Ocular Pathology (ocular + pathology)

Distribution by Scientific Domains

Selected Abstracts

Recent developments in retinopathy of prematurity

The retinopathy remains the principal severe ophthalmologic complication of neonates with a gestationalage of 32 weeks or less. It's a major cause of lifelong blindness beginning in infancy. As many other ocular pathologies, including diabetic retinopathy, and age-related macular degeneration, result in vision loss because of aberrant neoangiogenesis. A common feature of these conditions is the presenceof hypoxic areas and overexpression of the proangiogenic vascular endothelialgrowth factor (VEGF). Its prevantion can be made by a better management of the oxygenation of these children but also by a better knowledge of the other risk factors. The prevailing current treatment, laser ablation of the retina, is destructive and only partially effective. Preventive and less destructive therapies are much more desirable. So, Angiogenesis, or the formation of new retinal blood vessels is a key feature of many proliferative retinal diseases including diabetic retinopathy,retinal vein occlusions, and retinopathy of prematurity. [source]

Ocular blood flow autoregulation and the clinical implications of its alteration

Autoregulation is commonly defined as the ability of a vascular bed to adapt blood flow to changes in ocular perfusion pressure (pressure autoregulation) or to adapt to changes in metabolic need (metabolic autoregulation). Considering the high metabolic turnover of the eye, its intact function is strongly dependent on a stable blood supply, assured by an intact vascular autoregulation. However, it has been shown that in the recent years that several ocular diseases such as glaucoma, diabetic retinopathy or age related macula degeneration are associated with an impaired autoregulation. This vascular dysregulation may lead to an under- or overperfusion of the tissue and in turn to ischemia and/or oxidative stress. This talk seeks to summarize our current knowledge of autoregulation in the ocular vascular beds. Furthermore, the possible reasons of impaired autoregulation and how this may relate to ocular pathologies will be discussed. [source]

Translational Mini-Review Series on Complement Factor H: Genetics and disease associations of human complement factor H

S. Rodríguez De Córdoba
Summary Factor H is an abundant plasma glycoprotein that plays a critical role in the regulation of the complement system in plasma and in the protection of host cells and tissues from damage by complement activation. Several recent studies have described the association of genetic variations of the complement factor H gene (CFH) with atypical haemolytic uraemic syndrome (aHUS), age-related macular degeneration (AMD) and membranoproliferative glomerulonephritis (MPGN). This review summarizes our current knowledge of CFH genetics and examines the CFH genotype,phenotype correlations that are helping to understand the molecular basis underlying these renal and ocular pathologies. [source]

Interferon-induced retinopathy and its risk in patients with diabetes and hypertension undergoing treatment for chronic hepatitis C virus infection

Summary Background, Ocular complications are amongst many side-effects of interferon based therapy for hepatitis C virus (HCV) infection. Some suggest that diabetic and hypertensive patients are at increased risk of these complications. Aim, To determine the frequency of ophthalmological complications related to interferon use. Methods, Retrospective analysis of patients undergoing HCV treatment with pegylated interferon ,-2a, ,-2b or consensus interferon plus ribavirin between 2005 and 2007. All patients underwent a baseline eye examination and any visual complaints during treatment prompted a repeat examination. Data recorded included HCV genotype, treatment duration, interferon type, pre-treatment and on treatment visual complaints, known ocular pathology, and retinal findings at baseline and at follow-up. Results, Of 183 patients, 29 (16%) had diabetes and 85 (46%) had hypertension. Seventy-one (38%) received interferon ,-2a, 100 (55%) ,-2b, and 12 (7%) consensus interferon. Seven (3.8%) had retinal changes on follow-up and treatment was discontinued in 3 (1.6%). Of seven with ocular changes two had hypertension and one had both hypertension and diabetes. Conclusion, The incidence of symptomatic retinopathy in HCV patients undergoing interferon therapy appears low and treatment cessation is rarely needed. Furthermore, patients with hypertension and diabetes may not be at higher risk for interferon-induced retinopathy. [source]

