Effect of serum cytokines and VEGF levels on diabetic retinopathy and macular thickness.

PURPOSE: To investigate the role of serum inflammatory cytokines and vascular endothelial growth factor (VEGF) in diabetic retinopathy (DR) and evaluate their relationship with macular thickness measurements obtained with optical coherence tomography (OCT). METHODS: The study enrolled 28 healthy subjects (Group 1), 31 patients without DR (Group 2), 49 patients with nonproliferative DR (Group 3), and 46 patients with proliferative DR (Group 4). Macular profile was assessed with Stratus OCT-3 and the serum concentrations of VEGF and interleukin-1 alpha (IL-1 alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), macrophage inflammatory protein (MIP-1 alpha), monocyte chemoattractant protein (MCP-1), and epidermal growth factor (EGF) were measured using multiplex bead immunoassay. RESULTS: The median value of the visual acuity was 20/20 (Groups 1 and 2), and 20/100 (Group 3), and 20/125 (Group 4). The median value of central subfield macular thickness was estimated as 165.50 microm in Group 1, 202.5 microm in Group 2, 318 microm in Group 3, and 310 microm in Group 4. The median serum VEGF level, which was 98.20 pg/ml in Group 1, demonstrated a progressive rise to 125.37 pg/ml in Group 2, to 153.07 pg/ml in Group 3, and to 149.12 pg/ml in Group 4. Statistical significance was found between all groups (p<0.05) except between Groups 3 and 4 (p=0.87). The median levels of IL-1 alpha and IL-6 were zero in all groups. The median serum levels of IL-8, IL-10, MIP-1 alpha, and EGF revealed a wide range within each group but no statistical significance between the groups (p>0.05). The median serum levels of IL-8, IL-10, MIP-1 alpha, and EGF revealed a wide range within each group, however, no statistically significant relationship was found between the groups (p>0.05). The median values of the serum MCP-1 concentrations presented a statistically significant rise with the progression of DR (p=0.02). No correlation was found between macular thickness and serum cytokine and VEGF levels (p>0.05). CONCLUSIONS: Increased serum levels of VEGF and MCP-1 may act as a key regulator of DR and provide a potential tool for risk assessment in diabetic patients. Further studies that evaluate both vitreous and serum levels in various stages of DR are needed to provide a better understanding of the interaction between systemic and local inflammatory and angiogenic factors.

The effect of hypothyroidism on color contrast sensitivity: a prospective study.

BACKGROUND: Thyroid hormone has been shown to control retinal cone opsin expression, the protein of color vision, in adult rodents. OBJECTIVES: The aim of this study was to evaluate the effect of hypothyroidism on color contrast sensitivity in adult overt hypothyroid patients. METHODS: Thirty-eight overt hypothyroid (31 females, 7 males) subjects and 20 euthyroid (16 females, 4 males) controls were studied prospectively. Color vision examination was performed by Chromatest, a software program analyzing the tritan (blue-yellow) color contrast threshold (tritan CCT) and protan (red-green) color contrast threshold (protan CCT). Color contrast sensitivity analyses of hypothyroid subjects were performed on admission and after L-thyroxine treatment when biochemical euthyroidism was achieved. RESULTS: After a median period of 90 (90-210) days, 24 (19 females, 5 males) patients were euthyroid and eligible for a second color vision examination. Baseline tritan CCT and protan CCT values were significantly higher in the hypothyroid group compared to euthyroid controls, which clinically translates into impaired color contrast sensitivity (p < 0.001 and p < 0.001, respectively). There was a significant decrease in tritan CCT (p = 0.002) and protan CCT (p < 0.001) values in the hypothyroid group after euthyroidism was achieved, which denotes improvement in color contrast sensitivity. CONCLUSIONS: It is a novel finding of the current study that color contrast sensitivity is impaired in hypothyroidism and significantly improves after euthyroidism is achieved.

Plasma homocysteine level and uveitis in Behçet's disease.

BACKGROUND: Behçet's disease is a chronic relapsing systemic vasculitis of unknown origin in which orogenital ulceration, skin lesions and uveitis are prominent features. Patients with BD have been recognized to be at greater risk for vascular diseases such as thrombosis and aneurysms. Uveitis in BD is usually accompanied by retinal vaso-occlusive disease. OBJECTIVE: To investigate the possible role of hyperhomocysteinemia as a prethrombotic disorder in the development of uveitis. METHODS: The study population consisted of 29 patients with BD (13 males and 16 females with a mean age of 32.3 years, range 21-52) and 24 healthy controls. All patients fulfilled the criteria of the International Study Group for BD. The patients were categorized as having active (n = 8) or inactive disease (n = 11) or only uveitis (n = 10). Plasma fasting homocysteine and C-reactive protein levels were studied in all patients and controls. The fasting homocysteine level was significantly higher in patients with only uveitis than in inactive patients and controls (P = 0.029 and P = 0.26 respectively). It was also higher in patients with active disease compared to healthy controls (P = 0.,001). However, no significant difference was found between homocysteine levels of patients with active or inactive disease (P = 0.69). CRP, as a marker of disease activity, was higher in active BD and in patients with only uveitis than in controls (P = 0.01 and P = 0.001 respectively). CONCLUSION: Homocysteine may play a role in ocular involvement of BD. Chronic inflammation can induce hyperhomocysteinemia, thereby leading to thrombosis in the retinal vascular bed in a way similar to that recently proposed for the pathogenesis of coronary artery disease.

