Use of three-dimensional printing for adapting and optimizing smartphone ophthalmoscopy to existing SD-OCT instrumentation for rodent and teleost ocular research.

Use of animal models for human vision research is now pervasive. To address a range of technical challenges, laboratories either modify existing equipment or purchase products that are purpose designed. Three-dimensional (3D) printing technology now allows the do-it-yourself capability to invent, innovate, and manufacture for a specific purpose. Ophthalmic imaging is often used with a range of other sophisticated experimental retinal imaging techniques, such as spectral domain optical coherence tomography (SD-OCT). The handheld smartphone camera and cost-effective, readily available professional-quality apps now allow accessible high-definition video ophthalmic image recording. However, to our knowledge, there are few reports of adapting smartphone ophthalmic imaging to existing experimental SD-OCT imaging instrumentation. This would offer better accuracy, reproducibility, and most importantly, precision. The objective of the present study was to use 3D printing to enhance the functionality and precision of existing SD-OCT instrumentation and smartphone-based ophthalmic imaging through construction of a custom 3D-printed assembly. The assembly can be controlled either manually or by the highly precise rodent stage of the SD-OCT instrument. Using this technical approach, 3D printing facilitated a novel methodology for high-quality ophthalmic imaging with low cost and ease of production either manually or by enhancing existing SD-OCT instrumentation.

Telemedicine-based digital retinal imaging vs standard ophthalmologic evaluation for the assessment of diabetic retinopathy.

OBJECTIVE: To study the cost benefit analysis of using a telemedicine-based digital retinal imaging evaluation compared to conventional ophthalmologic fundus examination of diabetic patients for diabetic retinopathy. METHODS: In this study, diabetic patients from Community Health Center, Inc. (CHCI), a large multi-site Federally Qualified Health Center) were evaluated by teleophthalmology using the Canon CR-1 nonmydriatic fundus camera. Digital images were acquired in the CHCI offices and saved on the EyePACS server network. The images were later evaluated by retinal specialists at the Yale Eye Center, Yale University Department of Ophthalmology and Visual Science. The costs for the standard of care ophthalmic examinations were calculated based on 2009 Medicaid reimbursement rates. The process of telemedicine-based diagnosis was based on a take-store-forward-visualize system. The cost of telemedicine-based digital retinal imaging examination included cost for devices, training, annual costs and a transportation fee. Current Medicaid reimbursement, transportation, and staff labor costs were used to calculate the conventional retinal examination cost as a comparison. RESULTS: Among the 611 patients digital retinal images screened in the first year of this program and for whom data are available, 166 (27.2%) cases of diabetic retinopathy were identified. Seventy-five (12.3%) patients screened positive with clinically significant disease and were referred for further ophthalmological evaluation and treatment. The primary direct cost of the telemedicine was $3.80, $15.00, $17.60, $1.50, and $2.50 per patient for medical assistant, ophthalmologist, capital cost (Equipment + Training), equipment maintenance, and transportation fee, respectively. The total cost in the telemedicine-based digital retinal imaging and evaluation was $40.40. The cost of conventional retinal examination was $8.70, $65.30, and $3.80 per patients for round-trip transportation, 2009 national Medicaid Physician Fee Schedule allowable for bilateral eye examination, and medical assistant personnel, respectively. The total costs of conventional fundus examination were $77.80. An additional conventional ophthalmologic retinal examination was required for 75 (12.3%) patients with clinically significant disease on telemedicine evaluation, which involves an averaged additional cost of $ 9.55 per patient for all the patients in the study. If the cost of subsequent examination was added, the total cost of telemedicine-based digital fundus imaging was $49.95 per patient in our group of 611 patients evaluated. CONCLUSIONS: Our cost analysis indicates that telemedicine-based diabetic retinopathy screening cost less ($49.95 vs $77.80) than conventional retinal examination and the telemedicine-based digital retinal imaging examination has the potential to provide an alternative method with greater convenience and access for the remote and indigent populations. Diabetes mellitus and diabetic retinopathy are growing problems in the United States and worldwide. Large scale adoption of telemedicine should be encouraged as a means toward providing improved access, increasing compliance with annual evaluation, at a low cost for patients with diabetes with direct access to an eye care specialist.

