N-acetylcysteine supplementation reduces oxidative stress for cytosine arabinoside in rat model.

Cytosine arabinoside (ARA-C) is a pyrimidine analog that may cause keratoconjunctivitis when used in high doses. The underlying mechanism may be the increased amounts of reactive oxygen radicals that may damage the DNA synthesis of corneal and conjunctival epithelial cells. Topical corticosteroids are one of the prophylactic treatments for keratoconjunctivitis induced by ARA-C. Forty Wistar-type albino rats were included in this study the rats were divided into four groups. The first group (Group 1) received only ARA-C, the second group (Group 2) received ARA-C and N-acetylcysteine (NAC), the third group (Group 3) received only NAC and the fourth group (Group 4) was the control group. The total oxidant status (TOS), the total antioxidant capacity and the oxidative stress index (OSI) measurements of the cornea and the conjunctiva were evaluated in these four groups. The mean TOS and OSI value was the highest in Group 1 and the lowest in Group 3. The differences in TOS and OSI values were statistically significant between Group 1 and Group 2. There are decreases in TOS and OSI values in rats which received ARA-C with NAC administration. NAC may have a protective effect on ARA-C-induced keratoconjunctivitis.

Ocular pulse amplitude and retina nerve fiber layer thickness in migraine patients without aura.

BACKGROUND: To evaluate the ocular pulse amplitude (OPA), the posterior pole asymmetry analysis (PPAA), the peripapillary retinal nerve fiber layer (RNFL) thickness, the ganglion cell layer (GCL) thickness, macular thickness and visual field testing in migraine patients without aura. METHODS: In this prospective, cross-sectional and comparative study 38 migraine patients and 44 age and sex matched controls were included. OPA was measured by dynamic contour tonometry (DCT), PPAA, RNFL, GCL and macular thickness were measured by Heidelberg Spectral Domain Optical Coherence Tomography (SD-OCT) and standard perimetry was performed using the Humphrey automated field analyzer. RESULTS: The difference in OPA was not statistically significant between the two groups (p ≥ 0.05). In the PPAA there was no significant difference between two hemispheres in each eye (p ≥ 0.05). The RNFL thickness was significantly reduced in the temporal and nasal superior sectors in the migraine group (p ≤ 0.05). The GCL and macular thickness measurements were thinner in migraine patients but the difference between groups was not statistically significant (p ≥ 0.05). There was no correlation between RNFL, GCL, macular thickness measurements and OPA values. There was no significant difference in the mean deviation (MD) and pattern standard deviation (PSD) between the two groups (p ≥ 0.05). CONCLUSIONS: Migraine patients without aura have normal OPA values, no significant asymmetry of the posterior pole and decreased peripapillary RNFL thickness in the temporal and nasal superior sectors compared with controls. These findings suggest that there is sectorial RNFL thinning in migraine patients without aura and pulsative choroidal blood flow may not be affected during the chronic course of disease.

Evaluation of ocular elasticity in high myopia.

PURPOSE: Our aim was to evaluate the ultrasound (US) elastography of ocular and periocular structures in high myopia. METHODS: There were 20 eyes of 20 high myopic patients in the study group, whereas there were 20 eyes of 20 age- and sex-matched healthy participants in the control group. The eyes in the study group had myopia greater than -5.0 diopters and had axial length (AL) greater than 25.0 mm. The US elastography measurements were performed with the LOGIQ E9 Ultrasound Elastography. The elastography values of anterior vitreous, posterior vitreous (PV), retina-choroid-sclera complex (RCS), and retrobulbar fat tissue (RF) were measured in each eye. RESULTS: Anterior vitreous US elastography values were similar in both groups (p = 0.17), whereas PV is more elastic in high myopic eyes (p = 0.01). There was a moderate negative correlation between AL and RCS/RF elastography ratio (r = -0.35, p = 0.03) and a positive correlation between refractive error and RCS/RF elastography ratio (r = 0.36, p = 0.02). CONCLUSIONS: High myopia is associated with more elastic PV. Elasticity of posterior RCS increases as the AL increases.

Subfoveal Choroidal Thickness Is Associated with Blood Hematocrit Level.

