Mei-Ling Tay-Kearney

Intravitreal voriconazole for the treatment of endogenous endophthalmitis caused by Scedosporium apiospermum.

Scedosporium apiospermum is an increasingly recognized cause of endogenous fungal endophthalmitis in immunocompromised patients. The authors describe two patients with endogenous S. apiospermum endophthalmitis treated with intravitreal and systemic voriconazole. Despite a prolonged course of systemic antifungal treatment, both patients subsequently required enucleation for intractable ocular pain due to secondary scleritis. Histological examination of the globes demonstrated the presence of fungal hyphae. Endogenous S. apiospermum endophthalmitis need to be considered in the differential diagnosis of necrotizing retinitis. Despite its efficacy in suppressing disseminated S. apiospermum infection, voriconazole may be ineffective in the treatment of endogenous S. apiospermum endophthalmitis especially if treatment is delayed.

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 × 106, 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 initiation. 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.

Retinal image registration and comparison for clinical decision support.

Background For eye diseases, such as glaucoma and age-related macular degeneration (ARMD), involved in long-term degeneration procedure, longitudinal comparison of retinal images is a common step for reliable diagnosis of these kinds of diseases.

Intravitreal triamcinolone acetonide injection for the treatment of posterior uveitis.

Mei-Ling Tay-Kearney Senior Lecturer, UWA/COVS, Head of Department of Ophthalmology, Royal Perth Hospital, Western Australia Despite its study limitations, Abdullah Özkiris showed, in a small number of patients with non-infectious posterior uveitis, that a single dose of 8 mg of triamcinolone injected intravitreally was just as effective as oral prednisolone and/or immunosuppressive drugs in controlling the ocular inflammatory response at 5 months. Systemic associations included Behçet’s disease and sarcoidosis. The resurgence of intravitreal corticosteroids occurred only a few years ago, and one only needs to perform a PubMed search on the topic for confirmation. Triamcinolone acetonide is most commonly used due to its relative insolubility, long duration action, and apparent lack of intraocular toxicity. Triamcinolone (Kenacort -40, Bristol-Meyers-Sqibbs Pharmaceuticals, Noble Park, Australia) in its current form is being used off-label by ophthalmologists. Apart from its active ingredient, it also contains 15 mg benzyl alcohol, 0.4 mg polysorbate 80, and 7.5 mg carmellose. Numerous studies, generally small retrospective and uncontrolled, have shown repeatedly that it is effective in reducing retinal edema from many and varied causes. It has been used in wet macular degeneration, diabetic macula edema, retinal vein occlusions complicated by macular edema, non-infectious posterior uveitis, post-cataract surgery, and in rarer conditions such as retinitis pigmentosa and juxtafoveal telangiectasia. However, it quickly became evident that its therapeutic effect does not last long. Animal and human studies have shown that the steroid effect generally lasts three months when 4 mg is used, and up to a year if much higher doses are used. This means repeated injections are often necessary to maintain its effect, a strategy that can become challenging in chronic diseases. Having said that, Ohguro et al.1 recently reported good control of recalcitrant Behçet’s associated posterior uveitis with one monthly triamcinolone injections for one year. However, the numbers involved were small, and longer follow-up is needed.

Retinal image enhancement and registration for the evaluation of longitudinal changes

Retinal images are long-accepted clinical diagnostic method for ocular diseases. Of late, automated assessment of retinal images has proven to be a useful adjunct in clinical decision support systems. In this paper, we propose a retinal image registration method, which combine retinal image enhancement and non-rigid image registration methods, for longitudinal retinal image alignment. A further illumination correction and gray value matching methods are applied for the longitudinal image comparison and subtraction. The solution can enhance the assessment of longitudinal changes of retinal images and image subtraction in a clinical application system. The performance of the proposed solution has been tested on longitudinal retinal images. Preliminary results have demonstrated the accuracy and robustness of the solutions and their potential application in a clinical environment.

