Multifocal electroretinographic responses in sector retinitis pigmentosa.

HEADINGS: Multifocal electroretinography (mfERG) may be useful in the management of sector retinitis pigmentosa (SRP). AIM: To compare multifocal electroretinographic responses in SRP, generalised retinitis pigmentosa (GRP), and healthy controls. METHODS: Eighteen patients with SRP, twelve with GRP, and fifteen controls were included in the study. All participants underwent: complete ophthalmological examination, Humphrey visual field testing, full-field ERG, and mfERG. The mean P1 amplitude, the implicit time (IT), and the mapping of the local responses were evaluated. RESULTS: The mean P1 amplitude was higher in the SRPs than in GRPs (p < 0.001), while it did not differ between SRPs and controls (p = 0.913). In the SRPs, the P1 amplitude in pathologic areas was higher than in the GRPs (p < 0.001). In normal areas, this parameter did not differ from the controls (p = 0.499). Moreover, in the SRPs, no differences in the P1 amplitude and the IT between pigmented and non-pigmented areas were found. CONCLUSION: In the present study, the mfERG examination displayed significant differences between sector and generalised RP, showing normal values in sector RP even in pigmented areas. Considering the patients included in this study, SRP seems to represent a favourable variant of the disease, characterised by a limited retinal involvement and apparently mild functional damage. It is still unclear how these results can be extended to other forms of SRP.

Atherosclerotic and thrombophilic risk factors in patients with ischemic central retinal vein occlusion.

PURPOSE: To investigate atherosclerotic and thrombophilic risk factors in patients affected by acute ischemic and nonischemic central retinal vein occlusions (CRVOs). METHODS: One hundred and three patients with acute unilateral CRVO (41 ischemic and 62 nonischemic) were studied. The frequency of traditional cardiovascular risk factors was assessed, and the plasma levels of a variety of thrombophilic markers were measured. Univariate logistic regression was performed to determine risk factors for ischemic CRVO. RESULTS: Arterial hypertension, hypercholesterolemia, postmethionine hyperhomocysteinemia (HHcy), elevated factor VIII, and reduced folic acid and B6 plasma levels were more frequent in patients with ischemic CRVO than in those with nonischemic CRVO (P = 0.030, P = 0.025, P = 0.011, P < 0.001, P < 0.001, and P = 0.044, respectively). Risk factors for ischemic CRVO were arterial hypertension (odds ratio [OR], 3.22; 95% confidence interval [CI], 1.13-9.21; P = 0.037), hypercholesterolemia (OR, 3.03; 95% CI, 1.06-8.65; P = 0.042), reduced folic acid levels (OR, 6.77; 95% CI, 1.59-28.79; P = 0.011), and elevated FVIII levels (OR, 6.17; 95% CI, 2.56-14.82; P < 0.001). Postmethionine HHcy was associated with low folic acid levels (r = -0.413; P = 0.007; OR, 9.33; 95% CI, 2.06-42.18; P = 0.005). CONCLUSION: The results of the present study suggest that some atherosclerotic and thrombophilic risk factors may increase the risk of having an ischemic form of CRVO.

Evaluation of traditional and emerging cardiovascular risk factors in patients with non-arteritic anterior ischemic optic neuropathy: a case-control study.

