Proteomic analysis of the aqueous humour in eyes with pseudoexfoliation syndrome.

BACKGROUND/AIMS: Pseudoexfoliation syndrome (PEX) is characterised by the production and accumulation of extracellular fibrillar material in the anterior segment of the eye. The pathogenesis of PEX is multifactorial with genetic factors and ageing as contributing factors. Previously, an increased concentration of beta-crystalline B2 (CRYBB2) was observed in the aqueous humour (AH) in eyes with PEX in a pooled material. Here, the protein content was examined on individual basis. METHODS: During cataract surgery, AH was sampled from patients with and without PEX, 10 eyes in each group. The proteins were digested and labelled with isotopomeric dimethyl labels, separated with high-pressure liquid chromatography and analysed in an Orbitrap mass analyzer. RESULTS: The concentration of complement factor 3, kininogen-1, antithrombin III and vitamin D-binding protein was increased in all eyes with PEX. Retinol-binding protein 3, glutathione peroxidase, calsyntenin-1 and carboxypeptidase E were decreased in eyes with PEX. Beta-crystalline B1 and CRYBB2 and gamma-crystalline D were up to eightfold upregulated in 4 of 10 in eyes with PEX. CONCLUSION : The results indicate that oxidative stress and inflammation are contributing factors in the formation of PEX. Knowledge about the proteome in PEX is relevant for understanding this condition.

Variance components in confocal scanning laser tomography measurements of neuro-retinal rim area and the effect of repeated measurements on the power to detect loss over time.

PURPOSE: To estimate the variation in measurements of neuro-retinal rim area (NRA) determined by confocal scanning laser tomography and consequences for clinical follow-up. METHODS: Altogether, 24 healthy subjects were randomized on -320 µm, Moorfields and Standard NRA plane strategies. Additionally, NRA was measured in 32 glaucoma subjects. Variance components for subjects, visits and measurements were estimated with analysis of variance. Sample sizes required to detect a 6.0 × 10-2  mm2 NRA change were estimated assuming a significance level of 0.05 and a power of 0.8. Consequences for independent group, and paired comparison design, respectively, were analysed. Further, precision in estimates within subjects over time was investigated. RESULTS: The variation of NRA among subjects was considerably larger than the variation among visits and measurements. For glaucoma subjects, the variation among visits and measurements were of the same order but larger than in healthy subjects. It was found that independent group comparisons require inconveniently large sample sizes. Within-subject paired comparisons over time require sample sizes of below 15 subjects. The estimated variations for glaucoma subjects imply that 54 months of follow-up is required for detection of change from baseline. CONCLUSIONS: The variance for subjects is substantial in relation to those for visits and measurements. Cross-sectional independent group comparisons of levels of NRA are unsuitable, due to considerable subject variation. Levels of NRA differences within subjects between visits can be estimated with acceptable precision. Neuro-retinal rim area (NRA) measurement can be used for long-term follow-up of glaucoma progression.

Latanoprost in the treatment of glaucoma.

Prostaglandins are approved by the European Glaucoma Society guidelines as first-line treatment for glaucoma. This review focuses on latanoprost, an ester prodrug of prostaglandin (PG) F2α, which was the first of the currently available topical PGF2α analogs to be launched for glaucoma or ocular hypertension and which still accounts for the majority of prescriptions. It is better absorbed than the parent compound through the cornea, and peak concentration of the active drug is in the aqueous humor 1-2 hours after topical dosing (15-30 ng/mL). Metabolism occurs mainly in the liver. Latanoprost (0.005%) has been very well studied in clinical trials and meta-analyses that show it to be generally as effective as the other PG analogs (bimatoprost, travoprost, and tafluprost) and more effective than timolol, dorzolamide, and brimonidine. Latanoprost has good short- and long-term safety and tolerability profiles. In common with other prostaglandins, it lacks systemic effects, but can cause ocular adverse events such as conjunctival hyperemia, pigmentation of the iris, periocular skin or eyelashes, hypertrichosis, and ocular surface effects or irritation. Latanoprost is significantly better tolerated than either bimatoprost or travoprost. Patients treated with latanoprost have better compliance and persist with therapy longer than those that are given other drugs. An improved formulation of latanoprost without the preservative benzalkonium chloride has recently been developed. It is as effective as conventional latanoprost, has a lower incidence of hyperemia, and can be stored at room temperature. In conclusion, latanoprost has the best efficacy-tolerability ratio of the PG analogs available for glaucoma treatment, and has good compliance and persistence. These factors should be improved further by the recent development of preservative-free latanoprost.

