RESUMEN
PURPOSE: To investigate interocular differences in retrobulbar flow velocities in patients with asymmetric glaucomatous visual field loss. METHODS: Twenty-five patients with primary open-angle glaucoma (POAG) and asymmetric visual field loss were included in this study. Asymmetric visual field loss was defined as a difference of the global index mean deviation (MD) >6 dB between the two eyes. Flow velocities (peak systolic velocity PSV and end-diastolic velocity EDV) and resistive indices (RI) of the ophthalmic artery (OA), central retinal artery (CRA), and nasal and temporal posterior ciliary arteries were measured by means of colour Doppler imaging. RESULTS: MD of eyes with more severe glaucomatous visual field loss was -18.3+/-7.8 dB vs -6.8+/-5.5 dB (p<0.0001) in the less affected eyes. The PSV and the EDV of the CRA and the PSV of the OA were significantly decreased in eyes with more severe glaucomatous visual field loss (CRA PSV: 7.6+/-2.0 cm/s vs 8.3+/-1.7 cm/s, p=0.04; CRA EDV: 2.24+/-0.5 cm/s vs 2.55+/-0.6 cm/s, p<0.007; OA PSV: 29.7+/-9.9 cm/s vs 32.7+/-11.5 cm/s, p<0.02). None of the other differences in velocity or resistive index were significant. CONCLUSIONS: Patients with asymmetric glaucomatous visual field loss exhibit asymmetric flow velocities of the CRA and OA. Patients with more severe damage display reduced flow velocities in retrobulbar vessels in POAG.
Asunto(s)
Arterias Ciliares/fisiología , Glaucoma de Ángulo Abierto/fisiopatología , Arteria Oftálmica/fisiología , Arteria Retiniana/fisiología , Trastornos de la Visión/fisiopatología , Campos Visuales , Velocidad del Flujo Sanguíneo , Presión Sanguínea , Humanos , Presión Intraocular , Flujometría por Láser-Doppler , Persona de Mediana Edad , Flujo Sanguíneo Regional/fisiología , Tonometría OcularRESUMEN
BACKGROUND: To evaluate fluorescein filling defects of the optic nerve head in normal tension glaucoma (NTG), primary open-angle glaucoma (POAG), ocular hypertension (OHT) and controls. METHODS: Forty patients with NTG (mean age 55 +/- 10 years), 40 patients with POAG (mean age 55 +/- 11 years), 40 patients with OHT (mean age 53 +/- 13 years), and 40 age-matched controls (mean age 54 +/- 11 years) were included in a prospective study. Video fluorescein angiograms were performed by means of a scanning laser ophthalmoscope. The extent of absolute filling defects of the optic nerve head was assessed (as a percentage of the disc area) using digital image analysis. Visual fields were tested by automatic static perimetry (Humphrey Field Analyzer, programme 24-2). RESULTS: Absolute filling defects were significantly larger in patients with NTG (12.2 +/- 15.5%) and POAG (12.9 +/- 13.1%) compared to patients with OHT (1.2 +/- 3.6%) and healthy controls (0.1 +/- 0.5%) (p < 0.0001). The area under the receiver operating characteristic (ROC) curve was 0.806 for NTG vs healthy controls, and 0.812 for POAG vs OHT. Absolute filling defects are significantly correlated to the global indices mean deviation (r = -0.63, p < 0.0001), pattern standard deviation (r = 0.61, p < 0.0001), and corrected pattern standard deviation (r = 0.62, p < 0.0001) and significantly correlated to horizontal (r = 0.50, p < 0.0001) and vertical (r = 0.53, p < 0.0001) cup-to-disc-ratios. CONCLUSIONS: Fluorescein filling defects of the optic disc representing capillary dropout are present in NTG and POAG. The extent of these filling defects is correlated to visual field loss and morphological damage. Fluorescein angiography may be useful in the diagnosis and management of NTG and POAG.
