Studies of retinopathy and the plasma co-factor of platelet hyperaggregation in type 1 (insulin-dependent) diabetic children.

Only one out of 73 children with young-onset Type 1 (insulin-dependent) diabetes for less than 10 years had retinopathy detectable with fluorescein retinal angiography. Although these fluorescent studies were normal, retinal abnormalities were detected in 19 out of 53 patients by electro-retinography and in four out of 28 patients by the 100-hue colour test. We were unable to confirm recent reports indicating that most Type 1 diabetic patients have retinopathy detectable by fluorescein angiography. The diabetic plasma co-factor induces normal platelets to hyperaggregate in vitro. Plasma co-factor activities in adult diabetic patients have previously been shown to correlate with the degree of hyperaggregation, although in general, only those patients with severe retinopathy or nephropathy have high plasma activities. The plasma activities of 192 Type 1 diabetic patients were significantly higher than those of normal subjects (p less than 0.01). Of ten children with markedly elevated activities, nine did not have retinopathy.

Amines in the subretinal fluid and aqueous.

We examined 49 samples of subretinal fluid and nine samples of aqueous from patients with retinal detachments. Seven amines (histamine, dopamine, methylamine, ethanolamine, dimethylamine, pyridoxamine, and piperidine) were positively identified and quantitated. The amines in the subretinal fluid were similar to those present in the aqueous. The presence of histamine in the subretinal fluid, observed only in fresh retinal detachment, suggested an inflammatory process, at least in the early stages of some cases of retinal detachment. This is consistent with the clinical observations that mild uveitis frequently accompanies a rhegmatogenous retinal detachment.

Partial purification and studies of the plasma co-factor that potentiates platelet aggregation in diabetes mellitus.

A co-factor is present in the plasma of some diabetics that potentiates the degree of in vitro aggregation of normal platelets after ADP stimulus. This paper presents important changes in the analysis technique that utilize recently appreciated knowledge about platelet aggregation and that were needed to permit characterization of the co-factor. By this new technique, the plasma co-factor activity of 33 normal adults and 43 normal children was significantly lower (p less than 0.001) than that of the corresponding diabetic groups. Thirty-two percent of the adult and 23% of the child diabetics had an elevated plasma co-factor activity. None of the 71 diabetic children and only 12 of the 65 diabetic adults had severe retinopathy. These results correlate well with previous reports wherein the plasma co-factor activity was highest in patients who had severe retinopathy or nephropathy and was usually normal when microangiopathy was not evident. The co-factor was completely precipitated from the plasma of a diabetic with ammonium sulfate at the concentration of 34% of saturation. An aqueous solution of this precipitate retained co-factor activity during incubation at 56 degrees for 30 min but lost activity at neutral pH conditions. Co-factor activity eluted during gel filtration to indicate an estimated molecular weight of 21,000 daltons. The improved technique reported here should facilitate study of the platelet hyperaggregation co-factor and the pathophysiology of diabetic microangiopathy.

Recurrent traumatic hyphema. A sequel of injury to the Schlemm canal.

A patient with recurrent hyphema following blunt trauma to the left eye was found to have an angle recession with a laceration of the trabecular meshwork and Schlemm canal. Active bleeding from the Schlemm canal proved to be the cause of the recurrent hyphema. Repeated trials of bed rest and bilateral eye patching provided only temporary control of the bleeding. Cessation of the active bleeding and subsequent resolution of the hyphema was achieved following argon laser photocoagulation to the traumatized portion of the Schlemm canal. While hyphema is a common manifestation of blunt ocular trauma, visible rupture of the Schlemm canal is most unusual. This paper describes the gonioscopic findings of a rupture of the Schlemm canal in a patient who had a traumatic hyphema and recurrent bleeding.

Central areolar pigment epithelial dystrophy.

We examined nine members of a family with a unique hereditary macular dystrophy by using stereoscopic color photography, fluorescein angiography, electroretinography, electro-oculography, dark adaptation, H-R-R color plates, and the Farnsworth-Munsell 100-hue test. The disorder was transmitted as an autosomal-dominant trait with increased penetrance and variable expression. Four of the family members, representing three successive generations, exhibited defects in macular pigmentation ranging from a 1-disk diameter excavation to a more subtle central loss of macular pigment. Only one eye with macular hemorrhage had decreased visual acuity; visual acuity in this eye was 20/25 when the hemorrhage resolved. All other retinal function studies were normal. The unusual nonprogressive areolar depigmentation of the central macula together with normal retinal functions made it impossible to classify this disorder, and indicated a new and unreported dominant macular dystrophy, central areolar pigment epithelial dystrophy.

Central areolar pigment epithelial (cape) dystrophy.

A family with a unique hereditary macular dystrophy is presented. The disorder is transmitted as an autosomal dominant trait having high penetrance and variable expression. The characteristics of this dystrophy are: childhood onset; nonprogressive areolar depigmentation of the central macula; and with the exception of one eye with a macular hemorrhage, normal vision acuity and retinal-function studies.