Efficacy of Sunitinib, Sunitinib-Hesperetin, and Sunitinib-Doxycycline Combinations on Experimentally-Induced Corneal Neovascularization.

Purpose: To investigate the preventive effects of topical sunitinib, sunitinib-hesperetin and sunitinib-doxycycline combinations on corneal neovascularization (CNV), apoptosis and fibrosis in a corneal alkali burn model. Materials and Methods: The corneas of 32 Wistar albino rats were cauterized with silver nitrate to induce CNV. Four groups were created receiving artificial tears (sham), sunitinib (0.5 mg/ml), sunitinib-hesperetin (0.5 mg/ml-0.2 mg/ml), and sunitinib-doxycycline (0.5 mg/ml-20 mg/ml) treatments. Corneal photographs were taken on days 0, 7 and 15 . Photographs of the cornea were digitally analyzed to measure the size of the neovascularization area in comparison to the total corneal surface area. On the 15th day, the animals were euthanized, and the eyes were enucleated for immunohistochemical staining to investigate neovascularization, apoptosis, and fibrosis. Results: CNV areas on the 7th day in the sunitinib (4.8% ± 0.07%) and sunitinib-hesperetin (1.1% ± 0.03%) groups were smaller than those in the sham group (33.9% ± 0.12%) (p = 0.001 and, p < 0.001 respectively). On the 15th day, the CNV area in the sunitinib-hesperetin (20.8% ± 0.37%) group was significantly smaller than that of the sham group (74.6% ± 0.32%) (p = 0.039). The combination groups had lower levels of VEGF, TUNEL and α-SMA positivity than the sunitinib monotherapy group. TUNEL positivity was lowest in the sunitinib-hesperetin and sunitinib-doxycycline groups, and α-SMA positivity was lowest in the sunitinib-hesperetin group. Conclusion: Topical sunitinib-hesperetin was more effective than sunitinib alone and the sunitinib-doxycycline combination in the treatment of CNV. The combination of sunitinib and hesperetin seems to be a promising treatment for preventing corneal fibrosis and apoptosis.

The Effect of Smoking on Corneal Endothelial Cells.

PURPOSE: To investigate the effect of chronic cigarette smoking on the endothelial cells of the cornea via non-contact specular microscopy. METHOD: In this prospective, cross-sectional study, 25 eyes of 25 chronic smokers and 21 eyes of 21 age-matched, healthy non-smokers were enrolled. The Fagerström Test for Nicotine Dependence on Cigarettes was used to determine the nicotine dependency level. The level of cotinine, a major metabolite of nicotine, was measured in urine samples from the control group to detect whether they were passively affected by cigarette smoke. All participants underwent measurement of tear break-up time (TBUT), central corneal thickness (CCT), and axial length. Endothelial cell density and endothelial cell morphology were evaluated by non-contact specular microscopy. RESULTS: On average, the cigarette smokers consumed 19.2 ± 8.3 cigarettes per day and had been smoking for 14.5 ± 6.8 years. The mean TBUT value was significantly lower in the smoker group compared to the non-smoker group (p < 0.05). No statistically significant difference was found in the mean CCT, mean endothelial cell density, or parameters of endothelial cell morphology between smokers and non-smokers. CONCLUSION: This study showed that cigarette smoking seems to affect the TBUT value but no effects were found on the parameters of corneal endothelial cells.

Evaluation of Macular Ganglion Cell-inner Plexiform Layer and Choroid in Psoriasis Patients Using Enhanced Depth Imaging Spectral Domain Optical Coherence Tomography.

PURPOSE: To evaluate changes in the thickness of the central macula, macular ganglion cell-inner plexiform layer (mGCIPL), and subfoveal choroid in patients with psoriasis using spectral domain optical coherence tomography (SD-OCT). METHODS: The measurements of macular, mGCIPL thicknesses and subfoveal choroidal thickness (SFCT) obtained by SD-OCT of psoriasis patients (n = 46). These measurements were compared with those of 50 healthy controls. RESULTS: The macular, mGCIPL, and choroidal thicknesses did not differ between the controls and psoriatic subjects (p>0.05). When the patients were divided into two distinct groups, only the SFCT was significantly thicker in the severe psoriasis group compared with the mild psoriasis group (p = 0.003). CONCLUSIONS: These findings suggest that choroidal alterations are seen without macular changes in patients with psoriasis. Severe psoriasis appears to be related to increases in SFCT as a consequence of possible inflammatory cascades that are part of the disease's pathogenesis.

Effect of Systemically Used Anti-Tumor Necrosis Factor-α Medication on the Corneal Epithelium and Stroma of Patients with Ankylosing Spondylitis.