Validation of grading scales for contact lens complications

Nathan Efron
Summary The validity of use of two artist-rendered and two photographic sets of grading scales (grading ,systems') designed for gauging the severity of contact lens-related ocular pathology was assessed in terms of precision and reliability. Thirteen observers each graded 30 images , by interpolation or extrapolation to the nearest 0.1 increment , of each of the three contact lens complications (corneal staining, conjunctival redness and papillary conjunctivitis) that were common to all four grading systems. This entire procedure was repeated approximately two weeks later, yielding a total data base comprising of 9360 individual grading estimates. Analysis of variance revealed statistically significant differences in both precision and reliability between systems, observers and conditions (p<0.03 for system reliability; p=0.0001 for all other combinations). The artist-rendered systems generally afforded lower grading estimates and better grading reliability than the photographic systems. Corneal staining could be graded less reliably than conjunctival redness and papillary conjunctivitis. Grading reliability was generally unaffected by the severity of the condition being assessed. Notwithstanding the above differences, all four grading systems are validated for clinical use and practitioners can initially expect to use these systems with average 95% confidence limits of ±1.2 grading scale units (observer range ±0.7 to ±2.5 grading scale units). In view of the significant between-system differences revealed in this study, it is advisable to consistently use the same grading system. It may be possible to reduce between-observer differences by applying personalised correction factors to normalise grading estimates. [source]

2354: The range of waveform score of Ocular Response AnalyzerTM (ORA) in healthy subjects: interim analysis

Purpose To assess the range of waveform score in IOP measurements with ocular response analyzer (ORA, Reichert) in healthy subjects. Methods Prospective study including both eyes of healthy subjects with no ocular pathology or previous refractive surgery. The IOP measurements with ORA from both eyes were performed. The inclusion criteria of the measurements were solely based on good waveforms by an experienced clinician. The waveform score of three measurements were included for statistical analysis. Other parameters including age, central corneal thickness (CCT) and axis length were also analysed to evaluate possible correlations. Spearman correlation coefficient was used to assess the correlation. Results To date, both eyes of 42 healthy subjects are included (Mean age: 46.6 ± 14.3 yrs, Axial length: 23.7 ± 1.1, CCT: 554 ± 34 µm). The mean waveform scores from the first IOP measurement were 4.2±2.3 and for the 2de and 3th respectively 4.2±1.9 and 4.2±2.1 (not significantly different). The mean waveform score of 252 signals (both eyes and 3 measurements) was 4.2±2.1 and ranged from 0.3 to 9.6. Considering the best signal value per patient, the mean of all best signal values was 5.5±2.0 and it ranged from 1.9 to 9.5. The lowest 10% of all the best signal value was<3. Conclusion The waveform score is a new parameter indicating the reliability of each measurement signal. The best signal value indicates the best measurements of each session (Not the mean of the measurements). To date, our results show that the lower 10% percentile is <3. This could suggest that all the measurements with waveform score lower than 3 should be discarded. [source]

Daytime levels of melatonin in patients with age-related macular degeneration

Katharina E. Schmid-Kubista
Abstract. Purpose:, Melatonin (N-acetyl-5-methoxytryptamine) (MT) is a hormone that acts as an antioxidant. It is produced by the pineal gland and within the retina; its release is blocked by light entering the eye. We examined whether MT daytime levels differ between pseudophakic patients with age-related macular degeneration (ARMD) and pseudophakic subjects without any ocular pathology of the same age. Methods:, A prospective, cross-sectional, observational study was performed. Pseudophakic patients of the same age group were included. Patients underwent complete ophthalmic examinations and blood sampling between 08:00 and 10:00 hr. MT daytime value in the serum was the main outcome measure. Results:, Sixty-nine pseudophakic patients were included. Fifty patients with exudative and non-exudative ARMD were in the study group while 19 patients were controls. Patients with ARMD had significantly higher daytime levels of MT (P = 0.003). There were significant differences in MT daytime levels between the exudative and non-exudative forms (P = 0.009). MT values also correlated with the best-corrected visual acuity (r = ,0.285, P = 0.019). Conclusion:, These data indicate that pseudophakic patients with ARMD produce more MT during the day compared to pseudophakic subjects without ARMD. This may be caused by the reduced visual acuity in patients with ARMD, whereby less light reaches the photoreceptors, allowing MT secretion to continue during the day. Because MT also acts as an antioxidant and daytime levels are higher in patients with ARMD, these results might be interpreted as a rescue factor. [source]

