Orbital cellulitis in Scotland: current incidence, aetiology, management and outcomes.

PURPOSE: Orbital cellulitis is a potentially blinding and life-threatening condition. There are little published data on the incidence of orbital cellulitis and little is known about the differences between children and adults affected. The purpose of this study was to identify the incidence, aetiology, management and outcome of orbital cellulitis in children and adults in Scotland. METHODS: This study was a 1-year prospective observational study using the Scottish Ophthalmic Surveillance Unit reporting system among Scottish ophthalmologists. RESULTS: The response rate from ophthalmologists was 66.4%. There were 15 children and 5 adults reported giving an incidence of 1.6 per 100 000 and 0.1 per 100 000 in children and adults, respectively. 47% of children had a preceding upper respiratory tract infection with 87% having radiological evidence of sinus disease. Within the adult group, there was preceding immunosuppression and trauma. Streptococcus (66%) and Haemophilus (46%) species were the most commonly isolated pathogens in children. Respiratory pathogens were less predictable in adults. All patients were treated with intravenous antibiotics. All children with orbital and subperiosteal abscesses had surgery; one adult with orbital abscess did not have surgery. There were two cases of series morbidity: one intracranial spread of infection and one evisceration. DISCUSSION: The incidence of orbital cellulitis is higher in children than in adults. In children, it commonly follows upper respiratory infection and sinus disease; however, in adults, preceding illness and trauma are more common. Respiratory pathogens are common in affected children. Intravenous antibiotics and surgical treatment of abscesses remain the preferred management.

Orbital lymphoma presenting as an unstable ocular prosthesis: a salutary lesson.

We report the unusual presentation of an extranodal marginal zone B-cell lymphoma presenting as instability of an ocular prosthesis. More commonly, the stability of an ocular prosthesis can be affected by orbital implant migration, sunken superior sulcus, eyelid malformations, shallow inferior fornix, and contracted sockets (Charlton & Weinstein, 1995). Although rare, this case highlights the importance of meticulous examination of the socket, including careful palpation for any potential masses. To our knowledge, instability of an ocular prosthesis in association with orbital lymphoma has not been described previously.

Can we predict which patients are at risk of having an ungradeable digital image for screening for diabetic retinopathy?

PURPOSE: We aimed to determine the reasons for, and variables which predicted, ungradeable retinal photographs during screening patients for diabetic retinopathy. MATERIALS AND METHODS: Age, duration of diabetes, visual acuity, and HbA1c were recorded. Following dark adaptation, a single 45 degrees nonmydriatic photograph was taken of each fundus. The pupils were then dilated and the photograph repeated. Using slit lamp biomicroscopy, lenticular changes (LOCS III), and fundus appearance were recorded. RESULTS: In ungradeable photographs the fovea could not be visualised in 98% of cases of images from nonmydriatic photography, and in 88% if mydriasis was used. Poor definition in the nonmydriatic image was associated with a subsequent ungradeable mydriatic photograph (P=0.001), however, the positive predictive value was poor (34%). Age, posterior subcapsular cataract, and near vision predicted ungradeable status of nonmydriatic photographs (P<0.001, P=0.004, P=0.006, respectively; regression analysis). Nuclear colour and poor definition of the nonmydriatic photograph predicted ungradeable status of mydriatic photographs (P=0.006 & P=0.001, respectively). CONCLUSION: Inability to visualise the fovea is the commonest cause of an ungradeable image from digital retinal photography. Age and posterior subcapsular cataract were best predictors of ungradeable status of nonmydriatic fundus photographs. Nuclear colour was the strongest predictor for ungradeable mydriatic photography.

Patients' attitudes towards mydriasis for diabetic eye disease screening.

