Year : 1983 | Volume
: 31 | Issue : 7 | Page : 903--905
Removal of dislocated lens material from the posterior segment
Hemant Doshi, SS Badrinath
Sankara Nethralaya, Medical Research Foundation, 18 College Road, Madras, India
Sankara Nethralaya, Medical Research Foundation, 18 College Road, Madras
|How to cite this article:|
Doshi H, Badrinath S S. Removal of dislocated lens material from the posterior segment.Indian J Ophthalmol 1983;31:903-905
|How to cite this URL:|
Doshi H, Badrinath S S. Removal of dislocated lens material from the posterior segment. Indian J Ophthalmol [serial online] 1983 [cited 2021 Sep 28 ];31:903-905
Available from: https://www.ijo.in/text.asp?1983/31/7/903/29701
Dislocation of the lens or lens material in to the posterior segment can occur in many situations, particularly it may be due to trauma or spontaneous dislocation in condition like Marfan's syndrome, hypermature cataract or can occur during any procedure for the extraction of the cataract.
The availability of vitreous surgery techniques augmented by ultrasonic emelsification method provided new capabilities to deal with retained lens material in various circumstances. The purpose of this presentation is to describe a technique of pars plana vitrectomy for the removal of a dislocated lens or lens material in the posterior segment and enumerates the advantage of this technique over other methods employed in the past.
MATERIAL AND METHODS
This is a presentation of five cases who were seen and operated in Sankara Nethralaya, Medical Research Foundation, Madras. Two of them were male and three females.
Preoperative visual acuity in all the five cases ranges from counting fingers 1 foot to light perception and projection.
Age ranges from 9 years to 60 years.
The causes for dislocation of the lens in the posterior segment were marfan's syndrome, after conventional cataract extraction and trauma [Table 1].
The indication for removal of the lens in these cases are shown in [Table 2].
In three of the above cases there was associated retinal detachment. Fellow eye was normal in three cases, blind in one and phthisical in one case.
With the patient under general anoesthesia carefully site for pars plana sclerotomy were selected and three sclerotomies were made using myringotomy knife and stillete. 1st site for infusion cannula which is fixed to the sclera by a 4/0 nylon mattress suture. 2nd site for Ocutoma/Fragmatome probe and 3rd site for fibre optic endoillumination or accessory instruments.
Preparatory total pars plana vitrectomy is done with the vitrectomy instrument. This is to avoid exerting unrecognised traction on the retina as the vitreous flows more readily than the more solid lens material. It is not possible to remove hard lens matter with any suction technique without first creating a sizeable liquid filled compartment. When the preparatory vitrectomy is over the Ocutome probe is taken out and 20 gauge ultrasonic fragmatome is introduced in the vitreous cavity. The hard or soft lens masses were lifted with the probe and the endoillumination or the illuminated membrane picked into the mid vitreous cavity and it is made confirm that there is no vitreous nearby then small pieces are removed with continuous sonification at full power (aspiration). The harder masses like hard dislocated nuclei are cut in to small pieces and then aspirated (Cut and aspiration). Once all the pieces are removed and if any smaller particles are seen on the retinal surface they are gently aspirated till all are removed. Then the instruments are carefully removed after - stopping the infusion and the wound are closed with a temporary scleral plug. Then one by one each sclerotomy is closed with a running shoe lace 8/0 monofilament nylon.
OBSERVATIONS AND DISCUSSION
All the five cases were seen regularly in the post-operative period and the final check-up of vision and detail examination was done two months after the surgical procedure. The visual acuity attended by five cases is listed in [Table 3].
Though our presentation is very small but our results with this method are definitely encouraging. In this small study we have achieved satisfactory visual improvements in all cases. In three cases who had retinal detachment, two of them were of traumatic origin and one was recurrent rhegmatogenous retinal detachment associated with Marfan's syndrome. All three cases we did the scleral buckling procedure at the same sitting with pars plana vitrectomy and all of them had successful anatomical attachment particularly the case of Marfan's syndrome who had detachment surgery twice before elsewhere had recurrent retinal detachment with a lens hindering the view of the retinal surface. In another case whose nucleus was floating in the vitreous cavity had conventional cataract extraction elsewhere came to us with persistent pain, redness and unable to see. When we saw her first she had severe uveitis and fundus examination with binocular indirect ophthalmoscope revealed lens nucleus floating in the vitreous cavity. Once, the eye became quiet with medical treatment she was subjected to surgery. On final check-up she was found to have vision of 6/18 with necessary correction in the operated eye and she was quite happy too.
Another advantage we had by doing the removal dislocated lens material by Ooutome/Fragmatome is that we were able to do the scleral buckling procedure at the same sitting thus preventing the patient to have two surgeries and thus reducing the disadvantages of two surgeries.
Though indication for removal of retained lens or posteriorly dislocated lens have not been agreed upon. Sever qlaucome, intraocular inflammation, mechanical damage to the retina and major visual disturbances caused by the lens matter are possible indications for lens removal.
Various surgical techniques for such cases have been described in the past, but each was associated with certain limitations. Like soft material may readily be removed by aspiration but this method may be difficult if nonencapsulated lens material is mixed with vitreous gel. Techniques have been described using needle to trap the lens in the anterior chamber after positioning the patient face down before or during the operation. Verheff used a saline solution stream to float a posteriorly dislocated lens into the pupillary space where it could be grasped. Other surgeons have used a diathermy spear, cryo probe or other instrument to remove the lens directly from the vitreous cavity with or without excision of vitreous gel.
These previous techniques were usually not effective in treating non encapsulated lens material mixed with vitreous gel and they were associated with other difficulties. Aspiration techniques were not effective if the lens material was firm and techniques reguiring intraoperative placement of a needle through the pars plane with the patient face down position are technically difficult and hazarduous. Direct extraction of a dislocated lens through an open sky approach requires a large limbal incision and the corneal endothelium may be damaged by prolonged exposure to air or by direct trauma during open sky vitrectomy and lens removal. Surgical visualisation is not optimal while mobilising and removing a lens from the posterior segment through an open sky approach and the method is not suitable if the lens is adherent to the retina or if retinal detachment is present. A saline stream used to float the lens in to the pupillary space may cause a retinal tear.
Vitrectomy technique offers certain advantage including a closed eye approach and optimal trans-corneal illumination. Also vitrectomy instrument permit precise bite by bite excision of lens material, vitreous gel, blood and inflammatory debris mixed with lens matter and this technique can be used in eyes with pre-existing complications such as glaucoma, vitreous haemorrhage and retinal detachment. Vitrectomy technique also permits excision. of appropriate amount of vitreous gel, thus reducing the likelihood of post-operative complications.
Regarding the complications of the technique, we have not encountered any in these five cases, may be due to a small study.
This is a presentation based on the study of five cases of dislocated lens or lens material in the posterior segment which were removed successfully by pars plana vitrectomy. The paper emphasises the importance and advantage of the technique of removal of the dislocated lens material by pars plana vitrectomy over other techniques.