Results from the International Cataract Surgery Outcomes Study

ACTA OPHTHALMOLOGICA, Issue thesis2 2007
Jens Christian Norregaard MD
Abstract It is widely accepted that cataract extraction with intraocular lens implantation is a highly effective and successful procedure. However, quality assessments and studies of effectiveness should still be undertaken. As with any surgical treatment modality, complications may occur, leading to suboptimal outcomes, additional health costs and deterioration in patients' functional capacity. International variation in clinical practice patterns and outcomes can serve as important pointers in the attempt to identify areas amenable to improvements in quality and cost-effectiveness. Once demonstrated, similar clinical results obtained in different health care systems can improve the level of confidence in a clinical standard against which the quality of care can be evaluated. The International Cataract Surgery Outcomes Study was established in 1992. The objective of this international comparative research project was to compare cataract management, outcomes of surgery and quality of care in four international sites. The study was conducted in the 1990s, since when many developments and refinements have emerged within cataract surgery. The actual figures reported in this thesis may no longer be of specific relevance as a decade has passed since their collection. However, the research questions and methods used in the study are still highly important and justify the publication of this report. The report deals with problems related to quality assessment, benchmarking, and the establishment and design of nationwide clinical databases , issues that are currently the focus of much attention. Moreover, the problems related to cross-national comparisons are increasingly relevant as more international databases are established. The study makes suggestions on how to report and compare objective as well as subjective criteria for surgery. The issue of how to report subjective criteria is a particular subject of current discussion. Four sites with high-quality health care systems were examined in this study: the USA, Denmark, the Province of Manitoba (Canada), and Barcelona (Spain). The design of the international research programme was based on methods developed by the US National Cataract Surgery Outcomes Study conducted by the US Cataract Patients Outcomes Research Team. The International Cataract Surgery Outcomes Study comprised three separate studies: a survey of ophthalmologists; a prospective cohort study, and a retrospective register-based cohort study. The survey study was based on data generated by a self-administered questionnaire completed by ophthalmologists in the four study areas. The questionnaire examined routine clinical practice involving patients considered for cataract surgery, and included questions on anaesthesia, monitoring and surgical techniques. The prospective cohort study was a large-scale, longitudinal observational study of patients undergoing first-eye cataract surgery in each study site. Patients were sampled consecutively from multiple clinics and followed for 4 months postoperatively. The retrospective cohort study was based on the Danish National Patient Register and claims data from the USA. This study could not be carried out in Barcelona or Manitoba as no suitable administrative databases were available. The papers based on register databases deal with retinal detachment and endophthalmitis but are not included in this thesis as the material was previously reported in my PhD thesis. The application of the studies was highly co-ordinated among the four sites and similar methods and instruments were used for data collection. The development of the data collection strategy, questionnaires, clinical data forms and data analyses were co-ordinated through weekly telephone conferences, annual in-person conferences, correspondence by mail or fax, and the exchange of sas programs and data files via the Internet. The survey study was based on responses from 1121 ophthalmologists in the four sites and results were presented in two papers. Within the previous year the participating ophthalmologists had performed a total of 212 428 cataract surgeries. With regard to preoperative ophthalmic testing, the present study reveals that refraction, fundus examination and A-scanning were performed routinely by most surgeons in all four sites. Other tests were reported to be performed routinely by some surgeons. It is unclear why any surgeon would use these other tests routinely in cataract patients with no ocular comorbidity. It appears that if this recommendation from the US Clinical Practice Guidelines Panel was broadly accepted, the use of these procedures and costs of care could be reduced, especially in Barcelona, the USA and Canada. Restricted use of medical screening tests was reported in Denmark. If this restricted screening were to be implemented in the USA, Canada and Barcelona, it would have significant resource implications. The most striking finding concerned the difference in monitoring practice between Denmark and each of the other three sites. In Denmark, monitoring equipment is seldom used and only occasionally is an anaesthesiologist present during cataract surgery. By contrast, in the other study sites, the presence of an