Bilateral radiant damage to the cornea and retina after exposure to a 700-V electric discharge.
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Adult↗
Biomedical subjects
H Lincoff
Publications and source records attributed to H Lincoff.
Tractional elevations of the retina in patients with diabetes.
Tractional retinoschisis and tractional retinal detachment are both complications of proliferative diabetic retinopathy. The two conditions are frequently confused because they are similar in diagnostic features. We determined the respective incidence of tractional retinoschisis and tractional retinal detachment in 200 eyes with tractional elevations of the retina in patients with diabetes. In 39 eyes, the diagnosis was unequivocally tractional retinoschisis because the retinal elevation maintained its concave contour despite the development of retinal holes. In 65 eyes, tractional retinal detachment was diagnosed with equal certainty, either because pigment lines were present or because the elevation, after a retinal hole developed, rapidly became convex and extended to the ora serrata. The remaining 96 eyes, in which retinal holes or pigment lines were absent, were classified by other features that had been tested for significance in the already diagnosed eyes. On that basis, the diagnosis was retinoschisis in 46 eyes and retinal detachment in 50 eyes.
Diabetes Mellitus, Type 1↗
Treating detachments with a temporary balloon buckle without fixating sutures and without drainage.
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Aphakia↗
Longevity of expanding gases in vitrectomized eyes.
The effect of lensectomy and vitrectomy on the disappearance of intraocular gas was studied in a rabbit model. Ten rabbits underwent lensectomy and vitrectomy in one eye, and ten others underwent vitrectomy alone in one eye. The second eye of each rabbit served as a control. Equal amounts of perfluorocarbon gas, either perfluoromethane (CF4) or perfluoromethane (C2F6), was injected into both eyes of the 20 animals. After an interval corresponding to one or more half-lives of the gases had elapsed, the residual volumes of gas in the paired eyes were measured directly by an invasive method and compared. The volume of gas in the aphakic vitrectomized eye was 1.3 times greater, on average, than in the paired control eye. There was no significant difference between eyes that had undergone only vitrectomy and the control eyes. It is postulated that vascular congestion and decreased aqueous secretion caused by surgical trauma were responsible for the delay in the disappearance of gas in the eyes that underwent both lensectomy and vitrectomy.
Animals↗
A fiberoptic stylette for localizing the balloon buckle.
A third-generation balloon catheter that accepts a fiberoptic has been developed. The fiberoptic is inserted through the catheter to the center of the balloon when the balloon is in the area of the retinal break. Viewed with the ophthalmoscope light at dim to off, the balloon can be seen glowing through the wall of the eye. The position of the balloon can then be shifted until the glow is precisely under the retinal break.
Catheterization↗
A technique for the transfer of retinal images from the mirror of a contact lens.
In 1965 Rene Dufour developed a method for the direct transfer of retinal images reflected in the mirrors of a contact lens to retinal drawing paper. The retinal images are drawn on the reverse side of semi-transparent paper that is oriented such that the sector of the retinal diagram is aligned with the mirror of the contact lens that is viewing the sector. The images can be drawn exactly as they are seen in the mirror. When the drawing is viewed right-side-up over a light box, the detail is oriented correctly. The method is valuable for the precise localization of retinal breaks that are discovered through the slit-lamp microscope but are too small to be seen by indirect ophthalmoscopy. The breaks can be oriented in relation to other fundus detail large enough to be seen through the ophthalmoscope and then found at the operating table without the aid of a microscope.
Contact Lenses↗
Results of a temporary balloon buckle in the treatment of 500 retinal detachments and a comparison with pneumatic retinopexy.
Five hundred detachments with a single break or a group of breaks close together were treated with parabulbar balloon and cryopexy in Tübingen between November 1980 and September 1986. Follow-up ranged from six to 91 months. Primary attachment was achieved in 466 eyes (93%). Twelve (2.4%) redetached after the balloon was removed. After a second operation, 490 eyes (98%) were attached and after a third, 493 (99%) were attached. The results with the extraocular balloon were compared with results of a similar group of detachments treated with an intraocular gas bubble. The primary attachment rate with the expanding gas operation was 91%; 11% of these eyes redetached. Although the final attachment rate was 99%, the complications after gas were much more frequent and of serious consequence.
