Anna Dastiridou

Perimetric and retinal nerve fiber layer findings in patients with Parkinson’s disease

BackgroundVisual dysfunction is common in Parkinson’s disease (PD). It remains, however, unknown whether it is related to structural alterations of the retina. The aim of this study is to compare visual field (VF) findings and circumpapillary retinal nerve fiber layer (RNFL) thickness in a series of PD patients and normal controls, in order to assess possible retinal anatomical changes and/or functional damage associated with PD.MethodsPD patients and controls were recruited and underwent VF testing with static automated perimetry and RNFL examination with optical coherence tomography (OCT). Cognitive performance using Mini Mental State Examination (MMSE), PD staging using modified Hoehn and Yahr (H-Y) scale and duration of the disease was recorded in PD patients.ResultsOne randomly selected eye from each of 24 patients and 24 age-matched controls was included. OCT RNFL thickness analysis revealed no difference in the inferior, superior, nasal or temporal sectors between the groups. The average peripapillary RNFL was also similar in the two groups. However, perimetric indices of generalized sensitivity loss (mean deviation) and localized scotomas (pattern standard deviation) were worse in patients with PD compared to controls (p < 0.01). 73% of eyes of PD patients had glaucomatous-like asymmetrical hemifield defects with abnormal Glaucoma Hemifield Test and various combinations of arcuate defects (n = 12), nasal steps (n = 11) and paracentral scotomas (n = 16). Bilateral defects were found in 14 patients (58%). No correlation was found between VF indices and MMSE or H-Y scores.ConclusionPD patients may demonstrate glaucomatous-like perimetric defects even in the absence of decreased RNFL thickness.

Retinal vasculitis in rheumatic diseases: an unseen burden

Retinal vascular inflammation, a potentially blinding condition (herein: retinal vasculitis (RV)) is commonly associated with a heterogeneous group of diseases characterized by systemic inflammatory cell infiltration and/or necrosis of blood vessel walls. RV may arise as an isolated ocular disorder, as part of systemic vasculitis (Wegener’s granulomatosis and Adamantiadis–Behcet Disease), or it can be secondary to an underlying connective tissue disease (systemic lupus erythematosus, sarcoidosis, and rheumatoid arthritis), systemic infection, or malignancy. Depending on the type of RV, it can be a potentially disabling condition, in the short or long term. Early diagnosis is the key to successful treatment and better prognosis. However, early diagnosis can be difficult, because these conditions usually present with nonspecific visual symptoms for a long period before diagnostic manifestations occur. The retina should be examined in warranted patients with verified rheumatic disease, since retinal vasculitis may be asymptomatic at the beginning (peripheral retinal disease). RV can be detected clinically (often accompanied by uveitis, scleritis, or macular edema) or revealed on fluorescein fundus angiography, even if minimal signs of retinal vessel inflammation are present. RV may also represent one of the possible extra-articular manifestations of the rheumatic disease. Rheumatologists should be familiar with the ocular manifestations of these disorders, since they may not only be sight-threatening, but more importantly, could be the presenting or even the very first manifestations of active, potentially lethal systemic disease in a patient with nonspecific rheumatologic presentation.