Glaucoma management in Sweden -- results from a nationwide survey.

PURPOSE: To report the results from a nationwide survey on glaucoma management in Sweden, performed as a part of an Open Angle Glaucoma project conducted by the Swedish Council on Health Technology Assessment 2004-2008. METHODS: In 2005, a survey was distributed to all providers of glaucoma care in Sweden: public eye departments, public outpatient departments and private practices. The questionnaire included questions on number of examined patients, types of examinations during one defined week, internal organization and access to diagnostic equipment. The questionnaire was endorsed by the Swedish Ophthalmological Society. Reminders were sent out to nonresponders. RESULTS: Response rate was high; 97% (33/34) of eye departments, 85% (39/46) of outpatient departments and 55% (69/125) of private practices. Out of 29 282 visits in ophthalmic care during the study week, 7737 (26%) were related to glaucoma. Diagnostic equipment was generally available; all public eye facilities and 92% of private practices had at least one computerized perimeter, while equipment for fundus photography/imaging was available at 100% of eye departments, 82% of outpatient departments and 62% of private practices. The number of visual field tests and fundus images was rather low. Survey results indicate that patients on the average underwent bilateral field testing every 2nd year and fundus imaging every 8th year. CONCLUSION: Glaucoma care generated about a quarter of all patient visits in Swedish ophthalmic care. Access to diagnostic facilities was good. To meet modern standards of glaucoma care, glaucoma damage must be measured and followed more closely than at the time of the survey.

Is quantitative spectral-domain superior to time-domain optical coherence tomography (OCT) in eyes with age-related macular degeneration?

PURPOSE: The aim of this study was to determine the variability of macular map measurements, for two generations of optical coherence tomography (OCT) instruments, in eyes with wet age related macular degeneration (AMD) and low visual acuity. METHODS: Patients were examined with Stratus OCT and Cirrus HD-OCT. The macular thickness was assessed with the 'macular thickness map scan' and 'fast protocol' in Stratus and with the 512 × 128 and 200 × 200 cube protocols in Cirrus OCT. Two measurements were taken one directly after the other, at the first visit to analyse repeatability. Approximately 1 week later, a third measurement was taken to analyse reproducibility. In Cirrus OCT, a manual correction of foveal location was also performed. Repeatability and reproducibility were calculated as a coefficient of variance (CoV) and a coefficient of repeatability/reproducibility. RESULTS: Repeatability for central macular thickness (expressed as CoV) was about three per cent for all protocols, and the coefficient of repeatability between 34 and 54 µm. Reproducibility (also expressed as CoV) was between four to seven per cent and coefficient of repeatability between 64 and 89 µm. After manual adjustment of foveal location in Cirrus OCT, the coefficient of repeatability improved to 12-18 µm, and the coefficient of reproducibility to 44-47 µm. CONCLUSIONS: In eyes affected by wet AMD, there were small differences in repeatability and reproducibility when comparing quantitative maps in Stratus and Cirrus OCT. However, when the software for manual correction of foveal position in Cirrus OCT was used, the variability decreased markedly, and the repeatability was close to what had been reported in normal eyes, demonstrating a significant, potential advantage of spectral-domain over time-domain OCT.

Proteins in aqueous humor from cataract patients with and without pseudoexfoliation syndrome.