PURPOSE: To compare subfoveal choroidal thickness (SFCT), retinal vessel caliber, and ocular pulse amplitude between treated polycythemia vera (PV) patients and healthy adults. METHODS: Forty patients with PV and 40 age- and sex-matched healthy controls were recruited for this cross-sectional study. Spectral-domain optical coherence tomography was used for SFCT and retinal vessel caliber measurements. The Pascal dynamic contour tonometer was used for ocular pulse amplitude measurements. The correlations of blood hematocrit levels with the studied ocular parameters were analyzed. RESULTS: There were no statistically significant differences between the PV patients and controls in SFCT, retinal vessel caliber, and ocular pulse amplitude (p > 0.05). SFCT was associated with hematocrit level in both PV patients and healthy adults (p < 0.05). CONCLUSIONS: Although SFCT, retinal vessel caliber, and ocular pulse amplitude parameters are similar in treated PV patients and healthy controls, SFCT is associated with hematocrit level.

Assessment of anterior chamber parameters after cataract surgery by Galilei dual Scheimpflug analyzer.

OBJECTIVE: To quantify the difference between anterior chamber parameters determined by the Galilei dual Scheimpflug analyzer after uneventful cataract surgery in normotensive eyes. METHODS: In this study, 39 eyes of 30 patients (11 men and 19 women) who had uneventful cataract surgery with phacoemulsification were evaluated preoperatively, and at 1 month postoperatively with the Galilei. We investigated the measurements including anterior chamber depth (ACD), anterior chamber angle (ACA), anterior chamber volume (ACV), central corneal thickness (CCT), and the 3-, 5-, and 7-mm corneal thickness (CT) preoperatively and postoperatively. RESULTS: The differences between ACD (P=0.01), ACA (P=0.07), ACV (P=0.01), and 7-mm CT (P=0.01), and intraocular pressure (P=0.03) were statistically significant after the first month of phacoemulsification. However, the differences between CCT (P=0.60), 3-mm CT (P=0.75), and 5-mm (P=0.17) CT were not statistically significant. CONCLUSIONS: After the first month of cataract surgery, a significant increase was observed in ACD, ACV, ACA, and 7-mm CT parameters, which were practically determined by a new noncontact Scheimpflug imagining system.

Choroidal thickness and retinal vascular caliber correlations with internal carotid artery Doppler variables.

PURPOSE: Decreased retinal arteriolar caliber and increased retinal venular caliber have been associated with increased cardiovascular mortality. This study aimed to evaluate correlations of choroidal thickness and retinal vascular caliber measurements with internal carotid artery (ICA) Doppler ultrasound variables. METHODS: In this cross-sectional and observational study, 43 eyes and ICAs of 43 healthy volunteers were examined. Spectral domain optical coherence tomography was used to measure subfoveal choroidal thickness (SFCT) and retinal vascular caliber. The ICA Doppler ultrasonographic parameters were diameter, flow volume, peak-systolic velocity, end-diastolic velocity, resistance index (RI), and pulsatility index (PI). RESULTS: Negative correlations emerged between ICA RI and SFCT (p = 0.017, r = -0.36) as well as between ICA PI and retinal arteriolar caliber (p = 0.015, r = -0.37). A negative linear correlation appeared between ICA diameter and SFCT (p = 0.005, r = -0.42), although ICA diameter and flow volume showed no association with retinal vessel caliber (p > 0.05). CONCLUSIONS: Choroidal thickness is negatively correlated with ICA diameter and ICA RI, while retinal arteriolar caliber is inversely related with ICA PI in normal volunteers.

Effect of intracameral carbachol in phacoemulsification surgery on macular morphology and retinal vessel caliber.

OBJECTIVE: To investigate the effects of intracameral carbachol in phacoemulsification surgery on central macular thickness (CMT), total macular volume (TMV) and retinal vessel caliber (RVC). MATERIALS AND METHODS: In this prospective consecutive case series, 82 patients underwent uneventful phacoemulsification and in-the-bag intraocular lens implantation. Unlike patients in the control group (43 eyes), patients in the study group (42 eyes) were injected with intracameral 0.01% carbachol during surgery. Spectral-domain optical coherence tomography (OCT) was used to analyze the parameters of CMT, TMV and RVC. RESULTS: On the first postoperative day, mean CMT and TMV decreased markedly in the carbachol group, though these values did not change significantly in the control group. During follow-up visits, no statistically significant differences between the groups occurred regarding changes in mean CMT (p = 0.25, first day; p = 0.80, first week; p = 0.95, first month). However, change in mean TMV between groups on the first postoperative day was statistically significant (p = 0.01, first day; p = 0.96, first week; p = 0.68, first month). RVC values were similar on the preoperative and postoperative first days in both groups (p > 0.05). DISCUSSION: Results suggest that the effect of intracameral carbachol on macular OCT is related to pharmacological effects, as well as optic events (e.g. miosis). CONCLUSION: Intracameral carbachol given during cataract surgery decreases macular thickness and volume in the early postoperative period but does not exert any gross effect on RVC.

