Long-term drusen study

OCT and OCT Angiography Update: Clinical Application to Age-Related Macular Degeneration, Central Serous Chorioretinopathy, Macular Telangiectasia, and Diabetic Retinopathy

Similar to ultrasound adapting soundwaves to depict the inner structures and tissues, optical coherence tomography (OCT) utilizes low coherence light waves to assess characteristics in the eye. Compared to the previous gold standard diagnostic imaging fluorescein angiography, OCT is a noninvasive imaging modality that generates images of ocular tissues at a rapid speed. Two commonly used iterations of OCT include spectral-domain (SD) and swept-source (SS). Each comes with different wavelengths and tissue penetration capacities. OCT angiography (OCTA) is a functional extension of the OCT. It generates a large number of pixels to capture the tissue and underlying blood flow. This allows OCTA to measure ischemia and demarcation of the vasculature in a wide range of conditions. This review focused on the study of four commonly encountered diseases involving the retina including age-related macular degeneration (AMD), diabetic retinopathy (DR), central serous chorioretinopathy (CSC), and macular telangiectasia (MacTel). Modern imaging techniques including SD-OCT, TD-OCT, SS-OCT, and OCTA assist with understanding the disease pathogenesis and natural history of disease progression, in addition to routine diagnosis and management in the clinical setting. Finally, this review compares each imaging technique's limitations and potential refinements.

Negative Regulators of Angiogenesis, Ocular Vascular Homeostasis, and Pathogenesis and Treatment of Exudative AMD

Angiogenesis, the formation of new blood vessels from pre-existing capillaries, is very tightly regulated and normally does not occur except during developmental and reparative processes. This tight regulation is maintained by a balanced production of positive and negative regulators, and alterations under pathological conditions such as retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration can lead to growth of new and abnormal blood vessels. Although the role of proangiogenic factors such as vascular endothelial growth factor has been extensively studied, little is known about the roles of negative regulators of angiogenesis in the pathogenesis of these diseases. Here, we will discuss the role of thrombospondin-1 (TSP1), one of the first known endogenous inhibitors of angiogenesis, in ocular vascular homeostasis, and how its alterations may contribute to the pathogenesis of age-related macular degeneration and choroidal neovascularization. We will also discuss its potential utility as a therapeutic target for treatment of ocular diseases with a neovascular component.

Photobiomodulation reduces drusen volume and improves visual acuity and contrast sensitivity in dry age-related macular degeneration

Purpose

To evaluate the efficacy of photobiomodulation (PBM) treatment for patients with dry age‐related macular degeneration (AMD).

Methods

Assessments on 42 eyes with dry AMD (age related eye disease study (AREDS) 2–4) were conducted. Multiwavelength light emitting diode (LED) light comprising of yellow (590 nm), red (670 nm) and near‐infrared (790 nm) bandwidths was applied to subjects’ eyes for a treatment course of 3 weeks. Outcome measures were changes in best‐corrected visual acuity (BCVA), contrast sensitivity (CS), drusen volume and central drusen thickness.

Results

Significant improvement in mean BCVA of 5.90 letters (p < 0.001) was seen on completion of the 3‐week treatment and 5.14 letters (p < 0.001) after 3 months. Contrast sensitivity improved significantly (log unit improvement of 0.11 (p = 0.02) at 3 weeks and 3 months (log unit improvement of 0.16 (p = 0.02) at three cycles per degree. Drusen volume decreased by 0.024 mm³ (p < 0.001) and central drusen thickness was significantly reduced by a mean of 3.78 μm (p < 0.001), while overall central retinal thickness and retinal volume remained stable.

Conclusion

This is the first study demonstrating improvements in functional and anatomical outcomes in dry AMD subjects with PBM therapy. These findings corroborate an earlier pilot study that looked at functional outcome measures. The addition of anatomical evidence contributes to the basis for further development of a non‐invasive PBM treatment for dry AMD.