The aim of this study was to investigate the protein content in aqueous humor in eyes with and without pseudoexfoliations (PEX) and to evaluate the quantitative proteomics method, isobaric tagging for relative and absolute protein quantification (iTRAQ), in combination with two separation methods followed by matrix-assisted Laser desorption/ionization (MALDI) mass spectrometry and tandem mass spectrometry (MS/MS). During cataract surgery, samples of aqueous humor were collected from 20 eyes with PEX and from 18 control eyes. The relative concentrations of proteins in the pooled samples of ten PEX eyes and eight controls were evaluated after trypsin digestion and Labeling of the peptides with (iTRAQ) reagent. Two separation methods, Liquid chromatography (LC) and capillary electrophoresis (CE) were used, followed by MALDI mass spectrometry and MS/MS. Furthermore, 1D gel electrophoresis was performed on the remaining ten pooled PEX samples and ten control samples. The gel material was separated by nano-liquid chromatography (nano-LC) followed by Linear-ion-trap quadrupole Fourier transformation ion cyclotron resonance (FT-ICR). Fifty four proteins were identified in the LC runs and 24 with CE. The relative concentrations of beta-crystallines B2 and S were raised and those of angiotensinogen and osteopontin Lowered in the PEX sample compared to the control. The trends regarding beta-crystallines B2, angiotensinogen and osteopontin were confirmed by the 1D gel electrophoresis.

Macular edema and visual outcome following cataract surgery in patients with diabetic retinopathy and controls.

BACKGROUND: Cystoid macular edema (CME) is a well-known complication after cataract surgery, and diabetic retinopathy is reported to be an important risk factor for impaired visual recovery. In this prospective study, we compared visual outcome 6 months after surgery in eyes with moderate retinopathy and no previous ME with a control group, and observed the incidence of ME seen on fluorescein angiography (FA) and optical coherence tomography (OCT). METHODS: Thirty-four patients with type-2 diabetes and 35 controls were enrolled. Best-corrected visual acuity (VA) letters ETDRS was measured pre-op, at day 7, week 6 and month 6. FA performed pre-op and at week 6 was divided into three leakage patterns. OCT performed pre-op, at week 6 and month 6 was qualitatively divided into three types. Macular thickness was measured in three circular fields (central subfield, inner and outer circle) from the macular maps. RESULTS: There was no statistically significant difference in VA before surgery, at day 7 or at 6 months, but at 6 weeks there was a significant difference with lower VA in the diabetic group. Six percent of control and 12% of diabetic eyes developed a clinical CME defined as a loss of >5 letters between day 7 and week 6. Incidence of FA leakage was 23% in control and 76% in diabetic eyes. At 6 weeks, 20% of control and 44% of the diabetic eyes had qualitative changes on OCT. A statistically significant increase in thickness was observed for all three macular areas in both groups, part of it remaining at 6 months. There were, however, no differences in central macular thickness between the groups at any visit. Retinal thickening had poor correlation with VA. CONCLUSION: The final visual outcome in eyes with mild to moderate retinopathy, without previous ME, is as good as in normal eyes, but an increased frequency of macular changes may protract recovery of full vision. Changes on OCT or FA are often seen without any obvious effect on VA. OCT is as good as FA at detecting a clinical CME, and is the technique recommended for follow-up before FA is considered.

Retinal nerve fibre layer thickness in full-term children assessed with Heidelberg retinal tomography and optical coherence tomography: normal values and interocular asymmetry.

PURPOSE: This study aimed to investigate normal values and interocular differences in retinal nerve fibre layer (RNFL) thickness, using optical coherence tomography (OCT) and Heidelberg retinal tomography (HRT), in 5-16-year-old children born at full-term with normal birthweights. METHODS: Fifty-six children with normal visual acuity and refraction were examined with Stratus OCT and HRT. Three examinations were performed in each eye. One eye in each child was randomized for analyses of normal values. Findings in 54 eyes were evaluated. Mean values of RNFL thickness were calculated. Coefficients of variance and intraclass correlations were calculated. The correlation between right and left eyes and the limits of difference were determined for both methods. RESULTS: Mean RNFL thickness was 98.4 µm (standard deviation [SD] 7.88 µm) assessed with OCT and 213.0 µm (SD 54.0 µm) assessed with HRT. No correlations between age or gender and RNFL thickness were found. The coefficients of variance were 2.9% and 5.6% for OCT and HRT, respectively, and intraclass correlations were 0.85 and 0.88, respectively. The limits of difference between the two eyes ranged from -9 µm to 9 µm with OCT and from -109 µm to 87 µm with HRT. CONCLUSIONS: Both OCT and HRT can be used in children aged 5-16 years, but OCT provides less variability in determinations of RNFL thickness, both in repeated examinations of the same eye and in comparisons between the two eyes. The present study provides values for normal RNFL thickness in healthy children which can be used to make comparisons with values in children with optic nerve diseases.

