|Year : 1969 | Volume
| Issue : 5 | Page : 216-221
KR Mehta, S Franken
Christian Medical College and Brown Memorial Hospital, Ludhiana, India
|Date of Web Publication||11-Jan-2008|
K R Mehta
Christian Medical College and Brown Memorial Hospital, Ludhiana
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Mehta K R, Franken S. Trans-vitreal surgery. Indian J Ophthalmol 1969;17:216-21
| Definition|| |
The term applies to all surgical manipulations inside or extending through the vitrous body, whether it is in its normal anatomical position or has prolapsed either into the anterior chamber or in a wound.
To date, the surgery of the vitreous is in itself, almost exclusively concerned with the management of complications of other phases of ophthalmic surgery.
Vitreous loss, during intra-ocular surgery on the iris, cornea, lens or sclera is correctly considered as a serious event, which is likely to open the door to further complications, such as, vitreous touch syndrome, updrawn pupil, glaucoma and retinal detachment with poor prognosis.
In traumatic injuries with vitreous loss, excision of the vitreous which has prolapsed out of the wound has to be done before scleral suturing is contemplated and even following the repair the eye has to be watched for long periods under the omen of a guarded prognosis.
It is not, however, this type of unpleasant interference forced upon the surgeon which I wish to discuss today, but that for which the term `Elective', can be applied, that is, vitreal surgery as a procedure carried out in a well-contemplated planned way under careful ophthalmoscopic control.
The possible indications for Trans. Vitreal surgery can be :
(1) Approach and removal of a non - magnetic or magnetic intra-ocular foreign body.
(2) Removal of a parasite located in the vitreous body.
(3) Cutting of Vitreous traction bands which prevent a detached retina from settling after routine procedure for re-attachment has been carried out properly.
(4) Injection of saline solution, vitreous transplant/implant or liquid silicone into the vitreous space.
(5) Retinopexy of a retina in the case of giant tears where the vitreous body is continuous and perhaps identical with the subretinal fluid.
Site of Operative Access
Various methods of entry have been propounded by many authors for Trans-Vitreal manipulation. Probably, the safest and most promising entry is through the sclera and pars-plana of the ciliary body. After opening of the conjunctiva, the incision can be made parallel to the limbus at a distance of 6 mm from the same and as small an incision as would be adequate for the manoeuvre contemplated. This site is chosen because direct injury to the retina is thus avoided as the site is anterior to the ora serrata. It equally avoids the secretory part of the ciliary body with its rich blood supply and bulk of its muscle. Preplacing of a scleral mattress suture (4-0 silk/ Dacron) should be done before penetration of the choroid which would permit immediate and firm closure of the wound if and when desired.
Diathermy of the underlying flat portion of the ciliary body not only coagulates the blood vessels in this area, but also usually suffices to open the globe and permit introduction of the instrument desired.
A different approach may have to be contemplated for removal of an intra-ocular vitreal foreign body, depending upon its site in the globe and wound of entry. Each surgeon varies in his preference for an individual roentgenographic localisation technique, but as long as an adequate proficiency is attained in accurate localisation, any procedure would suffice.
The visual control for various procedures differ. In general, the binocular distant direct ophthalmoscopy (Schepens/Keeler) is satisfactory as it permits, being worn on the head, both hands of the observer free for surgigical manipulation, at the same time giving sterioscopic visualisation. One hand is used to steady and/or rotate the globe while the other holds the instruments for removal of the foreign body the tip of which is in the Vitreous. The undisturbed corneal curvature and moistened surface of the cornea is a necessary requisite for this procedure.
The surgical manoeuvre for magnetic foreign bodies would be to utilise an electromagnet, preferably through the route of entrance, or an incision placed through the pars-plana; but if imbedded in the retina over any place, a circum-diathermic barrage and an appropriate incision over the site of the foreign body would suffice, care being taken to exclude the 3 o'clock and 9 o'clock positions to prevent injury to the long ciliary vessels and nerves.
A third approach in exceptional cases may be through the anterior segment. After opening of the cornea at the limbus and a broad iridectomy, the lens is delivered in its capsule. Thereafter manipulation through the vitreous surface can take place.