Laser treatment of drusen to prevent progression to advanced age-related macular degeneration

BACKGROUND

Drusen are amorphous yellowish deposits beneath the sensory retina. People with drusen, particularly large drusen, are at higher risk of developing age-related macular degeneration (AMD). The most common complication in AMD is choroidal neovascularisation (CNV), the growth of new blood vessels in the centre of the macula. The risk of CNV is higher among people who are already affected by CNV in one eye.It has been observed clinically that laser photocoagulation of drusen leads to their disappearance and may prevent the occurrence of advanced disease (CNV or geographic atrophy) associated with visual loss.

OBJECTIVES

To examine the effectiveness and adverse effects of laser photocoagulation of drusen in AMD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015, Issue 7), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to August 2015), EMBASE (January 1980 to August 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to August 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 3 August 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of laser treatment of drusen in AMD in which laser treatment had been compared with no intervention or sham treatment. Two types of trials were included. Some trials studied one eye of each participant (unilateral studies); other studies recruited participants with bilateral drusen and randomised one eye to photocoagulation or control and the fellow eye to the other group.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. We pooled data from unilateral and bilateral studies using a random-effects model. For the bilateral studies, we estimated the within-person correlation coefficient from one study and assumed it was valid for the others.

MAIN RESULTS

The update of this review found two additional studies, totaling 11 studies that randomised 2159 participants (3580 eyes) and followed them up to two years, of which six studies (1454 participants) included people with one eye randomised to treatment and one to control. Studies were conducted in Australia, Europe and North America.Overall, the risk of bias in the included studies was low, particularly for the larger studies and for the primary outcome development of CNV. Photocoagulation did not reduce the development of CNV at two years' follow-up (odds ratio (OR) 1.07, 95% confidence interval (CI) 0.79 to 1.46, 11 studies, 2159 participants (3580 eyes), high quality evidence). This estimate means that, given an overall occurrence of CNV of 8.3% in the control group, we estimated an absolute risk reduction by no more than 1.4% in the laser group, according to the lower CI limit. Only two studies investigated the effect on the development of geographic atrophy and could not show a difference, but estimates were imprecise (OR 1.30, 95% CI 0.38 to 4.51, two studies, 148 participants (148 eyes), low quality evidence).Among secondary outcomes, photocoagulation led to drusen reduction (OR 9.16, 95% CI 6.28 to 13.4, three studies, 570 participants (944 eyes), high quality evidence) but was not shown to limit loss of 3 or more lines of visual acuity (OR 0.99, 95% CI 0.81 to 1.22, nine studies, 2002 participants (2386 eyes), moderate quality evidence).In a subgroup analysis, no difference could be shown for conventional visible (eight studies) versus subthreshold invisible (four studies) photocoagulation for the primary outcomes (P value = 0.29). The effect in the subthreshold group did not suggest a relevant benefit (OR 1.27, 95% CI 0.82 to 1.98). No study used micropulse subthreshold photocoagulation.No other adverse effects (apart from development of CNV, geographic atrophy or visual loss) were reported.

AUTHORS' CONCLUSIONS

The trials included in this review confirm the clinical observation that laser photocoagulation of drusen leads to their disappearance. However, treatment does not result in a reduction in the risk of developing CNV, and was not shown to limit the occurrence of geographic atrophy or visual acuity loss.Ongoing studies are being conducted to assess whether the use of extremely short laser pulses (i.e. nanosecond laser treatment) cannot only lead to drusen regression but also prevent neovascular AMD.

Progressing geographic atrophy: choroidal thickness and retinal sensitivity identify two clinical phenotypes

PURPOSE

To analyse changes in choroidal thickness and retinal sensitivity (Se) in patients with geographic atrophy (GA) with or without choroidal neovascularisation (CNV) in the fellow eye.

PARTICIPANTS

Patients with bilateral GA (B-GA group) and patients with unilateral GA and CNV in the fellow eye (U-GA group) were followed every 6 months, and enhanced depth imaging optical coherence tomography (OCT), blue and near infrared-wavelength fundus autofluorescence (B- and NIR-FAF), and microperimetry were evaluated.