anaesthesiologist using monitoring equipment is the norm. Adopting the Danish model in other sites would potentially yield significant cost savings. The results represent part of the background data used to inform the decision to conduct the two large-scale, multicentre Studies of Medical Testing for Cataract Surgery. The current study is an example of how surveys of clinical practice can pinpoint topics that need to be examined in randomized clinical trials. For the second study, 1422 patients were followed from prior to surgery until 4 months postoperatively. Preoperatively, a medical history was obtained and an ophthalmic examination of each patient performed. After consent had been obtained, patients were contacted for an in-depth telephone interview. The interview was repeated 4 months postoperatively. The interview included the VF-14, an index of functional impairment in patients with cataract. Perioperative data were available for 1344 patients (95%). The 4-month postoperative interview and clinical examination were completed by 1284 patients (91%). Main reasons for not re-evaluating patients were: surgery was cancelled (3%); refusal to participate (2%); lost to follow-up (1%), and death or being too sick (1%). The results have been presented in several papers, of which four are included in this thesis. One paper compared the preoperative clinical status of patients across the four sites and showed differences in both visual acuity (VA) and VF-14 measures. The VF-14 is a questionnaire scoring disability related to vision. The findings suggest that indications for surgery in comparable patients were similar in the USA and Denmark and were more liberal than in Manitoba and Barcelona. The results highlight the need to control for patient case mix when making comparisons among providers in a clinical database. This information is important when planning national databases that aim to compare quality of care. A feasible method may be to use one of the recently developed systems for case severity grading before cataract surgery. In another paper, perioperative clinical practice and rates of early complications following cataract surgery were compared across the four health care systems. Once again, the importance of controlling for case mix was demonstrated. Significant differences in clinical practice patterns were revealed, suggesting a general trend towards slower diffusion of new medical technology in Europe compared with North America. There were significant differences across sites in rates of intra- and early postoperative events. The most important differences were seen for rates of capsular rupture, hyphaema, corneal oedema and elevated pressure. Rates of these adverse events might potentially be minimized if factors responsible for the observed differences could be identified. Our results point towards the need for further research in this area. In a third paper, 4-month VA outcomes were compared across the four sites. When mean postoperative VA or crude proportions of patients with a visual outcome of <,0.67 were compared across sites, a much poorer outcome was seen in Barcelona. However, higher age, poorer general health status, lower preoperative VA and presence of ocular comorbidity were found to be significant risk factors associated with increased likelihood of poorer postoperative VA. The proportions of patients with these risk factors varied across sites. After controlling for the different distributions of these factors, no significant difference remained across the four sites regarding risk of a poor visual outcome. Once again the importance of controlling for case mix was demonstrated. In the fourth paper, we examined the postoperative VF-14 score as a measure of visual outcomes for cataract surgery in health care settings in four countries. Controlling for case mix was also necessary for this variable. After controlling for patient case mix, the odds for achieving an optimal visual function outcome were similar across the four sites. Age, gender and coexisting ocular pathology were important predictors of visual functional outcome. Despite what seemed to be an optimal surgical outcome, a third of patients still experienced visual disabilities in everyday life. A measure of the VF-14 might help to elucidate this issue, especially in any study evaluating the benefits of cataract surgery in a public health care context. [source]

Carotid artery ectasia coexistent with primary open angle glaucoma

Mark F Ellis FRACO
ABSTRACT A 60-year-old smoker presented with high intraocular pressure in the right eye with a right afferent pupil defect and visual field suggestive of primary open angle glaucoma in the right eye only, when an examination 2 years earlier had revealed no hint of ocular pathology. Radiological investigations demonstrated prominent ectasia of the internal carotid arteries extending into the proximal middle cerebral arteries. The changes in the carotids extended throughout the cavernous sinus regions, encroached on the under surface of the optic chiasm and were closely related to the internal aspects of both optic canals. In primary open angle glaucoma management, neural imaging is not normally recommended; however, neural imaging investigations should be considered if the presentation is not typical of a chronic bilateral optic neuropathy. [source]