Asunto(s)
Angiografía con Fluoresceína/métodos , Glaucoma/patología , Hipertensión Ocular/patología , Disco Óptico/irrigación sanguínea , Presión Sanguínea/fisiología , Femenino , Glaucoma/fisiopatología , Glaucoma de Ángulo Abierto/patología , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Presión Intraocular/fisiología , Masculino , Persona de Mediana Edad , Hipertensión Ocular/fisiopatología , Estudios Prospectivos , Curva ROC , Sensibilidad y Especificidad , Distribución por SexoRESUMEN
PURPOSE: Numerous studies have confirmed the enhancement of ocular circulation by carbonic anhydrase inhibitors (CAIs). Topical CAI treatment with dorzolamide averts the significant pericentral visual function loss accompanying retinal and choroidal vasoconstriction during acute hyperventilation-induced hypocapnia. This study was designed to discern whether dorzolamide might similarly enhance macular function in patients with age-related maculopathy (ARM). METHODS: In a masked, placebo-controlled study, 40 patients with ARM and acuity > 20/50 were randomized to receive either dorzolamide or placebo for 12 weeks, thrice daily. After pre-study perimetric training, pericentral function (mean sensitivity) was quantified using Humphrey 10-2 short-wavelength automated perimetry (SWAP), before and after 12 weeks of topical therapy. RESULTS: Dorzolamide-treated eyes demonstrated a significant increase in mean sensitivity of + 1.55 dB (p = 0.04); placebo-treated eyes showed no significant change (+ 0.58 dB; p = 0.10). Given the non-significant increase of mean sensitivity in the placebo-treated group, fewer than 100 subjects per group would be required to afford > 70% power to yield a significant direct comparative difference between treatment and placebo in a prospective, randomized study of equally short duration. CONCLUSIONS: This study demonstrated a significant increase in short-wavelength sensitivity in ARM with dorzolamide and the lack thereof with placebo. These encouraging pilot study data suggest a potential role for topical CAIs in ARM patients, and establish objective parameters for prospective studies to further evaluate the effects of dorzolamide in ARM.
Asunto(s)
Inhibidores de Anhidrasa Carbónica/uso terapéutico , Degeneración Macular/tratamiento farmacológico , Sulfonamidas/uso terapéutico , Tiofenos/uso terapéutico , Agudeza Visual/efectos de los fármacos , Administración Tópica , Anciano , Método Doble Ciego , Femenino , Humanos , Degeneración Macular/fisiopatología , Masculino , Proyectos Piloto , Estudios Prospectivos , Agudeza Visual/fisiología , Pruebas del Campo Visual , Campos Visuales/efectos de los fármacos , Campos Visuales/fisiologíaRESUMEN
PURPOSE: To identify and quantify the role of capillary leakage of the optic nerve head in digital fluorescein angiography in normal subjects and patients with open-angle glaucoma. METHODS: We conducted a prospective cross-sectional study in the Department of Ophthalmology of the Technical University of Aachen. Thirty patients with primary open-angle glaucoma (POAG) and 30 healthy age-matched subjects were included. Fluorescein angiograms were performed using the scanning laser ophthalmoscope. The fluorescence of the optic nerve head and the surrounding retina (ratio of leakage) was measured using digital imaging analysis in the late phases of the angiogram (9-10 min). RESULTS: The ratio of optic nerve head fluorescence to retinal reference loci was significantly increased (p=0.01) in patients with glaucoma (POAG, 1.38+/-0.34) compared with normal subjects (1.20+/-0.19). Intraocular pressure (p=0.0001), visual field indices (mean deviation, p<0.0001; pattern standard deviation, p<0.0001; corrected pattern standard deviation, p<0.0001), and cup to disc ratios (p=0.02) differed significantly between the groups. Age and systolic and diastolic blood pressure showed no significant differences between groups. CONCLUSION: Fluorescein angiography revealed significantly increased vascular leakage of glaucomatous optic nerve heads. An endothelial disruption and fluorescein leakage might be the result of mechanical stress at the level of the lamina cribrosa and/or a sign of ischemic damage. This measurement approach might enable us to judge the severity of optic nerve head leakage, and it is a potential way to evaluate therapeutic regimens.
Asunto(s)
Permeabilidad Capilar , Fluoresceína/metabolismo , Glaucoma de Ángulo Abierto/metabolismo , Disco Óptico/irrigación sanguínea , Enfermedades del Nervio Óptico/metabolismo , Vasos Retinianos/metabolismo , Barrera Hematorretinal , Estudios Transversales , Femenino , Angiografía con Fluoresceína , Humanos , Presión Intraocular , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Flujo Sanguíneo Regional , Campos VisualesRESUMEN
PURPOSE: To identify and quantify the role of retinal circulation, capillary leakage and/or nonperfusion of the optic nerve head in digital fluorescein angiography in normal subjects and patients with open angle glaucoma. METHODS: Eighteen patients with primary open angle glaucoma (POAG) and 18 healthy age matched subjects were included. Fluorescein angiograms were performed using the scanning laser ophthalmoscope. The arteriovenous passage time (AVP) was assessed by dye dilution technique and describes the shortest passage through a retinal vascular segment. Optic nerve head nonperfusion was marked manually in early angiographic images and is given as percentage of the optic disk area. The fluorescence of the optic nerve head (as measure of the disruption of the blood-brain barrier) and the surrounding retina (ratio of leakage) was measured using digital imaging analysis in the late phases of the angiogram (9-10min). RESULTS: The AVP time was significantly prolonged ( P=0.001) in patients with open angle glaucoma (AVP 2.29+/-0.32 s) compared to healthy subjects (AVP 1.37+/-0.42 s). The mean percentage of the optic nerve head nonperfusion was 16%. The ratio of optic nerve head fluorescence compared to retinal reference loci was significantly increased (P = 0.02) in patients with glaucoma (1.32+/-0.25) compared with normal subjects (1.32+/-0.19). CONCLUSIONS: Fluorescein angiography revealed altered retinal perfusion along with optic nerve head nonperfusion and increased vascular leakage in open angle glaucoma patients. These factors appear to influence each other, with ultrastructural changes of the lamina cribrosa accompanying changes in the vasculature and nerve fibers. Longitudinal and interventive studies should help better elucidate the relationship between circulatory and neural loss, adding vasoprotective therapeutic approaches to interfere with the glaucomatous neurodegenerative chain of events.