AIMS: The purpose of the questionnaire was to explore attitudes of patients towards mydriasis for diabetic retinopathy screening. METHODS: Two groups of patients were invited to take part: group 1 comprised patients attending the diabetic clinic and had previous experience of mydriasis, group 2 patients attending the mobile screening unit for non-mydriatic digital retinal photograph and who were not previously used to receiving mydriatic eye drops. Basic demographic data was recorded and the volunteers invited to complete a questionnaire. RESULTS: 292 patients were recruited into group 1 (median age 63 years range 20-94) and 103 into group 2 (median age 68 years range 29-96). 42% of patients in group 2 indicated that they were unhappy with the use of dilating eye drops and 26% of this group reported that they may be discouraged from attending screening for diabetic retinopathy if drops were introduced. These figures were statistically lower in group 1 at 8% and 1-8% respectively (p < 0.001). Blurring of vision was identified as the most troublesome feature of the use of mydriasis for patients. A large proportion of patients drove themselves to their last screening appointment; 58% in group 2 and 39% in group 1. A third of all patients (33%) indicated that they worked outside the home. CONCLUSIONS: Many patients attending diabetic eye screening return to driving and work immediately after the appointment. Introduction of the use of routine drops may discourage attendance. Education and experience may have an important role in improving acceptability of mydriatic eye drops. Retinal screeners need to have clear guidelines with which to advise patients.

Effect of mydriasis and different field strategies on digital image screening of diabetic eye disease.

AIMS: To assess the effects of (1) mydriasis and (2) single versus three field photography on screening for diabetic eye disease using digital photography METHOD: Slit lamp examination findings were compared to digital fundal photographs for the detection of any retinopathy and for referable retinopathy in 398 patients (794 eyes). A Topcon TRC-NW6S digital non-mydriatic fundus camera was used. Three photographic strategies were used: undilated single field, dilated single field, and dilated multiple fields. The photographs were presented in random order to one of two retinal screeners. For the single field photographs the screeners were masked to the use of mydriatics. In 13% of fundal photographs, grading was performed by both, rather than just one grader. RESULTS: Mydriasis reduced the proportion of ungradable photographs from 26% to 5% (p<0.001). Neither mydriasis nor three field photography improved the sensitivity or specificity for the detection of any retinopathy or of referable retinopathy when compared with undilated single field photography. The sensitivity and specificity for detecting referable retinopathy using undilated single field photography was 77% (95% CI 71 to 84) and 95 % (95% CI 93 to 97) respectively. Using dilated single field photography the figures were 81% (95% CI 76 to 87) and 92% (95% CI 90 to 94) respectively. Using dilated three field photography the figures were 83% (95% CI 78 to 88) and 93% (95% CI 91 to 96) respectively. Intergrader reliability for the detection of referable retinopathy in gradable photographs was excellent (Kappa values 0.86-1.00). CONCLUSIONS: Mydriasis reduces the technical failure rate. Mydriasis and the three field photography as used in this study do not increase the sensitivity or specificity of detecting diabetic retinopathy.

The use of ultrasound as an aid in the diagnosis of giant cell arteritis: a pilot study comparing histological features with ultrasound findings.

AIMS: We present our preliminary experience with the use of ultrasound in aiding the diagnosis of giant cell arteritis (GCA). Schmidt et al have previously described a hypoechoic or "halo" effect surrounding the walls of affected arteries on examination with ultrasound. We illustrate these features and explore the attributes and limitations of this technique. METHOD: Two groups of patients were recruited: (1) patients with suspected GCA awaiting temporal artery biopsy and (2) patients with no history or symptoms of GCA of a similar age group. All the recruited patients underwent ultrasound examination of both temporal arteries. The findings on ultrasound were compared with the results of the histological specimens in group 1. For this study, the histological findings alone were used to define if a patient was suffering from GCA. No biopsies were taken in the patients in group 2. RESULTS: Out of 26 patients with suspected GCA, seven patients were found to be positive on biopsy, of which six had been identified on ultrasound. Six patients were found to be false positive on ultrasound, but all had moderate-to-severe features of arteriosclerosis on histology. A total of 13 patients were found to be negative on ultrasound and negative on biopsy for GCA, two of these patients had histological features of arteriosclerosis. In the group with no symptoms of GCA (12 patients), in two patients hypoechoic areas were detected. The results presented give a sensitivity of 86%, specificity of 68%, and positive predictive value of 50% for the use of ultrasound in the diagnosis of GCA. CONCLUSIONS: This preliminary study indicates that this test may be helpful in those patients with symptoms suggestive of GCA, but currently we cannot recommend any change of present practice.

Defective hMSH2/hMLH1 protein expression is seen infrequently in ulcerative colitis associated colorectal cancers.

