Comparison of colour contrast sensitivity in eyes at high risk of neovascular age-related macular degeneration with and without subsequent choroidal neovascular membrane development

BACKGROUND

Neovascular age-related macular degeneration (nAMD) is a leading cause of blind registrations in the elderly. Unfortunately, it is difficult to detect the early stage of the disease, when treatment is more likely to be successful. Subjects with very early disease are likely to have abnormal macular function, even in the pre-symptomatic stage. In this study, colour vision was evaluated to establish if subjects at high risk of developing nAMD can be identified, thus allowing earlier diagnosis and possible treatment.

METHODS

Colour contrast sensitivity (CCS) was evaluated over time in the fellow unaffected eye of subjects with unilateral nAMD. Participants were divided into Group 1 (182 participants) or Group 2 (15 participants) according to whether nAMD did not or did develop in the study period respectively and the two groups were compared.

RESULTS

CCS was increased (i.e. worse colour vision) compared with the age-matched reference range in a high proportion of fellow eyes in both Groups 1 and 2. Global mean CCS values did not show statistically significant differences between the two groups. However, there was a statistically significant difference between mean Group 1 CCS values and the last CCS value prior to nAMD diagnosis from Group 2 subjects.

CONCLUSION

This study shows that in patients with unilateral nAMD, colour vision is frequently abnormal in the fellow unaffected eye. Abnormal CCS does not predict the development of nAMD within the 12 month period of the study and therefore it is not a viable screening tool for this pathology.

Conjunctival Neutrophils Predict Progressive Scarring in Ocular Mucous Membrane Pemphigoid

Purpose

Ocular mucous membrane pemphigoid (OcMMP) is a rare autoimmune disorder resulting in progressive conjunctival fibrosis and ocular surface failure leading to sight loss in up to 50%. This study was designed to optimize an ocular surface sampling technique for identification of novel biomarkers associated with disease activity and/or progressive fibrosis.

Methods

Fifty-seven patients with OcMMP underwent detailed examination of conjunctival inflammation and fibrosis using fornix depth measurement. Ocular surface impression cytology (OSIC) to sample superior bulbar conjunctiva combined with flow cytometry (OSIC-flow) profiled infiltrating leukocytes. Profiles were compared with healthy controls (HC) and disease controls (primary Sjögren's syndrome, pSS). Thirty-five OcMMP patients were followed every 3 months for 12 months.

Results

Overall neutrophils were elevated in OcMMP eyes when compared to pSS or HC (109 [18%] neutrophils/impression [NPI]; 2 [0.2%]; 6 [0.8%], respectively [P < 0.0001]) and in OcMMP patients with no visible inflammation when compared with HC (44.3 [7.9%]; 5.8 [0.8%]; P < 0.05). At 12 months follow-up, 53% of OcMMP eyes progressed, and this was associated with baseline conjunctival neutrophilia (P = 0.004). As a potential biomarker, a value of 44 NPI had sensitivity, specificity, and positive predictive values of 75%, 70%, and 73%, respectively. Notably, eyes with no visible inflammation and raised conjunctival neutrophils were more likely to progress and have a greater degree of conjunctival shrinkage compared to those without raised neutrophils.

Conclusions

These data suggest that OSIC-flow cytometric analyses may facilitate repeated patient sampling. Neutrophils may act as a biomarker for monitoring disease activity, progressive fibrosis, and response to therapy in OcMMP even when the eye appears clinically uninflamed.

The dominant human conjunctival epithelial CD8αβ+ T cell population is maintained with age but the number of CD4+ T cells increases

The conjunctiva is a highly specialized ocular mucosal surface that, like other mucosa, houses a number of leukocyte populations. These leukocytes have been implicated in age-related inflammatory diseases such as dry-eye, but their phenotypic characteristics remain largely undetermined. Existing literature provides rudimentary data from predominantly immunohistochemical analyses of tissue sections, prohibiting detailed and longitudinal examination of these cells in health and disease. Using recovered cells from ocular surface impression cytology and flow cytometry, we examined the frequency of leukocyte subsets in human conjunctival epithelium and how this alters with age. Of the total CD45+ leukocyte population within the conjunctival epithelium, 87% [32-99] (median) [range] comprised lymphocytes, with 69% [47-90] identified as CD3 + CD56- T cells. In contrast to peripheral blood, the dominant conjunctival epithelial population was TCRαβ + CD8αβ + (80% [37-100]) with only 10% [0-56%] CD4+ cells. Whilst a significant increase in the CD4+ population was seen with age (r = 0.5; p < 0.01) the CD8+ population remained unchanged, resulting in an increase in the CD4:CD8 ratio (r = 0.5;p < 0.01). IFNγ expression was detectable in 18% [14-48] of conjunctival CD4+ T cells and this was significantly higher among older individuals (<35 years, 7[4-39] vs. >65 years, 43[20-145]; p < 0.05). The elevation of CD4+ cells highlights a potentially important age-related alteration in the conjunctival intra-epithelial leukocyte population, which may account for the vulnerability of the aging ocular surface to disease.