Ocular pulse amplitude and retinal vessel caliber changes after intravitreal ranibizumab.

The purpose of the present study was to examine the effects of intravitreal ranibizumab on ocular pulse amplitude (OPA) and retinal vessel caliber (RVC) in wet age-related macular degeneration (AMD). Thirty-two eyes of 32 wet AMD patients were included in this case series. Three consecutive monthly injections of ranibizumab were performed. The OPA was measured with the Pascal dynamic contour tonometer. RVC measurements were taken with spectral-domain optical coherence tomography. Pre-injection mean OPA value was 2.55 ± 0.76 mmHg and post-injections mean OPA value was 2.79 ± 0.88 mmHg at the last visit (p = 0.10). Pre-injection mean arteriole and venule RVC were 96.7 ± 9.4 and 125.9 ± 8.4 µm; while post-injections arteriole and venule RVC were 96.0 ± 8.7 and 125.6 ± 8.9 µm, respectively (p > 0.05). OPA and RVC are unchanged after triple intravitreal ranibizumab injections, indicating that this treatment does not significantly alter gross retina-choroidal vasculature and hemodynamics.

Evaluation of the impact of Nd:YAG laser posterior capsulotomy on ocular pulse amplitude and anterior segment morphology.

BACKGROUND AND OBJECTIVE: Posterior capsular opacification (PCO) is the most frequent complication after cataract surgery. The most used method in order to disrupt the opacified posterior capsule is Nd-YAG laser posterior capsulotomy. Our aim was to evaluate the impact of Nd-YAG laser posterior capsulotomy on ocular pulse amplitude (OPA), central corneal thickness (CCT), corneal volume (CV), iridocorneal angle (ICA), and anterior chamber depth (ACD). MATERIALS AND METHODS: Thirty-three eyes of 30 pseudophakic patients who underwent Nd-YAG capsulotomy due to posterior capsule opacification, were included in this prospective cross-sectional consecutive case series. The OPA was measured with the Pascal dynamic contour tonometer. The CCT, CV, ICA, and ACD measurements were taken with the Scheimpflug imaging system (Pentacam HR). The examinations were performed preoperatively, and repeated at the postoperative first hour, week, and month. RESULTS: The mean OPA, ICA, and ACD values did not change statistically significantly after the posterior capsulotomy (P > 0.05). The mean CCT increased markedly and the mean CV increased slightly after one hour from the capsulotomy (P = 0.001 and P = 0.02, respectively), and then returned to the baseline values at the first week and first month visits (P > 0.05). CONCLUSIONS: Nd:YAG capsulotomy does not significantly alter OPA, ICA, and ACD; but it causes temporary increase of CCT and CV in the short term.

Effect of chronic smoking on lens nucleus as assessed by Pentacam HR lens densitometry in young adults.

OBJECTIVE: To evaluate the effects of chronic tobacco smoking on lens nucleus by Pentacam HR lens densitometry (LD) in young adults. DESIGN: Prospective cross-sectional case series. METHODS: Thirty subjects (23 M, 7 F) who were chronic cigarette smokers (≥10 cigarettes/day for at least 2 years) (group 1) and another 30 subjects (23 M, 7 F) who did not smoke (group 2), were included in this study. The patients were matched for age and sex between the groups. The exclusion criteria were any history of ocular surgery, any systemic disorders and any ocular diseases except for mild refractive disorders. Lens densitometry measurements were done with the Pentacam HR (Oculus, Wetzlar, Germany). The Schirmer test and pachymetry measurements were also performed. RESULTS: Mean age of the patients for both groups was 28.90 ± 8.20 years (range: 18-40 years). Mean lens densitometry (LD) measurements of Group 1 (chronic cigarette smoking group) were higher than those of Group 2 (control group) in all LD techniques; however only mean "peak" LD measurements showed a statistically significant difference between these two groups (Group 1: 8.67 ± 0.61, Group 2: 8.44 ± 0.70, p = 0.04). The mean Schirmer test value was 12.43 ± 5.60 mm in Group 1 and 13.00 ± 4.26 mm in Group 2 (p = 0.55). The mean central corneal thickness (CCT) value was 564.23 ± 34.61 µm in Group 1 and 550.47 ± 32.94 µm in Group 2 (p = 0.03). DISCUSSION: The Pentacam HR LD seems to be an important option for the evaluation of lens nucleus in young adults, because it gives objective and quantitative data. CONCLUSION: Although chronic smoking increases lens nucleus density in young adults, the effect is not statistically significant when compared with the control group.

