Automated classifiers for early detection and diagnosis of retinopathy in diabetic eyes

BACKGROUND: Artificial neural networks (ANNs) have been used to classify eye diseases, such as diabetic retinopathy (DR) and glaucoma. DR is the leading cause of blindness in working-age adults in the developed world. The implementation of DR diagnostic routines could be feasibly improved by the integration of structural and optical property test measurements of the retinal structure that provide important and complementary information for reaching a diagnosis. In this study, we evaluate the capability of several structural and optical features (thickness, total reflectance and fractal dimension) of various intraretinal layers extracted from optical coherence tomography images to train a Bayesian ANN to discriminate between healthy and diabetic eyes with and with no mild retinopathy. RESULTS: When exploring the probability as to whether the subject's eye was healthy (diagnostic condition, Test 1), we found that the structural and optical property features of the outer plexiform layer (OPL) and the complex formed by the ganglion cell and inner plexiform layers (GCL + IPL) provided the highest probability (positive predictive value (PPV) of 91% and 89%, respectively) for the proportion of patients with positive test results (healthy condition) who were correctly diagnosed (Test 1). The true negative, TP and PPV values remained stable despite the different sizes of training data sets (Test 2). The sensitivity, specificity and PPV were greater or close to 0.70 for the retinal nerve fiber layer's features, photoreceptor outer segments and retinal pigment epithelium when 23 diabetic eyes with mild retinopathy were mixed with 38 diabetic eyes with no retinopathy (Test 3). CONCLUSIONS: A Bayesian ANN trained on structural and optical features from optical coherence tomography data can successfully discriminate between healthy and diabetic eyes with and with no retinopathy. The fractal dimension of the OPL and the GCL + IPL complex predicted by the Bayesian radial basis function network provides better diagnostic utility to classify diabetic eyes with mild retinopathy. Moreover, the thickness and fractal dimension parameters of the retinal nerve fiber layer, photoreceptor outer segments and retinal pigment epithelium show promise for the diagnostic classification between diabetic eyes with and with no mild retinopathy

Cost analysis of childhood glaucoma surgeries using the US Medicaire allowable costs

AIM: To analyze and calculate the relative cost of various childhood glaucoma surgical interventions per mm Hg intraocular pressure (IOP) reduction ($/mm Hg). METHODS: Representative index studies were reviewed to quantitate the reduction of mean IOP and glaucoma medications for each surgical intervention in childhood glaucoma. A US perspective was adopted, using Medicare allowable costs to calculate cost/mm Hg IOP reduction ($/mm Hg) at 1y postoperatively. RESULTS: At 1y postoperatively, the cost/mm Hg IOP reduction was $226/mm Hg for microcatheter-assisted circumferential trabeculotomy,$284/mm Hg for cyclophotocoagulation, $288/mm Hg for conventional ab-externo trabeculotomy,$338/mm Hg for Ahmed glaucoma valve, $350/mm Hg for Baerveldt glaucoma implant,$351/mm Hg for goniotomy, and $400/mm Hg for trabeculectomy. CONCLUSION: Microcatheter-assisted circumferential trabeculotomy is the most cost-efficient surgical method to lower IOP in childhood glaucoma, while trabeculectomy is the least cost-efficient surgical method

Combined pars plana vitrectomy and Baerveldt glaucoma implant placement for refractory glaucoma

To evaluate outcomes of combined pars plana vitrectomy and Baerveldt glaucoma implant (PPV-BGI) placement for refractory glaucoma

Treatment outcomes of endogenous fungal endophthalmitis

Endogenous fungal endophthalmitis may present in a debilitated or otherwise healthy host, may be increasing in prevalence, and is most commonly caused by Candida albicans. Recognizing the potential for complications with systemic amphotericin B use, recent investigators have developed several newer principles governing the treatment of such cases. For cases of simple choroiditis or very minimal endophthalmitis (ie, vitritis), systemic treatment with oral fluconazole may be effective; however, if vitritis symptoms persist or progress, vitrectomy allows for better clearing of the organism. Intravitreal amphotericin B in conjunction with vitrectomy has been advocated by many. The most recent series have shown that an extended course of oral fluconazole following vitrectomy without intravitreal amphotericin B affects resolution of infection in the vast majority of patients. Final visual acuity outcomes depend most on the site of initial choroiditis. If the macula is spared and preretinal membranes can be effectively removed, visual acuity results can be exceedingly good

Nonmedical costs and implications for patients seeking vitreoretinalcare

To measure nonreimbursable, nonmedical costs incurred by patients attending a vitreoretinal clinic appointment. A nurse-administered questionnaire designed to capture the nonmedical costs for a single clinical appointment was administered to patients attending an appointment at a single-center, single-physician, university-based vitreoretinal clinic. First day postoperative visits were excluded. End points were time commitment, time missing work, and median total nonmedical costs incurred. A subgroup analysis of Medicare patients who lived locally was performed. Three hundred and six patients completed the survey. The median nonreimbursable, nonmedical cost incurred was $23.32; the mean cost was$236.53 (range, $0-$7,259). The largest component of cost was transportation costs ($13.43). The patient took at least a day off from work in 27$21.53); the mean cost was $51.29 (range,$0-$1,255.80). This cohort also had a lower incidence of missing work (6%), and a higher incidence of an accompanying person (68%) who had a lower incidence of missing work (16%). The costs and distributions varied minimally by visit type. Physicians and policymakers may not recognize or consider the potential impediment to care that nonreimbursable costs may present when developing treatment strategies and designing policies

Spontaneous macular hole closure with appearance of epiretinal membrane: implications for therapy

A 69-year-old man had spontaneous closure of a macular hole 2 years after his initial presentation that was documented by optical coherence tomography. This was related to an increase in an associated epiretinal membrane. Preretinal tissue proliferation is a necessary prerequisite for macular hole closure, whether spontaneous or induced surgically. A guiding template, such as the overlying posterior hyaloid surface or a gas bubble interface, facilitates closure. In this case, the posterior hyaloid was visibly separated and the macular hole was well developed. It is possible that the contraction of the epiretinal membrane narrowed the gap enough to allow closure. This mechanism may have important implications for developing surgical management techniques