Five-year, multicenter safety study of fixed-combination latanoprost/timolol (Xalacom) for open-angle glaucoma and ocular hypertension.

PURPOSE: To evaluate the safety of fixed-combination latanoprost/timolol (Xalacom) in patients requiring additional intraocular pressure (IOP) reduction over 5 years. METHODS: This phase 3b, open-label, multicenter study included prostaglandin-naive participants with open-angle glaucoma or ocular hypertension insufficiently responsive to ß-blockers and requiring additional IOP reduction. Participants were evaluated at eleven 6-month visits. A masked assessor evaluated iris/eyelash changes at baseline and 12, 36, and 60 months. Increased iris pigmentation incidence was compared with a historic control from a similarly designed study evaluating latanoprost. Ocular and systemic adverse events were recorded. RESULTS: Among 828/974 treated participants with assessable iris photographs, 233 (28.1%) developed increased iris pigmentation versus 127/380 (33.4%) in the historic controls. Participants with mixed eye colors exhibited greater susceptibility to overall increased iris pigmentation (85.8% in both studies). In this study, most participants (80.3%) with increased iris pigmentation developed only a weak increase. Eyelash changes were seen in 58.1% of participants and darkening of the eyelids in 5-6%; 14.1% experienced a serious adverse event. Adverse events resulted in treatment withdrawal in 133 (13.7%) participants. Most were nonserious ocular adverse events, about half of them ocular irritation. Only 3 of 13 serious systemic adverse events were considered to be drug related by the investigator. Mean IOP reductions were stable over 5 years. CONCLUSIONS: After 5 years, more than 70% of participants treated with fixed-combination latanoprost/timolol had no increased iris pigmentation. The fixed combination is safe and well tolerated for long-term treatment in patients with open-angle glaucoma or ocular hypertension.

The optic nerve head assessed with HRT in 5-16-year-old normal children: normal values, repeatability and interocular difference.

PURPOSE: To investigate the normal values, repeatability and interocular difference of the optic nerve head, using Heidelberg retina tomography (HRT), in 5-16-year-old full-term children with normal birth weights. METHODS: Fifty-six children with normal visual acuity and refraction were examined with HRT-II/III. Three examinations were performed on each eye. One eye was randomized for analyses of normal values and repeatability, and 54 eyes could be evaluated. The coefficient of variance and the intraclass correlation (ICC) were calculated, and the ISNT rule was noted. The correlation between right and left eyes and the limits of difference were determined in 50 pair of eyes. RESULTS: The mean values of disc and rim areas were 2.16 (SD 0.47) and 1.75 (SD 0.39) mm(2) respectively. The coefficients of variance varied between optic nerve parameters from 1.8% to 21%, and the ICCs were >0.88. All parameters except retinal nerve fibre layer thickness correlated with the disc area. The ISNT rule was fulfilled in 56% of the eyes. The interocular difference was large but not statistically significant. CONCLUSION: We conclude that HRT can be used in children between 5 and 16 years of age, and normal values presented in the study can be used for comparison of children with optic nerve diseases. Because the assessment of rim area varied the least, it may be the parameter to use for follow-up. The normal large interocular difference should be taken into account when comparing eyes in the individual child.

Uveoscleral outflow--a review.

The uveoscleral outflow route was described more than 40 years ago. Part of aqueous leaves the eye through the iris root. The ciliary muscle, and there are large species differences in the fraction of aqueous outflow that leaves the eye through this route. In non-human primates 40-50% of aqueous leaves the eye by the uveoscleral route. In human eyes most data has been collected by indirect calculations, with results suggesting a similar fraction, at least in eyes from younger individuals. An age-dependent reduction in uveoscleral flow in human eyes may explain the initial difference seen between non-human primate and human eyes. Unlike trabecular outflow, intraocular pressures within the normal range have little effect on uveoscleral outflow. This may be explained by the fact that changes in intraocular pressure have little effect on the pressure gradient for flow through the ciliary muscle, which is likely to be the rate-limiting step in uveoscleral outflow. The state of the ciliary muscle is important and contraction reduces while relaxation increases uveoscleral flow. Similar effects are achieved with cholinergic agonists and antagonists. Epinephrine increases uveoscleral flow, most likely through stimulating beta(2)-adrenergic receptors. Prostaglandin F(2alpha) and prostaglandin F(2alpha)-analogues effectively reduce intraocular pressure by increasing uveoscleral flow. This is mediated by structural changes in the extracellular matrix of the ciliary muscle, and is likely to contribute to a valuable excess route for aqueous and proteins during intraocular inflammation. Whether uveoscleral flow plays a significant role in any other eye disease is not clear. Thus, 40 years later we are able to successfully increase aqueous flow through the uveoscleral route, a valuable contribution to glaucoma treatment, but we still have only a limited understanding on its physiological role.