Screening for open angle glaucoma: systematic review of cost-effectiveness studies.

PURPOSE: To systematically review current evidence on the cost-effectiveness of screening strategies for open angle glaucoma (OAG). MATERIALS AND METHODS: Studies that reported both costs and outcomes of alternative screening strategies for OAG were identified by a highly sensitive search of electronic databases (eg, MEDLINE, EMBASE, NHS EED, HTA Database), last search December 2005. Data on costs regarding cases and years of visual impairment prevented, cases of blindness prevented, and cases of OAG detected were extracted. Incremental cost-effectiveness ratios were calculated using data provided in the included studies. RESULTS: Four studies met the inclusion criteria. The latest of these was published in 1997. The screening tests and treatments reported in these studies are now not considered to be best practice. Furthermore, data were not reported in sufficient detail to reinterpret the results of the studies in terms of a common outcome measure. Finally, these studies suffered from methodologic weaknesses that further limit their usefulness for decision making. CONCLUSIONS: Currently, there is insufficient economic evidence on which to base recommendations regarding screening for OAG. New technologies, potentially suitable as screening devices, and new treatments are available. Further research, both in terms of economic models and conduct of clinical trials with concurrent economic evaluation, may help inform policy makers regarding cost-effectiveness and acceptability of screening for OAG.

Cost analysis of remote telemedicine screening for retinopathy of prematurity.

OBJECTIVE: To compare costs of 2 screening modalities for retinopathy of prematurity (ROP): telemedicine imaging with remote interpretation versus in-person binocular indirect ophthalmoscopy (BIO). DESIGN: Retrospective chart review. PARTICIPANTS: Infants from an existing telemedicine screening program at 2 cities in Ontario, Canada. METHODS: We conducted a cost analysis comparison from the perspective of the Ministry of Health. Patient level data was used for the telemedicine group. A hypothetical control group consisted of the minimum number of BIO and interhospital transfers if the existing patients were screened in person. Costs included in-person examinations, transfers, setting up, and ongoing costs of telemedicine screening. Costs were compared using the Mann-Whitney U test and are reported in 2014 Canadian dollars. RESULTS: A total of 102 and 72 infants were screened from Sudbury and Barrie, respectively; 3% and 2% of infants in the telemedicine group were transferred for BIO from Sudbury and Barrie, respectively. All infants in the control group would have required at least one transfer for BIO. The average total cost per eye examination was $4855 ± $5616 and $4540 ± $3129 for the telemedicine group and $19 834 ± $13 814 and $2429 ± $1664 for the control group from Sudbury and Barrie, respectively (p < 0.001). Interhospital transfer cost for the control group was $19 489 ± $13 605 and $2055 ± $1471 compared to $635 ± $3968 and $30 ± $197 for the telemedicine group (p < 0.001) in Sudbury and Barrie, respectively. CONCLUSIONS: Telemedicine appears to be an economically attractive option depending on the location and number of infants screened. This information is useful for planning similar ROP screening programs.

Diabetic retinopathy screening: the first telemedical approach in an Italian hospital.

PURPOSE: To assess the feasibility of a telemedical approach for diabetic retinopathy (DR) screening in the Italian population and to evaluate advantages/disadvantages in comparison to standard slit-lamp funduscopic examination (SFE). METHODS: This 1-year, Italian, single-center, observational study evaluated semiautomatic fundus photography (FP) DR screening, performed during routine type 2 diabetes (T2D) systemic visits and examined remotely. Adults with T2D underwent SFE and 3-field FP. The study was divided into 2 stages (stage 1 validated the screening procedure, stage 2 evaluated the screening impact on the clinical practice). Annual costs of SFE ± FP screening were compared. Patients completed a DR screening questionnaire. RESULTS: Of 1,281 T2D patients enrolled, 61% were male (mean age 65.69 ± 12.64 years). In stage 1, 71% and 15% of patients were considered nongradable when FP was performed before (BPD) versus after pupil dilation (APD). The FP specificity was higher with APD vs BPD (79% vs 25%); therefore, FP APD only was used for stage 2. Of 1,281 patients screened using FP APD, 240 (18.7%) had unreadable images; 64.3% did not have DR, and 17.0% were diagnosed with DR. There was a cost saving of €801.25 when screening was performed using FP. Overall, 98% of patients had a positive opinion of FP screening. CONCLUSIONS: The telemedicine approach provides a convenient, simple test that is well-received by patients and minimizes unnecessary referrals. Telemedicine may also reduce screening costs in our setting.