PURPOSE: To evaluate the effect of systemically used anti-tumor necrosis factor alpha (TNF-α) medication on the thickness of corneal epithelium and stroma in patients with ankylosing spondylitis (AS). METHODS: A total of 125 eyes of 69 participants were included in this retrospective study of three groups: healthy participants (Group 1), AS patients receiving anti-TNF-α medication (Group 2), and AS patients receiving a nonsteroidal anti-inflammatory medication (Group 3). RESULTS: According to anterior segment optical coherence tomography, the mean thickness of the corneal epithelium was significantly thicker in Group 2 than in Group 3 (51.6 ± 3.2 µm versus 50.4 ± 3 µm, p = 0.01), as was that of the stroma (475 ± 33 µm versus 443 ± 29 µm, p = 0.002). CONCLUSIONS: Anti-TNF-α medication and/or avoidance of nonsteroidal anti-inflammatory drugs could improve the thickness of both the corneal epithelium and stroma in AS patients.

Effect of Reduced Meal Frequency during Ramadan Fasting on Retinal and Choroidal Thickness.

PURPOSE: To evaluate the effects of Ramadan fasting on central foveal thickness (CFT) and subfoveal choroidal thickness (SFCT) in healthy individuals using enhanced depth imaging optical coherence tomography (EDI-OCT). MATERIALS AND METHODS: The EDI-OCT scans of 42 healthy individuals obtained after about 12 hours of fasting on at least the twenty-first consecutive day of fasting were compared to scans of the same patients taken one month after the last day they had fasted. RESULTS: CFT values were similar for both time periods (p > 0.05). The SFCT was significantly higher after consecutive fasting days towards the end of Ramadan, compared to the SFCT after one month of no fasting (one month after Ramadan ended) (p < 0.001). CONCLUSIONS: Ramadan fasting may lead to a significant increase in subfoveal choroidal thickness without affecting the central foveal thickness.

Repeatability of contrast sensitivity testing in patients with age-related macular degeneration, glaucoma, and cataract.

PURPOSE:: To analyze the intrasession and intersession repeatability of contrast sensitivity (CS) measurements in patients with glaucoma, cataract, or age-related macular degeneration (AMD) and healthy controls. METHODS:: CS measurements were performed using the OPTEC-Functional Vision Analyzer (FVA), which uses a standardized and closed (view-in) system. Measurements for patients with glaucoma, cataract, or AMD and healthy controls were repeated within 30 minutes (intrasession) and during two sessions (intersession), separated by one week to one month. Test-retest reliability and correlation were measured using the intraclass correlation coefficient (ICC) and coefficient of repeatability (COR). RESULTS:: Ninety subjects (90 eyes) with visual acuity of 0.17 logMAR or higher in the cataract group or 0.00 logMAR in the other groups were included. During the first session, the ICC values were 0.87, 0.90, 0.76, and 0.69, and COR values were 0.24, 0.20, 0.38, and 0.25 for the control, glaucoma, cataract, and AMD groups, respectively. The reliability scores significantly improved during the second session, except in the glaucoma group. There was an acceptable floor effect and no ceiling effect at higher frequencies in the glaucoma and AMD groups. CONCLUSION:: In subjects with good visual acuity, the FVA system is useful for evaluating CS and demonstrates good repeatability, as shown by ICC and COR. Because there is no ceiling effect, this system is beneficial for evaluation of early changes in CS, particularly in patients with glaucoma or AMD.

Repeatability of contrast sensitivity testing in patients with age-related macular degeneration, glaucoma, and cataract / Reprodutibilidade dos escores de sensibilidade ao contraste em pacientes com degeneração macular relacionadas à idade, glaucoma e catarata

ABSTRACT Purpose: To analyze the intrasession and intersession repeatability of contrast sensitivity (CS) measurements in patients with glaucoma, cataract, or age-related macular degeneration (AMD) and healthy controls. Methods: CS measurements were performed using the OPTEC-Functional Vision Analyzer (FVA), which uses a standardized and closed (view-in) system. Measurements for patients with glaucoma, cataract, or AMD and healthy controls were repeated within 30 minutes (intrasession) and during two sessions (intersession), separated by one week to one month. Test-retest reliability and correlation were measured using the intraclass correlation coefficient (ICC) and coefficient of repeatability (COR). Results: Ninety subjects (90 eyes) with visual acuity of 0.17 logMAR or higher in the cataract group or 0.00 logMAR in the other groups were included. During the first session, the ICC values were 0.87, 0.90, 0.76, and 0.69, and COR values were 0.24, 0.20, 0.38, and 0.25 for the control, glaucoma, cataract, and AMD groups, respectively. The reliability scores significantly improved during the second session, except in the glaucoma group. There was an acceptable floor effect and no ceiling effect at higher frequencies in the glaucoma and AMD groups. Conclusion: In subjects with good visual acuity, the FVA system is useful for evaluating CS and demonstrates good repeatability, as shown by ICC and COR. Because there is no ceiling effect, this system is beneficial for evaluation of early changes in CS, particularly in patients with glaucoma or AMD.