Investigation of oxidative stress in pterygium tissue.

PURPOSE: To investigate changes in the oxidant-antioxidant system in pterygium tissue. METHODS: Tissue samples ablated from 40 patients during pterygium surgery constituted the study material, while normal nasal conjunctiva tissue samples from 20 patients matched for age group (who had undergone surgery for strabismus or extracapsular cataract surgery) were used as controls. The samples were kept at -70 °C until the time of analysis. Catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) enzymatic activity and the levels of nitric oxide (NO) and malone dialdehyde (MDA) were studied in both groups. RESULTS: The mean age was 54.0±12 years in the pterygium patients and 49.0±19 in the controls (p=0.270). The enzyme activity levels were significantly lower in the pterygium group when compared to the controls (p<0.001 in each case), while in the same group a significant increase was observed in the MDA and NO levels (also p<0.001, in both cases). CONCLUSIONS: These findings indicating oxidative stress in the pterygium tissue suggest that oxidative stress can play a role in pterygium etiopathogenesis.

Heparin mimetic peptide nanofibers promote angiogenesis.

New blood vessel formation (angiogenesis) is one of the most important processes required for functional tissue formation. Induction of angiogenesis is usually triggered by growth factors released by cells. Glycosaminoglycans (e.g., heparan sulphates) in the extracellular matrix aid in proper functioning of these growth factors. Therefore, exogeneous heparin or growth factors were required for promoting angiogenesis in previous regenerative medicine studies. Here we report for the first time induction of angiogenesis by a synthetic nanofibrous peptide scaffold without the addition of any exogenous growth factors or heparin. We designed and synthesized a self-assembling peptide amphiphile molecule that is functionalized with biologically active groups to mimic heparin. Like heparin, this molecule has the ability to interact with growth factors and effectively enhance their bioactivity. The nanofibers formed by these molecules were shown to form a 3D network mimicking the structural proteins in the extracellular matrix. Because of heparin mimicking capabilities of the peptide nanofibers, angiogenesis was induced without the addition of exogenous growth factors in vitro. Bioactive interactions between the nanofibers and the growth factors enabled robust vascularization in vivo as well. Heparin mimetic peptide nanofibers presented here provide new opportunities for angiogenesis and tissue regeneration by avoiding the use of heparin and exogenous growth factors. The synthetic peptide nanofiber scaffolds enriched with proper chemical functional groups shown in this study can be used to induce various desired physiological responses for tissue regeneration.

Molecular identification of adenoviral conjunctivitis in Turkey.

PURPOSE: The aim of the study was isolation of adenoviruses by cell culture and identification using polymerase chain reaction (PCR) and phylogenetic analyses in patients clinically diagnosed with viral conjunctivitis in Ankara, Turkey. METHODS: Conjunctival swabs from 34 patients with acute conjunctivitis were tested using cell culture isolation and PCR for adenovirus detection. PCR-positive samples were sequenced and typed. RESULTS: The positive results of adenovirus were 26.5% (9 of 34) by the PCR method and 20.6% by culture isolation. Nine samples positive at PCR were identified by phylogenetic analyses as human adenovirus 8 (HAdV-8) (4 of 9), HAdV-3 (3 of 9), HAdV-4 (1 of 9), and HAdV-B (1 of 9). CONCLUSIONS: Our study showed types of adenoviruses in patients with ocular infection that occurred in this region of Turkey for the first time. Furthermore, sequence-based typing method is an efficient, accurate, and rapid means of diagnosis and typing of the adenovirus and has significant clinical and epidemiologic implications. HAdV-8 was major type for acute conjunctivitis in Ankara, Turkey. Further studies are required to reveal the major types of HAdVs that cause ocular diseases in this region of the world.