Adolescent↗
Giant retinal tears. Surgical techniques and results using perfluorocarbon liquids.
Three low-viscosity perfluorocarbon liquids provided an intraoperative tool during vitrectomy to manage giant retinal tears. These clear fluids have a high specific gravity (1.8 to 1.9) and are immiscible with water. In six eyes, the giant tear was less than 180 degrees; in 11 eyes, it was 180 degrees or greater. In all eyes, the tear was unfolded and the retina was flattened while the patient was supine. The perfluorocarbon liquid was aspirated and replaced by air-perfluorocarbon gas mixtures (16 eyes) or silicone oil (one eye) at the end of the operation. The retina was reattached in 16 eyes (94%), with a minimum follow-up period of 6 months. In five eyes (29%), the retina was reattached without scleral buckling. Residual droplets of perfluorocarbon liquid were observed in four patients. These new materials complement present surgical techniques for managing giant retinal tears.
Air↗
Air travel with intraocular gas. I. The mechanisms for compensation.
The absolute intraocular pressure of the gas-containing eye of a rabbit fell with the fall in cabin pressure during a simulated airplane ascent but lagged behind. The lag was manifested clinically as a relative rise in transscleral pressure. The amount of lag depended on the amount of gas in the eye at takeoff. As there is no significant transfer of gas out of the eye during the ascent, the fall in absolute intraocular pressure could only be mediated by expansion of the bubble. The enabling mechanisms for expansion are choroidal compression, scleral expansion, and accelerated aqueous outflow.
Aerospace Medicine↗
Air travel with intraocular gas. II. Clinical considerations.
The patient with a residual intraocular gas volume of 0.6 mL, approximately 10% of the volume of the eye, can compensate for the decrease in cabin pressure as an airplane ascends without a symptomatic rise in intraocular pressure. Larger volumes may be accommodated in aircraft that decompress to less than 8000 ft or that take off from altitudes above sea level. The patient with residual intraocular gas who experiences pain or dimness of vision in an ascending airplane can obtain relief if the cabin altitude is decreased by 2000 ft. This will require a modest adjustment in the altitude of the airplane.
Aerospace Medicine↗
Irradiation of choroidal melanomas before enucleation?
The eyes of 26 patients with choroidal melanomas were irradiated before enucleation at the University Eye Clinic in Tübingen. Preoperative external beam radiation therapy (PERT) was administered between July 1980 and July 1986. Follow-up ranged from 25 months to 8 years, 4 months with a mean follow-up of 53 months. The average diameter of the tumor base was 15 mm and the height 10 mm. Before enucleation vertical stationary electron beam irradiation (10-12 meV) was applied to the tumor-containing eye and the orbit. The dose was increased during the course of the study from 12 to 40 Gy. Enucleation was performed by a technique that cauterized the vasculature before severing it and avoided maneuvers that would cause changes in intraocular pressure. The patients were reexamined between August and November 1988. Nine (34.6%) had died of metastases of melanoma, six of them during the second postoperative year; one patient was alive with metastases. Subsequent death occurred in all patients who had melanomas of epithelioid cell type (3 of 3) and in no patients who had melanomas of spindle A cell type (0 of 3). In this small series PERT had no apparent beneficial effect on the patient's life expectancy.
Adult↗
Retinoschisis associated with optic nerve pits.
Stereoscopic transparencies studied with magnification and projection suggest that the retinal elevation that communicates with optic pits is frequently a schisislike separation of the internal layers of retina. Thirteen of 15 eyes with optic pits and maculopathy fit the schisis pattern. Separation of the outer layers of the retina is a secondary phenomenon that starts in the macula.