RESUMO Objetivo: Analisar a reprodutibilidade intrassessão e intersessão das medidas de sensibilidade ao contraste (CS) em pacientes com degeneração macular relacionada à idade (AMD), glaucoma e catarata. Método: As medidas de CS foram feitas pelo OPTEC-Funcional Visão Analyzer (FVA), que utiliza um sistema padronizado e fechado de avaliação da acuidade visual. Medidas em pacientes com AMD, glaucoma, catarata e nos controles saudáveis foram repetidas no prazo de 30 minutos (intrassessão) em duas visitas (intersessão), separadas por uma semana a um mês. A confiabilidade e correlação teste-reteste foram calculados por meio do coeficiente de correlação intraclasse (ICC) e coeficiente de reprodutibilidade (COR). Resultados: Noventa olhos de 90 indivíduos foram recrutados com acuidade visual de 0,17 logMAR ou melhor em catarata e 0,00 logMAR nos outros grupos. A confiabilidade da CS na primeira visita dos grupos normal, glaucoma, catarata e AMD foram, respectivamente, ICC 0,87; 0,90; 0,76; 0,69, e COR 0,24; 0,20; 0,38; 0,25. Os índices de confiabilidade foram significativamente melhorados nas segundas visitas, exceto no grupo glaucoma. Houve um efeito chão aceitável e nenhum efeito teto em frequências mais altas nos grupos glaucoma e AMD. Conclusões: Em indivíduos com boa acuidade visual, o sistema FVA de avaliação da CS é útil e apresenta boa confiabilidade, como mostrado pelas análises de ICC e COR. Por não apresentar efeito teto, este sistema parece ser benéfico para a avaliação das alterações precoces de CS, especialmente no glaucoma e AMD.

Non-invasive assessment of corneal and conjunctival deterioration in soft contact lens users using anterior segment optical coherence tomography.

BACKGROUND: The aim was to evaluate the corneal and bulbar conjunctival thicknesses of soft contact lens (SCL) wearers using anterior segment optical coherence tomography (AS-OCT). METHODS: The epithelial and overall thicknesses of both the central cornea and the infero-temporal bulbar conjunctiva of SCL wearers (30 subjects) were obtained by Cirrus HD-OCT and compared with those of refraction-matched controls (30 subjects) and patients with emmetropia (30 subjects). RESULTS: The mean corneal epithelial thicknesses in SCL wearing, spectacle-wearing and emmetropic groups were 48.97 ± 5.45, 52.18 ± 4.84 and 53.18 ± 5.05 µm, respectively. The corneal epithelium of members of the SCL group was significantly thinner than in both the spectacles and emmetropic groups (p = 0.044 and 0.006, respectively), whereas the central corneal thickness did not differ between groups (p = 0.210). The mean conjunctival epithelial thicknesses in SCL, spectacles and emmetropic groups were 41.50 ± 7.75, 54.33 ± 8.39 and 49.10 ± 7.11 µm, respectively. Conjunctival epithelium in the SCL group was significantly thinner than in both spectacle-wearing and emmetropic groups (p < 0.001 and p = 0.001, respectively). The conjunctiva was significantly thinner in the SCL group compared to the spectacles group (p = 0.001) but not the emmetropic group. CONCLUSIONS: Contact lens wear is related to thinning of both corneal and conjunctival layers. AS-OCT is a non-invasive and clinically applicable technique for assessing the involvement of the cornea and conjunctiva in contact lens wearers.

Noninvasive assessment of the retina and the choroid using enhanced-depth imaging optical coherence tomography shows microvascular impairments in childhood obesity.

PURPOSE: To evaluate the retinal vascular diameters and macular and subfoveal choroidal thicknesses of obese and nonobese children using enhanced-depth imaging spectral domain optical coherence tomography (EDI SD-OCT). METHODS: The retinal vascular diameters of the 4 largest retinal arterioles and venules and macular and subfoveal choroidal thickness measurements of 40 obese children (body mass index [BMI] z score above +2.0 standard deviations) were obtained by EDI SD-OCT and compared with those of 40 age- and sex-matched nonobese children. Anthropometric measures, including weight and height, were also obtained. BMI z score was defined using standardized protocols. RESULTS: The mean BMI z scores of obese children were 2.59 ± 0.62; of nonobese children, -0.20 ± 0.92. The mean diameter of retinal arterioles was significantly smaller (P = 0.002) in obese children compared to nonobese children, whereas the mean diameter of retinal venules was larger (P = 0.008). The macular and subfoveal choroidal thicknesses were significantly thinner (P = 0.031 and 0.014, resp.) in obese children compared to nonobese children. CONCLUSIONS: The narrower retinal arterioles, wider retinal venules, and thinner macular and subfoveal choroidal thicknesses in obese children seem to be associated with microvascular impairments in childhood obesity.

Does Retinal Neurodegeneration Seen in Diabetic Patients Begin in the Insulin Resistance Stage?