The activities of paraoxonase, xanthine oxidase, adenosine deaminase and the level of nitrite in pseudoexfoliation syndrome.

AIM: Our purpose was to investigate the possible roles of nitrite levels and the activity of paraoxonase (PON), xanthine oxidase (XO) and adenosine deaminase (ADA) in the pathogenesis of pseudoexfoliation (PEX) syndrome. METHODS: Serum samples were taken from 43 patients with PEX and 41 control subjects. The serum PON, XO and ADA activities and nitrite levels were assayed by spectrophotometric methods. RESULTS: The PON, ADA and XO activities and nitrite levels (means +/- standard deviation) were 81.72 +/- 42.56 U/ml, 19.75 +/- 5.72 U/l, 0.16 +/- 0.09 U/l and 94.23 +/- 27.72 micromol/l in the PEX group, respectively. In the control group, the PON, ADA and XO activities and the nitrite levels were 111.02 +/- 43.51 U/ml, 15.21 +/- 3.93 U/l, 0.13 +/- 0.06 U/l and 61.96 +/- 19.05 micromol/l, respectively. The serum PON activity was significantly lower in the PEX group when compared with the control group. The serum XO and ADA activities and nitrite levels were significantly higher in the patients with PEX when compared with the control subjects. CONCLUSION: Decreased PON (an antioxidant enzyme) activity as well as increased ADA and XO activities and nitrite levels indicate that oxidative stress is increased and purine metabolism is altered in PEX syndrome.

Effects of erytropoietin treatment and hemodialysis on the serum endothelin level and intraocular pressure of hemodialysis patients.

AIM: The aim of this study is to evaluate the effect of erythropoietin and hemodialysis (HD) on serum Endotheli-1 (ET-1) and intraocular pressure (IOP) levels in HD patients. METHODS: The study group was composed of 34 chronic HD patients undergoing erythropoietin (EPO) treatment, while the control group was composed of 16 chronic HD patients without EPO treatment. Serum samples for measuring levels of ET-1 were taken 1 h before and after HD. Endothelin-1 levels were determined using a commercially available Elisa kit. IOP was measured with a calibrated Goldmann applanation tonometer in the right eyes of patients 1 h before and after HD just after blood samples were taken. RESULTS: In the EPO group, serum ET-1 levels were significantly higher than those of the control group both before and after HD. Despite increased ET-1 levels in the EPO group, there was no statistically significant difference in pre- and post-dialysis IOP measurements between the erythropoietin and control groups (P > 0.05). In both the HD and control groups, the IOP levels significantly decreased following HD (P < 0.05). CONCLUSION: EPO treatment caused an increase in plasma ET-1 concentration compared to the control group, while there was no related increase in IOP with EPO treatment. The role of ET-1 in glaucoma development must involve a mechanism other than increased IOP.

Evaluation of Aqueous Endocan and Endostatin Levels in Patients With Pseudoexfoliation Syndrome.

PURPOSE: The purpose of the present study was to evaluate the aqueous humor endocan and endostatin levels in patients with pseudoexfoliation (PEX) syndrome and to compare the results with healthy individuals. MATERIALS AND METHODS: Twenty nine cataract patients with PEX syndrome (PEX group) and 32 cataract patients without PEX syndrome (control group) were enrolled in the study. Endocan and endostatin were measured in the aqueous humor of the PEX and control groups by enzyme-linked immunosorbent assay. RESULTS: There was no difference between the PEX and control groups in terms of age (P=0.721) and sex (P=0.902). The aqueous levels of endocan in patients with PEX (26.39±5.80 pg/mL) was significantly higher than in the control group (11.42±2.44 pg/mL) (P=0.039). The aqueous levels of endostatin was 12.00±1.35 ng/mL in the PEX group and 14.22±3.31 ng/mL in the control group, however, the difference was not statistically significant (P=0.41). CONCLUSIONS: The findings of the present study could suggest that the increased levels of aqueous endocan may be related to pathogenesis of PEX. However, levels of aqueous endostatin did not show any significant difference in PEX.