Improvement of retinal blood vessel detection by spur removal and Gaussian matched filtering compensation

Retinal photography is a non-invasive and well-accepted clinical diagnosis of ocular diseases. Qualitative and quantitative assessment of retinal images is crucial in ocular diseases related clinical application. In this paper, we proposed approaches for improving the quality of blood vessel detection based on our initial blood vessel detection methods. A blood vessel spur pruning method has been developed for removing the blood vessel spurs both on vessel medial lines and binary vessel masks, which are caused by artifacts and side-effect of Gaussian matched vessel enhancement. A Gaussian matched filtering compensation method has been developed for removing incorrect vessel branches in the areas of low illumination. The proposed approaches were applied and tested on the color fundus images from one publicly available database and our diabetic retinopathy screening dataset. A preliminary result has demonstrated the robustness and good performance of the proposed approaches and their potential application for improving retinal blood vessel detection.

Region-based multi-step optic disk and cup segmentation from color fundus image

Retinal optic cup-disk-ratio (CDR) is a one of important indicators of glaucomatous neuropathy. In this paper, we propose a novel multi-step 4-quadrant thresholding method for optic disk segmentation and a multi-step temporal-nasal segmenting method for optic cup segmentation based on blood vessel inpainted HSL lightness images and green images. The performance of the proposed methods was evaluated on a group of color fundus images and compared with the manual outlining results from two experts. Dice scores of detected disk and cup regions between the auto and manual results were computed and compared. Vertical CDRs were also compared among the three results. The preliminary experiment has demonstrated the robustness of the method for automatic optic disk and cup segmentation and its potential value for clinical application.

Evaluation of Artificial Intelligence–Based Grading of Diabetic Retinopathy in Primary Care

Key Points Question How will an artificial intelligence (AI)–based grading system for diabetic retinopathy perform in a real-world clinical setting? Findings In a diagnostic study evaluating 193 patients (386 images), the AI system judged 17 as having diabetic retinopathy of sufficient severity to require referral. While the system correctly identified the 2 patients with true disease (severe diabetic retinopathy), the positive predictive value was only 12%, with 15 patients misclassified as needing referral. Meaning Grading of diabetic retinopathy using AI has both potential benefits and challenges, and further study in real-world settings is needed.

Detection and measurement of retinal blood vessel pulsatile motion

Retinal photography is a non-invasive and well-accepted clinical diagnosis of ocular diseases. Qualitative and quantitative assessment of retinal images is crucial in ocular diseases related clinical application. Pulsatile properties caused by cardiac rhythm, such as spontaneous venous pulsation (SVP) and pulsatile motion of small arterioles, can be visualized by dynamic retinal imaging techniques and provide clinical significance. In this paper, we aim at vessel pulsatile motion detection and measurement. We proposed a novel approach for pulsatile motion measurement of retinal blood vessels by applying retinal image registration, blood vessel detection and blood vessel motion detection and measurement on infrared retinal image sequences. The performance of the proposed methods was evaluated on 8 image sequences with 240 images. A preliminary result has demonstrated the good performance of the method for blood vessel pulsatile motion observation and measurement.

Ocular syphilis in Western Australia

vitrectomized eyes, may decrease the retinal threshold to tolerate acidic or alkaline toxins. In addition, the volume of the vitreous space, into which the toxins can diffuse, is also important in detoxification, as the size of this space is inversely related to the concentration of toxic materials. Buffering capacity depends on the volume of the vitreous as well. Therefore, with reduction of vitreous space amount of acid or base able to be tolerated will be reduced. Intraocular tamponades such as silicone oil and intraocular gases have important clinical relevance in this regard. Consider what would happen if the vitreous was largely replaced by silicone oil. Reduction of functional vitreous would lead to a decreased buffering capacity of the vitreous space, and titration with the same amount of acid or base would lead to a greater change in pH value. Moreover, the same amount of toxin would lead to a greater concentration as well. This in turn may explain some deleterious effects of silicone oil on the retina, the lens and other nearby structures. In conclusion, the vitreous humour has an important role in antitoxic retinal armamentarium. Its role, however, may be more important clinically in conditions such as intravitreal drug injections where the retina is subjected to a substantial increase in toxins.