGROUND: To evaluate the effects of thalidomide treatment on the temporal course of TNF-alpha, VEGF production and the histopathological changes in ischemia/reperfusion (I/R) injured guinea pigs retina. METHODS: Control, ischemia, and thalidomide/ischemia groups including seven animals each were formed. Retinal ischemia was induced in male guinea pigs by cannulating anterior chambers and lifting the bottle to a height of 205 cm for 90 min in the ischemia and thalidomide/ischemia groups. The thalidomide/ischemia group received thalidomide (300 mg/kg/day) via nasogastric tube 24 h before ischemia and during 7 days of reperfusion. Guinea pigs were sacrificed for histopathological examination to evaluate the mean thickness of the inner plexiform layer (IPL), polymorphonuclear leukocyte (PMNL) infiltration, and biochemical analysis of retinal VEGF and TNF-alpha levels by ELISA. RESULTS: The mean retinal VEGF and TNF-alpha levels of the control, ischemia, and thalidomide/ischemia groups were 10.22 +/- 2.58 and 270.41 +/- 69.77 pg/ml; 35.80 +/- 5.97 and 629.93 +/- 146.41 pg/ml; 19.01 +/- 3.01 and 340.93 +/- 158.26 pg/ml, respectively. The retinal VEGF levels were significantly higher in I/R injured groups. The thalidomide/ischemia group retinal VEGF level was significantly lower versus the ischemia group. The retinal TNF-alpha levels were significantly elevated in the ischemia group, but no difference was observed between the thalidomide/ischemia and control groups. Also, the retinal TNF-alpha level was significantly lower in the thalidomide/ischemia group versus the ischemia group. The mean thickness of IPL and PMNL infiltration showed no difference between the control and thalidomide/ischemia groups. However, there was a significant difference between the control and ischemia groups. CONCLUSION: Thalidomide treatment decreases PMNL infiltration, retinal edema, VEGF, and TNF-alpha synthesis following I/R injury to the guinea pig retina.