Angioid streaks associated with hereditary spherocytosis

Systemic disease associations with angioid streaks in a large healthcare claims database

BACKGROUND/OBJECTIVES

To assess systemic associations of angioid streaks (AS) using a large US healthcare database.

SUBJECTS/METHODS

A retrospective cross-sectional study was conducted of patients diagnosed with AS in a large, national US insurer from 2000-2019. Cases were matched 1:5 to controls. The prevalence rates of established associated disease states and other systemic diseases were calculated and compared using logistic regression. Additionally, the rate of anti-VEGF treatment was assessed as a proxy for the incidence of choroidal neovascularization (CNV).

RESULTS

One thousand eight hundred fifty-two cases of AS and 9028 matched controls were included. The rates of association between AS and the well-characterized conditions included: Pseudoxanthoma elasticum (PXE)-228 patients (12.3%), Ehlers-Danlos syndrome-18 patients (1.0%), Paget's disease-6 patients (0.3%), hemoglobinopathies-30 patients (1.6%), and idiopathic-1573 patients (84.9%). There was a statistically higher prevalence of the following less classically associated diseases among patients with AS compared to controls: hereditary spherocytosis (1.7% vs. 0.6%, p < 0.001), connective tissue disease (1.0% vs 0.3%, p < 0.001) and non-exudative age-related macular degeneration (33.9% vs 10.6%, p < 0.001). Among 1442 eligible cases analyzed, 427 (29.6%) received at least 1 anti-VEGF injection with 338 (23.4%) patients having the injection after their AS diagnosis.

CONCLUSIONS

In the largest collection of AS patients to date, the classical teaching of systemic disease associations occur at rates far, far lower than previously reported. The association of AS with other less reported diseases highlights new potential associations and may contribute to the understanding of AS formation.

Bilateral central serous retinopathy in a patient with paroxysmal nocturnal hemoglobinuria treated with deferoxamine

PURPOSE

To report a case of acute bilateral central serous retinopathy associated with deferoxamine therapy in the context of paroxysmal nocturnal hemoglobinuria.

METHODS

Spectral-domain optical coherence tomography and fundus autofluorescence were used to investigate posterior segment changes.

RESULTS

A 76-year-old man with paroxysmal nocturnal hemoglobinuria and hereditary spherocytosis was started on deferoxamine for iron overload secondary to previous blood transfusions. Four days after initiation of treatment, he developed bilateral reduced vision and metamorphopsia. He was noted to have bilateral central serous retinopathy. Symptoms and serous retinal detachment resolved rapidly following discontinuation of treatment.

CONCLUSIONS

This case represents the first report of acute bilateral central serous retinopathy associated with deferoxamine therapy. Cessation of deferoxamine resulted in rapid visual recovery.

Anterior ischemic optic neuropathy in patient with hereditary spherocytosis and coexisting angioid streaks

Purpose. To describe a rare case of hereditary spherocytosis (HE) with angioid streaks that developed anterior ischemic optic neuropathy (AION).
Method. Case report.
Results. A 53-year-old woman with HE had a 3-day history of blurred vision in the lower hemifield in the left eye. At presentation, her visual acuity was 20/20 OD and 20/200 OS. Perimetric testing showed a relative scotoma in the superior parafoveal region in the right eye and an inferior altitudinal field defect in the left eye. Fundus examination demonstrated angioid streaks in both eyes with swelling of the optic disc in the left eye. Both parvovirus B19 immunoglobulin M and immunoglobulin G were identified in her serum. 
Conclusions. This is the first report of AION in HE and coexisting angioid streaks. The infection by parvovirus itself might be involved in the development of AION.