METHODS

GA area, choroidal thickness, and Se were measured in the eye with GA at baseline and every 6 months up to the last follow-up visit.

RESULTS

19 patients (8 in the B-GA group (16 eyes) and 11 in the U-GA group (11 eyes)) were studied. The mean±SD follow-up was 1.66±0.71 years (range 0.74-2.60 years) in the U-GA group, and 1.51±0.86 years (range 0.58-2.95 years) in the B-GA group (p=0.6766). Mean GA area was not significantly different between groups at baseline (p=0.4118 in the B-FA and p=0.6806 in the NIR-FAF) or at follow-up (p=0.5734 in the B-FAF and p=0.8945 in the NIR-FAF). Mean GA area significantly increased in both groups during follow-up (p=0.0050 for B-FAF and p=0.0052 for NIR-FAF in the U-GA group; p=0.0049 for B-FAF and p=0.0072 for NIR-FAF in the B-GA group). Choroidal thickness was significantly greater in the B-GA group compared with the U-GA group both at baseline (mean choroidal thickness 170.5±78.5 μm vs 129.1±36.1 μm; p=0.0371) and at last follow-up (173.2±86.1 μm vs 123±32.1 μm; p=0.0340). During follow-up mean choroidal thickness significantly decreased only in the U-GA group (p=0.0276); conversely mean Se significantly decreased only in B-GA group (p=0.0405).

CONCLUSIONS

During follow-up, changes in Se and choroidal thickness differed in patients with GA with or without CNV in the fellow eye. These results identify at least two GA phenotypes, in which the development and progression of GA may be primarily due to different pathophysiologic mechanisms.

Age-related macular degeneration and changes in the extracellular matrix

Age-related macular degeneration (AMD) is the leading cause of permanent, irreversible, central blindness (scotoma in the central visual field that makes reading and writing impossible, stereoscopic vision, recognition of colors and details) in patients over the age of 50 years in European and North America countries, and an important role is attributed to disorders in the regulation of the extracellular matrix (ECM). The main aim of this article is to present the crucial processes that occur on the level of Bruch’s membrane, with special consideration of the metalloproteinase substrates, metalloproteinase, and tissue inhibitor of metalloproteinase (TIMP).

A comprehensive review of the literature was performed through MEDLINE and PubMed searches, covering the years 2005–2012, using the following keywords: AMD, extracellular matrix, metalloproteinases, tissue inhibitors of metalloproteinases, Bruch’s membrane, collagen, elastin.

In the pathogenesis of AMD, a significant role is played by collagen type I and type IV; elastin; fibulin-3, -5, and -6; matrix metalloproteinase (MMP)-2, MMP-9, MMP-14, and MMP-1; and TIMP-3. Other important mechanisms include: ARMS2 and HTR1 proteins, the complement system, the urokinase plasminogen activator system, and pro-renin receptor activation.

Continuous rebuilding of the extracellular matrix occurs in both early and advanced AMD, simultaneously with the dysfunction of retinal pigment epithelium (RPE) cells and endothelial cells. The pathological degradation or accumulation of ECM structural components are caused by impairment or hyperactivity of specific MMPs/TIMPs complexes, and is also endangered by the influence of other mechanisms connected with both genetic and environmental factors.

Molecular mechanisms of retinal pigment epithelium damage and development of age-related macular degeneration

Age-related macular degeneration (AMD) is attributed to a complex interaction of genetic and environmental factors. It is characterized by degeneration involving the retinal photoreceptors, retinal pigment epithelium (RPE) and Bruch's membrane, as well as alterations in choroidal capillaries. AMD pathogenesis is strongly associated with chronic oxidative stress and inflammation that ultimately lead to protein damage, aggregation and degeneration of RPE. Specific degenerative findings for AMD are accumulation of intracellular lysosomal lipofuscin and extracellular drusens. In this review, we discuss thoroughly RPE-derived mechanisms in AMD pathology.

Intraretinal crystalline deposits in neovascular age-related macular degeneration

PURPOSE

The purpose of this study was to describe intraretinal crystalline deposits detected in eyes with neovascular age-related macular degeneration.

