Year : 1981 | Volume
: 29 | Issue : 4 | Page : 345--349
Retinal detachment with coloboma of the choroid
Bijayananda Patnaik, Rajinder Kalsi
Department of Retina Care, Gurunanak Eye Centre, Maulana Azad Medical College, and Associated Hospitals New Delhi, India
Department of Retina Care, Gurunanak Eye Centre, Maulana Azad Medical College, and Associated Hospitals New Delhi
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Patnaik B, Kalsi R. Retinal detachment with coloboma of the choroid.Indian J Ophthalmol 1981;29:345-349
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Patnaik B, Kalsi R. Retinal detachment with coloboma of the choroid. Indian J Ophthalmol [serial online] 1981 [cited 2021 Jan 17 ];29:345-349
Available from: https://www.ijo.in/text.asp?1981/29/4/345/30928
A retinal detachment in an eye with a coloboma of the choroid requires special management. In the absence of choroid and chorio-capillaries, it is not possible to produce chorio-retinal adhesion with retinopexy around the retinal tear over the coloboma if they can be detected at all.
This article reports on the brief findings in 14 cases with choroidal coloboma in 22 eyes of which retinal detachment was present in 5. It will also deal with the gradual evolution of a surgical technique through agony and ecstasy in treating 4 cases of retinal detachments.
MATERIALS AND METHODS
Fourteen cases with coloboma of the choroid have been seen in last 5 years in the Department of Retina Care, Gurunanak Eye Centre, Maulana Azad Medical College and Associated Hospitals, New Delhi.
These cases were investigated, which included a careful examination with an indirect ophthalmoscope using scleral depression technique. All cases of retinal detachment were also examined with a biomicroscope using a Goldman's 3 mirror contact glass. Four cases out of 5 of retinal detachments were operated upon [Figure 1]. Five cases were treated for prophylactic photocoagulation. The operative techniques will be briefly mentioned in the individual case note. Special equipments used cryosurgical unit, Keelers, England. Ophthalmic Diathermy, Keelers, Radiofrequency Diathermy, MIRA, USA and Photocoagulator, Carl Zeiss. Jena.
OBSERVATIONS AND DISCUSSION
The brief clinical data of 14 cases with coloboma of the choroid has been summarised in [Table 1]. Brief case notes have also been presented in chronological order. Though it is not safe to draw any conclusion on the sex incidence it is interesting to note that in our series of 14 cases there were 9 males and 5 females. In Jesberg and Schepens were 9 males and 4 females.
Choroidal colobomas were visible in 22 eyes. There were invariably situated below the disc and varied from an isolated small coloboma of the size of a disc (case 3) to large coloboma involving a little less than half the fundus. Four more eyes were blind with low ocular pressure and degenerative corneal changes. It is probable that these were cases of old retinal detachment with choroid coloboma. In 19 out of 28 eyes there was also iris coloboma. These were characteristically present in the inferior often slightly nasal quadrant.
All 24 eyes where fundus was visible there was evidence of low myopic refractive error (less than -4 D). It is possible the remaining 4 eyes where fundus was not visible were also myopic.
Micro-cornea with micro-ophthalmos was detectable in 15 eyes. Retinal detachment was visible in 5 eyes. Four more eyes probably had retinal detachment. Of the 5 eyes where retinal detachment could be studied by indirect ophthalmoscope, in 4 the detachment extended onto the coloboma. In only one case it did not. In all cases where the detachment was involving the coloboma retinal breaks could be identified by indirect ophthalmoscopy and slit lamp fundus copy. In 3 cases (cases 1, 2 and 12) the breaks over the coloboma seem to be the only retinal lesions maintaining total retinal detachments in 2 and partial detachment in one. In 2 cases (No. 2 and 9) the outlines of the detachments were consistant with the tears in the colobomatous area as the causative holes. Case 9 was also having additional tears. Jesberg and Schepens reported 5 cases where no tears on the coloboma were detectable yet there were definite tears outside the coloboma in 3 and suspected tears in 2. The treatment of these tears did not result in reattachment of retina strongly suggesting that retinal breaks though undetected, were nevertheless present, in the retina overlying the coloboma.