[Angioid streaks]

Angioid streaks represent breaks in Bruch's membrane, appearing as dark or reddish radial streaks eminating from the optic disc. Usually asymptomatic, these streaks may develop neovascularisation and lead to a maculopathy with marked loss of vision. Some associations with systemic disease are classically described, especially pseudoxanthoma elasticum. This condition may involve cardiovascular complications. A mutation has been found in the ABCC6 gene, which encodes for a membrane transport protein involved in the synthesis of the extracellular matrix. Imaging allows for visualization of the extent of the streaks, and autofluorescence is particularly informative. Spectral domain OCT may also demonstrate early breaks in Bruch's membrane. Neovascular complications, previously responsible for inevitable visual impairment at some point after their occurrence, are now managed by intravitreal injections of anti-VEGFs with clear efficacity. The ophthalmologist must be aware of this condition, in order to guide the patient towards a systemic work-up if necessary, and also to insure quick and targeted treatment in the case of neovascular complications.

Hereditary spherocytosis

Hereditary spherocytosis is a common inherited disorder that is characterised by anaemia, jaundice, and splenomegaly. It is reported worldwide and is the most common inherited anaemia in individuals of northern European ancestry. Clinical severity is variable with most patients having a well-compensated haemolytic anaemia. Some individuals are asymptomatic, whereas others have severe haemolytic anaemia requiring erythrocyte transfusion. The primary lesion in hereditary spherocytosis is loss of membrane surface area, leading to reduced deformability due to defects in the membrane proteins ankyrin, band 3, beta spectrin, alpha spectrin, or protein 4.2. Many isolated mutations have been identified in the genes encoding these membrane proteins; common hereditary spherocytosis-associated mutations have not been identified. Abnormal spherocytes are trapped and destroyed in the spleen and this is the main cause of haemolysis in this disorder. Common complications are cholelithiasis, haemolytic episodes, and aplastic crises. Splenectomy is curative but should be undertaken only after careful assessment of the risks and benefits.

Congenital dyserythropoietic anaemia, type I, in a Caucasian patient with retinal angioid streaks (homozygous Arg1042Trp mutation in codanin-1)

A congenital dyserythropoietic anaemia (CDA) was recognised in a French Caucasian male patient. Blood smears showed a pronounced aniso-poikilocytosis. Bone marrow light microscopy showed signs of dyserythropoesis, but no internuclear chromatin bridges. Electron microscopy disclosed erythroblast nuclei with the Swiss cheese aspect and the presence of cytoplasmic organelles, assessing the diagnosis of CDA I. The presence of internuclear chromatin bridges may thus be missing in CDA I. The patient proved to be homozygous for the Arg1042Trp mutation in codanin-1 (the 'Bedouin mutation'). By the age of 25, the patient's vision started to deteriorate as a result of retinal angioid streaks and macular abnormalities. Evolution was controlled and the patient, being nearly 50 yr old now, still has a partial use of his eyes. This second case of retinal angioid streaks reported in CDA I adds to the non-haematological features likely to be associated with this condition.

Choroidal neovascular membrane secondary to primary hemochromatosis

PURPOSE

To describe the findings for a patient with hemochromatosis, angioid streak-like changes, and choroidal neovascularization.

METHODS

Case report.

RESULTS

A 63-year-old man with primary hemochromatosis presented with recent vision loss. Visual acuity was 20/20 in the right eye and 20/70 in the left eye. Funduscopic examination and fluorescein angiography disclosed diffuse retinal pigment epithelial mottling, peripapillary hyperfluorescence, and a choroidal neovascular membrane lesion.

CONCLUSION

Hemochromatosis may be associated with angioid streak-like changes in Bruch membrane, choroidal neovascularization, and diffuse retinal pigment epithelial changes.

