Year : 1984 | Volume
: 32 | Issue : 5 | Page : 281--283
Perforating injuries of cornea (immediate and delayed surgical approach)
|How to cite this article:|
Kalevar V. Perforating injuries of cornea (immediate and delayed surgical approach).Indian J Ophthalmol 1984;32:281-283
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Kalevar V. Perforating injuries of cornea (immediate and delayed surgical approach). Indian J Ophthalmol [serial online] 1984 [cited 2021 Sep 26 ];32:281-283
Available from: https://www.ijo.in/text.asp?1984/32/5/281/27492
Ocular Injury is perhaps the only emergency in ophthalmic practice. Cornea being the anterior most tissue, is frought with danger from external factors which may be sharp implements, blunt objects, finger nails, shattered glass pieces, stones or other objects in case of road accidents.
It is good to assess the type of injury, time elapsed since injury, tissues involved and the visual status of the injured eye. The possibility of a retained intro-ocular foreign body must always be kept in mind.
In many cases of perforating, injuries, involvement of sclera is not umcommon. Grading of a perforating injury of anterior segment and its management in brief is being described here.
Any of these injuries can be associated with trauma of para-ocular tissues, common amongst these are lids and lacrimal drainage system, usually the canaliculi.
It is a good practice to take x-ray pictures; lateral and an antero-posterior, to exclude the possibility of a radio-opaque retained intraocular foreign body in all cases of perforating injury, otherwise a meticulous and good repair during surgery will be of no avail if a foreign body is missed and the eye is lost due to siderosis or the good eye is endangered due to sympathetic ophthalmitis.
1. An incised wound without any other involvement usually seals adequately and the anterior chamber reforms. It heals well to leave a fine linear scar which is finer than sutured scar. If at all, a tag of anterior synechia forms which can be tackled later.
Some of these cases may need suturing and restoration of anterior chamber when spontaneous sealing is inadequate. It is advisable in these cases to look for a glass splinter in the lips of the wound when cause of the injury is shattering of spectacle lenses.
Association of iris prolapse definitely requires surgical intervention. In earlier days, an iris prolapse was always excised to prevent transfer of infection from extraocular environments. With availability of a wide range of anti-bacterial agents, there is no fear of this complication. A careful surgical procedure can retain a round pupil and complete iris diaphragm.
A well planned surgery under general anaesthesia should be preferred instead of an emergency procedure. Therefore a few hours' interval does not make much difference. The iris can be gently separated from the wound edges and returned to its place to obtain a normal iris diaphragm and round pupil.
3. An injury involving cornea-sclera and which has caused greater uveal involvement also needs a well planned surgery under general anaesthesia. A few hours' planned delay neither does any harm nor changes the final outcome and prognosis of the case.
Careful cleaning and inspection of wound area is very important to assess the exact of the injury. Many a times the scleral wound extends under the extra-ocular muscle and is detected only on the table. That the muscle is not involved should be carefully assessed. The principles of repair are same. Replacement of uveal tissue, good apposition of wound, close suturing and restoration of anterior chamber. The scleral wound should be ideally covered with available or undermined conjunctiva.
It is better to undertake a tectonic penetrating graft in cases, where the wound edges are irregular and a good apposition is not possible.
A trephine can not be applied in these cases. Instead, a caliper can measure the size of the graft required. Caliper points dipped in gentian violet can mark the circumference on the injured eye so that excision of the lacerated cornea to the desired size can be done as correctly as possible.
Obviously, the above procedure is to be considered only when there is a chance, however remote, of restoring vision.
4. In cases of perforating injury with a foreign body, removal of foreign body is the major step. A foreign body in the wound or in anterior chamber, should be removed at the time of wound repair. A foreign body in the posterior segment must be located accurately before attempting its removal.
All these cases should receive therapeutic doses of steroids post-operatively. Steroids not only reduce the inflammation and organisation but help prevent any sympathetic reaction in the good eye. Although sympathetic ophthalmitis is much less common than usually believed, it must be kept in mind in cases of gross injuries.
How to deal with a traumatised lens has to be decided on the table.
A swollen opaque lens will have to be aspirated at the time of corneal repair through the wound itself. One risk that has to be taken is vitreous presentation when the posterior lens capsule is ruptured due to the injury. It can not however be avoided and has to be taken care of adequately. If a swollen lens is not dealt with, restoration of anterior chamber will be difficult thus increasing chances of anterior synechia formation. Secondary rise of intra-ocular tension may be a serious post-operative complication when anterior chamber restoration has been difficult.
There are occasions when a perforating trauma results in nearly half eviscerated eye ball. These cases usually lose even perception of light. Restoring anatomical integrity of the eye ball is also not possible. If a repair surgery is accomplished, more often than not, the eye ends up as a phthisical eye and may even continue to be irritable. Such a thing can lead to sympathetic reaction in the good eye. It is therefore very important to weigh the situation and consider all probabilities before hastening into an elaborate repair procedure. The patient and/or his attendant should be clearly appraised of the slim chances of visual recovery, loss of anatomical integrity of the injured eye and danger to the normal other eye. If they agree, and they usually do, removal of the injured eye is the only alternative. Instead of a straight enucleation, an evisceration with an intrascleral spherical prosthesis should be done for the cosmetic advantages that the procedure offers.
Associated injuries to para-ocular structures should be adequately taken care of to avoid such complications as ectropion, disfigurement and distortion of lids, persistent epiphora due to canalicular injury not having been attended to adequately and at proper time.
There are two important aspects in the anterior segment in cases of old perforating injuries of cornea, corneal scars and traumatic lens opacities.
Corneal scars are to be assessed for corneal grafting on more or less the same criteria as in other corneal pathology, that, is, extent and depth of the scar, presence of vascularisation and degree of iris involvement in the scar.
A paracentral scar with anterior synechia making the pupil eccentric will need only a synechiotomy to bring the pupil to the centre and give good visual improvement.
Associated traumatic lens opacity is to be dealt with on its merit. One should always be ready to remove lens and be prepared for anterior vitrectomy. A triple procedure (PKLens extraction and IOL) should also be kept in mind.
One significant point to be kept in mind is the possibility of posterior segment involvement at the time of injury and thus the uncertainty of visual prognosis even if perfect projection of light is present and an optically clear graft is obtained. It is from this point of view that getting into the details of history of injury, any surgical procedure undergone etc., may prove to be very helpful. In many of these cases, ultrasonography helps assessment of prognosis better.
With all the above factors, sometimes limitations in assessment of prognosis, when a grafting procedure for a corneal scar due to an old injury is to be undertaken, due consideration must be given to all the aspects of the case and each possibility is to be explained to the patient/or attendant.