OBJECTIVES: To investigate whether retinal neurodegeneration and impairment in contrast sensitivity (CS), which have been demonstrated to begin in diabetic patients before the presence of signs of diabetic retinal vasculopathy, also occur in the stage of insulin resistance. MATERIALS AND METHODS: The average, minimum and sectoral (inferior, superior, inferonasal, superonasal, inferotemporal and superotemporal) thicknesses of the ganglion cell-inner plexiform layer (GCIPL) measured using optical coherence tomography were compared between an insulin-resistant group and control group in order to evaluate the presence of retinal neurodegeneration. The CS of the two groups was also compared according to the logarithmic values measured at spatial frequencies of 1.5, 3, 6, 12 and 18 cycles per degree in photopic light using functional acuity contrast test (FACT). RESULTS: Twenty-five eyes of 25 patients with insulin resistance (insulin resistant group) and 25 eyes of 25 healthy subjects (control group) were included in this study. There were no statistically significant differences between the two groups in any of the spatial frequencies in the FACT. The mean average GCIPL thickness and mean GCIPL thickness in the inferotemporal sector were significantly less in the insulin-resistant group when compared with the control group (mean average GCIPL thicknesses in the insulin-resistant and control groups were 83.6±4.7 µm and 86.7±3.7 µm respectively, p=0.01; mean inferotemporal GCIPL thicknesses in the insulin-resistant and control groups were 83±6.0 µm and 86.7±4.6 µm respectively, p=0.02). CONCLUSION: Although it may not lead to functional visual impairment such as CS loss, the retinal neurodegeneration seen in diabetic patients may begin in the insulin resistance stage.

Evaluation of possible factors affecting contrast sensitivity function in patients with primary Sjögren's syndrome.

PURPOSE: The contrast sensitivity (CS) function in patients with primary Sjögren's syndrome (pSS) may be impaired either frequently as a result of dry eye diseases or rarely as a result of optic neuropathy. In this study, we aimed to evaluate the CS function in pSS patients as well as to assess corneal aberrations and thickness of the peripapillary retinal nerve fiber layer (pRNFL). METHODS: Fourteen eyes of 14 pSS patients (pSS group) and 14 eyes of 14 healthy participants (control group) were subjected to assessment of CS at the spatial frequencies of 1.5, 3.0, 6.0, 12, and 18 cycles/degree (cpd) using a functional visual acuity contrast test (FACT); measurement of corneal high-order aberrations (HOAs) in terms of coma-like, spherical-like, and total HOAs using Scheimpflug corneal topography; and measurement of the thickness of both the macular ganglion cell-inner plexiform layer (mGCIPL) and pRNFL in all quadrants using optical coherence tomography. None of the participants were under treatment with artificial tears. RESULTS: The results of the CS test did not differ between the 2 groups at all spatial frequencies (p>0.05). In addition, there were no statistically significant differences between the 2 groups in terms of corneal HOAs (p>0.05) and thickness of mGCIPL (p>0.05). However, among all quadrants, only the inferior quadrant of pRNFL in pSS patients was statistically significantly thinner than that in the healthy participants (p=0.04). CONCLUSIONS: The CS function in pSS patients can be maintained with normal thickness of both pRNFL and mGCIPL and with lack of increased corneal HOAs, which may be present even in the absence of artificial tear usage.

Evaluation of possible factors affecting contrast sensitivity function in patients with primary Sjögren’s syndrome / A avaliação dos possíveis fatores que afetam a função de sensibilidade ao contraste em pacientes com síndrome de Sjögren primária

ABSTRACT Purpose: The contrast sensitivity (CS) function in patients with primary Sjögren’s syndrome (pSS) may be impaired either frequently as a result of dry eye diseases or rarely as a result of optic neuropathy. In this study, we aimed to evaluate the CS function in pSS patients as well as to assess corneal aberrations and thickness of the peripapillary retinal nerve fiber layer (pRNFL). Methods: Fourteen eyes of 14 pSS patients (pSS group) and 14 eyes of 14 healthy participants (control group) were subjected to assessment of CS at the spatial frequencies of 1.5, 3.0, 6.0, 12, and 18 cycles/degree (cpd) using a functional visual acuity contrast test (FACT); measurement of corneal high-order aberrations (HOAs) in terms of coma-like, spherical-like, and total HOAs using Scheimpflug corneal topography; and measurement of the thickness of both the macular ganglion cell-inner plexiform layer (mGCIPL) and pRNFL in all quadrants using optical coherence tomography. None of the participants were under treatment with artificial tears. Results: The results of the CS test did not differ between the 2 groups at all spatial frequencies (p>0.05). In addition, there were no statistically significant differences between the 2 groups in terms of corneal HOAs (p>0.05) and thickness of mGCIPL (p>0.05). However, among all quadrants, only the inferior quadrant of pRNFL in pSS patients was statistically significantly thinner than that in the healthy participants (p=0.04). Conclusions: The CS function in pSS patients can be maintained with normal thickness of both pRNFL and mGCIPL and with lack of increased corneal HOAs, which may be present even in the absence of artificial tear usage. .