A Focus on the Epidemiology of Uveitis

ABSTRACT Purpose: Uveitis is a common, sight-threatening inflammatory ocular disease and includes multiple heterogeneous clinical entities. The prevalence of various types of uveitis depends upon multiple factors, such as age, sex, race, geographic distribution, environmental influence, genetics, and social habits. Epidemiologic research of uveitis is necessary to understand the etiology and immunopathogenesis of this group of diseases. The present study attempts to concentrate on the most recent information on the epidemiology of uveitis and compare it with previous knowledge. Methods: An extensive literature search was performed in the Medline database (PubMed) and included surveys completed until 2015. Articles that reported prevalence and incidence were studied. References cited in the articles were also studied. Results: The incidence and prevalence of uveitis differs based on age, anatomic location of the inflammatory process (anterior, intermediate, posterior uveitis, panuveitis), gender, histopathology (granulomatous, non-granulomatous), type of inflammatory process (acute, chronic, recurrent), and etiology (infectious, non-infectious). Prevalence differs by geographic location. Idiopathic anterior uveitis is the most common form of uveitis in the community. Infectious causes are common (30–60%) in the developing countries. Herpes and toxoplasmosis are the leading infectious causes of uveitis. Non-infectious uveitic conditions are generally more common in the developed world. An increase in the prevalence of infectious etiologies, including tuberculosis and syphilis, has been seen in developed countries. Introduction of new treatment options has also changed patterns of disease. Conclusions: Introduction of new uveitis entities, changes in the incidence of already known disease and increased availability of diagnostic testing have all altered the epidemiology of uveitis in recent years. Knowledge of regional patterns of disease is essential. A more detailed classification of uveitis with the establishment of uniform diagnostic criteria and prospective population based studies would certainly benefit epidemiologic research and clinical practice.

Ocular rigidity, ocular pulse amplitude, and pulsatile ocular blood flow: the effect of axial length.

PURPOSE Previous studies have shown a negative correlation between axial length (AL) and pulsatile ocular blood flow (POBF). This relation has been questioned because of the possible confounding effect of ocular volume on ocular rigidity (OR). The purpose of this study was to investigate the relation between AL, as a surrogate parameter for ocular volume, and OR, ocular pulse amplitude (OPA), and POBF. METHODS Eighty-eight cataract patients were enrolled in this study. A computer-controlled device comprising a microdosimetric pump and a pressure sensor was used intraoperatively. The system was connected to the anterior chamber and used to raise the intraocular pressure (IOP) from 15 to 40 mm Hg, by infusing the eye with a saline solution. After each infusion step, the IOP was continuously recorded for 2 seconds. Blood pressure and pulse rate were measured during the procedure. The OR coefficient was calculated from the pressure volume data. OPA and POBF were measured from pressure recordings. RESULTS Median AL was 23.69 (interquartile range 3.53) mm. OR coefficient was 0.0218 (0.0053) μL(-1). A negative correlation between the OR coefficient and AL (ρ = -0.641, P < 0.001) was documented. Increasing AL was associated with decreased OPA (ρ = -0.637, P < 0.001 and ρ = -0.690, P < 0.001) and POBF (ρ = -0.207, P = 0.053 and ρ = -0.238, P = 0.028) at baseline and elevated IOP, respectively. CONCLUSIONS Based on manometric data, increasing AL is associated with decreased OR, OPA, and POBF. These results suggest decreased pulsatility in high myopia and may have implications on ocular pulse studies and the pathophysiology of myopia.

Ocular Rigidity, Outflow Facility, Ocular Pulse Amplitude, and Pulsatile Ocular Blood Flow in Open-Angle Glaucoma: A Manometric Study

PURPOSE To compare ocular rigidity (OR) and outflow facility (C) coefficients in medically treated open-angle glaucoma (OAG) patients and controls, and to investigate differences in ocular pulse amplitude (OPA) and pulsatile ocular blood flow (POBF) between the two groups. METHODS Twenty-one OAG patients and 21 controls undergoing cataract surgery were enrolled. Patients with early or moderate primary or pseudoexfoliative OAG participated in the glaucoma group. A computer-controlled system, consisting of a pressure transducer and a microstepping device was employed intraoperatively. After cannulation of the anterior chamber, IOP was increased by infusing the eye with microvolumes of saline solution. IOP was recorded after each infusion step. At an IOP of 40 mm Hg, an IOP decay curve was recorded for 4 minutes. OR coefficients, C, OPA, and POBF were estimated from IOP and volume recordings. RESULTS There were no differences in age or axial length in the two groups. The OR coefficient was 0.0220 ± 0.0053 μl(-1) in the OAG and 0.0222 ± 0.0039 μl(-1) in the control group (P = 0.868). C was 0.092 ± 0.082 μL/min/mm Hg in the glaucoma group compared with 0.149 ± 0.085 μL/min/mm Hg in the control group at an IOP of 35 mm Hg (P < 0.001) and 0.178 ± 0.133 μL/min/mm Hg vs. 0.292 ± 0.166 μL/min/mm Hg, respectively, at an IOP of 25 mm Hg (P < 0.001). There were no differences in OPA or POBF between the two groups in baseline and increased levels of IOP (P > 0.05). CONCLUSIONS Manometric data reveal lower C in OAG patients and increased C with increasing IOP. There were no differences in the OR coefficient, OPA, and POBF between medically treated OAG patients and controls, failing to provide evidence of altered scleral distensibility and choroidal blood flow in OAG.

