Management of Ocular Manifestations of Atopic Dermatitis: A Consensus Meeting Using a Modified Delphi Process.

There is a need for unified guidance on the management of ocular manifestations of atopic dermatitis and ocular manifestations associated with dupilumab in the Nordic region (Denmark, Finland, Norway and Sweden). This initiative gathered Nordic dermatologists and ophthalmologists to identify consensus in this area using a modified Delphi process. The initiative was led by a Nordic expert panel who developed a questionnaire that was circulated to a wider group. The results informed an agenda consisting of 24 statements to be voted on using a 5-point Likert scale at a meeting in Copenhagen on 24 April 2019. A facilitator moderated discussion and revised statements according to expert feedback for a second vote when required to reach consensus. Consensus was reached for 23 statements regarding the diagnosis, treatment and referral of these patients, which we hope will improve patient management in the Nordic region.

Eye Complications During Dupilumab Treatment for Severe Atopic Dermatitis.

Dupilumab, the first biologic approved for treatment of atopic dermatitis, has demonstrated significant clinical effect and quality of life-enhancing capacity in clinical trials. In these, dupilumab-associated conjunctivitis where reported in a minority of patients. The present case series describe 10 patients treated with dupilumab where eye complications were very common. We have described patient characteristics, including FLG mutations, atopic history and clinical effect of dupilumab. Nine of 10 developed eye-complications, most commonly conjunctivitis (in 7/10). Other adverse events were herpes simplex virus uveitis and varicella-zoster virus meningitis. Although our case series is small, we conclude that dupilumab is an effective treatment option in severe atopic dermatitis, but that the risk of adverse events from the eyes and recurrence of herpes virus infections should be kept in mind. Close collaboration with an ophthalmologist is recommended, especially among patients with severe, long-lasting atopic dermatitis and/or previous eye disease.

A novel melano-lysosome in the retinal epithelium of rhesus monkeys.

The large phagocytic load that confronts the retinal pigment epithelium (RPE) is thought to play a possible role in the pathogenesis of age related macular degeneration (AMD) that afflicts both humans and monkeys. Our knowledge of how RPE degrades phagosomes and other intra-cellular material by lysosomal action is still rudimentary. In this paper we examine organelles that play a role in this process, melanosome, lysosomes and phagosomes, in the RPE of young and old rhesus monkeys in order to better understand lysosomal autophagy and heterophagy in the RPE and its possible role in AMD. We used electron microscopy to detect and describe the characteristics of melanosomes and lysosome-like organelles in the macular RPE of rhesus monkeys (Macaca mulatta) that were 1, 6, 24, 24, 26 and 35 years of age. The measurements include the number, shape and size of these organelles located in the basal, middle and apical regions of RPE cells. Phaagosomes were also examined but not counted or measured for size or shape because of their rarity. Melanosomes were homogeneously dark with a circular or elliptical shape and decreased in number with age. Smaller melanosomes were more common at the basal side of the RPE. Among the small melanosomes, we found an organelle that was losing melanin in varying degrees; in some cases was nearly devoid of melanin. Because of the melanin loss, we considered this organelle to be a unique type of autophagic melano-lysosome, which we called a Type 1 lysosome. We found another organelle, more canonically lysosomal, which we called a Type 2 lysosome. This organelle was composed of a light matrix containing melanosomes in various stages of degradation. Type 2 lysosomes without melanosomes were rare. Type 2 lysosomes increased while Type 1 decreased in number with age. Phagosomes were rare in both young and old monkeys. They made close contact with Type 2 lysosomes which we considered responsible for their degradation. Melanosomes are being lost from monkey RPE with age. Much of this loss is carried out by two types of lysosomes. One, not defined as unique before, appears to be autophagic in digesting its own melanin; it has been called a Type 1 lysosome. The other, a more canonical lysosome, is both heterophagic in digesting phagosomes and autophagic in digesting local melanosomes; it has been called a Type 2 lysosome. Type 1 lysosomes decrease while type 2 lysosomes increase with age. The loss of melanin is considered to be detrimental to the RPE since it reduces melanin's protective action against light toxicity and oxidative stress. Phagosomes appear to be degraded by membrane contacts with Type 2 lysosomes. The loss of melanin and the buildup of Type 2 lysosomes occur at an earlier age in monkeys than humans implying that a greater vulnerability to senescence accelerates the rate of AMD in monkeys.

