The field of application of fluoroscopy as an aid to ophthalmologist has been considerably enhanced by image intensification (electron acceleration for amplification of the fluoroscopic image), which has made possible the development of practical techniques of cinefluorography, television monitoring and recording.
The use of a television monitoring system allows viewing by several observers in addition to the fluoroscopist, and the advantage of working in a lighted fluoroscopic room, instead of in the dark, contributes to both safety and efficiency.
A monoplane TV fluoroscope (SIEMEN 500mA) and a 90 degrees rotating "two-planes TV fluoroscope (Siremobile 2, SIEMEN) recently installed in the Departments of Radiology and Orthopedic Surgery at St. Mary´s Hospital, Catholic Medical College (Fig.3).
Author has removed successfully an intra-vitreal metal foreign body under direct visualization -with the TV fluoroscopy image intensifier.
Case 1.
Man, aged 29, stevedore, with a penetrating wound of the left eye from a hammer upon an .old mobile-engine, had ocular pain and visual disturbance with posterior synechia and a visible well-defined grayish-white exudate mass at inferior portion of vitreous body near the equator. X-ray studies for the localization of FB, revealed that the body was about 1 X 4mm in size and embedded in the exudate which is locating 8-12mm apart from the corneal limbus of 5: 30 o´clock portion.
A removal attempt using a hand magnet was unsuccessful, and then the scleral wound was closed. 22 days later the inferior conjunctiva was incised, a sclerotomy (posterior route procedure) was done and 6-0 black silk sutures were preplaced with cryothermy (-70°C) around the sclerotomy site. The pars plana was perforated with a knife, and teethless iris forceps (Gill) was introduced into the vitreous. The metal foreign body was visualized under the aid of TV fluoroscopy. The forceps was"gfadually inserted until the foreign body(iron) war grasped and removed.
Experiments
Rabbits, weighed 2-3kg, were used as experimental animals. Under general anesthesia a stab-wound on the sclera (3 mm long) after the fixation of eye ball by traction sutures was-made and then copper-wire piece (1 X1 X1 mm) as a nonmagnetic foreign body was inserted in to the vitrous. body.
A removal attemp using a toothless iris-forceps was done under the x-ray with fluoroscopy image intensifier television monitoring system (Siremobile 2). The body was visualized by rotating 90 degrees of an image intensifier.
The forceps was then inserted until the F.B. was grasped and removed, with more easy way.
Anathor experiments for intra-orbital copper foreign body were also performed. And same results were obtained as intra-vitreal foreign bodies experiment.
Comments and Summery :
Presently, nonmagnetic intraocular foreign bodies are more difficult to remove and tend generally to be more toxic than magnetic bodies
Opaque media from´ extensive hemorrhages .or exudates would be caused the difficulty -of direct visualization. The use of ultrasonic technique may make a help for the localization of F.B. and requires a second operator.
Most hospitals have a TV fluoroscopy(fmage intensifier). mounted on a C arm or bi-planed: fluoroscopy.
The total fluoroscopy time in the present instances was the range of 5?8 minutes. Irradiation was estimated about 5^-10 R. to the eye and 300% maximum of secondary irradiation to, the operatior´s hand.
The application of the image intensification TV monitoring system in the cases of media hazy intraocular nonmagnetic F.B. or intra-orbital nonmagnetic F.B. combines the advantages of accurate localization and the ease and simplicity of direct visualization in TV monitor. With 90-degrees rotation, both the forceps and foreign body could be viewed in two planes 90 degrees apart; with alternating vertical and horizontal projections, the forceps could be guided to the foreign body.
This technique is surely a practical efficient way to remove non-magnetic opaque intraocular and/or intra-orbital foreign bodies at safe radiation levels. It would be also possible as a second step in cases of magnetic foreign bodies which were failed to removal with a magnet aid.
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