- •Diabetic Retinopathy
- •Preface
- •Acknowledgments
- •Contents
- •Contributors
- •Pathophysiology of Diabetic Retinopathy
- •1.1 Retinal Anatomy
- •1.1.1 History
- •1.1.2 Anatomy
- •1.1.3 Microanatomy of the Retina Neurons
- •1.1.4 Intercellular Spaces
- •1.1.5 Internal Limiting Membrane
- •1.1.6 Circulation
- •1.1.7 Arteries
- •1.1.8 Veins
- •1.1.9 Capillaries
- •1.2 Hemodynamics, Macular Edema, and Starling’s Law
- •1.3 Biochemical Basis for Diabetic Retinopathy
- •1.3.1 Increased Polyol Pathway Flux
- •1.3.2 Advanced Glycation End Products (AGEs)
- •1.3.3 Activation of Protein Kinase C (PKC)
- •1.3.4 Increased Hexosamine Pathway Flux
- •1.4 Macular Edema
- •1.5 Development of Proliferative Diabetic Retinopathy
- •1.6 Summary of Key Points
- •1.7 Future Directions
- •References
- •Genetics and Diabetic Retinopathy
- •2.1 Background for Clinical Genetics
- •2.2 The Role of Polymorphisms in Genetic Studies
- •2.3 Types of Genetic Study Design
- •2.4 Studies of the Genetics of Diabetic Retinopathy
- •2.4.1 Clinical Studies
- •2.4.2 Molecular Genetic Studies
- •2.4.3 EPO Promoter
- •2.4.4 Aldose Reductase Gene
- •2.4.5 VEGF Gene
- •2.5 Genes in or Near the HLA Locus
- •2.6 Receptor for Advanced Glycation End Products (RAGE) Genes
- •2.7 Endothelial NOS2 and NOS3 Genes
- •2.9 Solute Carrier Family 2 (Facilitated Glucose Transporter), Member 1 Gene (SLC2A1)
- •2.11 Potential Value of Identifying Genetic Associations with Diabetic Retinopathy
- •2.12 Summary of Key Points
- •2.13 Future Directions
- •Glossary
- •References
- •Epidemiology of Diabetic Retinopathy
- •3.1 Introduction and Definitions
- •3.2 Epidemiology of Diabetes Mellitus
- •3.3 Factors Influencing the Prevalence of Diabetes Mellitus
- •3.4 Epidemiology of Diabetic Retinopathy
- •3.5 Diabetes and Visual Loss
- •3.6 Prevalence and Incidence of Diabetic Retinopathy
- •3.7 By Diabetes Type
- •3.8 By Insulin Use
- •3.10 By Duration of Diabetes Mellitus
- •3.11 By Ethnicity
- •3.12 Gender
- •3.13 Age at Onset of Diabetes
- •3.14 Socioeconomic Status and Educational Level
- •3.15 Family History of Diabetes
- •3.16 Changes Over Time
- •3.17 Epidemiology of Diabetic Macular Edema (DME)
- •3.18 Epidemiology of Proliferative Diabetic Retinopathy (PDR)
- •3.19 Socioeconomic Impact of Diabetes
- •3.20 Socioeconomic Impact of Diabetic Retinopathy
- •3.21 Summary of Key Points
- •3.22 Future Directions
- •References
- •Systemic and Ocular Factors Influencing Diabetic Retinopathy
- •4.1 Introduction
- •4.2 Systemic Factors
- •4.2.1 Glycemic Control
- •4.2.1.1 Type 1 Diabetes Mellitus
- •4.2.1.2 Type 2 Diabetes Mellitus
- •4.2.1.3 Rapidity of Improvement in Glycemic Control
- •4.2.2 Glycemic Variability
- •4.2.3 Insulin Use in Type 2 Diabetes
- •4.2.5 Blood Pressure
- •4.2.6 Serum Lipids
- •4.2.7 Anemia
- •4.2.8 Nephropathy
- •4.2.9 Pregnancy
- •4.2.10 Other Systemic Factors
- •4.2.11 Influence on Visual Loss
- •4.3 Effects of Systemic Drugs
- •4.3.1 Diuretics
- •4.3.3 Aldose Reductase Inhibitors
- •4.3.4 Drugs That Target Platelets
- •4.3.5 Statins
- •4.3.6 Protein Kinase C Inhibitors
- •4.3.7 Thiazolidinediones (Glitazones)
- •4.3.8 Miscellaneous Drugs
- •4.4 Ocular Factors Influencing Diabetic Retinopathy
- •4.6 Economic Consequences
- •4.7 Summary of Key Points
- •4.8 Future Directions
- •References
- •Defining Diabetic Retinopathy Severity
- •5.1 Summary of Key Points
- •5.2 Future Directions
- •5.3 Practice Exercises
- •References
- •6.1 Optical Coherence Tomography (OCT)
- •6.2 Heidelberg Retinal Tomograph (HRT)
- •6.3 Retinal Thickness Analyzer (RTA)
- •6.4 Microperimetry
- •6.5 Color Fundus Photography
- •6.6 Fluorescein Angiography
- •6.7 Ultrasonography
- •6.8 Multifocal ERG
- •6.9 Miscellaneous Modalities
- •6.10 Summary of Key Points
- •6.11 Future Directions
- •6.12 Practice Exercises
- •References