Survey of expert practice and perceptions of the supporting clinical evidence for the management of uveitis-related cataract and cystoid macular oedema

PURPOSE

To survey the practice of uveitis experts in the management of uveitic cataract and cystoid macular oedema (CMO).

METHODS

A structured questionnaire containing two clinical scenarios was sent to members of the International Uveitis Study Group (IUSG). The questionnaire surveyed both respondents' current practice and their perception of the supporting clinical evidence.

RESULTS

For uveitic cataract, 70% required a 3-month inflammation-free period before surgery, and 76% gave a prophylactic preoperative systemic corticosteroid. For uveitic CMO, 87% gave corticosteroids, usually orally. Preferred second-line agents were methotrexate (39%), cyclosporin (24%), azathioprine (17%), and mycophenolate (7%). Respondents suggested the evidence underlying their decisions was either absent or relatively weak (levels III or IV), and in most cases personal experience was a factor.

CONCLUSIONS

This survey highlights areas of consensus and variation among uveitis experts in managing uveitic cataract and CMO, and emphasizes the need for further clinical trials to establish the best practice.

Safety profile of anterior chamber paracentesis performed at the slit lamp

BACKGROUND

Anterior chamber paracentesis is a valuable diagnostic tool in the management of uveitis, but may be underutilized because of concerns over its safety. We evaluated the safety profile of anterior chamber paracentesis performed at the slit lamp as an outpatient procedure.

DESIGN

Retrospective, observational case series in a single tertiary centre.

PARTICIPANTS

Five hundred and sixty patients with uveitis undergoing anterior chamber paracentesis.

METHODS

All anterior chamber paracenteses performed at the slit lamp for diagnostic or research purposes between January 1997 and June 2009 were analysed with regard to adverse events and pipet/syringe used. Procedures were included whether carried out on undilated or dilated pupils.

MAIN OUTCOME MEASURES

Adverse events and serious adverse events.

RESULTS

Out of 560 paracenteses, 510 were performed with a 27-gauge fixed-needle tuberculin syringe, and 50 using an O'Rourke aqueous pipet. All patients were prescribed a short course of topical antibiotic and examined post-procedure and 1-2 weeks later. Out of 560 procedures there were four complications (0.7%). Two patients had inadvertent injection of sterile air into the anterior chamber but with spontaneous resolution and no adverse outcome (O'Rourke pipet for both). One patient had anterior lens capsule touch that was self-sealing and left a tiny localized opacity (tuberculin syringe). One patient had an allergic reaction to povidone iodine. No patients reported pain, and there were no cases of iris trauma, entry site leak, hypotony, hyphaema or endophthalmitis.

CONCLUSION

Anterior chamber paracentesis can be performed safely as an outpatient procedure at the slit lamp following adequate aseptic precaution, and appropriate counselling.

Is ethnicity a risk factor for severe retinopathy of prematurity?

OBJECTIVE

To assess the risk of severe retinopathy of prematurity (ROP) requiring treatment in different ethnic groups.

DESIGN

Retrospective observational study on ROP screening and treatment. It involved a cross-sectional review of all eligible infants over a seven-year period. Statistical tests used were the Kruskal-Wallis test and Mann-Whitney U test. Logistic regression was used to control for any differences in birth weight and gestational age.

SETTING

City Hospital and Birmingham Women's Hospital, Birmingham, UK.

RESULTS

1690 preterm infants underwent ROP screening. Birth weight was lower in black (1142.5 g) and Asian infants (1180 g) when compared to white infants (1196.5 g). Gestational age was lower in black infants (28.5 weeks) compared to Asian and white infants (both 29 weeks). Compared to white infants, the odds of severe ROP requiring treatment was higher in Asian infants (odds ratio (OR): 2.52; 95% CI 1.41 to 4.50) and black infants (OR: 2.51; 95% CI 1.30 to 4.86). The additional risk from ethnicity was present even after adjusting for birth weight and gestational age (adjusted OR for Asian vs white infants: 2.45; 95% CI 1.334 to 4.497); (adjusted OR for black vs white infants: 2.0; 95% CI 1.004 to 4.014).

CONCLUSIONS

Ethnicity is a risk factor for severe ROP. Asian and black infants have a higher risk of developing threshold ROP compared to white infants.

Distinct types of fibrocyte can differentiate from mononuclear cells in the presence and absence of serum

Background

Fibrocytes are bone-marrow derived cells, expressing both haematopoietic and stromal cell markers, which contribute to tissue repair as well as pathological fibrosis. The differentiation of fibrocytes remains poorly characterised and this has limited understanding of their biology and function. In particular two methods are used to generate fibrocytes in vitro that differ fundamentally by the presence or absence of serum.