BACKGROUND: Non-arteritic anterior ischemic optic neuropathy (NAION) is a multifactorial disease that is caused by an infarction of the vessels that supply the optic nerve head. This study aims at evaluating the role of traditional and emerging cardiovascular risk factors on the development of NAION. METHODS: A total of 85 newly diagnosed NAION patients and 107 age- and gender-matched healthy controls were studied. All participants underwent blood testing for homocysteine and lipoprotein(a). Plasma levels of vitamin B6 and B12, and folic acid were also determined. Plasma values of all these parameters were evaluated as continuous variables, by a logarithmic transformation. In addition, traditional cardiovascular risk factors were considered. RESULTS: With univariate analysis, higher values of homocysteine and Lp(a) (OR 4.24, 95% CI 2.01-8.94, p < 0.0001; OR 1.32, 95% CI 1.04-1.67, p = 0.03, respectively) and lower values of vitamin B6 (OR 0.44, 95% CI 0.25-0.76, p = 0.003) were significantly associated with NAION. At multivariate analysis, adjusted for age, gender, smoking habit, hypertension, dyslipidemia, diabetes, sleep apnea, and thrombophilic risk factors, the higher homocysteine and Lp(a) values (OR 5.74, 95% CI 2.41-13.67, p = 0.0001; OR 1.27, 95% CI 1.01-1.63, p = 0.04) and lower vitamin B6 values (OR 0.42, 95% CI 0.23-0.77, p = 0.005) maintained their significant relationship with NAION. CONCLUSIONS: This study demonstrated that elevated plasma homocysteine and lipoprotein(a) levels, as well as low vitamin B6 levels, may increase the risk of developing NAION. A screening for these thrombophilic markers could be useful in subjects experiencing NAION.

Ocular surface temperature in diabetic retinopathy: a pilot study by infrared thermography.

PURPOSE: To compare ocular surface temperature (OST) measures in patients with nonproliferative diabetic retinopathy (NPDR) and healthy controls. METHODS: A total of 51 consecutive patients with different severity degrees of NPDR and 53 age- and gender-matched healthy volunteers were recruited. OST was evaluated by infrared thermography in five conjunctival (points 1, 2, 4, 5) and corneal (point 3) points. RESULTS: In diabetic eyes, OST values were lower than in controls at all the studied points (p<0.001 at points 1, 2, 3, 4, and p=0.003 at point 5). CONCLUSIONS: Ocular surface temperature measurements, by estimating ocular blood flow, may be helpful in the management of patients with diabetic retinopathy.

Deep sclerectomy with SkGel implant: 5-year results.

PURPOSE: To evaluate the results of deep sclerectomy with SkGel at 3 and 5 years. MATERIALS AND METHODS: This retrospective trial comprised 200 eyes with open angle glaucoma having a 3-year follow-up, 97 having a 5-year follow-up. Visual acuity, intraocular pressure (IOP), and slit-lamp examination were recorded at baseline and at follow-up visits. Visual field (VF) testing was repeated every 6 months. RESULTS: Mean IOP decreased from 21.01+/-5.56 mm Hg before surgery to 13.13+/-2.24 mm Hg at 36 months and from 20.61+/-5.50 to 12.85+/-1.84 mm Hg at 60 months (P<0.0005). At 3 and 5 years, complete success rates (IOP16 mm Hg) 11% and 10.31%, respectively. VF testing revealed stable mean deviation and corrected pattern standard deviation values at 3 and 5 years (P>0.05). At 3 years, success rate was greater if goniopuncture was performed within 3 months after surgery (P=0.022). Complications of the surgery were not observed after goniopunctures. CONCLUSIONS: Deep sclerectomy with SkGel provides stable control of IOP and VF.

Role of haemorheological factors in patients with retinal vein occlusion.

Retinal vein occlusion (RVO) is an important cause of permanent visual loss. Hyperviscosity, due to alterations of blood cells and plasma components, may play a role in the pathogenesis of RVO. Aim of this case-control study was to evaluate the possible association between haemorheology and RVO. In 180 RVO patients and in 180 healthy subjects comparable for age and gender we analysed the whole haemorheological profile: [whole blood viscosity (WBV), erythrocyte deformability index (DI), plasma viscosity (PLV), and fibrinogen]. WBV and PLV were measured using a rotational viscosimeter, whereas DI was measured by a microcomputer-assisted filtrometer. WBV at 0.512 sec(-1) and 94.5 sec(-1) shear rates as well as DI, but not PLV, were found to be significantly different in patients as compared to healthy subjects. At the logistic univariate analysis, a significant association between the highest tertiles of WBV at 94.5 sec(-1) shear rate (OR: 4.91, 95% CI 2.95-8.17; p < 0.0001), WBV at 0.512 sec(-1) shear rate (OR: 2.31, 95% CI 1.42-3.77; p < 0.0001), and the lowest tertile of DI (OR: 0.18, 95% CI 0.10-0.32; p < 0.0001) and RVO was found. After adjustment for potential confounders, the highest tertiles of WBV at 0.512 sec(-1) shear rate (OR: 3.23, 95% CI 1.39-7.48; p = 0.006), WBV at 94.5 sec(-1) shear rate (OR: 6.74, 95% CI 3.06-14.86; p < 0.0001) and the lowest tertile of DI (OR: 0.20,95% CI 0.09-0.44, p < 0.0001) remained significantly associated with the disease. In conclusion, our data indicate that an alteration of haemorheological parameters may modulate the susceptibility to the RVO, by possibly helping to identify patients who may benefit from haemodilution.