- •Diabetic Macular Edema
- •7.1 Epidemiology and Risk Factors
- •7.2 Pathophysiology and Pathoanatomy
- •7.2.1 Anatomy
- •7.3 Physiology
- •7.4 Clinical Definitions
- •7.5 Focal and Diffuse Diabetic Macular Edema
- •7.6 Subclinical Diabetic Macular Edema
- •7.7 Refractory Diabetic Macular Edema
- •7.8 Regressed Diabetic Macular Edema
- •7.9 Recurrent Diabetic Macular Edema
- •7.10 Methods of Detection of Diabetic Macular Edema
- •7.11 Case Report 1
- •7.12 Case Report 2
- •7.13 Other Ancillary Studies in Diabetic Macular Edema
- •7.14 Natural History
- •7.15 Treatments
- •7.15.1 Metabolic Control and Effects of Drugs
- •7.16 Focal/Grid Laser Photocoagulation
- •7.16.1 ETDRS Treatment of CSME
- •7.17 Evolution in Focal/Grid Laser Treatment Since the ETDRS
- •7.18 Macular Thickness Outcomes After Focal/Grid Photocoagulation
- •7.19 Resolution of Lipid Exudates After Focal/Grid Laser Photocoagulation
- •7.20 Inconsistency in Defining Refractory Diabetic Macular Edema
- •7.21 Alternative Forms of Laser Treatment for Diabetic Macular Edema
- •7.22 Peribulbar Triamcinolone Injection
- •7.23 Intravitreal Triamcinolone Injection
- •7.24 Intravitreal Dexamethasone Delivery System
- •7.27 Combined Intravitreal and Peribulbar Triamcinolone and Focal Laser Therapy
- •7.28 Vitrectomy
- •7.29 Supplemental Oxygen and Hyperbaric Oxygenation
- •7.30 Resection of Subfoveal Hard Exudates
- •7.31 Subclinical Diabetic Macular Edema
- •7.32 Cases with Simultaneous Indications for Focal and Scatter Laser Photocoagulation
- •7.34 Factors Influencing Treatment of Diabetic Macular Edema
- •7.35 Sequence of Therapy
- •7.36 Interaction of Cataract Surgery and Diabetic Macular Edema
- •7.37 Summary of Key Points
- •7.38 Future Directions
- •References
- •Diabetic Macular Ischemia
- •8.1 Introduction
- •8.2 Pathogenesis, Anatomy, and Physiology
- •8.3 Natural History
- •8.4 Clinical Evaluation
- •8.5 Clinical Significance of Diabetic Macular Ischemia
- •8.6 Controversies and Conundrums
- •8.7 Summary of Key Points
- •8.8 Future Directions
- •References
- •Treatment of Proliferative Diabetic Retinopathy
- •9.1 Introduction
- •9.2 Laser Photocoagulation
- •9.2.1 Indications
- •9.2.2 PRP Technique
- •9.2.3 Complications
- •9.2.4 Outcome
- •9.3 Intraocular Pharmacological Therapy
- •9.4 Vitreoretinal Surgery
- •9.4.1 Indications
- •9.4.2 Preoperative Management
- •9.4.3 Instrumentation
- •9.4.4 Techniques
- •9.4.5 Postoperative Management
- •9.4.6 Complications
- •9.4.7 General Outcome
- •9.5 Follow-Up Considerations in PDR
- •9.6.1 Cataract and PDR
- •9.6.2 Dense Vitreous Hemorrhage and Untreated PDR
- •9.6.3 Untreated PDR with Diabetic Macular Edema
- •9.6.4 PDR with Severe Fibrovascular Proliferation/Traction Retinal Detachment
- •9.6.5 PDR with Neovascular Glaucoma
- •9.6.6 Conditions Altering the Clinical Course of PDR
- •9.7 Summary of Key Points
- •9.8 Future Directions
- •References
- •Cataract Surgery and Diabetic Retinopathy
- •10.1 Scope of the Problem of Diabetic Retinopathy Concomitant with Surgical Cataract
- •10.2 Visual Outcomes After Cataract Surgery in Patients with Diabetic Retinopathy
- •10.3 Postoperative Course and Special Considerations After Cataract Surgery in Patients with Diabetic Retinopathy
- •10.4 The Influence of Cataract Surgery on Diabetic Retinopathy
- •10.5 The Role of Ancillary Testing in Managing Cataract Surgery in Eyes with Diabetic Retinopathy
- •10.6 Candidate Risk and Protective Factors for Diabetic Macular Edema Induction or Exacerbation Following Cataract Surgery and Suggested Management Actions
- •10.7 The Problem of Adherence to Preferred Practice Guidelines
- •10.8 Management of the Diabetic Eye Without Macular Edema About to Undergo Cataract Surgery
- •10.9 Treatment of Diabetic Macular Edema Detected Before Cataract Surgery When the Macular View Is Clear