Topographic and age-related changes of the retinal epithelium and Bruch's membrane of rhesus monkeys.

PURPOSE: To examine structural differences in the retinal pigmented epithelium (RPE) and Bruch's membrane of rhesus monkeys (Macaca mulatta) as a function of topography and age. METHODS: The retinas of two old (24 and 26 years old) and two young (1 and 6 years old) female monkeys were examined by light fluorescence and electron microscopy at the macula, equator, and ora serrata. RESULTS: All monkeys lacked fluorescence and lipofuscin granules in the RPE at the ora serrata where photoreceptors are absent. The equator and macula showed intense fluorescence and many lipofuscin granules in the RPE of the old but not the young monkeys. At the ora, the RPE contained many dense round melanin granules throughout the cell. At the equator and macula, melanin granules were more apical, less frequent, and often elongated. Mitochondria were clustered at the basal side of the RPE cell near infolds of the plasma membrane. Both mitochondria and infolds tended to increase toward the macula. In all regions, the basal lamina of the RPE did not penetrate the extracellular space adjacent to infolds. The elastin layer of Bruch's membrane was wide at the ora and equator and thinner at the macula. In the old monkeys, drusen were found at all retinal regions between the basal lamina and the internal collagen layer of Bruch's membrane. The drusen were often membrane-bound with a basal lamina and contained material resembling structures in the RPE. CONCLUSIONS: Lack of fluorescence and lipofuscin in the RPE at the ora serrata, where photoreceptors are absent, confirms that RPE fluorescence occurs only where outer segments are phagocytized. Mitochondrial clustering indicates that the basal side of the RPE cell uses the most energy and this becomes maximal at the macula. The presence of age-related degenerative changes and drusen at all retinal locations in the older monkeys, even at the ora where RPE lipofuscin was absent, indicates that these processes are not dependent on local lipofuscin accumulation. Therefore lipofuscin toxicity may not be the sole cause of age-related RPE degeneration.

The Ultrastructure, Spatial Distribution, and Osmium Tetroxide Binding of Lipofuscin and Melanosomes in Aging Monkey Retinal Epithelium.

PURPOSE: To examine the ultrastructure of lipofuscin bodies and melanosomes in retinal epithelium of elderly rhesus monkeys and determines changes in their number and morphology as a function of retinal eccentricity. METHODS: Electron microscopy was used to describe and quantify two major organelles in elderly monkey retinal epithelium, lipofuscin bodies and melanosomes, at different retinal loci extending from the macula to the peri-macula, equator, periphery and ora serrata. Osmium tetroxide was used to distinguish lipofuscin bodies from melanosomes. RESULTS: Lipofuscin bodies and melanosomes diminished in number with advanced age but there was an inverse relationship between these two organelles. Lipofuscin bodies were more numerous in the macula and melanosomes more numerous in the peripheral retina. Three types of lipofuscin bodies were identified: 1) smaller and tending to locate in the middle third of the epithelial cell, 2) larger, less common, and located more basally, and 3) extremely rare, melano-lipofuscin, containing a melanosome. When osmicated, all lipofuscin bodies contained electron dense materials. When osmium tetroxide was not used for fixation, the first two types of lipofuscin bodies lost their electron densities while the third type retained its electron density due to the melanosome it contained. CONCLUSION: As previously reported for human retina, lipofuscin is most abundant in the macular and peri-macular epithelium and least abundant in the periphery, whereas melanosomes show the opposite relationship. This distribution pattern could contribute to the macula's greater vulnerability to photo-toxicity. Three types of lipofuscin bodies are found in aging monkey retinal epithelium. All types contain electron dense material, but the most prominent two types lose their densities in the absence of osmium tetroxide during fixation. Most of the electron densities in lipofuscin bodies must contain a material that binds strongly to osmium tetroxide such as polyunsaturated fatty acids.

Drusenoid maculopathy in rhesus monkeys: autofluorescence, lipofuscin and drusen pathogenesis.