Role of diabetologist in evaluating diabetic retinopathy.

OBJECTIVE: To evaluate the ability of diabetologists to screen diabetic patients for diabetic retinopathy. RESEARCH DESIGN AND METHODS: Comparison of eye examination performed by diabetologists with direct ophthalmoscopy through an undilated pupil and by ophthalmologists through a dilated pupil with seven-field stereoscopic fundus photography (gold standard). The study consisted of 67 insulin-dependent and non-insulin-dependent diabetic outpatients attending a diabetes clinic. RESULTS: On the basis of fundus photography, patients were classified as having no or insignificant (30%), minimal (31%), moderate (24%), or severe (15%) retinopathy. The diabetologists and ophthalmologists performed similarly in their ability to classify severity of diabetic retinopathy accurately. When no or insignificant retinopathy (isolated microaneurysms only) was detected by examination, clinically significant retinopathy detected by fundus photography was highly unlikely (less than 5%). On the other hand, if more than isolated microaneurysms were seen on examination, all examiners missed more severe lesions detected by fundus photography. Patients with corrected visual acuity worse than 20/30 had a high likelihood (100%) of moderate or severe retinopathy. CONCLUSIONS: Motivated well-trained diabetologists can screen for diabetic retinopathy. The absence of detectable lesions by direct ophthalmoscopy indicates that automatic referral to an ophthalmologist is not necessary. However, if any level of retinopathy is detected or corrected acuity is worse than 20/30, referral to an ophthalmologist is required. In this setting, fundus photography is advised because it is the most sensitive means of detecting clinically significant retinopathy. If other nonophthalmologists can be trained to achieve similar results, current recommendations for ophthalmologic referral that require annual ophthalmologic examinations for most diabetic patients may need to be reconsidered.

Glaucoma screening. A cost-effectiveness analysis.

We designed an intricate model of the process of glaucoma screening, diagnosis, and treatment in order to evaluate the medical care costs of such efforts in relation to the benefits in terms of quality-adjusted years of vision saved, utilizing the economic principles of cost-effectiveness analysis. Although a relatively limited data base and numerous assumptions concerning the accuracy of diagnostic tests, the natural history of ocular hypertension and glaucoma, and the effectiveness of available treatment modalities, limit our ability to draw definitive conclusions concerning the cost-effectiveness of various glaucoma screening options, our analysis indicates that glaucoma screening is probably cost-effective when targeted at certain subgroups of the population. Our analysis suggests that changes in several aspects of existing screening policies may be appropriate if cost-effectiveness is to be used as one of the criteria for the efficient allocation of resources to and within screening programs. Specifically, combinations of screening tests and screening targeted at high risk populations such as blacks, diabetics, and relatives of glaucoma patients are probably more cost-effective than screening of the general population with a single test. In younger populations, the importance of detecting ocular hypertension argues for the use of tonometry. Ophthalmoscopy may be more cost-effective in older age groups in whom the higher prevalence of glaucoma outweighs the need for identifying ocular hypertensives. In the very elderly, automated perimetry becomes cost-effective since the detection of established field loss will have greater yield. In addition, it is evident that diversion of resources away from actual screening efforts and towards efforts aimed at improving follow-up and compliance would be an additional cost-effective strategy.

An inexpensive method of indirect ophthalmoscopy.

Attention is drawn to the possibility of performing monocular indirect ophthalmoscopy with a pen torch and a condensing lens when facilities for binocular indirect ophthalmoscopy are not available.