Evaluation of ocular surface temperature and retrobulbar haemodynamics by infrared thermography and colour Doppler imaging in patients with glaucoma.

BACKGROUND: Ocular surface temperature (OST) could berelated to retrobulbar haemodynamics in patients with glaucoma. AIMS: To compare OST measurements in patients with glaucoma and healthy controls, and to investigate the correlation between OST, intraocular pressure (IOP) and retrobulbar haemodynamics in patients with glaucoma. METHODS: 32 patients with primary open-angle glaucoma (POAG) and 40 controls were included in the study. The parameters considered both in patients with POAG and in controls were IOP and OST values measured by infrared ocular thermography. Colour Doppler imaging was used to determine haemodynamic parameters in ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCAs) in patients with POAG. RESULTS: OST values were significantly lower in patients with POAG than in controls (p<0.001). OST was negatively related with resistivity index of OA (p<0.001), CRA (p = 0.001) and SPCAs (p<0.001), and positively related with end-diastolic velocity of OA (p = 0.02) and SPCAs (p = 0.05). CONCLUSION: This study suggested that OST could be a marker of impaired retrobulbar haemodynamics in patients with glaucoma.

Cardiovascular and thrombophilic risk factors in patients with retinal artery occlusion.

This article evaluates the prevalence of cardiovascular and thrombophilic risk factors in patients with retinal artery occlusion. Forty-one patients with a first episode of a retinal artery occlusion underwent complete ophthalmic examination, routine blood testing and specific laboratory tests for thrombophilia, such as fasting and postmethionine homocysteine, lipoprotein(a), plasminogen activator inhibitor-1, factor VIII, factor V Leiden, factor II G20210A polymorphism, lupus anticoagulant and anticardiolipin antibodies. The control population consisted of 100 healthy individuals comparable as regards age and sex. At univariate analysis, hypertension, smoking, dyslipidaemia (both high cholesterol and triglyceride levels), antiphospholipid antibodies, hyperhomocysteinaemia, elevated factor VIII and lipoprotein(a) levels were significantly associated with retinal artery occlusion; at multivariate analysis, adjusted for age, sex, traditional and thrombophilic risk factors, smoking, hypercholesterolaemia, elevated homocysteine and lipoprotein(a) levels confirmed their independent role as risk factors for retinal artery occlusion. In conclusion, the results of the present pilot study demonstrate that the prevalence of hypercholesterolaemia and smoking and the 'thrombophilic burden' are increased in patients with retinal artery occlusion. Our findings may have implications for the management of these patients, suggesting the need for an intensive and tailored secondary prevention and new therapeutic approaches.

Retinal nerve fiber layer thickness by Stratus and Cirrus OCT in retrobulbar optic neuritis and nonarteritic ischemic optic neuropathy.