METHODS

A retrospective review of patients seen during a 6-month period with the diagnosis of neovascular age-related macular degeneration was performed to identify patients with intraretinal crystalline deposits, defined as pinpoint refractile bodies within the neurosensory retina. The characteristics of the deposits, including their shape, size, distribution, and location within the retina, were determined by analyzing color and red-free fundus photographs and spectral domain-optical coherence tomography images.

RESULTS

Fourteen eyes of 13 patients with neovascular age-related macular degeneration manifesting intraretinal crystalline deposits were identified. The patients had no history of ocular or systemic disease or prior medication use known to be associated with intraretinal crystals. Intravitreal antivascular endothelial growth factor injection was used in 10 eyes, laser photocoagulation in 3 eyes, and intravitreal triamcinolone in 1 eye. The retinal crystals were detected in the macula overlying or adjacent to the areas of choroidal neovascularization. The crystalline deposits could be localized with spectral domain-optical coherence tomography to both the outer nuclear and the outer plexiform layers.

CONCLUSION

Intraretinal crystalline deposits localized to the outer nuclear and outer plexiform layers can be detected in eyes with a history of neovascular age-related macular degeneration, often after treatment with a variety of different modalities. Potential etiologies of these deposits include residual lipid material from choroidal neovascularization leakage, degenerated Müller cell elements, and because these deposits were found in eyes with assorted forms of treatment, an external factor such as diet may play a role.

Alzheimer's disease: visual system review

BACKGROUND

Ten million baby boomers in the United States will get Alzheimer's disease. Optometrists can benefit from understanding the impact the Alzheimer's disease process has on the visual system. This can result in more effective management of the condition and in more effective communication with members of the Alzheimer's disease multidisciplinary team.

METHODS

This is a review of the literature but by no means a completely exhaustive review. Alzheimer's disease is a complex disease. A rapidly expanding body of knowledge covers multiple disciplines.

RESULTS

The visual system shows deficits early in the degenerative process of Alzheimer's disease. Biomarkers through the visual system such as nerve fiber deficits, lens opacities, and functional losses in the magnocellular pathway, such as contrast sensitivity and temporal processing, may prove to not only help detect Alzheimer's disease early but also detect it before there are the classic cognitive and memory losses.

CONCLUSIONS

The effects of Alzheimer's disease are devastating. Optometrists, as primary care clinicians, can make critical contributions in the diagnosis, treatment, and management of this neurodegenerative disease.

Laser treatment of drusen to prevent progression to advanced age-related macular degeneration

BACKGROUND

Drusen are amorphous yellowish deposits beneath the sensory retina. People with drusen, particularly large drusen, are at higher risk of developing age-related macular degeneration (AMD). The most common complication in AMD is choroidal neovascularisation (CNV), the growth of new blood vessels in the centre of the macula. The risk of CNV is higher among patients who are already affected by CNV in one eye.It has been observed clinically that laser photocoagulation of drusen leads to their disappearance and may prevent the occurrence of advanced disease (CNV or geographic atrophy) associated with visual loss.

OBJECTIVES

To examine the effectiveness and adverse effects of laser photocoagulation of drusen in AMD.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE and EMBASE on 14 November 2008.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of laser treatment of drusen in AMD in which laser treatment had been compared with no intervention or sham treatment. Two types of trials were included. Some trials studied one eye of each patient (unilateral studies); other studies recruited patients with bilateral drusen and randomised one eye to photocoagulation or control and the fellow eye to the other group.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. We pooled data from unilateral and bilateral studies using a random-effects model. For the bilateral studies, we estimated the within-patient correlation coefficient from one study and assumed it was valid for the others.

MAIN RESULTS

We found nine studies which randomised 2216 people: four unilateral trials, three bilateral trials and two trials that included both a unilateral and a bilateral study arm.Overall, the studies were of moderate quality. Only half of the trials reported adequate allocation sequence generation, allocation concealment and masking of visual acuity outcome assessors.Although two (of the nine) studies reported significant drusen disappearance at two years, photocoagulation did not appear to affect the development of CNV at two years follow up (nine studies, 1767 people followed up, odds ratio (OR) 1.04, 95% CI 0.71 to 1.51) or the loss of three or more lines of visual acuity (six studies, 1628 people followed up, OR 1.17, 95% CI 0.75 to 1.82).