Asunto(s)
Fluoresceína , Glaucoma de Ángulo Abierto/etiología , Glaucoma de Ángulo Abierto/patología , Enfermedades del Nervio Óptico/diagnóstico por imagen , Enfermedades del Nervio Óptico/etiología , Adulto , Anciano , Medios de Contraste/administración & dosificación , Fluoresceína/administración & dosificación , Glaucoma/diagnóstico por imagen , Glaucoma/etiología , Glaucoma/patología , Glaucoma de Ángulo Abierto/diagnóstico por imagen , Humanos , Microscopía Confocal/métodos , Persona de Mediana Edad , Enfermedades del Nervio Óptico/patología , RadiografíaRESUMEN
OBJECTIVES: To evaluate absolute filling defects of the optic nerve head in normal tension glaucoma (NTG) and primary open-angle glaucoma (POAG) and to compare the filling defects with topographic analysis of the optic disc. METHODS: Twenty-five patients with NTG, 25 patients with POAG, and 25 age-matched controls were included. Fluorescein angiograms were performed by means of a scanning laser ophthalmoscope. The extent of absolute filling defects of the optic nerve head was assessed using digital image analysis of early-phase angiograms. Topographic measurements of the optic disc were acquired using the Heidelberg Retina Tomograph II. RESULTS: Absolute filling defects were significantly larger (P =.001) and were seen more often (P<.001) in patients with NTG (n = 18) and POAG (n = 19) compared with controls (n = 3). Rim area (P =.006), rim volume (P =.007), cup-disc area ratio (P =.008), linear cup-disc ratio (P =.005), maximum cup depth (P =.002), cup shape measure (P =.03), and nerve fiber layer thickness (P =.008) and cross-sectional area (P =.006) were significantly different between patients with glaucoma and controls. Absolute filling defects were significantly correlated with cup area (r = 0.31; P =.007), rim area (r = -0.38; P<.001), rim volume (r = -0.35; P =.002), cup-disc area ratio (r = 0.49; P<.001), linear cup-disc ratio (r = 0.48; P<.001), cup shape measure (r = 0.27; P =.02), and nerve fiber layer thickness (r = -0.33; P =.004) and cross-sectional area (r = -0.30; P =.009). CONCLUSIONS: Fluorescein filling defects of the optic disc are present in NTG and POAG. The extent of these filling defects is correlated with the morphologic disc damage.
Asunto(s)
Angiografía con Fluoresceína , Glaucoma de Ángulo Abierto/fisiopatología , Disco Óptico/irrigación sanguínea , Disco Óptico/patología , Enfermedades del Nervio Óptico/fisiopatología , Presión Sanguínea , Glaucoma de Ángulo Abierto/diagnóstico , Frecuencia Cardíaca , Humanos , Presión Intraocular , Rayos Láser , Persona de Mediana Edad , Oftalmoscopía/métodos , Enfermedades del Nervio Óptico/diagnóstico , Estudios Prospectivos , Trastornos de la Visión/diagnóstico , Campos VisualesRESUMEN
PURPOSE: The purpose of this prospective, randomized, cross-over study was to investigate and compare the microcirculatory effects of timolol, dorzolamide and latanoprost in newly diagnosed primary open-angle glaucoma (POAG) patients. Haemodynamics were assessed using fluorescein angiography by means of a scanning laser ophthalmoscope (SLO). Visual function and visual field indices were evaluated during all drug treatment phases. METHODS: Fourteen patients with newly diagnosed POAG (age 55 +/- 7 years; 10 male, four female) were recruited for the study. At baseline examination, blood pressure, heart rate, intraocular pressure (IOP), SLO angiograms, and contrast sensitivity (CS) were analysed. Patients then randomly received timolol, dorzolamide or latanoprost treatment for 4 weeks. Patients then returned and all procedures were repeated and assessed. Arteriovenous passage times (AVPs), peripapillary arterial and venous diameters were assessed from SLO angiograms, using digital image processing. Calculated ocular perfusion pressure was determined for each treatment phase. RESULTS: Intraocular pressure was significantly lowered by each drug compared to baseline (p < 0.0001). Arteriovenous passage times were significantly shortened after dorzolamide application compared to baseline (p = 0.009), whereas neither timolol nor latanoprost treatment resulted in significant AVP changes. Peripapillary arterial and venous diameters, systolic and diastolic blood pressure, heart rate and ocular perfusion pressures were not significantly altered during any treatment phase. Contrast sensitivity testing at 6 cycles/degree (c.p.d.) revealed a significant rise after dorzolamide compared to timolol (p = 0.007). CONCLUSION: Our results suggest that dorzolamide treatment significantly shortened AVP times in newly diagnosed open-angle glaucoma patients, whereas timolol and latanoprost had no significant effect. Given that prolonged AVP times have been associated with disease progression in glaucoma; dorzolamide treatment may benefit optic nervehead preservation by increasing ocular perfusion.