The cost-effectiveness of various modes of screening for primary open angle glaucoma.

Various modes of screening for glaucoma were defined in terms of different combinations of the three main tests (ophthalmoscopy (O), tonometry (T), and perimetry (P)), together with associated referral criteria. The number of referrals and true positives generated by each mode was estimated for a model population, which was distributed with respect to age, intraocular pressure (IOP), optic disc condition, visual field defects, family history of glaucoma, and myopic status, as indicated by epidemiological studies. The costs of primary examination, and also of the secondary examination of referrals, were estimated for each mode, thus enabling the total cost per true positive to be calculated (in Pound sterling at 1995 UK prices, subsequently converted to US dollars at Pound 1.00 = $1.55.) The modes using O and T routinely, with P either routinely or selectively on all glaucoma high-risk groups, were found to provide the best balance between sensitivity (> or = 80%) and cost per true positive. The latter was around $850 when the cost of ophthalmoscopy could be shared as part of a general eye examination. The calculations assumed a 0.6% prevalence of previously undetected glaucomas in the community: with higher prevalences, costs per true positive would be lower. Screening the 40-59 years age group was found to be about as economic as for older people, when life expectancy was taken into account. It was concluded that glaucoma screening of people over age 40 years could be justifiable, provided that it is worth more than about $850 to detect a new case. Whilst based on UK values, the analysis could be applied to different primary health care settings in other countries.

Comparison of examination fees and availability of routine vision care by optometrists and ophthalmologists.

A national telephone survey of eye care practitioners shows that the average fee for routine eye examinations was less among optometrists than ophthalmologists. The average wait for the earliest appointment was 5 days for optometrists and 20 days for ophthalmologists. Weekend and evening appointments were also more obtainable among optometrists. The study did not determine what tests were included in the routine examination of each practitioner. Optometrists are licensed to use diagnostic drugs in all 50 States and prescribe therapeutic drugs for the treatment of ocular diseases in 25 States. Legislation that would update State laws permitting doctors of optometry to prescribe and use pharmaceutical agents for the treatment of eye diseases has been introduced in many of the remaining States. Supporters of bills permitting therapeutic pharmaceutical optometry contend that these changes would ensure the availability of quality eye care at significant savings, since optometric fees are generally lower than ophthalmological fees. In addition, it has been argued that optometrists are equitably distributed geographically and are more likely to have weekend and evening office hours, thus enabling increased patient access to eye care. When considering cost-effectiveness and accessibility, this study may provide information to those States considering changes in the scope of optometric licensure.

Cost-effectiveness of glycemic control and ophthalmological care in diabetic retinopathy.

AIMS: Glycemic control and ophthalmological care are known to significantly diminish the risk of visual impairment and blindness by diabetic retinopathy (DRP). The (cost-)effectiveness of both strategies was studied to highlight their benefits for patients and care providers. METHODS: A computer analysis was developed, following the progression of DRP and the effectiveness of metabolic control and ophthalmological care continuously and individually in cohorts of type I and type II DM patients with divergent degrees of compliance. Costs relate to present medical charges in the Netherlands. RESULTS: Intensive glycemic control shortens the duration of blindness in a type I DM patient by 0.76 years, intensive ophthalmological care by 0.53 years. One year sight gain may cost 1126 euros by providing ophthalmological care and 50479 euros by glycemic control. The duration of blindness drops in a type II DM patient by 0.48 and 0.13 years, respectively, whereas the effectiveness decreases as the age of onset of DM rises. CONCLUSIONS: The vast majority of diabetic patients benefits from both intensive glycemic control and intensive ophthalmological care, but these cost-effective interventions which are not only complementary, but also substitute each other, require lasting, full compliance by all parties concerned.

Picture archiving and fundus imaging in a glaucoma clinic.