RESUMO Objetivo: A função de sensibilidade ao contraste em pacientes com síndrome de Sjögren primário (pSS) pode ser prejudicada, quer frequentemente como resultado de doenças do olho seco, ou mais raramente como um resultado de neuropatia óptica. Neste estudo, objetivamos avaliar a função de sensibilidade ao contraste de pacientes com pSS, além da avaliação das aberrações da córnea e a espessura da camada de fibras nervosas da retina (pRNFL). Métodos: Catorze olhos de 14 pacientes com pSS e 14 olhos de 14 participantes saudáveis foram submetidos, respectivamente, à avaliação do teste de sensibilidade aos contrastes (CS) nas frequências espaciais de 1,5, 3,0, 6,0, 12 e 18 ciclos/grau (cpd), utilizando teste de contraste acuidade visual funcional (FACT); a medida das aberrações de alta ordem da córnea (HOAs) em termos de coma, aberrações esféricas e aberrações totais, utilizando topografia corneana por Scheimpflug; e medida de espessura da camada de macular de células ganglionares plexiforme interna (mGCIPL) e a espessura de pRNFL em todos os quadrantes usando tomografia de coerência óptica. Nenhum dos participantes estava sob tratamento com lágrimas artificiais. Resultados: O teste CS em pacientes pSS não diferiu do que o teste CS em participantes saudáveis em todas as frequências espaciais (p>0,05). Não houve também nenhuma diferença estatisticamente significativa entre os dois grupos em termos de HOAs da córnea (p>0,05), e espessura de mGCIPL (p>0,05). No entanto, entre todos os quadrantes, apenas o quadrante inferior da pRNFL em pacientes pSS foi significativamente mais fino que o quadrante inferior da pRNFL em participantes saudáveis (p=0,04). Conclusões: A função de CS em doentes com pSS pode ser mantida em condições de ambas as espessuras normais de pRNFL e mGCIPL, assim como nas condições de falta de aumento HOAs da córnea, que pode ser mantida, mesmo na ausência do uso de lágrimas artificiais. .

Blood gas analyzer utility in evaluating oxygen kinetics of the aqueous humor.

PURPOSE: To measure the partial pressure of oxygen (PO2) and carbon dioxide (PCO2) and the pH of aqueous humor (AH) and arterial blood samples from rabbits using a blood gas analyzer. METHODS: Twenty New Zealand rabbits were anesthetized intramuscularly with ketamine and xylazine and were then allowed to breathe room air. Using a gas blood analyzer, arterial blood and AH samples were analyzed for PO2, PCO2, and pH. RESULTS: The mean arterial blood pressure was 87.14 ± 15.0 mmHg. The mean blood and AH PO2 were 95.18 ± 11.76 mmHg and 88.83 ± 9.92 mmHg, the mean blood and AH PCO2 were 25.86 ± 5.46 mmHg and 29.50 ± 5.36 mmHg, and the mean blood and AH pH were 7.38 ± 0.06 and 7.33 ± 0.09, respectively. CONCLUSIONS: The blood gas analyzer was easily employed to evaluate the aqueous humor in rabbits. When comparing the results of studies evaluating aqueous PO2, care should be taken to determine the methods used in these studies.

Quercetin protects the retina by reducing apoptosis due to ischemia-reperfusion injury in a rat model.

PURPOSE: This study aimed to investigate the effect of quercetin on apoptotic cell death induced by ischemia-reperfusion (I/R) injury in the rat retina. METHODS: Twenty-four rats were divided into four equal groups: control, ischemic, solvent, and quercetin. I/R injury was achieved by elevating the intraocular pressure above the perfusion pressure. Intraperitoneal injections of 20 mg/kg of quercetin and dimethyl sulfoxide (DMSO) were performed in the quercetin and solvent groups, respectively, immediately prior to I/R injury, and the researchers allowed for the retinas to be reperfused. Forty-eight hours after injury, the thicknesses of the retinal ganglion cell layer (RGCL), inner nuclear layer (INL), inner plexiform layer (IPL), outer plexiform layer (OPL), and outer nuclear layer (ONL) were measured in all groups. Moreover, the numbers of terminal deoxynucleotidyl transferase dUTP nick-end-labeled [TUNEL (+)] cells and caspase-3 (+) cells in both INL and ONL were evaluated in all groups. RESULTS: The administration of quercetin was found to reduce the thinning of all retinal layers. The mean thickness of INL in the quercetin and ischemic groups was 21 ± 5.6 µm and 16 ± 6.4 µm, respectively (P<0.05). Similarly, the mean thickness of ONL in the quercetin and ischemic groups was 50 ± 12.8 µm and 40 ± 8.7 µm, respectively (P<0.05). The antiapoptotic effect of quercetin in terms of reducing the numbers of both TUNEL (+) cells and caspase-3 (+) cells was significant in INL. The mean number of TUNEL (+) cells in INL in the ischemic and quercetin groups was 476.8 ± 45.6/mm2 and 238.72 ± 251/mm2, respectively (P<0.005). The mean number of caspase-3 (+) cells in INL of ischemic and quercetin groups was 633.6 ± 38.7/mm2 and 342.4 ± 36.1/mm2, respectively (P<0.001). CONCLUSION: The use of quercetin may be beneficial in the treatment of retinal I/R injury because of its antiapoptotic effect on the retinal layers, particularly in INL.