Glucose regulation influences treatment outcome in ranibizumab treatment for diabetic macular edema.

PURPOSE: To evaluate the effect of glucose regulation on intravitreal ranibizumab injection for clinically significant diabetic macular edema (DME). METHODS: This retrospective study enrolled 65 eyes of 65 patients with persistent DME treated with intravitreal ranibizumab injection. The main outcome measures were the change in best corrected visual acuity (BCVA), the central subfield macular thickness (CSMT) recorded with optical coherence tomography (OCT), and its correlation with the serum hemoglobin A(1c) values (HbA(1c)). RESULTS: The study included 24 (36.9%) female and 41 (63.1%) male patients with a mean age of 58.90±9.45 years. The mean HbA(1c) of the enrolled patients was 8.25±1.74% (range 5.7-12.7%). The median value of BCVA at baseline examination was 20/80 (52 letters), and the median CSMT was 468 µm (range 255-964 µm). In the final control after 4-6 weeks following injection, the median value of BCVA increased to 20/50 (59.50 letters) and the median CSMT decreased to 310 µm (range 129-652 µm). This change in BCVA and macular thickness was found to be significant (P<.001 for both). There was no correlation between BCVA and the change in macular thickness (coefficient=0.04, P=.78). The serum HbA(1c) values were found to be negatively correlated with the change in CSMT (coefficient=-0.50, P<.001). CONCLUSIONS: The results of intravitreal ranibizumab injection for DME demonstrated a beneficial effect on visual acuity and a decrease in CSMT which is inversely correlated with the serum HbA(1c) level.

Control of steroid-induced glaucoma with surgical excision of sub-Tenon triamcinolone acetonide deposits: a clinical and biochemical approach.

OBJECTIVE: To assess the efficacy of surgical excision of sub-Tenon triamcinolone acetonide (TA) deposits in the control of steroid-induced glaucoma. DESIGN: Prospective, nonrandomized, interventional case series. PARTICIPANTS: Eighteen eyes of 14 subjects with increased IOP within 6 months of sub-Tenon TA injection who did not respond to medical antiglaucomatous treatment were included in the study. METHODS: Under topical anaesthesia, steroid deposits were completely excised and placed in ethyl alcohol for the determination of the TA amount using high-performance liquid chromatography. The patients were followed up for 6 months and a paired-sample t test was used to compare mean IOP before and after excision of sub-Tenon TA deposits. RESULTS: The mean IOP levels before and after the sub-Tenon steroid injections were 15.9 (SD 2.9) mm Hg and 36.4 (SD 8.4) mm Hg, respectively (p < 0.001). IOP levels decreased significantly after the removal of the deposits (mean 15.3 [SD 2.1] mm Hg) (p < 0.001). Within 6 months of follow-up, all glaucoma medications were stopped in 9 subjects without further IOP increase, whereas IOP control in 5 subjects necessitated using glaucoma medications. The median TA amount was found to be 7.35 mg (range 3.3-29.68 mg). IOP decrease after the excision showed no correlation with the amount of TA (p = 0.8). CONCLUSIONS: Surgical excision of the sub-Tenon steroid deposit should be considered as the primary treatment for steroid-induced glaucoma refractory to medical treatment.

Relationship between eye dominance and pattern electroretinograms in normal human subjects.

The authors conducted a study in 100 non-smoker healthy normal human subjects to find a relationship between eye dominance and macular function as tested by using transient stimulus and electroretinography. Eye preference procedure was carried out using two reference points and pattern electroretinograms (PERGs) were recorded using black and white checks, each check subtending 23'. Trace averager was retriggered every 300 milliseconds (ms) with data collection time of 150 ms. The difference in PERG P50 amplitudes between right and left eyes was analyzed using Student's t test. There was no significant difference in PERG P50 amplitudes between the right and left eye dominant subjects as well as no significant differences between the right and left eyes in right eye dominants and left eye dominants, but in the left-eye dominant group the left eye PERG P50 amplitudes were significantly higher in females than males. Although pattern-reversal visual evoked potentials of healthy subjects provide electrophysiological evidence of lateralization in the nervous system, sensory eye dominance seems to have no correlation with macular function.

Do daily wear opaquely tinted hydrogel soft contact lenses affect contrast sensitivity function at one meter?

PURPOSE: To investigate the effects of daily wear opaquely tinted hydrogel soft contact lenses on contrast sensitivity functions, as measured using the Pelli-Robson chart viewed at 1 meter. METHODS: Contrast sensitivity was measured in 48 healthy individuals before and 6 hours after soft contact lens wear. Twenty-four subjects used clear soft contact lenses and 24 used tinted soft contact lenses. RESULTS: The contrast sensitivity scores were significantly decreased monocularly and binocularly (P = 0.000 and P = 0.002, respectively) in the colored contact lens group whereas there were no significant changes in the clear contact lens group (P = 0.317 and P = 0.317, respectively). CONCLUSIONS: Color-tinted contact lenses were associated with a reduction of contrast sensitivity function. Therefore, those who wear colored contact lenses should be informed about the possible consequences of tinted contact lens wearing.