Testing a mechanism of control in human cholesterol metabolism: relation of arginine and glycine to insulin and glucagon.

Eight men were given 2 casein meals, one with and one without a supplement of arginine and glycine, to measure the effect on plasma amino acids, insulin and glucagon. Supplementation resulted in increased levels of plasma glucagon, glycine and arginine, a tendency to decreased insulin and significantly lower insulin/glucagon ratio, tryptophan and tyrosine. The data suggest that insulin and glucagon, which control cholesterol metabolism, respond to dietary and postprandial plasma amino acid levels of arginine and glycine.

Subretinal fibrosis in retinal detachment.

In a series of 629 consecutive retinal detachments, 20 (3%) eyes had preoperative subretinal fibrosis without preretinal fibrosis. The incidence varied in a linear fashion with the duration of the detachment, varying from 0.8% in cases less than one month old to 22% in cases estimated to be more than two years old. Nineteen of the 20 detachments were anatomically cured by scleral buckling.

Lesions simulating serous detachment of the pigment epithelium. Occurrence after retinal detachment surgery.

Serous detachment of the retinal pigment epithelium (RPE) has been previously described in association with disorders of the underlying choroid and Bruch's membrane but has not been reported after retinal reattachment surgery. We have observed, for at least 16 months, three cases that clinically appeared to be RPE detachments after scleral buckling. In each case the lesions exhibited the typical biomicroscopic features of focal serous detachment of the RPE. However, the failure to show the typical fluorescein pooling has prompted us to regard these lesions as focal pockets of turbid subretinal fluid that simulate RPE detachments.

The removal of scleral buckles.

Six hundred consecutive retinal detachments were operated on with silicone scleral buckles. Twenty-three implants, or 3.8%, were removed. There was one solid silicone implant and 22 silicone sponges. Removal was required because of infection (seven eyes), foreign-body sensation without infection (seven eyes), recurrent subconjunctival hemorrhages (four eyes), impingement on the optic nerve (one eye), and distortion of the macula (four eyes). The postoperative infection rate was 1.8% for silicone sponges, and there were no infections in eyes buckled with solid silicone. Only one retina redetached after buckle removal, yielding a recurrence rate of 4%. The one recurrence was successfully managed by a second scleral buckle.

Scleral buckling for retinal detachments complicated by periretinal proliferation.

Scleral buckling alone used to treat retinal detachment with massive periretinal proliferation resulted in an overall cure rate of 34.7%. The success rate declined with increasing severity of massive periretinal proliferation. A detailed anatomic classification for massive periretinal proliferation was used to define the configuration of the eyes undergoing operation. We currently recommend scleral buckling alone for moderate degrees of massive periretinal proliferation; we reserve vitrectomy with preretinal membrane removal and scleral buckling for more advanced cases.

Adjustable length infusion needle for Ocutome vitrectomy.

We devised an adjustable length infusion needle for Ocutome vitrectomy. Visualization of the tip of the infusion terminal is not necessary and the risk of infusion into the uvea is eliminated.

Bare sclera closure in retinal detachment surgery.

Our modification of the limbal peritomy technique in retinal detachment surgery involved recession of the confunctiva 3 mm posterior to the corneoscleral limbus as the conjunctiva was closed. This recession offered some advantages over the standard nonrecessed method: fewer sutures were required; postoperative ophthalmoscopy was not impaired by conjunctiva swelling over the cornea; the eye was comfortable and quiet in appearance because there was no suture material or inflamed conjunctiva adjacent to the corneoscleral limbus. We have not encountered any disadvantages in several hundred cases.

A technique for improving corneal clarity during retinal surgery.

To maintain corneal clarity during scleral buckling operations, the surgeon firmly rolls a dry cotton applicator across the edematous corneal surface, and the epithelial edema fluid is pressed out and absorbed by the applicator. This technique, which may be repeated a number of times, reduces the number of cases that require removal of the epithelium.

Primary retinal detachments without apparent breaks.

In a prospective study of 415 consecutive eyes operated on for retinal detachment, there were no apparent retinal breaks in 41 eyes. Examination of the most likely site for breaks during, or shortly after, cryotherapy was helpful in detecting tiny breaks in several cases. All detachments without apparent breaks were operated on with a three-step operation: we applied two rows of confluent cryotherapy to all retinal breaks, drained subretinal fluid, and used buckles just anterior to the equator. Surgical cure, defined as reattachment for at least six months, was achieved in 93% of eyes with apparent breaks, and in 85% of eyes without apparent breaks. The latter figure increased to 91% when the seven patients with preoperative massive preretinal retraction were excluded.

Diagnostic modalities in choroidal melanoma.

We prospectively studied 51 patients with choroidal melanomas in a masked manner to determine the accuracy of clinical, ultrasound, and fluorescein diagnosis as well as the accuracy of tumor size measurements. In patients with clear media, clinical diagnosis was the most accurate means of detecting a choroidal melanoma. There was excellent correlation between clinical, ultrasound, and pathology measurements of tumor size. In small melanomas, clinical examination was the most accurate means of measuring tumor diameter and ultrasound the most accurate method of measuring tumor height. Even with a trained ocular oncologist, there was a significant variability in tumor measurements on serial ophthalmoscopic examinations.

Degenerative retinoschisis with giant outer layer breaks and retinal detachment.

Five unusual cases of retinal detachment were caused by giant (more than 90 degrees) posterior breaks in the outer layer of degenerative retinoschisis. All retinas were successfully reattached by a variety of surgical techniques. The two cases managed with scleral buckling required subsequent buckle removal because of macular distortion. Treatment with cryotherapy or laser, together with intraocular air and postoperative positioning, gave better anatomic results.

Bullous variant of idiopathic central serous chorioretinopathy.