Repeatability in and interchangeability between the macular and the fast macular thickness map protocols: a study on normal eyes with Stratus optical coherence tomography.

PURPOSE: To collect a normal material and to compare the macular and the fast macular thickness map protocols regarding normal values and repeatability. METHODS: Sixty-seven individuals underwent three repeated scans with the macular thickness protocol; 45 of them also had three scans with the fast thickness protocol in Stratus optical coherence tomography (OCT). The maps were divided into nine ETDRS fields, where thickness values were presented. The repeatability was calculated as intraclass correlation coefficient (ICC), coefficient of variance (CV) and coefficient of repeatability (CR). For comparison between the two protocols, limits of agreement were determined according to Bland-Altman. RESULTS: Normal values for the two protocols were very close. Repeatability was high. ICC for all areas was 0.92-0.98. CV was less than 1% and CR was 6-8 µm for both protocols, with the exception of the fovea in the fast protocol (where CV was 1.44% and CR 12.4 µm). Limits of agreement between the two protocols were less than 10 µm as a rule. CONCLUSION: Normal values for the protocols are equal and they both have excellent repeatability. The fast macular map is a good alternative with the possible exception of the fovea, where variation is twice that of the macular thickness map.

A population-based study of macular thickness in full-term children assessed with Stratus OCT: normative data and repeatability.

PURPOSE: We aimed to determine normal macular thickness values, assessed with optical coherence tomography (OCT), in a population of full-term children of normal birthweight. METHODS: A total of 56 children, aged 5-16 years, randomly chosen from the population register, were examined with Stratus OCT. Only children with visual acuity < 0.2 logMAR, spherical equivalent of - 3 to + 3 D and astigmatism < 2 D were included. The fast macular map protocol was used and three examinations were performed in each eye. One eye was then randomized for further analyses. Mean values for the nine ETDRS areas, foveal minimum thickness and macular volume were calculated for 55 eyes. Coefficients of variance and intraclass correlations were calculated for each area. RESULTS: All children co-operated well and no child was excluded for lack of concentration. Mean ± standard deviation central macular thickness was 204 ± 19 µm. Mean total macular volume was 7.11 ± 0.35 mm(3). No correlations were found between age, gender and macular thickness. Coefficients of variance were < 2% and intraclass correlations were > 0.9 in all areas, except the foveal minimum. CONCLUSIONS: Normal values for macular thickness in healthy full-term children were reported. As the Stratus OCT provides normal values only for adults, these data are a better alternative for comparison with children with retinal abnormalities. We concluded that OCT is suitable for examining the retina in children aged 5-16 years and has the same high level of repeatability as in adults.

Trabeculectomy with an active postoperative regimen: results and resource utilization.

PURPOSE: To evaluate intraocular pressure (IOP) and resource utilization after trabeculectomy, using an active postoperative regimen, in a Swedish population. METHODS: A retrospective analysis was performed on the patient charts of all patients who underwent trabeculectomy in a Swedish university hospital during 1 year (November 2000-December 2001). Trabeculectomy was performed in 34 eyes and trabeculectomy in combination with phacoemulsification in 10 eyes. Intraocular pressure, visual acuity, complications and numbers of injections of 5-fluorouracil, suture removal, needling procedures and visits to ophthalmologists were recorded for 2 years. RESULTS: Mean IOP before surgery was 30.4 mmHg (standard deviation [SD] 9.5) in eyes with capsular glaucoma and 28.7 mmHg (SD 9.3) in eyes with primary open-angle glaucoma. Mean IOP after 2 years was 15.3 mmHg (SD 3.9) in all eyes. Intraocular pressure of < 18 mmHg was achieved in 65% of the eyes after 2 years, as was IOP < or = 13 mmHg in 37%. Flap or suture manipulation was performed in 41 of 44 eyes. Needling procedures were carried out a mean of 2.3 times in 31 eyes. The mean number of visits to an ophthalmologist was 14.1 during the first postoperative year and 4.4 during the second. CONCLUSIONS: The results were encouraging, with few complications and modest resource utilization.