- •10.10 Management When Cataract Sufficient to Obscure the Macular View and DME Coexist or When Refractory DME and Cataract Coexist
- •10.11 Patients with Simultaneous Indications for Panretinal Photocoagulation and Cataract Surgery
- •10.12 Management of Cataract in Patients with Diabetic Retinopathy Undergoing Vitrectomy
- •10.13 Influence of Vitrectomy Surgery on Cataract Formation
- •10.15 Postoperative Endophthalmitis in Patients with Diabetic Retinopathy
- •10.16 Summary of Key Points
- •10.17 Future Directions
- •References
- •The Relationship of Diabetic Retinopathy and Glaucoma
- •11.1 Interaction of Diabetes and Glaucoma
- •11.2 Iris and Angle Neovascularization Pathoanatomy and Pathophysiology
- •11.3 Epidemiology
- •11.4 Clinical Detection
- •11.5 Classification
- •11.6 Risk Factors for Iris Neovascularization
- •11.7 Entry Site Neovascularization After Pars Plana Vitrectomy
- •11.8 Anterior Hyaloidal Fibrovascular Proliferation
- •11.9 Treatments for Iris Neovascularization
- •11.10 Modifiers of Behavior of Iris Neovascularization
- •11.11 Management of Neovascular Glaucoma
- •11.12 Summary of Key Points
- •11.13 Future Directions
- •References
- •The Cornea in Diabetes Mellitus
- •12.1 Introduction
- •12.2 Pathophysiology
- •12.3 Anatomy and Morphological Changes
- •12.4 Clinical Manifestations
- •12.5 Ocular Surgery
- •12.6 Treatment of Corneal Disease in Diabetes Mellitus
- •12.7 Conclusion
- •12.8 Summary of Key Points
- •12.9 Future Directions
- •References
- •Optic Nerve Disease in Diabetes Mellitus
- •13.1 Relevant Normal Optic Nerve Anatomy and Physiology
- •13.2 The Effect of Diabetes on the Optic Nerve
- •13.3 Nonarteritic Anterior Ischemic Optic Neuropathy and Diabetes
- •13.4 Diabetic Papillopathy
- •13.5 Disk Edema Associated with Vitreous Traction
- •13.6 Superior Segmental Optic Hypoplasia (Topless Optic Disk Syndrome)
- •13.7 Wolfram Syndrome
- •13.8 Summary of Key Points
- •13.9 Future Directions
- •References
- •Screening for Diabetic Retinopathy
- •14.1 Introduction
- •14.2 Who Does Not Need to Be Screened
- •14.5 Screening with Dilated Ophthalmoscopy by Ophthalmic Technicians or Optometrists
- •14.6 Screening with Dilated Ophthalmoscopy by Ophthalmologists
- •14.7 Screening with Dilated Ophthalmoscopy by Retina Specialists
- •14.8 Photographic Screening
- •14.9 Nonmydriatic Photography
- •14.10 Mydriatic Photography
- •14.11 Risk Factors for Ungradable Photographs
- •14.12 Number of Photographic Fields
- •14.13 Criteria for Referral
- •14.14 Obstacles to the Use of Teleophthalmic Screening Methods
- •14.15 Combination Methods of Screening
- •14.16 Case Yield Rates
- •14.17 Compliance with Recommendation to Be Seen by an Ophthalmologist
- •14.18 Intravenous Fluorescein Angiography and Oral Fluorescein Angioscopy
- •14.19 Automated Fundus Image Interpretation
- •14.20 Subgroups Needing Enhanced Screening Efforts
- •14.21 Screening in Pregnancy
- •14.22 Economic Considerations
- •14.23 Comparisons of the Screening Methods
- •14.24 Accountability of Screening Programs
- •14.25 Summary of Key Points
- •14.26 Future Directions
- •References
- •Practical Concerns with Ethical Dimensions in the Management of Diabetic Retinopathy
- •15.1 Incorporating Ancillary Testing in the Management of Patients with Diabetic Retinopathy
- •15.2.1 Case 1
- •15.2.2 Case 2
- •15.4 Working in a Managed Care Environment (Capitation)
- •15.5 Interactions with Medical Industry
- •15.7 Comanagement of Patients
- •15.9 Summary of Key Points
- •15.10 Future Directions
- •References
- •Clinical Examples in Managing Diabetic Retinopathy
- •16.1.1 Discussion
- •16.2 Case 2: Bilateral Proliferative Diabetic Retinopathy with Acute Vitreous Hemorrhage in One Eye and a Chronic Traction Retinal Detachment in the Other Eye
- •16.2.1 Discussion