BACKGROUND: Spontaneous bullous serous retinal detachment (RD) with subretinal exudation complicating idiopathic central serous chorioretinopathy (ICSC) is a rare and infrequently described clinical entity. Clinical observations are described on this variant form in 11 patients, the largest series reported to date. METHODS: 13 eyes of 11 Indian patients having this entity were followed up clinically and angiographically for 12-24 months (retrospective, longitudinal). None of the patients had any previous history of other diseases nor were they on any medications. Four eyes received laser treatment (group A); nine eyes were not treated (group B). RESULTS: All 11 patients were male, aged 23-49 years (median 37 years). The clinical and photographic records revealed subretinal exudation and inferior bullous serous RD complicating ICSC with evidence of large, single or multiple, leaking retinal pigment epithelial detachments (PEDs) in all the cases. In group A, resolution of serous RD occurred in 12 weeks (median) with a visual recovery of >/=20/30 in three out of four eyes while in group B resolution of serous retinal detachment was observed in 14 weeks (median) with eight out of nine eyes achieving a visual acuity of >/=20/30. Subretinal fibrosis developed in two eyes in group A and none of the eyes in group B. CONCLUSION: The disease is an exaggerated form of ICSC and can occur spontaneously without any history of corticosteroid therapy. Recognition of this atypical presentation is important to avoid inappropriate treatment. These observations suggest that with respect to the duration of the disease and the final visual outcome laser therapy offers no additional benefit over the natural course of this variant form of ICSC.

Extended retinal tamponade in the treatment of retinal detachment with proliferative vitreoretinopathy.

We have used intraocular sulphur hexafluoride or liquid silicone as an adjunct to vitreous surgery in the treatment of a non-randomised sequential series of 19 eyes with retinal detachment complicated by proliferative vitreoretinopathy. We have studied the surgical results and complications of these two tamponades and drawn preliminary conclusions on their use in retinal reattachment surgery. After a seven-month minimum follow-up 13 (68%) of the eyes have reattached retinas. Six (60%) of 10 eyes treated only with silicone have reattached retinas, and four (67%) of six eyes treated only with sulphur hexafluoride gas tamponade have reattached retinas. An additional three eyes treated initially with silicone oil subsequently developed retinal detachments; all were successfully reattached with sulphur hexafluoride tamponade after silicone oil removal. Intraoperative pneumatic retinal reattachment to assess relief of retinal traction combined with the production of widespread chorioretinal adhesions to wall off persistent anterior traction and detachment, as well as extended postoperative gas tamponade of the retina, appears to enhance the surgical results in retinal detachment complicated by proliferative vitreoretinopathy. Silicone oil tamponade of the retina appears to be useful in cases where retinal traction cannot be entirely relieved and in patients who are unable to tolerate the head positioning required for effective gas tamponade of the retina. A controlled clinical study recently begun will be required to define further the precise role of these methods of retinal tamponade.

Diffuse melanoma of the choroid.

An 81-year-old woman with good vision was followed up with the diagnosis of a minimally active melanoma. This tumour was eventually found to be a diffuse melanoma with extraocular extension. Diffuse melanomas of the uvea are difficult to diagnose, have frequent and early extrascleral extension, and have a poorer prognosis than most melanomas of the uveal tract.

The drainage of subretinal fluid: a randomized controlled clinical trial.

A randomized controlled clinical trial was conducted on a series of 120 consecutive cases of rhegmatogenous retinal detachment. One group of 60 eyes, randomly selected, was managed with a scleral buckling operation which included the drainage of subretinal fluid. The other group of 60 had a similar operation without drainage of subretinal fluid. A new method for evaluating complications, the "Complications Score," was devised. The score was significantly higher for the drainage group but this did not decrease the final anatomic or visual results. Eight-seven percent of the drainage group were reattached with one operation, a figure not significantly different from the 83% reattached in the nondrainage group. The final cure rate after reoperations was 97% for both groups. The best corrected visual acuity, measured six months postoperatively, was not significantly different for the two groups. This study concludes that equally good results can be obtained with either a drainage or nondrainage operation.

The complication of pneumatic retinopexy.

There have been 26 published series with a total of 1274 detachments operated with pneumatic retinopexy. Eighty percent were reattached with a single procedure and 98% with reoperations. New breaks occurred in 13% and PVR in 4%. The complications published in 101 papers on pneumatic retinopexy in the last 5 years are analyzed as to frequency, prevention, management, and results.

Pneumatic retinopexy: principles and practice.

Pneumatic retinopexy (PR) is an alternative to scleral buckling for the surgical repair of selected retinal detachments. A gas bubble is injected into the vitreous cavity, and the patient is positioned so that the bubble closes the retinal break (s), allowing absorption of the subretinal fluid. Cryotherapy or laser photocoagulation is applied around the retinal break(s) to form a permanent seal. The procedure can be done in an outpatient setting, and no incisions are required. A multicenter randomized controlled clinical trial has demonstrated that the anatomic success rate is comparable to scleral buckling, but the morbidity is significantly less with PR. If the macula was detached for less than two weeks, the visual results are significantly better with PR than with scleral buckling. Cataract surgery was required significantly more often following scleral buckling than following PR. Two independent reports have shown that an attempt with PR does not disadvantage the eye; such that the results of scleral buckling after failed PR are not significantly different than primary scleral buckling. A comprehensive review of the world literature on PR revealed 27 statistical series totaling 1,274 eyes. These combined series had a single-operation success rate of 80%, and 98% were cured with reoperations. Pneumatic retinopexy should be considered in cases without inferior or extensive retinal breaks and without significant proliferative vitreoretinopathy. The cost of buckling varies from 4 to 10 times that of PR.