Serum levels of natriuretic peptides in patients with Behcet's disease.

The objective of our study was to elucidate serum levels of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) in Behcet's disease (BD) patients with active and inactive period. The multicenter study included 53 patients with active (n = 28) and inactive (n = 25) BD (mean age, 34.3 +/- 9 years; 15 men and 38 women) satisfying the International Study Group criteria and 26 healthy controls (mean age, 34.4 +/- 6.1 years; seven men and 19 women) matched for age and gender from a similar ethnic background. Serum natriuretic peptides levels were determined by enzyme immunoassay kit. Mean serum ANP concentrations in the active patients (4.01 +/- 1.21 ng/ml) were significantly lower than in the healthy controls (5.76 +/- 1.99 ng/ml, p = 0.004). Mean serum BNP levels were found to be significantly higher in both the active (6.19 +/- 2.97 ng/ml) and inactive (6.49 +/- 2.88 ng/ml) BD groups compared with the control group (3.82 +/- 1.1 ng/ml, p = 0.004 and p = 0.001, respectively). Mean serum CNP concentrations in the active patients (0.49 +/- 0.12 ng/ml) were significantly lower than in the inactive patients (0.65 +/- 0.2 ng/ml, p = 0.017) and the healthy controls (0.8 +/- 0.27 ng/ml, p < 0.001). Our results suggest that changes in natriuretic peptide levels may be associated with vasculitis that play role in the etiopathogenesis of the BD.

Cyclosporin effectively inhibits posterior capsule opacification after phacoemulsification in rabbits: a preliminary study.

PURPOSE: To evaluate whether cyclosporin A prevents or reduce posterior capsule opacification after phacoemulsification surgery in rabbit eyes. METHODS: Twenty rabbits underwent cataract surgery in their right eyes were randomized into two groups. In group 1, 0.1 mL cyclosporin A (0.5 mg/mL) was given into the capsular bag after phacoemulsification and 0.1 mL cyclosporin A (0.5 mg/mL) was injected subconjunctivally once every 3 days for 1 week. Group 2 served as a control group. The development of posterior capsule opacification was assessed weekly, its density was graded clinically, and the proliferation of lens epithelial cells was evaluated histologically. RESULTS: On clinical assessment, cyclosporin A was significantly effective in preventing posterior capsule opacification compared with controls (P = 0.0045). On histological analysis, there was significantly reduced proliferative activity on posterior capsules in the treatment group, in contrast to multilayer lens epithelial cells proliferation in the control group. CONCLUSION: The preliminary results indicate that cyclosporin A is effective in suppressing posterior capsule opacification in rabbits, yet requires further investigation.

Inhibitory effects of topical thymoquinone on corneal neovascularization.

PURPOSE: Thymoquinone, one of the biologically active components of black seed oil, has anti-inflammatory and antioxidant properties. We aimed to study the effect of thymoquinone on corneal neovascularization in rats and to compare its efficacy with that of triamcinolone acetonide. METHODS: Chemical cauterization of the cornea was performed with silver nitrate/potassium nitrate sticks in 40 eyes in 40 rats. An examiner blinded to the experiments scored the intensity of the cauterization. Topical instillation of thymoquinone 0.1%, thymoquinone 0.4%, and triamcinolone acetonide was continued for 7 days. The inhibitory effects of the drugs on corneal neovascularization were tested and compared with each other and with controls with a computer program that evaluates percent areas of cornea covered by neovascularization. RESULTS: The means of percent area of corneal neovascularization in the thymoquinone 0.1%, thymoquinone 0.4%, triamcinolone acetonide, and control groups were 60.1%, 45%, 46%, and 72%, respectively. The inhibitory effect of thymoquinone 0.4% was found to be equal to that of triamcinolone acetonide (P = 0.87). The thymoquinone 0.4% and triamcinolone groups were different from the thymoquinone 0.1% and control groups (P < 0.05). There was also a significant difference between the percent area of corneal neovascularization in the thymoquinone 0.1% group and that of the controls (P < 0.05). The mean burn stimulus intensities were not different among the groups (P = 0.54). CONCLUSIONS: Thymoquinone was shown to have an inhibitory effect, comparable with that of triamcinolone, on corneal neovascularization in this rat model. However, thymoquinone decreased corneal neovascularization in a dose-dependent manner.