AUTHORS' CONCLUSIONS

The trials included in this review confirm the clinical observation that laser photocoagulation of drusen leads to their disappearance. However, there is no evidence that this subsequently results in a reduction in the risk of developing CNV, geographic atrophy or visual acuity loss.

The Natural History and Prognosis of Neovascular Age-Related Macular Degeneration

PURPOSE

To describe the natural history and progression of visual loss in eyes with untreated neovascular age-related macular degeneration (AMD).

DESIGN

Systematic review and meta-analysis.

PARTICIPANTS

Four thousand three hundred sixty-two untreated neovascular AMD patients from published interventional studies.

METHODS

A systematic review of the literature from 1980 to August 2005 was performed. Studies reporting disease progression outcomes for untreated patients with neovascular AMD were included. Outcome measures were summarized using simple counts and means. Random effects meta-analyses were conducted and tests of heterogeneity were performed where appropriate.

MAIN OUTCOME MEASURES

Changes in visual acuity (VA) loss, development of comorbidities, and fellow eye involvement.

RESULTS

Fifty-three primary studies were included. Nearly half of the studies (28) were randomized clinical trials. The quality of the studies was high, with over 80% providing level I or II evidence. Mean baseline VA among study patients was 0.64 logarithm of the minimum angle of resolution (logMAR) (approximately 20/87 Snellen). The mean VA change in logMAR progressed from 0.1 (1 line lost) at 3 months to 0.3 (2.7 lines lost) after 12 months and 0.4 (4 lines lost) after 24 months. The proportion of patients who developed severe vision loss (>6 lines) from baseline increased from 21.3% at 6 months to 41.9% by 3 years. The proportion of patients with VA worse than logMAR 1.0 (20/200 Snellen) increased from 19.7% at baseline to 75.7% by 3 years. Neovascular AMD developed in the fellow eye in 12.2% of patients by 12 months and in 26.8% by 4 years. Meta-analyses of vision outcome by subtype of neovascular AMD were not possible.

CONCLUSIONS

A doubling of the visual angle of presenting VA may be expected to occur in the year after initial presentation in eyes with untreated neovascular AMD. No conclusions can be drawn as to the differences in rates of disease progression by neovascular AMD subtype. The diversity of reporting formats, paucity of long-term natural history data, and heterogeneity among the reported clinical studies impose limits to the clear understanding of long-term prognosis for visual function in neovascular AMD.

Regression of macular drusen after pars plana vitrectomy in a patient with age-related macular degeneration

PURPOSE

To report a case of marked regression of drusen and a pigment epithelial detachment (PED) with visual improvements after pars plana vitrectomy (PPV).

METHODS

A 67-year-old man noticed gradual visual deterioration to 20/80 due to macular soft drusen and a PED. A posterior vitreous detachment (PVD) was not present in the affected eye.

RESULTS

PPV was performed to create a PVD, and there was marked regression of drusen and a PED with visual improvement to 20/30. Vision was maintained at the final examination 30 months after surgery.

CONCLUSION

Vitrectomy may be considered for treatment of macular drusen and prevention of choroidal neovascularization.

Crystalline Retinopathies

Many types of crystalline retinopathies have been described, associated with a myriad of medical conditions ranging from chronic retinal conditions to inherited systemic diseases. This comprehensive review summarizes the different types of crystalline retinopathies, including their clinical presentations, diagnostic criteria, pathology, and treatment options.

