Emergency eye care in rural Australia: role of internet

PURPOSE

Significant differences exist in the utilization of emergency eye care services in rural and urban Australia. Meanwhile, influence of internet-based technology in emergency eye care service utilization has not been established. This study aims to demonstrate, from a health provider perspective, an internet-based service's impact on emergency eye care in rural Australia.

METHODS

The teleophthalmology service was initiated in the Carnarvon Regional Hospital (CRH) of the Gascoyne region in Western Australia. A digital, slit lamp and fundus camera were used for the service. Economic data was gathered from the Department of Health of Western Australia (DOHWA), the CRH and the Lions Eye Institute.

RESULTS

During the study period (January-December, 2003) 118 persons took part in teleophthalmology consultations. Emergency cases constituted 3% of these consultations. Previous year, there were seven eye-related emergency evacuations (inter-hospital air transfers) from the Gascoyne region to City of Perth.

CONCLUSIONS

Analysis demonstrates implementation of internet-based health services has a marked impact on rural emergency eye care delivery. Internet is well suited to ophthalmology for the diagnosis and management of acute conditions in remote areas. Integration of such services to mainstream health care is recommended.

Microsporidial keratoconjunctivitis after HAART

A 44-year-old man presented with bilateral punctate corneal epitheliopathy complaining of worsening discomfort and photophobia over the previous several days. He was HIV positive, had a recent CD4 count of 4 x 10(6), and had started on highly active antiretroviral therapy (HAART) 14 days prior. Failure to respond to lubricant therapy with worsening of the epitheliopathy over the following week led to corneal biopsy and diagnosis of corneal microsporidiosis. Investigations revealed that he remained anergic and that his CD4 count had not changed. However, his viral load had decreased by at least 0.9 log10 units since HAART intiation. Therapy with albendazole led to complete resolution of his pre-existing symptoms of nasal congestion and epistaxis, as well as all recently occurring ocular signs and symptoms. It was concluded that the microsporidiosis was a pre-existing opportunistic infection, whose presence was unmasked by a form of immune restoration induced by HAART.

Bacillus circulans endophthalmitis

An 80-year-old woman presented with right endophthalmitis, characterized by chalky white deposits covering her posterior capsule. This occurred 17 months after uncomplicated right cataract surgery. A three-port pars plana vitrectomy and partial posterior capsulectomy isolated Bacillus circulans, and the patient made a rapid and full recovery on topical cephalothin and prednisolone acetate 1%. The case demonstrates that, unlike endophthalmitis due to other Bacillus spp., B. circulans endophthalmitis does not necessarily follow a fulminant course. It is the first report describing a subacute presentation, and response to posterior capsulectomy and simple antibiotic therapy It is also the first description of B. circulans causing white plaques in the posterior capsule, a finding characteristic of chronic endophthalmitis and previously considered pathognomonic of Proprionibacterium acnes endophthalmitis.

Telemedicine screening of diabetic retinopathy using a hand-held fundus camera

The objective was to evaluate digital images of the retina from a handheld fundus camera (Nidek NM-100) for suitability in telemedicine screening of diabetic retinopathy. A handheld fundus camera (Nidek) and a standard fundus camera (Zeiss) were used to photograph 49 eyes from 25 consecutive patients attending our diabetic clinic. One patient had cataracts, making it impossible to get a quality image of one of the eyes (retina). The Nidek images were digitized, compressed, and stored in a Fujix DF-10M digitizer supplied with the camera. The digital images and the photographs were presented separately in a random order to three ophthalmologists. The quality of the images was ranked as good, acceptable or unacceptable for diabetic retinopathy diagnosis. The images were also evaluated for the presence of microaneurysms, blot hemorrhages, exudates, fibrous tissue, previous photocoagulation, and new vessel formation. kappa Values were computed for agreement between the photographs and digital images. Overall agreement between the photographs and digital images was poor (kappa < 0.30). On average, only 24% of the digital images were graded as being good quality and 56% as having an acceptable quality. However, 93% of the photographs were graded as good-quality images for diagnosis. The results indicate that the digital images from the handheld fundus camera may not be suitable for diagnosis of diabetic retinopathy. The images shown on the liquid crystal display (LCD) screen of the camera were of good quality. However, the images produced by the digitizer (Fujix DF-10M) attached to the camera were not as good as the images shown on the LCD screen. A better digitizing system may produce better quality images from the Nidek camera.

Methods and limits of digital image compression of retinal images for telemedicine

PURPOSE

To investigate image compression of digital retinal images and the effect of various levels of compression on the quality of the images.

METHODS

JPEG (Joint Photographic Experts Group) and Wavelet image compression techniques were applied in five different levels to 11 eyes with subtle retinal abnormalities and to 4 normal eyes. Image quality was assessed by four different methods: calculation of the root mean square (RMS) error between the original and compressed image, determining the level of arteriole branching, identification of retinal abnormalities by experienced observers, and a subjective assessment of overall image quality. To verify the techniques used and findings, a second set of retinal images was assessed by calculation of RMS error and overall image quality.