BACKGROUND: Ulcerative colitis is associated with an increased risk of colorectal cancer above that of the normal population. The relative risk correlates with the extent and duration of the disease but the genetic basis of ulcerative colitis associated cancer risk is not known. AIMS: To assess the prevalence of microsatellite instability and mismatch repair gene abnormalities in ulcerative colitis associated colorectal cancer. PATIENTS: Forty six patients with colorectal cancer, with a previous histological diagnosis of ulcerative colitis. METHODS: The frequency of microsatellite instability and/or immunohistochemical expression of hMSH2 and hMLH1 was assessed. Thirty three cases were investigated using both approaches. RESULTS: Although 6/41 (14.6%) cases showed microsatellite instability at one or more markers, only one case (2. 4%) exhibited high level instability (at least two markers affected). Of 38 cases which were assessed using antibodies against hMSH2 and hMLH1, only one case (2.6%) showed loss of expression. This case, which showed loss of hMSH2 expression, was the same case which exhibited high level microsatellite instability. The 33 cases which were investigated using both approaches showed that loss of expression of either hMSH2 or hMLH1 was not seen in any case which exhibited microsatellite instability in no more than one marker. CONCLUSIONS: This study suggests that both high level microsatellite instability and loss of expression of hMSH2/hMLH1 are infrequent events in ulcerative colitis associated colorectal cancers. Low level microsatellite instability was not associated with loss of expression of either hMSH2 or hMLH1.

A comparison of microsatellite instability in early onset gastric carcinomas from relatively low and high incidence European populations.

We have investigated the genetic basis of gastric carcinomas occurring in patients aged under 40 years from a Portuguese population with a relatively high incidence of gastric cancer. We analysed a panel of 12 microsatellite loci in DNA extracted from gastric carcinomas arising in 16 patients aged 24-39 years from Braga, Portugal. Overall, microsatellite instability (MI) in at least 1 locus was detected in 44% (7 of 16) of carcinomas. A single patient demonstrated a mutator phenotype suggestive of the hereditary nonpolyposis colorectal cancer syndrome with instability in 82% of loci. This carcinoma showed loss of expression of the hMLH1 mismatch repair protein. In a previous study, we found no evidence of MI among 10 cases of early onset gastric carcinomas from an English population, which has a relatively low incidence of gastric cancer. Comparing the 2 series, we found that there was a significant difference (p = 0.04) in the prevalence of MI (at least 1 marker affected). This geographical difference in low-level MI may be related to a significantly higher prevalence of background chronic atrophic gastritis (8 of 16 vs. 0 of 8) and Helicobacter pylori infection (15 of 16 vs. 2 of 8) in Portuguese carcinomas compared with English cases. Genetic mechanisms underlying the hereditary non-polyposis colorectal cancer syndrome may play a role in a small number of early onset gastric carcinomas. The difference in prevalence of low-level MI between these relatively high and low incidence European populations requires further investigation.

Choice of management strategy for colorectal cancer based on a diagnostic immunohistochemical test for defective mismatch repair.

BACKGROUND: Despite intensive research into the molecular abnormalities associated with colorectal cancer (CRC), no diagnostic tests have emerged which usefully complement standard histopathological assessments. AIMS: To assess the feasibility of using immunohistochemistry to detect replication error (RER) positive CRCs and determine the incidence of RER positivity within distinct patient subgroups. METHODS: 502 CRCs were analysed for RER positivity (at least two markers affected) and/or expression of hMSH2 and hMLH1. RESULTS: There were 15/30 (50%) patients with metachronous CRCs, 16/51 (31%) with synchronous CRCs, 14/45 (31%) with a proximal colon carcinoma, and 4/23 (17%) who developed a CRC under the age of 50 showed RER positivity. However, 0/54 patients who developed a solitary carcinoma of the rectum/left colon over the age of 50 showed RER positivity. Immunohistochemical analysis revealed that 66/66 (100%) RER positive carcinomas were associated with complete lack of expression of either hMSH2 or hMLH1. This correlation was confirmed using a further 101 proximal colon carcinomas. Patients with a mismatch repair defective carcinoma showed improved survival but a 5.54 times relative risk of developing a metachronous CRC. A prospective immunohistochemical study revealed 13/117 (11%) patients had a mismatch repair defective carcinoma. A fivefold excess of hMLH1 defective cases was noted. CONCLUSIONS: All RER positive carcinomas were identified by the immunohistochemical test. This is the first simple laboratory test which can be performed routinely on all CRCs. It will provide a method for selecting patients who should be investigated for HNPCC, offered long term follow up, and who may not respond to standard chemotherapy regimens.