Longitudinal and Cross-Sectional Analyses of Age Effects on Retinal Nerve Fiber Layer and Ganglion Cell Complex Thickness by Fourier-Domain OCT

Purpose We studied the effects of age and intraocular pressure (IOP) on retinal nerve fiber layer (NFL) and macular ganglion cell complex (GCC) thickness in normal eyes. Methods Data from subjects from the multicenter Advanced Imaging for Glaucoma Study (AIGS) were analyzed. The data included yearly visits from the normal subjects in the AIGS study. Fourier-domain optical coherence tomography (FD-OCT) was used to measure retinal NFL and macular GCC on each visit. Mixed effect models were used to evaluate the longitudinal effect of age and IOP on the NFL and GCC thickness. The measurements at baseline were used to examine the cross-sectional effects. Results The analysis included 192 eyes (92 participants) from AIGS between 2009 and 2013. The longitudinal analyses showed overall GCC thickness decreased 0.25 ± 0.05 μm per year (P < 0.001) while the overall NFL thickness decreased 0.14 ± 0.07 μm per year (P = 0.04). The cross-sectional analyses showed the GCC thickness was 0.17 ± 0.05 μm thinner per year of baseline age (P < 0.001), while the NFL was 0.21 ± 0.06 μm thinner (P < 0.001). There was no significant IOP effect on either GCC or NFL from either the longitudinal or cross-sectional analysis. Conclusions Longitudinal and cross-sectional analyses provided consistent rates of approximately 0.2% per year of age-related thinning in NFL and GCC thicknesses. This is relevant in establishing criteria to detect glaucoma-related thinning (disease progression) in excess of normal aging. IOP does not seem to be a significant confounder for progression analysis. Translational Relevance This study demonstrated the relevance of advanced imaging technology in diagnosing and monitoring glaucoma disease.

Plasma and aqueous humour levels of ghrelin in open-angle glaucoma patients.

Background:  To compare aqueous humour and plasma levels of ghrelin, a peptide recently identified in human eyes, in patients with open‐angle glaucoma and controls.

Bimatoprost and Bimatoprost/Timolol Fixed Combination in Patients with Open-Angle Glaucoma and Ocular Hypertension

PURPOSE To investigate the intraocular pressure (IOP) lowering effect of bimatoprost (BIM) 0.03% and the potential additional effect of the BIM 0.03%/timolol 0.5% fixed combination (BTFC) in eyes with ocular hypertension, primary open-angle glaucoma, or exfoliation glaucoma. METHODS Following an appropriate washout period that varied with previous medication, participants with ocular hypertension, primary open-angle glaucoma, or exfoliation glaucoma were treated with evening-dosed BIM for 5 weeks. They were then given evening-dosed BTFC for another 5 weeks. One randomly selected eye was evaluated. Goldmann applanation tonometry was performed by the same investigator at 8 a.m., 12 noon, 4 p.m., and 8 p.m. at baseline and at the end of each treatment period. RESULTS Thirty-three participants completed the study. Three patients discontinued because of local adverse effects during the BIM treatment period. The mean diurnal IOP (mean ± SD) at baseline, on BIM, and on BTFC were 24.8 ± 5.4, 17.3 ± 3.5, and 14.9 ± 3.1 mmHg, respectively (repeated measures analysis of variance, P < 0.001 for all pairwise comparisons). The individual time-point IOP values showed similar significant reductions. The percentage of IOP reduction from baseline was 30.2% for BIM and 39.9% for the BTFC. The mean ± SD diurnal fluctuation at baseline was 6.8 ± 3.2 mmHg, which decreased to 4.0 ± 3.1 and 2.9 ± 1.4 mmHg on BIM and BTFC, respectively (P < 0.05 for both treatments versus baseline). CONCLUSIONS Both BIM 0.03% and the BTFC were effective in lowering IOP in eyes with ocular hypertension and open-angle glaucoma. However, the fixed combination provided an additional statistically significant reduction in IOP compared with BIM 0.03%.