Quercetin protects the retina by reducing apoptosis due to ischemia-reperfusion injury in a rat model / Quercetina protege a retina reduzindo a apoptose consequente à lesão por isquemia e reperfusão em um modelo de rato

Purpose: This study aimed to investigate the effect of quercetin on apoptotic cell death induced by ischemia-reperfusion (I/R) injury in the rat retina. Methods: Twenty-four rats were divided into four equal groups: control, ischemic, solvent, and quercetin. I/R injury was achieved by elevating the intraocular pressure above the perfusion pressure. Intraperitoneal injections of 20 mg/kg of quercetin and dimethyl sulfoxide (DMSO) were performed in the quercetin and solvent groups, respectively, immediately prior to I/R injury, and the researchers allowed for the retinas to be reperfused. Forty-eight hours after injury, the thicknesses of the retinal ganglion cell layer (RGCL), inner nuclear layer (INL), inner plexiform layer (IPL), outer plexiform layer (OPL), and outer nuclear layer (ONL) were measured in all groups. Moreover, the numbers of terminal deoxynucleotidyl transferase dUTP nick-end-labeled [TUNEL (+)] cells and caspase-3 (+) cells in both INL and ONL were evaluated in all groups. Results: The administration of quercetin was found to reduce the thinning of all retinal layers. The mean thickness of INL in the quercetin and ischemic groups was 21 ± 5.6 µm and 16 ± 6.4 µm, respectively (P<0.05). Similarly, the mean thickness of ONL in the quercetin and ischemic groups was 50 ± 12.8 µm and 40 ± 8.7 µm, respectively (P<0.05). The antiapoptotic effect of quercetin in terms of reducing the numbers of both TUNEL (+) cells and caspase-3 (+) cells was significant in INL. The mean number of TUNEL (+) cells in INL in the ischemic and quercetin groups was 476.8 ± 45.6/mm2 and 238.72 ± 251/mm2, respectively (P<0.005). The mean number of caspase-3 (+) cells in INL of ischemic and quercetin groups was 633.6 ± 38.7/mm2 and 342.4 ± 36.1/mm2, respectively (P<0.001). Conclusion: The use of quercetin may be beneficial in the treatment of retinal I/R injury because of its antiapoptotic effect on the retinal layers, particularly in INL. .

Objetivo: O objetivo deste estudo é investigar o efeito da quercetina, contra a morte celular por apoptose induzida por lesão consequente à isquemia-reperfusão (I/R) na retina de ratos. Método: Vinte e quatro ratos foram divididos em quatro grupos iguais: controle, isquêmico, solvente e quercetina. O modelo lesão por I/R foi realizado por meio da elevação da pressão intraocular acima da pressão de perfusão, em todos os grupos. Injecções intraperitoneais de 20 mg/kg de quercetina ou sulfóxido de dimetilo (DMSO) foram realizadas nos grupos quercetina e solvente, respectivamente, imediatamente antes da lesão por I/R, permitindo que as retinas fossem reperfundidas. Quarenta e oito horas após a lesão, as espessuras de camada de células ganglionares da retina (RGCL), camada nuclear interna (INL), camada plexiforme interna (IPL), camada plexiforme externa (OPL), e a camada nuclear externa (ONL) foram medidas em todos os grupos. Além disso, o número de células TUNEL (+) e caspase-3 (+) tanto na camada nuclear interna quanto na camada nuclear externa foi avaliada em todos os grupos. Resultados: A administração de quercetina diminuiu o afinamento de todas as camadas da retina em comparação com o grupo isquêmico. A espessura média da camada nuclear interna nos grupos quercetina e isquêmico foi de 21 ± 5,6 µm e 16 ± 6,4 µm, respectivamente (p<0,05). A espessura média da camada nuclear externa no grupo quercetina e isquêmico foi 50 ± 12,8 µm e 40 ± 8,7 µm, respectivamente (p<0,05). O efeito anti-apoptótico de quercetina em termos de redução do número de células TUNEL (+) e caspase-3 (+) foi significativa na INL. O número médio de células TUNEL (+) da camada nuclear interna no grupo isquêmico e quercetina foi 476,8 ± 45,6/mm2 e 238,72 ± 251/mm2, respectivamente (p<0,005). O médio número de células de caspase-3 (+) na INL do grupo isquêmico e quercetina foi 633,6 ± 38,7/mm2 e 342,4 ± 36,1/mm2, respectivamente (p<0,001). Conclusão: A utilização ...

