Robert W Acheson

Immunogenetics and clinical phenotype of sympathetic ophthalmia in British and Irish patients

BACKGROUND/AIMS Sympathetic ophthalmia (SO) is a classic example of autoimmune disease where human leucocyte antigen (HLA) genomic associations could provide further understanding of mechanisms of disease. This study sought to assess HLA genetic polymorphism in British and Irish patients with SO, and to assess whether HLA gene variants are associated with clinical phenotype or disease severity. METHODS High resolution DNA based HLA typing using polymerase chain reaction sequence specific primers was performed in 27 patients with SO and 51 matched healthy controls. Clinical phenotype and markers of disease severity were determined prospectively in 17 newly diagnosed patients and from medical record review and repeat clinical examination in 10 previously diagnosed patients. RESULTS HLA-Cw*03 (p=0.008), DRB1*04 (p=0.017), and DQA1*03 (p=0.014) were significantly associated with SO. For class II alleles at higher resolution, only HLA-DRB1*0404 (relative risk (RR) = 5.6, p = 0.045) was significantly associated with SO. The highest relative risk for any of the associated haplotypes was with HLA-DRB1*0404-DQA1*0301 (RR=10.9, p=0.019). Patients with the DRB1*04-DQA1*03 associated haplotype were significantly more likely to develop SO earlier, with fewer inciting ocular trauma events, and to require more systemic steroid therapy to control inflammatory activity. CONCLUSIONS Sympathetic ophthalmia is associated with HLA-DRB1*04 and DQA1*03 genotypes in white patients, similar to Japanese patients. Differences in DRB1*04 gene variant associations (−0404 in Britain and Ireland and −0405 in Japan) may have implications for HLA peptide binding in disease initiation. The DRB1*04–DQA1*03 haplotype is a marker of increased SO susceptibility and severity, as in Vogt-Koyanagi-Harada disease, which also has similar clinicopathological and HLA associations.

Sickle cell retinopathy in Jamaican children: further observations from a cohort study.

Serial retinal examinations were performed in children aged 5 years and older and fluorescein angiography/angioscopy in children 6 years and older participating in a cohort study of sickle cell disease. There were 1229 patient years of observation among 389 children aged 5-13 years. Peripheral retinal vessel closure was present in approximately 50% of children with SS and SC genotypes at age 6 years and increased to affect 90% of children by age 12 years. A matched pair analysis, comparing groups with minimal and complete closure, indicated that complete closure was associated with significantly lower total haemoglobin and fetal haemoglobin levels and significantly lower weight in SS disease, whereas in SC disease the risk factors appeared to be high mean cell volume and low platelet count. Proliferative retinopathy was rare, occurring only once in an 8-year-old boy with SC disease, despite 592 patient years of observation in children over this age.

Prevalence of diabetic retinopathy in patients with diabetes mellitus diagnosed after the age of 70 years

AIMS/BACKGROUND A hospital based prevalence study was undertaken to estimate the prevalence of diabetic retinopathy (DR) in patients diagnosed as having diabetes mellitus after the age of 70 years. The prevalence of visually threatening retinopathy at the time of diagnosis of diabetes was also determined. The association between prevalence of DR and duration of diabetes mellitus, mode of treatment, HbA1c levels, presence of hypertension, and sex of patient was examined and a comparison was drawn between this study and earlier prevalence studies of DR in older type II diabetics. METHODS Using data on the Irish Diabetic Retinopathy Register located in the Mater Misericordiae Hospital, Dublin, all patients who were diagnosed as having type II diabetes mellitus after the age of 70 years were invited to attend for ophthalmic review. Medical records were examined to determine the duration of diabetes mellitus, mode of treatment, recent HbA1c levels, and the presence of systemic hypertension. RESULTS Of the 150 patients examined, 21 (14%) had some form of DR and 10 of these patients (6.6%) had visually threatening retinopathy or previously treated visually threatening retinopathy. Five patients (3.3%) presented with visually threatening retinopathy at the time of diagnosis of diabetes. Those patients with DR had a significantly higher median duration of diabetes (5.0 years) compared with those patients without DR (3.5 years). A significantly higher proportion of patients with DR required treatment with insulin and a correspondingly lower proportion of patients without DR were controlled on diet alone. There was no significant association between prevalence of DR and HbA1c levels, systemic hypertension, or sex of patient. There was a lower overall prevalence of DR in comparison with earlier studies. CONCLUSIONS The prevalence of DR in these elderly type II diabetics is lower than that previously reported in patients with type II disease but a small percentage of patients had visually threatening retinopathy at presentation. Longer duration of diabetes and insulin use were associated with a significantly increased prevalence of DR. All elderly type II diabetic patients require thorough ophthalmic examination near to the time of first presentation and thereafter at regular intervals.

Diabetic retinopathy in Down's syndrome

AIM To determine the prevalence of diabetic retinopathy in patients with Down’s syndrome and diabetes mellitus. METHOD Nine patients with Down’s syndrome and diabetes mellitus were assessed. Factors recorded included type and duration of diabetes, level of diabetic control, blood pressure, urinalysis, and results of ophthalmological examination. RESULTS The duration of diabetes ranged from 8 to 41 years (mean 17.6 years). All had satisfactory glycaemic control and blood pressure measurements on the low side of normal (mean 106.6/70 mm Hg). One patient had early background diabetic retinopathy. The remainder had no evidence of diabetic retinopathy. CONCLUSION The low prevalence of diabetic retinopathy in these Down’s syndrome patients, despite the long duration, is an interesting finding. It suggests some inherent protective factor against the development of diabetic retinopathy in this patient subgroup.