- •16.2.2 Opinion 1
- •16.2.3 Opinion 2
- •16.2.4 Opinion 3
- •16.3 Case 3: Sight Threatening Diabetic Retinopathy in a Patient with Concomitant Medical and Socioeconomic Problems
- •16.3.1 Discussion
- •16.4 Case 4: Asymptomatic Retinal Detachment Following Vitrectomy in a Patient Who Has Had Panretinal Laser Photocoagulation
- •16.4.1 Discussion
- •16.5 Case 5: Management of Progressive Vitreous Hemorrhage Following Scatter Photocoagulation for Proliferative Diabetic Retinopathy
- •16.5.1 Discussion
- •16.6.1 Discussion
- •16.7 Case 7: Proliferative Diabetic Retinopathy with Macular Traction and Ischemia
- •16.7.1 Discussion
- •16.8 Case 8: What Is Maximal Focal/Grid Laser Photocoagulation for Diabetic Macular Edema?
- •16.8.1 Definition of the Problem
- •16.8.2 Discussion
- •16.9 Case 9: What Independent Information Does Macular Perfusion Add to Patient Management in Diabetic Retinopathy?
- •16.9.1 Discussion
- •16.10 Case 10: Macular Edema Following Panretinal Photocoagulation for Proliferative Diabetic Retinopathy
- •16.10.1 Discussion
- •16.11 Case 11: Diabetic Macular Edema with a Subfoveal Scar
- •16.11.1 Discussion
- •16.12.1 Definition of the Problem
- •16.12.2 Discussion
- •16.13.1 Definition of the Problem
- •16.13.2 Discussion
- •16.14 Case 14: How Is Diabetic Macular Ischemia Related to Visual Acuity?
- •16.14.1 Definition of the Problem
- •16.14.2 Discussion
- •References
- •Subject Index
Chapter 15
Practical Concerns with Ethical Dimensions in the Management of Diabetic Retinopathy
David J. Browning
In this chapter we will cover a number of diverse, yet practical topics, rarely covered in a book on diabetic retinopathy. What ties them together is the common thread of possessing an ethical dimension. Our goal will be to identify issues that arise daily in the care of patients with diabetic retinopathy that require a response by the ophthalmologist and examine what motivates the possible alternative behaviors by ophthalmologists. Scientific studies touching these topics are few. Whereas analogous issues arise in all fields of medicine, by tying them to our emphasis here on diabetic retinopathy the author hopes to establish immediacy. The perspective will be discursive, but not directive, because in many cases, a correct answer or solution based on evidence may not be clearly discernible or may be controversial. In each case, the concept of medicine as a profession operating under a tacit social contract is crucial. This social contract states that physicians are allowed ‘‘a high degree of autonomy in their professional affairs in return for vowing to use their medical and scientific expertise solely to promote the interests of their patients and the welfare of the public.’’1 In fact, the use of the word ‘‘solely’’ in this quotation indicates that the assertion is aspirational, not factual. Cases abound demonstrating that ophthalmologists are human and heir to self-interest. Ophthalmologists exhibit professionalism to the degree that we approach the goal and abjure self-interest and the perception of such in favor of our patients’ interest and that of the public.2
D.J. Browning (*)
Charlotte Eye Ear Nose & Throat Associates, Charlotte, NC 28210, USA
e-mail: dbrowning@ceenta.com
15.1Incorporating Ancillary Testing in the Management of Patients with Diabetic Retinopathy
Optical coherence tomography and fluorescein angiography are commonly used in the management of patients with diabetic retinopathy and require time to obtain. Practical aspects of integrating these studies into a clinic setting are worthy of discussion. How commonly the tests are used will vary from practice to practice, but we can define some useful bounds for the sake of discussion. The coauthors of this text were surveyed on the matter and five responded. The data are shown in Table 15.1.