PURPOSE: To compare retinal nerve fiber layer thickness (RNFLT) measurements by Stratus and Cirrus optical coherence tomography (OCT) and to evaluate agreement between the 2 instruments in retrobulbar optic neuritis (RON), nonarteritic ischemic optic neuropathy (NAION), and healthy controls. METHODS: A total of 89 eyes with RON, 92 with NAION (6 to 12 months after diagnosis of acute disease), and 159 control eyes were studied. Average RNFLT was measured by Stratus and Cirrus OCTs. Comparisons among groups were performed by analysis of variance. Agreement between the 2 instruments was assessed using intraclass correlation coefficient (ICC) with 95% confidence interval (CI) and Bland-Altman analysis. Statistical significance was set at p≤0.05. RESULTS: Average RNFLT was lower in NAION eyes than in RON and control ones using both OCT devices (60.0 ± 1.2, 69.9 ± 1.2, and 97.4 ± 0.9 µm, p<0.001 by Cirrus; 49.7 ± 1.5, 65.9 ± 1.9, and 99.2 ± 1.3 µm, p<0.001 by Stratus). The RNFLT values were higher with Cirrus than with Stratus in NAION (+10.30 µm, confidence interval [CI] 7.82-12.79 µm) and RON (+4.01 µm, CI 1.32-6.70 µm) eyes, and slightly lower in control ones (-1.75 µm, CI -3.51 to 0.01 µm). A stronger agreement between the 2 instruments was found in control and RON eyes than in NAION ones (ICC 0.682, CI 0.566-0.771; 0.635, CI 0.467-0.758; 0.321, CI 0.132-0.472, respectively). CONCLUSIONS: Both Stratus and Cirrus OCT can identify RNFLT reduction in previous RON and NAION. Absolute RNFLT values differ between the 2 instruments; hence they are not to be considered interchangeable.

Two Orthoptic Treatments in Dragged-Fovea Diplopia Syndrome.

BACKGROUND: "Dragged-fovea diplopia syndrome" is a type of central binocular diplopia that is secondary to a foveal displacement, caused by epiretinal membranes (ERMs) or other macular diseases. Its management is difficult, because prisms are not effective. CASE REPORTS: Two cases of dragged-fovea diplopia syndrome were presented. Both patients were affected with a unilateral epiretinal membrane. Therefore, the pathophysiology underlying their diplopia was the conflict between central and peripheral fusion mechanisms. CONCLUSIONS: Diplopia caused by ERM "shift" deserves a complex management. We suggest to be careful about subjective symptoms and to optimize the residual visual function to customize the orthoptic management. A strict cooperation between ophthalmologists and orthoptists could lead to a successful outcome.

The nitric oxide donating triamcinolone acetonide NCX 434 does not increase intraocular pressure and reduces endothelin-1 induced biochemical and functional changes in the rabbit eye.

BACKGROUND: NCX 434 is a nitric oxide (NO)-donating triamcinolone acetonide (TA), shown to enhance optic nerve head (ONH) oxygen saturation in non-human primate eyes. Here, the effects of a single intravitreal (IVT) injection of TA were compared with those of NCX 434 on intraocular pressure (IOP), retinal function and retrobulbar haemodymamics in endothelin-1 (ET-1) induced ONH ischaemia/reperfusion in rabbits. Biochemical changes were also assessed in the aqueous humour and in retinal biopsies. METHODS: IOP and resistivity index of ophthalmic artery (RI-OA) were recorded using TonoPen and ecocolor Doppler, respectively. Retinal function was assessed using photopic electroretinography. Cytokine expression and oxidative stress markers were evaluated with immunoassay techniques. RESULTS: At 4 weeks post IVT treatment, TA increased IOP and RI-OA while NCX 434 did not (IOP(Vehicle)=13.6±1.3, IOP(NCX 434)=16.9±2.2, IOP(TA)=20.9±1.9 mm Hg; p<0.05 vs vehicle; RI-OA(Vehicle)=0.44±0.03; RI-OA(NCX 434)=0.47±0.02; RI-OA(TA)=0.60±0.04). Both NCX 434 and TA reversed ET-1 induced decrease in electroretinography amplitude to similar extents. NCX 434 attenuated ET-1 induced oxidative stress markers and nitrotyrosine in retinal tissue, and interleukin-6 and tumour necrosis factor-α in aqueous humour more effectively than TA. CONCLUSION: NCX 434 attenuates ET-1 induced ischaemia/reperfusion damage without increasing IOP, probably due to NO release. If data are confirmed in other species and models, this compound could represent an interesting new therapeutic option for retinal and ONH diseases, including diabetic retinopathy.

Systemic vascular dysregulation and retrobulbar hemodynamics in normal-tension glaucoma.