Ophthalmological image archiving and distribution can be automated using a picture archiving and communication system (PACS). A fundus PACS has been in clinical use since February 2000 at the ophthalmology clinic of Tampere University Hospital. It consists of a digital fundus camera, an imaging workstation, from which new patients can be added to the archive, 10 viewing stations and an image archive server. In glaucoma imaging, the fundus images taken from a patient are transferred from the imaging workstation to the image archive server and are then immediately available from the physician's viewing workstation; the transfer time of an average image, of 350 kbit, is 0.0035 s, even though the archive is located 5 km away. After 18 months of operation there were over 16,000 images archived; these took 5.3 GByte of a total storage capacity of 41.9 GByte. The network and archive server achieved 99% reliability in use. Digital imaging makes it possible to shift ophthalmology clinics towards more patient-oriented treatment procedures.

[Is fundus photography useful in screening for diabetic retinopathy in patients with type II diabetes mellitus?]. / Is fundusfotografie zinvol bij de screening op diabetische retinopathie bij patiënten met diabetes mellitus type II?

OBJECTIVE: To determine the value of a screening programme with fundus photography for diabetic retinopathy in diabetes mellitus type II patients. DESIGN: Prospective. SETTING: General practices in the region Zwolle, The Netherlands. METHOD: 650 Patients from 50 general practices were photographed after dilating both eyes. Of these 215 were examined by an ophthalmologist. Data of patients who did not join the study were analysed in 13 general practices. Any symptom of retinopathy and/or photographs of poor quality implied referral to an ophthalmologist. RESULTS: Of a total of 1300 photographs 208 (16%) could hardly or not at all be assessed. The agreement in the group of 215 patients between photography and ophthalmoscopy was statistically significant at classification level (Cohen's kappa 0.41). The advice given to patients after photography did not differ from that after ophthalmoscopy (kappa: 0.50); photography did not miss any high-risk characteristics, it yielded more warnings, and underestimated the level of retinopathy in 8 out of 215 cases. With current ophthalmologic rates in the Netherlands fundus photography was not financially advantageous as 71 (33%) out of 215 patients needed to be referred to an ophthalmologist. However, in the other 144 (67%) patients photography sufficed. This may offer a solution where ophthalmic care is in short supply. Of 168/420 patients who did not apply for photography 116 (69%) were either under ophthalmic supervision already or too disabled to be screened. CONCLUSION: The use of a fundus camera is equivalent to funduscopy by an ophthalmologist in screening for retinopathy of type II diabetic patients. There are no financial benefits, but it reduces the work load of ophthalmologists.

Screening for diabetic retinopathy in a clinical setting: a comparison of direct ophthalmoscopy by primary care physicians with fundus photography.

BACKGROUND: Type II diabetes mellitus is a major health problem among Native Americans, and diabetic retinopathy is a frequent complication of this disease. Screening for retinopathy can identify early disease and prevent major vision loss, but the most cost-effective screening method has not yet been determined. METHODS: In a rural clinic that served more than 400 Native Americans with diabetes, we compared the accuracy of referrals made based on two screening methods: ophthalmoscopy by trained primary care physicians and seven-view nonstereoscopic, mydriatic fundal photography read by two general ophthalmologists and a retinal specialist. Patients in whom abnormal findings were detected by either screening method were then referred to a general ophthalmologist for further evaluation. RESULTS: Two hundred forty-three examinations were performed and 83 referrals made. Both screening methods had high sensitivity for referring patients with retinopathy that required treatment or follow-up sooner than 1 year (100% for direct ophthalmoscopy by primary care physicians, 94% for the general ophthalmologist photography readers, and 100% for the retinal specialist reader). The calculated costs of screening by direct ophthalmoscopy and by retinal photography were 64% less and 44% to 35% less, respectively, than the cost of yearly ophthalmological examinations by ophthalmologists. CONCLUSIONS: Careful screening for treatable diabetic eye disease by trained primary care physicians proved to be a clinically acceptable, cost-effective strategy. Screening methods for diabetic retinopathy should be evaluated based on the absolute sensitivity, specificity, and predictive values of their ability to correctly refer patients rather than their diagnostic accuracy.

Technology assessment applied: a comparison of ophthalmic diagnostic techniques to detect diabetic retinopathy among Aboriginal people in central Australia.