RESULTS

Plots and tabulations of the data as a function of the final image size showed that when the original image size of 1.5 MB was reduced to 29 KB using JPEG compression, there was no serious degradation in quality. The smallest Wavelet compressed images in this study (15 KB) were generally still of acceptable quality.

CONCLUSIONS

For situations where digital image transmission time and costs should be minimized, Wavelet image compression to 15 KB is recommended, although there is a slight cost of computational time. Where computational time should be minimized, and to remain compatible with other imaging systems, the use of JPEG compression to 29 KB is an excellent alternative.

Immune restoration disease after the treatment of immunodeficient HIV-infected patients with highly active antiretroviral therapy

BACKGROUND

To determine if infectious disease events in HIV-infected patients treated with highly active antiretroviral therapy (HAART) are a consequence of the restoration of pathogen-specific immune responses, a single-centre retrospective study of all HIV-infected patients commencing HAART prior to 1 July 1997 was undertaken to determine the incidence, characteristics and time of onset of disease episodes in HAART responders (decrease in plasma HIV RNA of > 1 log10 copies/mL).

METHODS

Baseline and post-therapy changes in CD4 T-cell counts and HIV RNA were compared in patients with and without disease and delayed-type hypersensitivity responses to mycobacterial antigens were measured in selected patients.

RESULTS

Thirty-three of 132 HAART responders (25%) exhibited one or more disease episodes after HAART, related to a pre-existent or subclinical infection by an opportunistic pathogen. Disease episodes were most often related to infections by mycobacteria or herpesviruses but hepatitis C virus (HCV), molluscum contagiosum virus and human papilloma virus were also implicated. They were most common in patients with a baseline CD4 T-cell count of < 50/uL and occurred most often during the first 2 months of therapy and when CD4 T-cell counts were increasing. Mycobacteria- and HCV-related diseases were associated with restoration of pathogen-specific immune responses.

CONCLUSIONS

We conclude that improved immune function in immunodeficient patients treated with HAART may restore pathogen-specific immune responses and cause inflammation in tissues infected by those pathogens.

Evaluation of a portable fundus camera for use in the teleophthalmologic diagnosis of glaucoma

PURPOSE

The digital images of the optic disk from a portable fundus camera were evaluated for suitability in teleophthalmologic screening for glaucoma.

METHODS

Fifty-one eyes of 27 consecutive patients from our glaucoma clinic were dilated and photographed with a Zeiss FF retinal camera (Carl Zeiss, Oberkochen, Germany) and a portable Nidek NM-100 (Nidek, Tokyo, Japan) fundus camera. Digital images from the portable fundus camera were digitized, compressed and stored in a Fujix DF-10M (Fuji, Tokyo, Japan) digitizer. Lossy compressed digital images and photographs from the Zeiss camera were presented separately in random order to three ophthalmologists for estimation of vertical cup:disk ratios (VCDR) and to evaluate image quality as good, acceptable, or unacceptable for screening glaucoma. Gold standard VCDRs were measured from monoscopic photographic slides obtained using the Zeiss camera by a fourth ophthalmologist.

RESULTS

Measurement of agreement (Kappa values) between estimated VCDR of digital images and photographs by the three ophthalmologists were 0.52, 0.38, and 0.50 respectively. Agreement between gold standard and estimated VCDR from photographs were 0.87, 0.45, and 0.84 respectively (specificity between 79% and 97%, sensitivity between 70% and 95%). Kappa values obtained between gold standard and estimated VCDR from digital images were 0.52, 0.49, and 0.49, respectively (specificity between 68% and 79%, sensitivity between 67% and 87%.

CONCLUSION

Moderate to good agreement indicates that the digital images from the portable fundus camera may be suitable for optic disk assessment in the current configuration. This easy to use Nidek hand-held camera could be a viable instrument for teleophthalmology if a better digitizing system is incorporated to improve the quality of the images.

T cell subsets and cytomegalovirus retinitis in human immunodeficiency virus-infected patients

A case-control study was done to investigate the relationship between T cell subsets and cytomegalovirus (CMV) retinitis in human immunodeficiency virus (HIV)-infected subjects with or without CMV retinitis and CD4+ cell counts of <0.050 x 10(9)/L. Cell surface markers on peripheral blood lymphocytes were evaluated using flow cytometry. Patients with CMV retinitis had significantly lower levels of CD8+ cells (median: 0.152 x 10(9)/L) compared with levels for controls (median: 0.296 x 10(9)/L, P < .001). Significant down-regulation of costimulatory molecule CD28+ and lymphocyte function-associated antigen-1 (LFA-1) expression was observed in patients versus controls (CD28+: 0.048 x 10(9)/L vs. 0.143 x 10(9)/L, P < .001; LFA-1: 0.238 x 10(9)/L vs. 0.400 x 10(9)/L, P < .001), but no significant differences were noted for NK cells. We propose that progressive loss of the CD3+ CD8+ cell subset and down-regulation of CD28 and LFA-1 accessory molecules are associated with an increased risk of CMV retinitis in HIV-infected patients.