PURPOSE: To investigate the influence of systemic vascular dysregulation on retrobulbar hemodynamics in normal-tension glaucoma (NTG). METHODS: Forty-four untreated patients with NTG and 40 healthy controls matched for age, sex, and intraocular pressure were included. Cold-induced nailfold capillaroscopic features, mean and diastolic ocular perfusion pressures (mOPP, dOPP), endothelin-1 (ET-1) and nitric oxide markers, as nitrates (NO(2)), plasma values were recorded. Peak-systolic velocity, end-diastolic velocity (EDV), and resistivity index (RI) were measured in the ophthalmic artery (OA), short posterior ciliary arteries, and the central retinal artery by color Doppler imaging. Differences between groups were determined by Student's t-test. Relationships among ET-1, NO(2), OPPs, and retrobulbar hemodynamics were assessed using correlation and multiple linear regression analyses. RESULTS: Altered capillaroscopy was more frequent (72.7% vs. 5.0%, P < 0.001), mOPP and dOPP values were lower (44.54 ± 2.81 vs. 52.18 ± 4.47 mm Hg; 57.89 ± 4.30 vs. 68.28 ± 6.91 mm Hg; P < 0.001), and ET-1 and NO(2) values were respectively higher and lower (1.62 ± 0.22 vs. 1.12 ± 0.20 pg/mL and 142.17 ± 14.34 vs. 231.30 ± 6.16 µmol/mg prot; P < 0.001) in patients than the same values in controls. EDV was lower and RI higher in OA (5.87 ± 1.17 vs. 11.41 ± 2.30 cm/s; 0.76 ± 0.03 vs. 0.64 ± 0.03; P < 0.001) in subjects with NTG than in controls. In patients RI-OA was positively related to ET-1 (t = 2.704, P = 0.010) and negatively related to NO(2) (t = -4.477, P < 0.001). CONCLUSIONS: Impaired retrobulbar hemodynamics may proceed from a vascular endotheliopathy in patients with NTG.

High lipoprotein (a) levels are associated with an increased risk of retinal vein occlusion.

INTRODUCTION: Retinal vein occlusion (RVO) is one of the most common retinal vascular disorders affecting ocular vessels. Few studies, with conflicting results and conducted in limited study populations, have hypothesised the role of high levels of lipoprotein (a) [Lp(a)] in the occurrence of RVO. The aim of this study was to investigate, in a large group of RVO patients, the role of such an emerging thrombophilic parameter on the pathogenesis of RVO. MATERIALS AND METHODS: We compared 262 patients [median age: 66 years (15-88); 122 M, 140 F] with 262 age- and sex-comparable healthy subjects. RESULTS: Circulating concentrations of Lp(a) were found to be significantly different in patients when compared to healthy subjects [189 (60-1898)mg/L vs. 119.5 (6-1216)mg/L; p<0.0001, respectively]. No significant differences were observed relating to the different types of occlusion (central or branch occlusion). In order to investigate the possible association between high Lp(a) levels and the disease we performed a logistic regression analysis. In the univariate analysis, Lp(a) levels>300mg/L were found to be associated with an increased risk of RVO (OR: 2.39, 95%CI 1.39-3.59; p<0.0001). Following this, three models of multivariate analysis were performed, firstly by adjusting for age, gender, and traditional cardiovascular risk factors, secondly for triglycerides and thirdly for homocysteine levels. In all the models, Lp(a) levels>300mg/L confirmed their role as a risk factor for RVO [first model, OR: 2.15 (95%CI 1.39-3.32), p=0.0001; second model, OR: 3.11 (95%CI 1.77-5.62), p<0.00001; third model, OR: 3.48 (95%CI 1.88-6.43), p<0.00001]. CONCLUSIONS: This study reports that, in a large population of RVO patients, high Lp(a) concentrations are significantly related to RVO, independent from other traditional and emerging risk factors, suggesting that they may play a role in its pathogenesis.

Ocular perfusion pressure and retrobulbar haemodynamics in pseudoexfoliative glaucoma.