Blood gas analyzer utility in evaluating oxygen kinetics of the aqueous humor / Utilidade de um analisador sanguíneo de gás para a avaliação cinética do oxigênio no humor aquoso

Purpose: To measure the partial pressure of oxygen (PO2) and carbon dioxide (PCO2) and the pH of aqueous humor (AH) and arterial blood samples from rabbits using a blood gas analyzer. Methods: Twenty New Zealand rabbits were anesthetized intramuscularly with ketamine and xylazine and were then allowed to breathe room air. Using a gas blood analyzer, arterial blood and AH samples were analyzed for PO2, PCO2, and pH. Results: The mean arterial blood pressure was 87.14 ± 15.0 mmHg. The mean blood and AH PO2 were 95.18 ± 11.76 mmHg and 88.83 ± 9.92 mmHg, the mean blood and AH PCO2 were 25.86 ± 5.46 mmHg and 29.50 ± 5.36 mmHg, and the mean blood and AH pH were 7.38 ± 0.06 and 7.33 ± 0.09, respectively. Conclusion: Conclusions: The blood gas analyzer was easily employed to evaluate the aqueous humor in rabbits. When comparing the results of studies evaluating aqueous PO2, care should be taken to determine the methods used in these studies. .

Objetivo: Medir a pressão parcial de oxigênio (PO2) e dióxido de carbono (PCO2), e o pH de humor aquoso (AH) e de amostras de sangue arterial de coelhos. Método: Vinte coelhos New Zealand foram anestesiados por via intramuscular com cetamina e xilazina, em seguida, foram liberados a respirar o ar ambiente. Utilizando um analisador sanguíneo de gás, amostras de sangue arterial e AH foram analisadas para PO2, PCO2, e pH. Resultados: A pressão arterial média foi de 87,14 ± 15,0 mmHg. A PO2 média do sangue e AH foi 95,18 ± 11,76 mmHg e 88,83 ± 9,92 mmHg; a PCO2 média do sangue e AH foi de 25,86 ± 5,46 mmHg e 29,50 ± 5,36 mmHg; o pH médio do sangue e AH foi 7,38 ± 0,06 e 7,33 ± 0,09, respectivamente. Conclusões: O analisador de gases no sangue foi facilmente empregadas para avaliar o humor aquoso em coelhos. Quando se comparam os resultados de estudos que avaliaram PO2 do humor aquoso, deve ser tomado cuidado para determinar os métodos utilizados nestes estudos. .

Changes in retinal nerve fiber layer thickness after spinal surgery in the prone position: a prospective study / Alterações da espessura da camada de fibras nervosas da retina após cirurgia da coluna vertebral em pronação: estudo prospectivo / Alteraciones del espesor de la capa de fibras nerviosas de la retina después de la cirugía de la columna vertebral en pronación: estudio prospectivo

BACKGROUND AND OBJECTIVES: Changes in ocular perfusion play an important role in the pathogenesis of ischemic optic neuropathy. Ocular perfusion pressure is equal to mean arterial pressure minus intraocular pressure. The aim of this study was to evaluate the changes in the intraocular pressure and the retinal nerve fiber layer thickness in patients undergoing spinal surgery in the prone position. METHODS: This prospective study included 30 patients undergoing spinal surgery. Retinal nerve fiber layer thickness were measured one day before and after the surgery by using optical coherence tomography. Intraocular pressure was measured by tonopen six times at different position and time-duration: supine position (baseline); 10 min after intubation (Supine 1); 10 (Prone 1), 60 (Prone 2), 120 (Prone 3) min after prone position; and just after postoperative supine position (Supine 2). RESULTS: Our study involved 10 male and 20 female patients with the median age of 57 years. When postoperative retinal nerve fiber layer thickness measurements were compared with preoperative values, a statistically significant thinning was observed in inferior and nasal quadrants (p = 0.009 and p = 0.003, respectively). We observed a statistically significant intraocular pressure decrease in Supine 1 and an increase in both Prone 2 and Prone 3 when compared to the baseline. Mean arterial pressure and ocular perfusion pressure were found to be significantly lower in Prone 1, Prone 2 and Prone 3, when compared with the baseline. CONCLUSIONS: Our study has shown increase in intraocular pressure during spinal surgery in prone position. A statistically significant retinal nerve fiber layer thickness thinning was seen in inferior and nasal quadrants one day after the spinal surgery. .

