Type a syndrome of insulin resistance: anterior chamber anomalies of the eye and effects of insulin-like growth factor-I on the retina.
BACKGROUND
The purpose of this work was to describe the anterior chamber and iris anomalies as well as to evaluate the effects of recombinant human insulin-like growth factor-I (rhIGF-I) on the retinal vessels in 2 diabetic patients with type A syndrome of insulin resistance, a rare condition associated with acanthosis nigricans.


METHODS
Ophthalmologic examinations, including photographs and fluorescein angiograms, were performed before, and 2 and 4 weeks after starting subcutaneous rhIGF-I treatment, and 3 months after withdrawal of rhIGF-I treatment.


RESULTS
Both patients had goniodysgenesis with mild elevation of the intraocular pressure. Before and after 2 weeks of treatment with rhIGF-I, the fundus and the fluorescein angiograms were mainly normal. After 4 weeks of rhIGF-I treatment both patients' retinas revealed leakage of fluorescein. Three (case 1) and 4 months (case 2) after withdrawal of rhIGF-I, the fundus of all four eyes were again without leakage.


CONCLUSIONS
The anterior chamber anomalies found in these patients may be part of the type A syndrome of insulin resistance and could alert clinicians that these patients might not have the usual type of diabetes. Moreover, the data show that exogenous rhIGF-I administration in patients with type A syndrome of insulin resistance alters the permeability of the superficial layer of retinal capillaries which is comparable to the earliest angiographic changes in childhood diabetic retinopathy. Whether this is a direct effect of rhIGF-I, as suggested by experiments in an animal model, or an indirect effect due to the near-normalization of the glucose levels by rhIGF-I warrants further investigations. Finally, this work points to an important caveat regarding the therapeutic use of rhIGF-I in this patient population.
Martin
X D
XD
Department of Ophthalmology, University Hospital, Zürich, Switzerland. xmartin@worldcom.ch
Zenobi
P D
PD
D000052:Acanthosis Nigricans / Q000150:complications; D000328:Adult; D000867:Anterior Chamber / Q000002:abnormalities*; D001786:Blood Glucose / Q000032:analysis; D002199:Capillary Permeability; D003920:Diabetes Mellitus / Q000175:diagnosis*; D005124:Eye Abnormalities / Q000175:diagnosis*; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D007334:Insulin-Like Growth Factor I / Q000627:therapeutic use*; D007429:Intraocular Pressure; D007498:Iris / Q000002:abnormalities*; D010781:Photography; D011994:Recombinant Proteins; D012160:Retina / Q000187:drug effects*; D012171:Retinal Vessels / Q000187:drug effects; D013577:Syndrome
D001786:Blood Glucose; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I