Fluctuations of intracellular iron modulate elastin production

Production of insoluble elastin, the major component of elastic fibers, can be modulated by numerous intrinsic and exogenous factors. Because patients with hemolytic disorders characterized with fluctuations in iron concentration demonstrate defective elastic fibers, we speculated that iron might also modulate elastogenesis. In the present report we demonstrate that treatment of cultured human skin fibroblasts with low concentration of iron 2-20 microm (ferric ammonium citrate) induced a significant increase in the synthesis of tropoelastin and deposition of insoluble elastin. Northern blot and real-time reverse transcription-PCR analysis revealed that treatment with 20 microm iron led to an increase of approximately 3-fold in elastin mRNA levels. Because treatment with an intracellular iron chelator, desferrioxamine, caused a significant decrease in elastin mRNA level and consequent inhibition of elastin deposition, we conclude that iron facilitates elastin gene expression. Our experimental evidence also demonstrates the existence of an opposite effect, in which higher, but not cytotoxic concentrations of iron (100-400 microm) induced the production of intracellular reactive oxygen species that coincided with a significant decrease in elastin message stability and the disappearance of iron-dependent stimulatory effect on elastogenesis. This stimulatory elastogenic effect was reversed, however, in cultures simultaneously treated with high iron concentration (200 microm) and the intracellular hydroxyl radical scavenger, dimethylthiourea. Thus, presented data, for the first time, demonstrate the existence of two opposite iron-dependent mechanisms that may affect the steady state of elastin message. We speculate that extreme fluctuations in intracellular iron levels result in impaired elastic fiber production as observed in hemolytic diseases.

Guidelines for the diagnosis and management of hereditary spherocytosis

Hereditary spherocytosis (HS) is a heterogeneous group of disorders with regard to clinical severity, protein defects and mode of inheritance. It is relatively common in Caucasian populations; most affected individuals have mild or only moderate haemolysis. There is usually a family history, and a typical clinical and laboratory picture so that the diagnosis is often easily made without additional laboratory tests. Atypical cases may require measurement of erythrocyte membrane proteins to clarify the nature of the membrane disorder and in the absence of a family history, occasionally molecular genetic analysis will help to determine whether inheritance is recessive or non-dominant. It is particularly important to rule out stomatocytosis where splenectomy is contraindicated because of the thrombotic risk. Mild HS can be managed without folate supplements and does not require splenectomy. Moderately and severely affected individuals are likely to benefit from splenectomy, which should be performed after the age of 6 years and with appropriate counselling about the infection risk. In all cases careful dialogue between doctor, patient and the family is essential. Laparoscopic surgery, when performed by experienced surgeons, can result in a shorter hospital stay and less pain.

Cardiovascular involvement in thalassaemic patients with pseudoxanthoma elasticum-like skin lesions: a long-term follow-up study

BACKGROUND

Congenital haemolytic anaemia may be associated with pseudoxanthoma elasticum (PXE)-like clinical manifestations.

METHODS

The cardiovascular system of 14 homozygous and double heterozygous beta-thalassaemia patients with skin and retinal vessel alterations similar to those in genetic PXE was analysed over a period of 12 years and compared with that of 13 relatives (five sets of parents, one single parent, two thalassaemic brothers), and that of the control group composed of 16, age- and sex-matched, thalassaemic patients.

RESULTS

All patients with clinical PXE-like skin lesions exhibited, by light and electron microscopy, dermal alterations and mineralization of elastic fibres identical to those typical of inherited PXE. None of the relatives and none of the control group showed clinical or structural findings of PXE. The follow-up started in 1988. After 12 years of clinical observation, six patients showed dramatic progression of skin involvement, angioid streaks had progressed in two subjects. One patient had recurrent gastrointestinal bleeding and underwent partial stomach removal for gastric artery aneurysm, one underwent colon resection for intestinal infarct, one patient had a transitory ischaemic attack, one died after an intracranial haemorrhage, two patients died from cardiovascular disease and one from neoplasia.

CONCLUSIONS

Thalassaemic patients with PXE-like skin lesions also manifest PXE-like vessel alterations that progress with time. Considering the severe outcome of these lesions, accurate monitoring should be routinely performed on the cardiovascular system of thalassaemic patients with PXE-like skin manifestations.