Asunto(s)
Antagonistas Adrenérgicos beta/uso terapéutico , Inhibidores de Anhidrasa Carbónica/uso terapéutico , Glaucoma de Ángulo Abierto/tratamiento farmacológico , Glaucoma de Ángulo Abierto/fisiopatología , Prostaglandinas F Sintéticas/uso terapéutico , Vasos Retinianos/efectos de los fármacos , Vasos Retinianos/fisiopatología , Sulfonamidas/uso terapéutico , Tiofenos/uso terapéutico , Timolol/uso terapéutico , Arterias , Presión Sanguínea/efectos de los fármacos , Sensibilidad de Contraste/efectos de los fármacos , Estudios Cruzados , Femenino , Humanos , Presión Intraocular , Latanoprost , Masculino , Microscopía Confocal , Persona de Mediana Edad , Oftalmoscopía , Flujo Sanguíneo Regional/efectos de los fármacos , VenasRESUMEN
BACKGROUND: The short-wavelength-sensitive (SWS) cone-mediated sensitivity is a sensitive indicator of functional changes of the macula in diabetic maculopathy. This study was performed to investigate whether functional losses of the macula are detectable in patients without a significant macular edema. METHODS: In 45 patients with diabetes mellitus with clear optical media and no macular edema, conventional white-on-white perimetry (WWP) and short-wavelength automated perimetry (SWAP) were performed in the central 10-deg field. Fifty-eight healthy subjects ranging in age from 16 to 62 years served as controls. The two groups did not differ in age. RESULTS: Variance analysis (ANOVA) revealed significantly lower sensitivity in patients with diabetes than in controls. SWAP thresholds were significantly more greatly reduced by diabetes than those of WWP (ANOVA interaction: P=0.003). Post-hoc testing revealed a sensitivity reduction of 2.8 dB ( P=0.0003) in patients with diabetes for SWAP versus 0.46 for WWP ( P=0.15). Subgroup analysis revealed that mean thresholds of SWAP and WWP predominantly were reduced in patients with advanced disease. In patients with no retinopathy, sensitivity was not affected at all. CONCLUSION: SWS sensitivity may be affected in patients with diabetic retinopathy without clinically significant macular edema. Sensitivity loss was pronounced with increasing severity of retinopathy, reflecting the global status of the eye.
Asunto(s)
Retinopatía Diabética/diagnóstico , Retinopatía Diabética/fisiopatología , Mácula Lútea/fisiopatología , Pruebas del Campo Visual , Adolescente , Adulto , Análisis de Varianza , Automatización , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Umbral Sensorial , Pruebas del Campo Visual/métodos , Percepción VisualRESUMEN
PURPOSE: To review the role of ocular perfusion in the pathophysiology of diabetic retinopathy, one of the leading causes of irreversible blindness in the industrialized world. METHODS: We carried out a Medline search of the literature published in English or with English abstracts from 1966 to 2000 using various combinations of relevant key words. RESULTS: Hyperglycaemia leads to a wide variety of vascular abnormalities at the microvascular and macrovascular levels, including abnormal autoregulation. CONCLUSION: Three major aspects of ocular perfusion in diabetic retinopathy require additional investigation. Firstly, the precise mechanisms that link elevated glucose to dysfunction of retinal vascular cells need to be identified. Secondly, those factors that lead to both capillary dropout and to angiogenesis, twin processes that are linked to tissue hypoxia and lead to excess perfusion, increased risk of extravascular leakage and frank haemorrhage, must be carefully delineated. Finally, once specific knowledge of disease fundamentals has been amassed, tests of therapies to reverse or prevent these pathological processes can move forward.