BACKGROUND: Previous investigations have shown that vascular factors are involved in pseudoexfoliative glaucoma (XFG). The present study aims at comparing ocular perfusion pressure (OPP), diastolic ocular perfusion pressure (dOPP), and retrobulbar haemodynamics in pseudoexfoliative glaucoma and primary open-angle glaucoma (POAG). METHODS: Forty-seven XFGs, 41 POAGs, and 38 healthy controls were evaluated. OPP and dOPP were calculated. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) were recorded in ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs) by color Doppler imaging (CDI). Correlations between OPP and CDI parameters and between dOPP and CDI parameters were determined. RESULTS: OPP and dOPP were significantly lower in XFGs than in POAGs and controls (p < 0.001). CDI investigation revealed decreased EDV of OA, SPCAs, and CRA (p < 0.001) and increased RI of all the three considered vessels in XFGs compared with POAGs and controls (p < 0.001). A negative correlation between OPP and RI of OA and between dOPP and RI of OA was found in XFGs (p = 0.022 and p = 0.015 respectively). CONCLUSIONS: Ocular perfusion pressure is decreased and retrobulbar haemodynamics are worse in pseudoexfoliative glaucoma patients than in primary open-angle glaucoma patients and healthy controls. An impaired ocular vascular regulation is suggested in pseudoexfoliative glaucoma.

Retrobulbar hemodynamics and corneal surface temperature in glaucoma surgery.

AIM: The purpose of this study was to investigate the effects of glaucoma surgery on retrobulbar hemodynamics and corneal surface temperature (CST). METHODS: A total of 22 primary open-angle glaucoma eyes underwent deep sclerectomy, and 19 trabeculectomy. The follow-up was of 3 months. The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) were evaluated in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs) by color Doppler imaging (CDI). CST was measured using infrared thermography. RESULTS: At 3 months, EDV was increased in OA (P<0.001 in deep sclerectomy, P=0.005 in trabeculectomy), CRA (P=0.044 and P<0.001), and SPCAs (P=0.011 and P=0.003), and RI decreased in OA, CRA, and SPCAs (P<0.001 in both groups). CST values were augmented (P<0.001 in both groups). A negative correlation between the postoperative changes in RI-OA and CST was found (P=0.023 and P=0.032, respectively). CONCLUSIONS: Deep sclerectomy and trabeculectomy seem to be equally effective in improving retrobulbar hemodynamics. Color Doppler imaging and infrared thermography might be useful to evaluate the vascular outcome of glaucoma surgery.

Low vitamin B6 and folic acid levels are associated with retinal vein occlusion independently of homocysteine levels.

Retinal vein occlusion (RVO) is one of the most common retinal vascular disorders. During the last years, high levels of homocysteine (Hcy) have been demonstrated to be an independent risk factor for RVO. Aim of this study was to investigate the association among circulating B-group vitamins, Hcy and RVO. Thus, we studied 262 RVO patients and 262 age- and sex-comparable healthy subjects. Serum vitamin B6 was measured by HPLC, serum folic acid and vitamin B12 by radioimmunoassay and plasma Hcy by FPIA. Blood levels of vitamin B6, folate and Hcy, but not of vitamin B12, were found to be significantly different in patients as compared to healthy subjects. At the univariate analysis, the lowest tertile of vitamin B6 [odds ratio (OR) 4.03; 95% confidence interval (CI) 2.58-6.31; P<0.0001)] and folate (OR 6.13; 95% CI 3.85-9.76, P<0.0001), and the highest tertile of Hcy (OR 8.08; 95% CI 5.05-12.92, P<0.0001) were found to be significantly associated with RVO. Moreover, at multivariate analysis, after adjustment for traditional cardiovascular risk factors, Hcy, and circulating levels of vitamins, respectively, the lowest tertile of vitamin B6 (OR 3.29; 95% CI 1.89-5.70, P<0.0001) and folate (OR 5.41; 95% CI 3.08-9.51, P<0.0001) and the highest tertile of Hcy (OR 2.58; 95% CI 1.12-5.94, P<0.0001) maintained their significant association with RVO. In conclusion, the present study documents, on a large sample of patients, that low vitamin B6 levels, low folic acid levels and elevated Hcy levels are each independently associated with RVO.