PURPOSE: To examine patterns of retinal pigment epithelial autofluorescence and lipofuscin accumulation in relation to drusen and to explore the pathogenesis of drusen in rhesus monkeys. METHODS: The macular areas of six rhesus monkeys, euthanized at 19 to 28 years of age, were studied by bright field and fluorescence light microscopy and transmission electron microscopy. RESULTS: There was strong autofluorescence in the retinal epithelium that tended to diminish over drusen. Electron microscopy revealed that all retinal epithelial cells had large concentrations of lipofuscin bodies. The epithelial cells overlying drusen, however, tended to have less lipofuscin than epithelial cells not associated with drusen. Electron microscopy revealed that the epithelial cells overlying drusen were losing segments of cytoplasm containing lipofuscin bodies. Macrophage-like cells were consistently present in Bruch's membrane microns away from this lipofuscin-containing cytoplasmic material. CONCLUSIONS: Retinal epithelial cells overlying drusen have less lipofuscin than neighboring epithelial cells. The loss of lipofuscin seems due to a loss of cytoplasm containing lipofuscin that contributes to drusen formation. Macrophages in Bruch's membrane may be responsible for removing this lipofuscin debris. The results support in vivo studies showing reduced autofluorescence over drusen and support the "budding" of epithelial cytoplasm as a source of drusen material.

Drusenoid maculopathy in rhesus monkeys (Macaca mulatta): effects of age and gender.

PURPOSE: To compare drusenoid maculopathy in monkeys with human age-related macular degeneration, and evaluate the influence of age, gender and caloric restriction. METHODS: Examination by indirect ophthalmoscopy, slit-lamp biomicroscopy and fundus photography, including in some cases fluorescein angiography, was performed on 61 male and 60 female rhesus macaques of ages 10-39 years. Fifty-four of the monkeys were maintained on a calorically restricted diet (approximately 30% lower than control levels) and 67 on an approximately ad libitum diet for 2-19 years, with all other environmental factors held constant. Maculopathies were graded on a 5-point scale and the effects of age, sex, and diet on prevalence and severity were examined. The retinas of six monkeys with macular drusen, 19-28 years old, were examined histologically. RESULTS: Rhesus monkeys showed a high prevalence (61%) of drusenoid maculopathy. The prevalence and severity of the maculopathy increased with age (p = 0.012). Fully half of all monkeys aged 10-12 years had some detectable degree of drusen. This high prevalence in young adulthood indicates that drusen develop much earlier in rhesus monkeys than in humans, who develop early maculopathy most rapidly at 50-60 years of age, even when correcting for the 3-fold difference in lifespan. No neovascularization or geographic atrophy was found. Females had a higher prevalence and severity than males (p = 0.019). Calorically restricted monkeys had a slightly lower prevalence and severity at 10-12 years than controls, but the difference was not statistically significant. This is an on-going project, and differences between the caloric restricted and ad-lib groups may emerge as the animals age. Some monkeys developed severe maculopathy in their 20s, with others unaffected in their 30s. The histology of drusen resembled those in human retina. CONCLUSION: Drusenoid maculopathy is common in rhesus monkeys, even in young adult life. Half of the rhesus monkeys examined have drusen at a much younger age than in humans. Severity of maculopathy was greater in female monkeys, a gender difference not consistently found in humans. No differences were detected due to caloric restriction, but a definitive test of this intervention will require a larger sample, longer period of observation, and/or an earlier institution of caloric restriction. Genetic factors are implied because with similar environments, some monkeys are affected at an early age, while older ones are not.

Alteration in choroidal blood flow produced by local pressure.

BACKGROUND: To investigate how transient pressure applied to the retinal pigment epithelium (RPE) layer and choroid affects choroidal blood flow in rabbits. METHODS: Twelve rabbits underwent vitrectomy and local retinectomy. In nine of the rabbits a glass rod was used to exert brief pressure on the RPE layer and choroid. Three of the rabbits had no pressure indentation and were considered to be controls. The choroidal circulation was studied by indocyanine green (ICG) angiography. The retina and choroid were studied by postmortem histology. RESULTS: Pressure on the RPE layer and choroid caused nonfluorescence in segments of retinal arteries and veins and reduced fluorescence in adjacent choroidal capillaries, producing a black region at the pressure site in the angiograms. The size of this region decreased during the angiogram, often accompanied by the appearance of fine channels considered to be flow through the partially blocked vessels; the obstructed ends of the vessels became increasingly hyperfluorescent. These changes lasted for about 24 h before the choroidal circulation recovered. Histology showed evidence of thrombotic-like material in choroidal arteries and veins at the areas of absent perfusion. After local retinectomies, there was no evidence of thrombosis in control eyes where no pressure had been applied. CONCLUSION: Brief pressure on the RPE and choroid causes immediate reduction in flow through choroidal vessels, which appears to be due to local thrombosis in small segments of these vessels that resolves slowly. This may reflect a tendency for thrombi to form rapidly in choroidal vessels; it may also depend on neural reflexes causing vasoconstriction. The long time course of recovery could result in retinal ischemia and may underlie the pathophysiology of other pressure insults to the choroid.