Adult↗
The treatment of giant tear detachments using retrohyaloidal perfluorocarbon gases without drainage or vitrectomy.
In a pilot study, an expanding perflurocarbon gas was injected into the retrohyaloidal space for treating giant tear detachments. Using the balloon-gas procedure with a single gas injection, a bubble was obtained that was large enough to tamponade a giant tear without prior drainage of subretinal fluid or vitrectomy. The procedure was performed under subconjunctival anesthesia in order to preserve the patient's light perception, the fading of which served as a safeguard against excessive gas injection. The posterior hyaloidal membrane was only attached to the anterior flap of the tear and to the circumference of the retina anterior to the equator. The retrohyaloidal gas injection was not followed by star-fold formation or other evidence of preretinal proliferation. During the follow-up, the detached posterior hyaloidal membrane appeared to have collapsed on the anterior retina in concertina-like folds. Reattachment occurred in four of the five cases; no retina redetached during an average follow-up of 2 years.
Adult↗
[A complication in gas surgery: injection of gas beneath the retina in a pseudophakic eye].
Report on an inadvertent injection of gas beneath the retina in a pseudophakic eye. The gas was injected through the pupil to tamponade a retinal break. Instead, however, it found its way under the retina, increasing the extent of the detachment. A thick, transparent membrane posterior to the intraocular lens prevented the gas from entering the vitreous space and diverted it laterally behind the iris to the ciliary body, where it penetrated between layers of the ciliary epithelium and entered the subretinal space. The gas became visible under the retina. The bullous redetachment had a mother-of-pearl-like opalescence characteristic of gas beneath the retina.
Aged↗
Treating avulsed vessels with a temporary balloon buckle.
We treated nine patients with avulsed retinal vessels by first expanding a balloon in the parabulbar space to buckle the vessel temporarily and then applying a laser beam to the avulsed segment. In three patients the avulsed vessel was an artery and in six it was a vein. The avulsion was the only abnormality in three patients; in six it was combined with a retinal break, which was accompanied by a detachment in five. The balloon brought the avulsed portion of the vessel into contact with the retina and the pigment epithelium and made it receptive to laser coagulation. Flow in the vessel could be slowed or stopped while the patient was undergoing laser treatment by further expanding the balloon.
Evaluation Studies as Topic↗
Morphological effects of gas compression on the cortical vitreous.
We used scanning electron microscopy to study vitreous in normal and perfluorocarbon gas-treated eyes of cynomolgus monkeys. The cortical vitreous of the normal (control) eye appeared to be a lamellar structure composed of sheets of collagen mesh. In the gas-treated eye there was shrinking and tearing of the lamellae. At six and 12 weeks after gas injection there was membrane formation at the edges of the torn lamellae.
Animals↗
Gas vitrectomy in a primate model.
Total displacement of vitreous by an expanding bubble of a perfluorocarbon gas was studied in cynomolgus monkeys. The clinical observations and the gross dissection suggested that cortical vitreous might have been stripped from the retina; however, electron microscopy of frozen sections demonstrated that the collagen structure of the vitreous was compressed against the retina.
Animals↗
The treatment of difficult retinal detachments with an expanding gas bubble without vitrectomy.
In a prospective study on the use of perfluorocarbon gases (CF4, C2F6, C3F8) without prior mechanical vitrectomy, 51 retinal detachments that were not suitable for scleral buckling were treated by injection of a small bubble of gas into the vitreous to form a tamponade. There were 23 patients with giant tears, 16 with posterior holes, 9 with breaks at different latitudes, and 3 in whom the gas was used for diagnostic purposes. The gases were sustained at therapeutic volumes for 10-70 days. The tears were sealed with argon or krypton laser. The overall reattachment rate was 71%. Postoperative visual acuity improved or remained the same in all patients with reattached retina. In a follow-up of 1 year-38 months there were no late complications, such as cataract, glaucoma, keratopathy, or subsequent visual deterioration.
Adolescent↗