Age-related macular degeneration--emerging pathogenetic and therapeutic concepts

Today, the average life expectancy in developed nations is over 80 years and climbing. And yet, the quality of life during those additional years is often significantly diminished by the effects of age-related, degenerative diseases, including age-related macular degeneration (AMD), the leading cause of blindness in the elderly worldwide. AMD is characterized by a progressive loss of central vision attributable to degenerative and neovascular changes in the macula, a highly specialized region of the ocular retina responsible for fine visual acuity. Estimates gathered from the most recent World Health Organization (WHO) global eye disease survey conservatively indicate that 14 million persons are blind or severely visually impaired because of AMD. The disease has a tremendous impact on the physical and mental health of the geriatric population and their families and is becoming a major public health burden. Currently, there is neither a cure nor a means to prevent AMD. Palliative treatment options for the less prevalent, late-stage 'wet' form of the disease include anti-neovascular agents, photodynamic therapy and thermal laser. There are no current therapies for the more common 'dry' AMD, except for the use of antioxidants that delay progression in 20%-25% of eyes. New discoveries, however, are beginning to provide a much clearer picture of the relevant cellular events, genetic factors, and biochemical processes associated with early AMD. Recently, compelling evidence has emerged that the innate immune system and, more specifically, uncontrolled regulation of the complement alternative pathway plays a central role in the pathobiology of AMD. The complement Factor H gene--which encodes the major inhibitor of the complement alternative pathway--is the first gene identified in multiple independent studies that confers a significant genetic risk for the development of AMD. The emergence of this new paradigm of AMD pathogenesis should hasten the development of novel diagnostic and therapeutic approaches for this disease that will dramatically improve the quality of our prolonged lifespan.

Prophylactic laser treatment in early age-related maculopathy: an 8-year follow-up in a randomized pilot study shows a reduced incidence of exudative complications

PURPOSE

To study the effect of mild laser treatment on the incidence of exudative complications in patients with soft drusen maculopathy in a longterm perspective.

METHODS

In a prospective study, 38 patients with early age-related maculopathy and good visual acuity (VA) were randomized either to laser treatment using an argon green laser or to observation. At 8 years, 29 patients remained in the study, 16 in the control group and 13 in the treatment group.

RESULTS

During follow-up, mean VA decreased significantly in both groups, to 0.53 in the treatment group (p < 0.05) and to 0.25 in the control group (p < 0.001). At 8 years, 9/16 in the control group showed exudative complications, whereas only 2/13 in the treatment group developed such changes (p < 0.03).

CONCLUSION

In this randomized pilot study, mild laser treatment of soft drusen maculopathy significantly reduced the rate of exudative complications in a longterm perspective. As the study is small, the results should be viewed with caution.

Clinical studies to implement Rheopheresis for age-related macular degeneration guided by evidence-based-medicine

In the majority of age-related macular degeneration (AMD) patients the therapeutic situation is very unsatisfactory, especially for patients with dry AMD. Rheopheresis is a safe and effective modality of therapeutic apheresis to treat microcirculatory disorders, and represents a novel therapeutic approach for patients with dry AMD and soft drusen. Elimination of a defined spectrum of high molecular weight proteins from human plasma including pathophysiologically relevant risk factors for AMD such as fibrinogen, LDL-cholesterol, alpha 2-macroglobulin, fibronectin, and von-Willebrand factor results in the reduction of blood and plasma viscosity as well as erythrocyte and thrombocyte aggregation. Pulses of lowering blood and plasma viscosity performed as series of Rheopheresis treatments lead to rapid changes of blood flow, subsequently inducing sustained improvement of microcirculation, and recovery of retinal function. Two controlled randomized clinical trials demonstrated safety and efficacy of Rheopheresis for the treatment of AMD patients, especially with the dry form. Recently the interim-analysis of the sham-controlled, double blinded, randomized multicenter MIRA-I trial confirmed these results. The RheoNet-registry and the development and continuous update of therapy guidelines provide an appropriate framework for the quality management of the interdisciplinary cooperation between ophthalmologists with apheresis specialists. A hypothesis based upon current knowledge of pathogenic mechanisms of the development and progression of AMD can be conclusively linked with the putative mechanism of action of Rheopheresis for AMD. A recommendation for high-risk AMD-patients was defined. Based on the positive results of the MIRA-1 interim analysis eight Rheopheresis treatments are currently recommended as the initial treatment series.