Protein content in aqueous humor from patients with pseudoexfoliation (PEX) investigated by capillary LC MALDI-TOF/TOF MS.

Analysis of proteins in human body fluids is challenging since the composition of the sample often is rather complex. Here we present a method for analysis of proteins in aqueous humor from two groups of cataract patients, with and without pseudoexfoliation (PEX). Aqueous humor is an extracellular fluid contained in the anterior chamber of the eye between the cornea and iris. The limited volume of sample requires sophisticated analysis techniques. Our method is based on a total tryptic digestion of the sample followed by capillary LC-MALDI MS and MS/MS analysis of the peptides. The method is rapid, efficient and suitable as a complement or alternative to more commonly used methods based on gel electrophoretic experiments. With this method we found and unambiguously identified 30 nonredundant proteins. Proteins found include general transport proteins such as albumin and apolipoprotein A1 but also specific proteins involved in immune response, such as complement factors. Cystatin C, clusterin, and crystallins were also found. Although the number of proteins was roughly the same in both groups there was a significant difference in their identities. These findings may give some new insights into the pathophysiology of the PEX syndrome.

Side effects associated with prostaglandin analog therapy.

Topical prostaglandin analogs, which have become first-line therapy in the medical management of glaucoma, have an excellent safety profile with regard to systemic side effects, but are associated with several ocular side effects. Some of these are common, with no apparent serious consequences other than cosmetic, whereas others are much less common but represent potentially sight-threatening side effects. The former group includes conjunctival hyperemia, elongation and darkening of eyelashes, induced iris darkening, and periocular skin pigmentation. The latter group of side effects, which are relatively rare and lack definitive causal relationship to prostaglandin analog therapy, includes iris cysts, cystoid macular edema, anterior uveitis, and reactivation of herpes simplex keratitis. Most of the literature regarding side effects associated with prostaglandin analogs involves the use of latanoprost, probably because it was the first to be studied. There is no evidence, however, aside from less conjunctival hyperemia with latanoprost, that the commercially available prostaglandin analogs differ significantly with regard to side effects.

Pseudoexfoliation as a risk factor for prevalent open-angle glaucoma.

PURPOSE: To estimate the risk of open-angle glaucoma (OAG) associated with exposure to pseudoexfoliation (PEX) and increased intraocular pressure (IOP). METHODS: In 1984-86, a cross-sectional, population-based survey was conducted in the municipality of Tierp, central Sweden. Its target population comprised 2429 residents aged 65-74 years. In addition to a sample of 760 people, patients previously diagnosed with glaucoma were examined. The prevalence of OAG in the target population was estimated from the prevalence in the sample and patients already diagnosed. A review of prevalent cases in 1984-86 was undertaken in 2006. RESULTS: Definite OAG was established in 77 cases, corresponding to a prevalence of 5.3% (95% confidence interval [CI] 4.4-6.2). Of these, 23 represented newly detected cases. The prevalence of PEX was 17.2% (95% CI 14.6-19.9), calculated from 134 cases in the population sample. When adjusting for gender, PEX was associated with a 4.7-fold (95% CI 2.2-9.4) increased risk of OAG. For clinical cases only, the risk was 16-fold (95% CI 4.8-56) greater in subjects with PEX, compared with those without PEX. In individuals without a previous diagnosis of glaucoma, an IOP > or = 20 mmHg was associated with a 9.7-fold (95% CI 3.7-27) increased risk, but PEX alone was not a risk factor for OAG (adjusted odds ratio = 0.96). CONCLUSIONS: Pseudoexfoliation was associated with OAG only in people previously diagnosed with the disease. In cases detected in the population-based survey, increased IOP was a serious risk factor.