In this type of approach through the open cornea and anterior vitreous surface the use of an operating microscope is imperative especially one with a coaxial arrangement for illumination and observation, (e.g. Zeiss). Later I shall illustrate this approach with case records.
| Illustrative Case Records|| |
(1) Recently a young man visited our clinic who had a cysticercous under the foveal area. The photograph taken at that time [Figure - 1] revealed that the head of the parasite had perforated the retina and obscured one of the retinal vessels from view. [Figure - 1]a is a schematic representation to demonstrate its probable site of origin prior to perforation. Later, [Figure - 2] the parasite moved out from its place between the choroid and retina and was found surrounded by vitreous. [Figure - 2]a shows the parasite in a different position to demonstrate its free movement in the vitreous. The vitreous remained fairly clear and there was just a mild aqueous flare. The retina in the meantime became detached [Figure - 3], a and the fundus sketch displays the cysticercus and the para-foveal retinal folds. There was a question whether there was exudate covering the hole in the fovea or a second cyst underneath. [Figure - 3]a a schematic sketch demonstrates the free floating cysticercus and para-foveal retinal folds which gave rise to the illusion. It was decided to attempt removal of the cyst through the pars-plana of the ciliary body. If an exudate covered the hole in the fovea, the retina might settle spontaneously, otherwise light coagulation might take care of the hole later.
After opening the sclera, 6 mm from the limbus at the pars-plana, the incision was made 9 mm long [Figure - 4] and penetrated with diathermy. An erisophake was introduced in the vitreous body [Figure - 5] under sterioscopic visual control of a binocular distant direct ophthalmoscope. There was virtually no vitreous loss and the cyst appeared in the first attempt with the cup of the erisophake in the scleral wound. Whatever vitreous presented in the wound, settled back after the parasite (still moving) was lifted from the wound. The preplaced sutures were closed and sub-conjunctival penicillin was given. The parasite lived and moved for another half hour in warm saline solution, ultimately ending its life, in formo-saline mixture in which it shrunk to about 1/2 its original diameter. The recovery from this surgery was without complication. The vitreous remained clear, however, the retinal folds were fixed and the eye retained only peripheral function.
A young lady of 20 years came to us having in her left eye a cysticercus cellulosae which was embedded in the vitreous body, barely discernable through a lens in the process of developing a complicated cataract. Light projection was still present, but that was the best to be said.
Surgery was carried out by an anterior segment incision as close to the limbus as possible followed by a broad iridectomy and intra-capsular lens extraction. The corneal flap was kept aside by a traction suture under direct microscopic control, the cyst measuring about 8 mm was brought out in a suction cup. There was negligible vitreous loss. The cornea was secured in its place and recovery was uneventful. The intra ocular pressure remained normal. No visual improvement occurred. A partial optic atrophy (probably of a toxic nature) could be seen.
A 48 year old man came with a metallic intra-ocular foreign body in his right eye. Radiographic visualisation revealed a radio-opaque elongated foreign body at least 15 mm in size with jagged edges lying horizontally in the vitreous. The entry wound belied the size of the foreign body and there was an irregular tear, 6 mm in size. Such a removal would necessitate an extremely large incision with doubtful prognosis. Extraction via the anterior route was done following corneal section, broad iridectomy and intra-capsular lens extraction. The eye retained vision of finger counting at four meters when the patient was last seen 3 months after surgery.
Case I V
As a fourth case illustration, I mention the case of a young boy who had complete retinal detachment with giant disinsertion over 180°. The retina could be seen flapping behind the lens sometimes obscuring the retina. There was apparently [Figure - 6] direct continuity between the subretinal fluid and the vitreous body. The retina did not settle with bed rest.
The following surgical procedure was followed. After opening of the conjuntiva the lateral rectus muscle was secured in a cat gut suture and detached from its insertion. A narrow lamellar scleral resection was done over the same extent as the disinsertion l mm beyond the ora serrata. An ordinary SWG 24 needle was taken and its tip was turned into a miniature hook. [Figure - 7] Following diathermy of that area, the needle was introduced and the retina was hooked [Figure - 8] and secured on the scleral resection with diathermy through the same improvised needle. There would have been no other way to bring the retina back to its position. A haemorrhage from a site which received inadequate diathermy obscured the view later on. The patient did not come for a follow-up.
| Instruments for Transvitreal Surgery|| |
Among the instruments being designed for Trans-Vitreal surgery by the 'Schepens' Group is a scissors for cutting vitreal bands with which they have had some success. The blades of the same are less than 2 mm long.
Another is the microforceps designed to grasp intra vitreal, non-magnetic foreign bodies having a horizontal action obviating any trauma to the scleral entrance site, and permitting adequate movement with a minimal sized entry incision.
There will probably be an extensive further development in this field.
| Summary|| |
Trans-vitreal surgery, perhaps is a drastic measure but where it is indicated, it is indispensable and should be attempted in a well contemplated proper way.
The required type of surgery is illustrated by case-records of 4 cases.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6], [Figure - 7], [Figure - 8]