Maintenance of perioperative antiplatelet and anticoagulant therapy for vitreoretinal surgery

The objective of this study was to prospectively assess the risk of bleeding from vitreoretinal surgery in a continuous unbiased cohort of patients taking unsuspended antiplatelet or anticoagulant therapy.Background The objective of this study was to prospectively assess the risk of bleeding from vitreoretinal surgery in a continuous unbiased cohort of patients taking unsuspended antiplatelet or anticoagulant therapy. Design Prospective hospital-based study. Participants Eighty-five patients taking unsuspended aspirin, clopidogrel and/or warfarin therapy undergoing all forms of vitreoretinal surgery at The Mater Misericordiae University and The Mater Private Hospital, Dublin, Ireland. Methods Consecutive patients undergoing vitreoretinal surgery taking unsuspended antiplatelet or anticoagulant therapy over a 1-year period were included in this prospective study to evaluate the intraoperative and postoperative bleeding complications. Main Outcome Measures The intraoperative and postoperative bleeding rates. Results One hundred and seven vitreoretinal procedures were performed on 85 patients taking unsuspended antiplatelet or anticoagulant therapy. The intraoperative bleeding rate was 23%, the majority of which consisted of mild bleeding into the vitreous cavity during vitrectomy. The postoperative bleeding rate was 22%, consisting of 3.7% anterior chamber haemorrhage, 11% dispersed vitreous cavity haemorrhage, 4.7% dense vitreous cavity haemorrhage, 0.9% subretinal haemorrhage and 1.9% localized choroidal haemorrhage. The single greatest significant independent predictor of intraoperative bleeding was proliferative diabetic retinopathy and of postoperative bleeding was the presence of diabetes mellitus. Conclusions There were no cases of uncontrolled intraoperative haemorrhage or serious postoperative choroidal haemorrhage. Mild haemorrhagic oozing during vitrectomy and dispersed vitreous cavity haemorrhage postoperatively were common. For the majority of patients taking antiplatelet or anticoagulant medication, these agents can be safely continued in the vitreoretinal surgical perioperative period.

Iris atrophy in sickle cell disease.

Iris atrophy, of unknown origin and believed to be secondary to the vaso-occlusive process of sickle cell disease, has been observed in 25 eyes of 22 patients (two SS disease, 20 SC disease). The crude prevalence was highest in males with SC disease, in whom 14.7% of patients were affected. Iris atrophy was closely associated with proliferative sickle retinopathy in the same eye. Analysis of haematological indices failed to reveal any significant differences between patients with and without iris atrophy. The characteristics and distribution of iris atrophy are described as well as the histopathology in one 68-year-old male patient with SS disease.

Epiretinal membranes in sickle cell disease.

Epiretinal membranes at the macula were seen in 4% of the eyes of 355 patients with homozygous sickle cell (SS) disease and sickle cell haemoglobin-C (SC) disease under the age of 60 years. The presence of proliferative sickle retinopathy (PSR), the extent of involvement of PSR, and vitreous haemorrhage all constitute risk factors for the formation of epiretinal membranes. The occlusion of PSR lesions by treatment appears to reduce the risk of epiretinal membranes being formed.

Preseptal cellulitis caused by community acquired methicillin resistant Staphylococcus aureus (CAMRSA).

Infections with methicillin resistant Staphylococcus aureus (MRSA) usually occur in individuals with well established risk factors such as a recent hospital admission, multiple antibiotic treatment, or chronic illness. We report on repeated ocular presentations of preseptal community acquired MRSA cellulitis in a previously healthy 20 year old male student. A 20 year old student presented to the eye department with a five day history of left periorbital swelling associated with a crusted lesion on the temporal border of his left eyebrow and preseptal cellulitis. Past medical history was remarkable for the appearance of similar skin lesions six weeks previously on the right calf, and mild eczema. Similar lesions were found on the patient’s neck, back, and right calf. The latter lesion was discharging and swabbed for culture and sensitivities (fig 1). Initial treatment with oral flucloxacillin failed to resolve the cellulitis and he was admitted 36 hours later. Examination revealed a tense swelling of his left upper lid, with periorbital erythema and oedema (fig …

Management of ganciclovir-resistant cytomegalovirus retinitis in HIV infection in the era of antiretroviral therapy.

The incidence of cytomegalovirus retinitis has decreased significantly since the advent of antiretroviral therapy. However, it remains an important problem in both the developed and developing worlds. Furthermore, long-term antiviral suppression is associated with a significant increase in viral resistance. We present the case of a 46-year-old man who developed cytomegalovirus retinitis one year after being diagnosed with HIV. While he initially demonstrated an excellent clinical response to ganciclovir, his cytomegalovirus viral load remained persistently elevated. Over the subsequent years, his virus developed ganciclovir resistance with a concomitant deterioration in his visual acuity. He responded poorly to salvage therapy with foscarnet and cidofovir. This case highlights the ongoing difficulty of managing cytomegalovirus disease nearly two decades into the era of antiretroviral therapy and underlines the need to develop new treatment strategies.