Age-related changes in the basement membrane of the retinal pigment epithelium of Rpe65 -/- and wild-type mice.

PURPOSE: To investigate unusual changes in the basal surface of the retinal pigment epithelium (RPE) cell layer in aging Rpe65 -/- and wild-type mice. METHODS: The retinas of Rpe65 -/- and wild-type mice of different ages-6 weeks and 3, 6, 12-13 and 16 months-were examined by electron microscopy. RESULTS: There was an age-related increase in the width of the basement membrane of both Rpe65 -/- and wild-type mice which was associated with loss of basal infoldings of the plasma membrane of the RPE cells and protrusions of basement membrane material deep into the cytoplasm of these cells. These changes were evident at 6 months of age in RPE65 -/- mice and became extensive at 1 year of age. Similar changes occurred in wild-type mice but were less extensive and were only evident after 1 year of age. CONCLUSIONS: There is an age-dependent abnormality that develops at the basal surface of murine RPE cells, which resembles some of the changes observed in human age-related macular degeneration. These changes occur earlier in life and are more extensive in Rpe65 mutant mice.

Long-term effects of short-term retinal bleb detachments in rabbits.

PURPOSE: To examine the effects of saline-induced bleb detachments in rabbit retina. METHODS: Retinal bleb detachments were produced by the injection of 50 microl of balanced salt solution (BSS) into the subretinal space of one eye of each of six rabbits using a glass pipette with a flat tip, 50 microm in diameter. The retina was examined by biomicroscopy, scanning laser ophthalmoscopy (SLO), auto-fluorescence and simultaneous fluorescein and indocyanine green (ICG) angiography. Histological examination was carried out at 1, 2, 3 and 4 months after surgery. RESULTS: All rabbits showed leakage of fluorescein for at least a day after detachment, but within 1 month the leakage ceased. ICG staining developed gradually at the level of the RPE or Bruch's membrane near sites of previous staining. Lipofuscin fluorescence also developed gradually around areas of staining. Histology revealed the source of the excessive lipofuscin to be in the RPE layer, especially in cells migrating away from Bruch's membrane. CONCLUSIONS: Short-term bleb detachments cause a transient breakdown in the blood-retinal barrier, long-term ICG staining at or deep to the RPE layer, hyperlipofuscinosis and migration of the RPE. The abnormal lipofuscin accumulation is apparent on fluorescence ophthalmoscopy and can be confused with markers such as green fluorescent protein.

Changes in the choroidal circulation of rabbit following RPE removal.

PURPOSE: To examine the effects of surgical removal of the retinal pigment epithelium (RPE) on the choroidal circulation of the rabbit. METHODS: The retina and choroid were examined by biomicroscopy, scanning laser ophthalmoscopy, fluorescein and indocyanine green angiography and histology at various times after the surgical removal of the RPE by gentle aspiration following a prior local vitrectomy and bleb detachment. Comparison was made between small and large areas of RPE removal, or only slight pressure to the retina without removal of RPE. RESULTS: Removal of the RPE layer causes transient leakage of vascular fluid into the subretinal space for at least a week after surgery and loss of perfusion in the underlying choroidal vessels and choriocapillaris at the débridement site. This reduction in local choroidal blood flow can occur within 15 min after RPE débridement and can be transient or permanent. Histology indicates that permanent changes are due to fibroblastic infiltration that compresses the choroidal vessels. Permanent changes tend to occur after removal of relatively large areas of RPE. The removal of small areas of RPE or slight pressure on the retina causes a transient loss of local choroidal perfusion, and fibroblastic infiltration into the choroid does not occur. CONCLUSION: Removal of the RPE causes changes throughout the underlying choroid. It reduces the circulation in the large choroidal vessels as well as the choriocapillaris. If large areas of RPE are removed, this choroidal non-perfusion can be permanent due to fibroblastic infiltration. Small areas of RPE removal or slight pressure on the retina lead to only transient reduction of the choroidal flow. The rapidity with which the choroidal blood flow can be reduced implies a reflex mechanism that responds to sudden RPE pressure and/or trauma. These changes are best observed with ICG angiography.