Age-related macular degeneration: etiology, pathogenesis, and therapeutic strategies

Age-related macular degeneration is the principal cause of registered legal blindness among those aged over 65 in the United States, western Europe, Australia, and Japan. Despite intensive research, the precise etiology of molecular events that underlie age-related macular degeneration is poorly understood. However, investigations on parallel fronts are addressing this prevalent public health problem. Sophisticated biochemical and biophysical techniques have refined our understanding of the pathobiology of drusen, geographic atrophy, and retinal pigment epithelial detachments. Epidemiological identification of risk factors has facilitated an intelligent search for underlying mechanisms and fueled clinical investigation of behavior modification. Gene searches have not only brought us to the cusp of identifying the culpable gene loci in age-related macular degeneration, but also localized genes responsible for other macular dystrophies. Recent and ongoing investigations, often cued by tumor biology, have revealed an important role for various growth factors, particularly in the neovascular form of the condition. Transgenic and knockout studies have provided important mechanistic insights into the development of choroidal neovascularization, the principal cause of vision loss in age-related macular degeneration. This in turn has culminated in preclinical and clinical trials of directed molecular interventions.

Detection of drusen in the fellow eye of Japanese patients with age-related macular degeneration using scanning laser ophthalmoscopy

OBJECTIVE

To study the prevalence of drusen in the fellow eye of Japanese patients with age-related macular degeneration (AMD).

DESIGN

Retrospective, cross-sectional study.

PARTICIPANTS

Seventeen eyes of 17 Japanese patients with unilateral AMD.

MAIN OUTCOME MEASURES

To compare the frequency of drusen based on photography and scanning laser ophthalmoscopy with confocal and ring apertures and a diode laser (780 nm).

RESULTS

Using the scanning laser ophthalmoscope (SLO) with a ring aperture, drusen were detected clearly as in topographic imaging. In the fellow eyes of the study patients with AMD, photography showed drusen in 10 cases (58.8%); however, SLO imaging detected drusen in 15 cases (88.2%). The number of drusen detected using SLO imaging was significantly greater than when using photography (P < 0.05).

CONCLUSIONS

Scanning laser ophthalmoscope imaging is superior to photography for detecting drusen in the fellow eyes of Japanese patients with unilateral AMD. The prevalence of drusen in the fellow eye of Japanese patients with AMD is much higher than previously speculated.

Rheopheresis for age-related macular degeneration: a novel indication for therapeutic apheresis in ophthalmology

Age-related macular degeneration (AMD) is the leading cause of visual impairment and blindness in the elderly. Successful therapy is not yet available for the majority of patients, especially not for patients with dry AMD. AMD at cellular and molecular levels is at least in part a microcirculatory disorder of the retina. Rheopheresis is a safe and effective modality of therapeutic apheresis to treat microcirculatory disorders and represents a novel treatment option for patients with dry AMD. Elimination of a defined spectrum of high molecular weight proteins from human plasma including pathophysiologically relevant risk factors for AMD such as fibrinogen, cholesterol, von Willebrand factor, and alpha 2-macroglobulin results in the reduction of blood and plasma viscosity as well as erythrocyte and thrombocyte aggregation. Pulses of lowering blood and plasma viscosity performed as a series of Rheopheresis treatments lead to rapid changes of blood flow, subsequently inducing sustained improvement of microcirculation and recovery of retinal function. Two controlled randomized clinical trials demonstrated the safety and efficacy of Rheopheresis for the treatment of AMD patients, especially for those with the dry form. Recently the interim analysis of the sham-controlled, double blind, randomized multicenter Multicenter Investigation of Rheopheresis for AMD (MIRA-I) trial confirmed these results. The framework of completed and still ongoing controlled clinical trials in combination with postcertification studies including the RheoNet registry represents a comprehensive quality management approach for this novel interdisciplinary therapy for AMD. The development and continuous update of guidelines for the precise indication of Rheopheresis for AMD follows the requirements of evidence-based medicine.