Diabetes mellitus is one of the non-communicable diseases that has accompanied Aboriginal exposure to Western life style. The prevalence of diabetes mellitus is higher in the Aboriginal population than in non-Aboriginal Australians (Holding, 1985) and many Aboriginals who have diabetes mellitus develop diabetic retinopathy. Early detection facilitates treatment and prevention of blindness, a sequela of diabetic retinopathy. This paper describes the use of technology assessment as a framework for comparing two diagnostic technologies, fundal camera and ophthalmoscope, for use with Aboriginal people in central Australia.

Do all candidemic patients need an ophthalmic examination?

Intraocular candidiasis is a potentially sight-threatening complication of candidemia. While the incidence of candidemia in North America has increased, the prevalence of intraocular candidiasis appears to be decreasing. In the USA and Europe, an ophthalmic examination is recommended for all candidemic patients to rule out intraocular involvement. However, improvements in management, clarification of the diagnosis, and trends in the epidemiology of intraocular candidiasis suggest that some candidemia patients might be safely managed without the recommended dilated ophthalmic examination.

Cost-utility analysis of telemedicine and ophthalmoscopy for retinopathy of prematurity management.

OBJECTIVE: To evaluate the cost-effectiveness of telemedicine and standard ophthalmoscopy for retinopathy of prematurity (ROP) management. METHODS: Models were developed to represent ROP examination and treatment using telemedicine and standard ophthalmoscopy. Cost-utility analysis was performed using decision analysis, evidence-based outcome data from published literature, and present value modeling. Visual outcome data were converted to patient preference-based time trade-off utility values based on published literature. Costs of disease management were determined based on 2006 Medicare reimbursements. Costs per quality-adjusted life year gained by telemedicine and ophthalmoscopy for ROP management were compared. One-way sensitivity analysis was performed on the following variables: discount rate (0%-7%), incidence of treatment-requiring ROP (1%-20%), sensitivity and specificity of ophthalmoscopic diagnosis (75%-100%), percentage of readable telemedicine images (75%-100%), and sensitivity and specificity of telemedicine diagnosis (75%-100%). RESULTS: For infants with birth weight less than 1500 g using a 3% discount rate for costs and outcomes, the costs per quality-adjusted life year gained were $3193 with telemedicine and $5617 with standard ophthalmoscopy. Sensitivity analysis resulted in ranges of costs per quality-adjusted life year from $1235 to $18,898 for telemedicine and from $2171 to $27,215 for ophthalmoscopy. CONCLUSIONS: Telemedicine is more cost-effective than standard ophthalmoscopy for ROP management. Both strategies are highly cost-effective compared with other health care interventions.

Cost-effectiveness of strategies for detecting diabetic retinopathy.

A computer model has been developed to determine cost-effectiveness of screening and treatment for diabetic retinopathy from a societal viewpoint. This model was used to evaluate biannual and annual screening programs using ophthalmoscopy, fundus photography with a "nonmydriatic camera," and photography with a "mydriatic camera." Computations were performed for three subpopulations formed by patients with younger onset diabetes (age at diagnosis less than 30 years) of 5 years or more duration, with older onset diabetes (age at diagnosis greater than or equal to 30 years) who are taking insulin, and with older onset diabetes not taking insulin. Population characteristics are from a well-described southern Wisconsin population where data are available, but the computer model may be specialized to other population. Generally costs of screening programs appear to be recovered by avoided costs of blindness in the population subgroups taking insulin; however, the cost of screening programs generally are not recovered by avoiding costs of blindness in the older onset population subgroup not taking insulin. It was estimated that supplying annual examination with mydriatic fundus photography as a screening program to a cohort of 1,000 diabetics from the younger onset population who have been diagnosed at least 5 years and who are currently not receiving care might save 319 sight years over the lifetime of the cohort. This program will save 62 sight years in an older onset cohort who are taking insulin, and 21 sight years in the older onset population not taking insulin (all benefits are presented as present values computed with an annual discount rate of 5%). Other programs achieve slightly lower savings in each subpopulation.