Comparison of Physiologic versus Pharmacologic Mydriasis on Anterior Chamber Angle Measurements Using Spectral Domain Optical Coherence Tomography

Purpose. To compare the effects of physiologic versus pharmacologic pupil dilation on anterior chamber angle (ACA) measurements obtained with spectral domain optical coherence tomography (SD-OCT). Methods. Forty eyes from 20 healthy, phakic individuals with open angles underwent anterior segment OCT imaging under 3 pupillary states: (1) pupil constricted under standard room lighting, (2) physiologic mydriasis in a darkened room, and (3) postpharmacologic mydriasis. Inferior angle Schwalbes line-angle opening distance (SL-AOD) and SL-trabecular-iris-space area (SL-TISA) were computed for each eye and pupillary condition by masked, certified Reading Center graders using customized grading software. Results. SL-AOD and SL-TISA under pupillary constriction to room light were 0.87 ± 0.31 mm and 0.33 ± 0.14 mm2, respectively; decreased to 0.75 ± 0.29 mm (P < 0.01) and 0.29 ± 0.13 mm2  (P < 0.01), respectively, under physiologic mydriasis; and increased to 0.90 ± 0.38 mm (P < 0.01) and 0.34 ± 0.17 mm2  (P = 0.06) under pharmacologic mydriasis compared to baseline. Conclusions. Using SD-OCT imaging, pharmacologic mydriasis yielded the widest angle opening, whereas physiologic mydriasis yielded the most angle narrowing in normal individuals with open iridocorneal angles. Accounting for the state of the pupil and standardizing the lighting condition would appear to be of importance for future studies of the angle.

Aqueous Angiography-Mediated Guidance of Trabecular Bypass Improves Angiographic Outflow in Human Enucleated Eyes.

Purpose To assess the ability of trabecular micro-bypass stents to improve aqueous humor outflow (AHO) in regions initially devoid of AHO as assessed by aqueous angiography. Methods Enucleated human eyes (14 total from 7 males and 3 females [ages 52–84]) were obtained from an eye bank within 48 hours of death. Eyes were oriented by inferior oblique insertion, and aqueous angiography was performed with indocyanine green (ICG; 0.4%) or fluorescein (2.5%) at 10 mm Hg. With an angiographer, infrared and fluorescent images were acquired. Concurrent anterior segment optical coherence tomography (OCT) was performed, and fixable fluorescent dextrans were introduced into the eye for histologic analysis of angiographically positive and negative areas. Experimentally, some eyes (n = 11) first received ICG aqueous angiography to determine angiographic patterns. These eyes then underwent trabecular micro-bypass sham or stent placement in regions initially devoid of angiographic signal. This was followed by fluorescein aqueous angiography to query the effects. Results Aqueous angiography in human eyes yielded high-quality images with segmental patterns. Distally, angiographically positive but not negative areas demonstrated intrascleral lumens on OCT images. Aqueous angiography with fluorescent dextrans led to their trapping in AHO pathways. Trabecular bypass but not sham in regions initially devoid of ICG aqueous angiography led to increased aqueous angiography as assessed by fluorescein (P = 0.043). Conclusions Using sequential aqueous angiography in an enucleated human eye model system, regions initially without angiographic flow or signal could be recruited for AHO using a trabecular bypass stent.