For the sake of discussion, the median values will be used. If an ophthalmologist sees 40 patients per day and works 10 h per day, then he spends on average approximately 15 min per patient. On average, in half of these patients an OCT will be obtained and 1.5 min will be spent reviewing and analyzing the images. This will involve review of the OCT, interpreting the OCT for the medical record, in some cases assisted by a scribe, and often using the OCT to educate the patient pictorially.
The review of the OCT often begins with a series of thumbnail images on a computer screen (Fig. 15.1) in offices with electronic records or may be by review of paper records in a chart. This may give a sense of progression over time by serially comparing the false color maps. A longitudinal comparison may be obtained by a spreadsheet analysis and graphical portrayal of the central subfield mean thickness or the total macular volume (Fig. 15.2).3
D.J. Browning (ed.), Diabetic Retinopathy, DOI 10.1007/978-0-387-85900-2_15, |
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Table 15.1 Sample data on ancillary imaging by retina specialists managing patients with diabetic retinopathy |
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Number of |
Hours in |
Time |
% |
% of DR |
% of DR |
Time to |
Time to |
|
patients seen |
clinic per |
spent per |
with |
patients who |
patients who |
analyze an |
analyze an |
Doctor |
per day |
day |
patient |
DR |
get an OCT |
get an FA |
OCT (min) |
FA (min) |
|
|
|
|
|
|
|
|
|
1 |
50 |
10 |
12 |
23 |
30 |
* |
3.0 |
4.0 |
2 |
47 |
8 |
10.2 |
20 |
50 |
25 |
0.5 |
0.5 |
3 |
40 |
10 |
15 |
20 |
17 |
10 |
5.0 |
5.0 |
4 |
37 |
10 |
16.2 |
50 |
80 |
10 |
1.5 |
3.5 |
5 |
40 |
10 |
15 |
25 |
80 |
5 |
1.0 |
2.0 |
Median |
40 |
10 |
15 |
23 |
50 |
10 |
1.5 |
3.5 |
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Sometimes respondents provided more than one value for a cell. For example, a Florida-based ophthalmologist saw more patients per day in the winter than the summer (‘‘snowbird effect’’). For simplicity in such cases, the midpoint of any range given was chosen for the cell entry. *= no response given.
Fig. 15.1 Screenshot of a series of optical coherence tomography studies performed over time. The overall picture can be sensed quickly, and by double clicking on a particular image, the ophthalmologist can study it in detail
Finally, morphological details can be gathered by study of the individual line scans and groups of scans (e.g., macular cube, series of raster line scans). The entry of the interpretation in the record
may be by free typing or by use of pick lists and drop-down menus in an electronic medical record or by ticking pre-printed options in a paper interpretation sheet or by a free handwritten note.
15 Practical Concerns with Ethical Dimensions in the Management of Diabetic Retinopathy |
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Fig. 15.2 Example of the graphical depiction of central subfield mean thickness (Y-axis, in microns) over time (X-axis, dates given). Interventions and their dates appear at the bottom of the screen. Spreadsheet software has been described for this purpose and it is included in some electronic medical records products3
Because the use of these studies is so common, the careful preparation of the drop-down lists can save time in the clinic.
The relationship of patient flow through the clinical encounter and imaging sequence deserves comment. Some physicians obtain OCTs on everyone, regardless of the clinical status.4–6 Other physicians obtain OCTs selectively. There are at least two possible models for arranging patient flow. The first is shown in Fig. 15.3.