Elastic tissue abnormalities resembling pseudoxanthoma elasticum in beta thalassemia and the sickling syndromes

The development of clinical and histopathologic manifestations of a diffuse elastic tissue defect, resembling inherited pseudoxanthoma elasticum (PXE), has been encountered with a notable frequency in patients with beta thalassemia, sickle cell disease, and sickle thalassemia. The PXE-like clinical syndrome, consisting of skin, ocular, and vascular manifestations, has a variable severity in these hemoglobinopathies and it is age-dependent, with a generally late onset, after the second decade of life. The defect is believed to be acquired rather than inherited and related to the consequences of the primary disease. The high prevalence of the findings implicates the elastic tissue injury as one of the main comorbid abnormalities encountered in beta thalassemia and the sickling syndromes. In these patients a number of complications, sometimes serious, has been recognized to be related to ocular and vascular elastic tissue defects. Because several organ systems are involved, each medical specialty should be aware of the phenomenon. This coexistence, on the other hand, introduces a novel pathogenetic aspect of PXE and an important research challenge.

Arterial elastorrhexis in beta-thalassaemia intermedia, sickle cell thalassaemia and hereditary spherocytosis

Arterial and stromal elastorrhexis, an elastic tissue disorder, was recently described in beta-thalassaemia major. Histopathological material from 10 patients with thalassaemia intermedia, 14 with sickle cell thalassaemia and 18 with hereditary spherocytosis was examined in order to investigate the specificity of the arteriopathy. Histological re-examination was made in a total of 42 spleens with parasplenic lymph nodes in 14 cases, 26 surgical liver biopsies and 16 gallbladders with associated regional lymph nodes. Arteriopathy, qualitatively similar to that seen in beta-thalassaemia major, was found in up to 90% of extrasplenic muscular arteries. Elastorrhexis lesions were also found in intrasplenic arteries and in stromal elastic tissue of spleens and parasplenic lymph nodes, in the absence of tissue iron overload. The arteriopathy appears in the first decade of life even in spleens of normal weight, and seems unrelated to the severity of permanent anaemia. It is suggested that patients suffering from hereditary chronic haemolytic diseases are subject to an elastic tissue disorder which is similar to hereditary pseudoxanthoma elasticum, the earliest and most frequent manifestation of which is arterial elastorrhexis of muscular extrasplenic arteries.

The diagnosis and management of hereditary spherocytosis

Hereditary spherocytosis (HS) is relatively common in Caucasian populations; most individuals have mild or only moderate disease. There is commonly a family history and a typical clinical and laboratory picture so that the diagnosis is usually easily made without additional laboratory tests. Atypical cases may require measurement of membrane proteins and molecular genetics to clarify the nature of the membrane disorder. It is particularly important to rule out stomatocytosis because splenectomy is contraindicated because of the thrombotic risk. Mild HS can be managed without folate supplements and does not require splenectomy. Moderately and severely affected individuals are likely to benefit from splenectomy, which should be performed after the age of 6 and with appropriate counselling about the risk of infection. In all cases careful dialogue between physician, child and the family is essential. Laparoscopic surgery can result in shorter hospital stay and less pain.

Myopic cracks, angioid streaks, and traumatic tears in Bruch's membrane

We studied the pattern of break formation in 60 eyes with myopic lacquer cracks, angioid streaks, or traumatic tears in Bruch's membrane, using a graphics composition technique and computer analysis of digitized images. Lacquer cracks were found in a reticular distribution within a posterior staphyloma; angioid streaks occurred in a spider-web configuration centered on the optic nerve; traumatic tears were characteristically curved, perineural, and eccentric temporally. The specific break patterns imply the operation of biomechanical forces.

Oral vitamin E supplements can prevent the retinopathy of abetalipoproteinaemia

Six patients with abetalipoproteinaemia are described who received large doses of oral vitamin E for between 12 and 18 years in addition to a low fat diet and supplements of the other fat soluble vitamins. The progressive retinopathy observed in untreated abetalipoproteinaemia was substantially modified and most probably prevented by this therapy. Angioid streaks were noted in one patient. Treatment with vitamin A alone did not prevent or arrest the progression of the retinal lesion.