Methodology/Principal Findings

We show here that fibrocytes grown in the absence of serum (SF) differentiate more efficiently from peripheral blood mononuclear cells than CD14⁺ monocytes, and respond to serum by losing their spindle-shaped fibrocyte morphology. Although fibrocytes generated in the presence of serum (SC) express the same range of markers, they differentiate more efficiently from CD14⁺ monocytes and do not change their morphology in response to serum. Transcriptional analysis revealed that both types of fibrocyte are distinct from each other, fibroblasts and additional monocyte-derived progeny. The gene pathways that differ significantly between SF and SC fibrocytes include those involved in cell migration, immune responses and response to wounding.

Conclusions/Significance

These data show that SF and SC fibrocytes are distinct but related cell types, and suggest that they will play different roles during tissue repair and fibrosis where changes in serum proteins may occur.

Does cardiovascular therapy affect the onset and recurrence of preretinal and vitreous haemorrhage in diabetic eye disease?

AIMS

To review the role of cardiovascular disease and therapy in the onset and recurrence of preretinal/vitreous haemorrhage in diabetic patients.

METHODS

Retrospective case note analysis of diabetic patients with vitreous haemorrhage from the Diabetic Eye Clinic at Birmingham Heartlands Hospital.

RESULTS

In total, 54 patients (mean age 57.1, 37 males, 20 type I vs 34 type II diabetic patients) were included. The mean (SD) duration of diagnosed diabetes at first vitreous haemorrhage was significantly longer, 21.9 (7.6) years for type I and 14.8 (9.3) years for type II diabetic patients (P < 0.01, unpaired t-test, two-tailed).Aspirin administration was not associated with a significantly later onset of vitreous haemorrhage. Four episodes were associated with ACE-inhibitor cough. There was a trend towards HMGCoA reductase inhibitor (statin) use being associated with a delayed onset of vitreous haemorrhage: 21.4 years until vitreous haemorrhage (treatment group) vs 16.2 years (nontreatment group) (P = 0.09, two-tailed, unpaired t-test, not statistically significant). During follow-up 56 recurrences occurred, making a total of 110 episodes of vitreous haemorrhage in 79 eyes of 54 patients. The mean (range) follow-up post haemorrhage was 1067 (77-3842) days, with an average of 1.02 recurrences. Age, gender, diabetes type (I or II) or control, presence of hypertension or hypercholesterolaemia, and macrovascular complications were not associated with a significant effect on the 1-year recurrence rate. Aspirin (and other antiplatelet or anticoagulant agents) and ACE- inhibitors appeared to neither increase nor decrease the 1-year recurrence rate. However, statin use was significantly associated with a reduction in recurrence (Fisher exact P < 0.05; two-tailed) with an odds ratio (95% CI) of 0.25 (0.1-0.95).

CONCLUSION

In this retrospective analysis, the onset of preretinal/vitreous haemorrhage was not found to be accelerated by gender, hypertension, hypercholesterolaemia, evidence of macrovascular disease, or HbA1c. Neither aspirin nor ACE-inhibitor administration accelerated the onset or recurrence of first vitreous haemorrhage. Statins may have a protective role, both delaying and reducing the recurrence of haemorrhage.

Ophthalmic features of Turner's syndrome

Turner's syndrome is one of the most common of all chromosomal abnormalities and is associated with significant ophthalmic morbidity. Turner's 1938 account included two patients with strabismus, and hitherto the condition has generated more interest among orthoptists than ophthalmologists. This systematic review of the literature seeks to redress the balance. Based on the pooled data of 274 patients with Turner's syndrome, it is the most complete evaluation so far of the prevalence and severity of ophthalmic problems in this population. This includes both a systematic review of the ophthalmic literature (via Medline) and the much larger body of work available in the orthoptic literature. Finally, we consider recent progress that enables the ophthalmologist to progress from the simple recognition of a phenotype to the correlation of genotypic variations with embryogenesis and consequent features of that phenotype.

The use of oxygen in acute exacerbations of chronic obstructive pulmonary disease: a prospective audit of pre-hospital and hospital emergency management

Treatment with high-flow oxygen in acute exacerbations of chronic obstructive pulmonary disease (AECOPD) can cause or aggravate acute hypercapnic respiratory failure and adversely affect prognosis. National guidelines for the management of COPD recommend an initial fractional inspired oxygen concentration (FiO2) of no more than 0.28. However, a prospective audit of 101 consecutive episodes of AECOPD demonstrated that oxygen therapy with an FiO2 in excess of 0.28 is common, potentially deleterious and predominantly initiated in the ambulance. Patient awareness, aids to disease identification and ambulance protocols are likely to hold the key to improvement in the acute care of these patients.