In the first model, a patient will experience anywhere from three to seven steps. In the second model (Fig. 15.4), the possibilities are three to six steps. The more time-efficient model will depend on the nature of the practice. If there are a high proportion of patients for routine examination and little pathology, then the first model is superior, because most of the patients will not require any ancillary testing. In such a practice, the second model will probably have more tests done that really were unnecessary, because it is unlikely that the technician, no matter how well trained, can make as accurate a choice as if the ophthalmologist makes all the decisions. Most of the visits in this scenario will follow the three-step pathway. The first model is inferior, however, if the ophthalmologist’s practice
is filled with problematic patients. In this case, few patients will travel through the three-step pathway and many more will follow the sixand seven-step paths. Under the second model, however, these problematic patients will pass through five or six steps, saving time. The disadvantage of this model is that it requires a highly trained technician who can properly execute guidelines for the ordering of ancillary tests.
There are many guidelines for the screening technician that could be used. An example is shown in Table 15.2.
In a practice in which the technician has the latitude to order an ancillary test before the patient sees the ophthalmologist, the potential exists for unnecessary testing. If the examination does not support the need for the testing, it cannot be billed, thus a certain fraction of tests will be wasted effort and will have to be written off. The compensating advantage has to do with savings in time through patient flow involving fewer steps. Fluorescein angiograms are unlikely to be treated the same way. First, they have some risk, unlike OCT. Furthermore, they are needed in approximately one-fifth the number of cases as OCT based on the survey data (Table 15.1).
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Fig. 15.3 Patient flow under a model in which decisions on ancillary imaging reside with the ophthalmologist alone
The reimbursement rules by payors of medical care for ancillary testing are interpreted by ophthalmologists with different perspectives. Some are concerned that the ophthalmologist must examine the patient first and indicate in the record an order to obtain the ancillary test. Other ophthalmologists interpret the matter such that guidelines like those listed in Table 15.2 under the supervision of the attending ophthalmologist are permissible for obtaining the OCT before the patient sees the physician.
The scientific basis for ancillary testing in management of diabetic retinopathy has been little explored. OCT and fluorescein angiography (FA) are used because ophthalmologists have these techniques, enjoy having the information they provide for documentation and education of the patient, appreciate the advantage of decision making based on objective data rather than subjective clinical examination findings, and in some healthcare systems they are a source of revenue. For FA, the randomized clinical trial proving treatment efficacy
used the tests to guide treatment.7 However, we do not know from scientific studies that our patients have better outcomes because we use FA and OCT in their management. Some evidence has been published to suggest that outcomes are similar if FA is
omitted, and the effect of using OCT on outcomes has not been studied.8,9 It may be an expensive
fallacy that the paradigm chosen for the purposes of a randomized trial should be translated without modification to routine clinical practice.10
With respect to OCT, the cost of adding these machines to practice has indisputably added to the cost of medical care of diabetic macular edema, and yet we have no clinical trial data that justify the added expense – data showing that outcomes using OCT for management are superior to outcomes without OCT. As spectral domain OCT displaces time domain OCT at further high expense, it is again paradoxical that we have no evidence that the extra financial outlay purchases better visual outcomes for our patients.
15 Practical Concerns with Ethical Dimensions in the Management of Diabetic Retinopathy |
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Fig. 15.4 Patient flow under a model in which decisions on ancillary imaging can be made by the technician who works up the patient based on decision rules devised by the ophthalmologist
Table 15.2 An example of indications for obtaining optical coherence tomography before the patient sees the ophthalmologist
1.Patient presents with referral note along the lines ‘‘suspect central retinal vein occlusion, branch retinal vein occlusion, macular hole, macular pucker, cystoid macular edema, macular edema, or diabetic macular edema’’
2.Patient has the diagnosis of central retinal vein occlusion, branch retinal vein occlusion, or diabetic macular edema and has not had an OCT in 4 months
3.A patient with neovascular age-related macular degeneration meets the following criteria:
a.Treatment within the past year
b.No OCT in the past 4 weeks
4.Patient is sent for a consultation following cataract surgery performed within the previous 6 months and the vision did not return as expected
5.Patient with type 1 diabetes with duration greater than 20 years and new to the retina doctor
6.Patient with type 2 diabetes of duration greater than 10 years and new to the retina doctor
7.Patient with diabetes of any type who has vision less than 20/20 best corrected and is referred to the retina doctor to explain subnormal vision
8.For an established patient if the previous note indicates the need for OCT at the next visit
OCT = optical coherence tomography.
The situation is different for fluorescein angiography. Although the modality has seen a transition from film to digital media, the expenses associated with its use are largely unchanged over the last 30
years. The usage of FA in managing DME has diminished over time, unlike the situation with OCT (see Chapter 7). However, as with OCT, this change has not been a response to clinical trial data