Ophthalmic complications of HIV infection

HIV retinopathy, a noninfectious microangiopathy, is the most common ocular manifestation of HIV infection. Opportunistic infections, neoplasms, neuro-ophthalmic lesions, and drug-induced lesions may also cause ocular problems. Opportunistic ocular infections, particularly CMV retinitis, are a major cause of morbidity in patients with AIDS. Because of the underlying chronic and progressive immune dysfunction, the ocular symptoms, signs, clinical course, and treatment are often atypical and severe, requiring protracted medical therapy.

Clinical features and associated systemic diseases of HLA-B27 uveitis

PURPOSE

To delineate the clinical features, course, complications, and associated systemic diseases in patients with HLA-B27-associated uveitis.

METHODS

We reviewed the records of 148 patients with HLA-B27-associated uveitis from two large uveitis practices.

RESULTS

There were 127 (86%) white and 21 (14%) nonwhite patients, and a male-to-female ratio of 1.5:1. The median age at onset of uveitis was 32 years; eight patients (5%) had their first attack after age 55 years. Acute anterior uveitis was noted in 129 patients (87%), and nonacute inflammation was noted in 19 (13%). Ocular involvement was categorized as unilateral or unilateral alternating in 138 patients (93%), but ten patients (7%) had bilateral, concurrent disease. The median duration of an attack was six weeks, and the median number of recurrences for patients with more than 12 months of follow-up was three. Cataracts were associated with posterior synechiae (P = .03), increased intraocular pressure (P = .003), and cystoid macular edema (P = .04). An HLA-B27-associated systemic disorder was present in 83 patients (58%), 30 of whom were women, and it was diagnosed in 43 of the 83 patients as a result of the ophthalmologic consultation. Thirty-four (30%) of 112 patients had a family history of a spondyloarthropathy.

CONCLUSIONS

Although HLA-B27-associated uveitis is usually described as a disease of young white men, women and nonwhites may also be affected. A subgroup of patients have severe disease and consequently more complications. Most patients have an associated systemic disease, including women, who appear to have more atypical spondyloarthropathies. The systemic diseases were frequently undiagnosed before the onset of the ocular disease and before the uveitis consultation.

Treatment of CMV retinopathy in patients with AIDS

Cytomegalovirus (CMV) retinitis, the most common intraocular infection in patients with AIDS, appears to be increasing in frequency as these patients live longer. Untreated, CMV retinitis progresses throughout the entire retina resulting in blindness. Ganciclovir and foscarnet, as intravenous formulations, are the only two drugs currently approved by the FDA for the treatment of CMV retinitis. In the Foscarnet-Ganciclovir Cytomegalovirus Retinitis Trial (FGCRT), both drugs were shown to be equally effective in controlling the retinitis. As these drugs have different toxic profiles, and different infusion times, the choice of initial therapy will depend on coexisting medical factors, concurrent medications and patient's lifestyle. Additionally, the FGCRT showed that ganciclovir was associated with a 50% greater mortality rate than with foscarnet. More recently, oral ganciclovir was recently approved for maintenance therapy. Local therapy for CMV retinitis has been used as intravitreal injections of either ganciclovir or foscarnet, or investigationally as a sustained release implant of ganciclovir. While it has been shown that local therapy is effective in controlling the retinitis, the contralateral eye and extraocular sites remain unprotected from CMV disease, which invariably is a systemic disease. Finally, clinical trials are underway to determine the effectiveness and toxicities of cidofovir, a nucleotide analogue (given intravenously or intravitreally) and a neutralizing monoclonal anti-CMV antibody used as adjunctive therapy to prolong the time to relapse.

Acanthamoeba keratitis. A masquerade of presentation in six cases

Acanthamoeba keratitis is an uncommon but devastating complication of contact lens wear causing significant ocular morbidity. Six consecutive cases occurring in Western Australia in an 18-month period are reported. In all cases either poor contact lens hygiene or an association with swimming pools and contact lens use is a feature. There is invariably a delay in making the diagnosis, with the appearance frequently mistaken for herpes simplex keratitis. In all cases corneal biopsy was required to confirm the diagnosis. Of the six patients, four responded to medical therapy alone, one required a corneal graft and one required enucleation. We suggest that earlier rather than later corneal biopsy is important in unresponsive cases of culture-negative keratitis, especially in contact lens wearers. We would agree that the treatment of choice is intensive topical propamidine and neosporin. Prevention by strict adherence to contact lens care and hygiene is urged.

Craniopharyngioma and the moustache sign

Craniopharyngiomas are common suprasellar tumours but these are rarely associated with vasogenic oedema. Because the oedema extends into the optic tracts and optic radiations, a characteristic pattern is produced that resembles a moustache. The oedema is though to be due to leakage of craniopharyngioma contents. Such a case is presented in this communication.