JUSTIFICATIVA E OBJETIVOS: As alterações de perfusão ocular desempenham um papel importante na patogênese da neuropatia óptica isquêmica. A pressão de perfusão ocular é igual à pressão arterial média menos a pressão intraocular. O objetivo deste estudo foi avaliar as alterações da pressão intraocular e da espessura da camada de fibras nervosas da retina em pacientes submetidos à cirurgia da coluna vertebral em pronação. MÉTODOS: Este estudo prospectivo incluiu 30 pacientes submetidos à cirurgia da coluna vertebral. A espessura da camada de fibras nervosas da retina foi medida um dia antes e um depois da cirurgia, com o uso da tomografia de coerência óptica. A pressão intraocular foi medida seis vezes com o Tonopen e o tempo de duração em posições diferentes: em supinação (basal), 10 minutos após a intubação (Supinação 1); após a pronação aos 10 minutos (Pronação 1), 60 minutos (Pronação 2) e 120 minutos (Pronação 3) e logo após a supinação no período pós-operatório (Supinação 2). RESULTADOS: Nosso estudo envolveu 10 pacientes do sexo masculino e 20 do feminino, com média de 57 anos. No pós-operatório, quando as medidas da espessura da camada de fibras nervosas da retina foram comparadas com os valores do pré-operatório, um afinamento estatisticamente significativo da retina foi observado nos quadrantes nasais e inferiores (p = 0,009 e p = 0,003, respectivamente). Observamos uma diminuição da pressão intraocular estatisticamente significante em Supinação 1 e um aumento em ambos momentos Pronação 2 e Pronação 3, em comparação com os valores basais. A pressão arterial média e a pressão de perfusão ocular foram significativamente mais baixas em Pronação 1, Pronação 2 e Pronação 3, em comparação com os valores basais. CONCLUSÕES: Nosso estudo mostrou aumento da pressão intraocular durante a cirurgia da coluna vertebral em pronação. Um afinamento estatisticamente significante da espessura da camada de fibras nervosas da retina foi observado ...

JUSTIFICACIÓN Y OBJETIVOS: Las alteraciones en la perfusión ocular desempeñan un rol importante en la patogénesis de la neuropatía óptica isquémica. La presión de perfusión ocular es igual a la presión arterial media menos la presión intraocular. El objetivo de este estudio fue evaluar las alteraciones de la presión intraocular y del espesor de la capa de fibras nerviosas de la retina en pacientes sometidos a cirugía de la columna vertebral en pronación. MÉTODOS: Este estudio prospectivo incluyó a 30 pacientes sometidos a cirugía de la columna vertebral. El espesor de la capa de fibras nerviosas de la retina se midió un día antes y uno después de la cirugía, con la tomografía de coherencia óptica. La presión intraocular se midió 6 veces con tonopen y el tiempo de duración en posiciones diferentes: en supinación (basal), 10 min después de la intubación (supinación 1); después de la pronación a los 10 min (pronación 1), 60 min (pronación 2) y 120 min (pronación 3), y justo después de la supinación en el período postoperatorio (supinación 2). RESULTADOS: Nuestro estudio contó con la participación de 10 pacientes del sexo masculino y 20 del femenino, con un promedio de edad de 57 años. En el postoperatorio, cuando las medidas del espesor de la capa de fibras nerviosas de la retina fueron comparadas con los valores del preoperatorio, se observó un adelgazamiento estadísticamente significativo de la retina en los cuadrantes nasales e inferiores (p = 0,009 y p = 0,003, respectivamente). Observamos una disminución de la presión intraocular estadísticamente significativa en supinación 1 y un aumento en pronación 2 y 3, en comparación con los valores basales. La presión arterial media y la presión de perfusión ocular fueron significativamente más bajas en pronación 1, pronación 2 y pronación 3, en comparación con los valores basales. CONCLUSIONES: Nuestro estudio mostró un aumento de la presión intraocular durante la cirugía de la columna vertebral ...

[Changes in retinal nerve fiber layer thickness after spinal surgery in the prone position: a prospective study]. / Alterações da espessura da camada de fibras nervosas da retina após cirurgia da coluna vertebral em pronação: estudo prospectivo.

BACKGROUND AND OBJECTIVES: Changes in ocular perfusion play an important role in the pathogenesis of ischemic optic neuropathy. Ocular perfusion pressure is equal to mean arterial pressure minus intraocular pressure. The aim of this study was to evaluate the changes in the intraocular pressure and the retinal nerve fiber layer thickness in patients undergoing spinal surgery in the prone position. METHODS: This prospective study included 30 patients undergoing spinal surgery. Retinal nerve fiber layer thickness were measured one day before and after the surgery by using optical coherence tomography. Intraocular pressure was measured by tonopen six times at different position and time-duration: supine position (baseline); 10min after intubation (Supine 1); 10 (Prone 1), 60 (Prone 2), 120 (Prone 3)min after prone position; and just after postoperative supine position (Supine 2). RESULTS: Our study involved 10 male and 20 female patients with the median age of 57 years. When postoperative retinal nerve fiber layer thickness measurements were compared with preoperative values, a statistically significant thinning was observed in inferior and nasal quadrants (p=0.009 and p=0.003, respectively). We observed a statistically significant intraocular pressure decrease in Supine 1 and an increase in both Prone 2 and Prone 3 when compared to the baseline. Mean arterial pressure and ocular perfusion pressure were found to be significantly lower in Prone 1, Prone 2 and Prone 3, when compared with the baseline. CONCLUSIONS: Our study has shown increase in intraocular pressure during spinal surgery in prone position. A statistically significant retinal nerve fiber layer thickness thinning was seen in inferior and nasal quadrants one day after the spinal surgery.