From our observations and that of it would be safe to presume that when the retinal detachment extends over the choroidal coloboma retinal breaks in this area is to be expected. It is quite possible that the breaks over the coloboma are the causative holes in most cases. On the other hand when the detachment does not extend on to the area of the coloboma the retinal breaks are to be found on the detached non colobomatous area and their treatment results in reattachment of retina (case 4). Three such cases have been reported by Jesberg and Schepens.
Case 1: was operated in 1973 using a similar technique namely to produce retinopexy by mild precise diathermy along the margins of the coloboma and drain the fluid. Instead of diathermy which could destroy the nerve fibers passing in the retina and is difficult to monitor precisely, we used cryopexy which was carried out under direct visual control by an indirect ophthalmoscope. Though the retina settled temporarily there was a recurrence. The method of delimiting the detachment to the colobomatous area by retinopexy and drainage is at best chancy. Case 2 : was operated in 1974 where the causative tear was on the coloboma close to its inferior nasal border. The tear was covered with transcleral diathermy and a local radial buckle. In order to maintain a permanent buckle an encircling element was passed over the buckle. The buckle remained prominent and retina settled temporarily postoperatively There was a recurrence. In absence of firm chorioretinal adhesion-as would be expected in area of choroidal coloboma, a permanent cure of detachment of retina is doubtful.
Case 4 : The tears in the area of detachment (not extending to the area of coloboma) explained its existence. Their closure resulted in reattachment.
Lastly case 9 was operated in April 1978. Nasal half of the retina over the coloboma was detached. There were detectable definite retinal breaks over this area. The detachment was found arching anticlockwise to reach the temporal border of the coloboma-not crossing it. There were 2 additional retinal breaks around 12h.
These 2 tears were treated by intrascleral silicon rod buckle after cryopexy. An episcleral silicon sponge rod buckle was placed radially to extend from the disc to the ora after applying cryopexy just beyond the nasal border of the coloboma. The fluid was drained by sclerotomy. The retina reattached completely. In order to eliminate the possibility of detachment over the area of coloboma (which continued to exist) breaking across its temporal border, a photocoagulation barrage was applied just beyond the temporal border from the disc to close to ora. The extreme periphery was treated in advance by cryopexy during the original operation. The retina remains settled. The disc oedema often develops when a buckle tend to press on the optic nerve. But it is always temporary and disappears with time as in this case.
It may be possible to apply a buckle which extends upto the optic nerve but does not press on it. But it would be more by chance than by design such an ideal can be achieved. Once the practicability of placing a radial buckle extending from the disc to the ora is established, it is safe to opine that this is the ideal surgical technique in treating cases of retinal detachment extending on to the area of choroidal coloboma.
It is true, the detection of retinal breaks over the thin underdeveloped 'diaphanous' retina, overlying the pigmentless featureless area of choroidal coloboma is extremely difficult. But with careful examination with an indirect ophthalmoscope we have been able to define them in all 4 cases we examined. The slit lamp funduscopy using contact glass does help to confirm ophthalmoscopic findings. Jesberg et al (1961) have observed retinal haemorrhages on the detached retina over the area of choroidal coloboma in 4 cases. They suspect this finding to be indicative of hidden retinal breaks in this area. Unfortunately we have not encountered any such haemorrhages.
Similarly, even when binocular ophthalmoscopy and slit lamp funduscopy revealed considerable bulging out of the scleral coat in the area of coloboma no thinning of sclera or clear ectasia of the sclera could be detected during the operations. It is possible, the outline was ill defined and thinning of the sclera small in terms of actual thinning. Considering the fact that a retinal detachment originating, associated with a choroidal coloboma is extremely difficult to treat and requires complicated surgery to delimit the detachment over the coloboma it was considered advisable to use photocoagulation and cryo to delimit the retina over the coloboma from the rest of the retina before detachment takes place as a prophylactive measure. Cryo is applied over the retine beyond the coloboma at extreme periphery-an area difficult to reach with the photocoagulator. Five eyes have been treated in this fashion.
Retinal detachment with coloboma of the choroid is a special and difficult surgical problem. Fourteen cases with choroidal coloboma in 22 eyes, out of which 5 had retinal detachment have been presented. Through the surgical experience of 4 cases an effective technique has been evolved.
Prophylactic photo coagulation and cryo has been advocated for delimiting the retina over the choroidal coloboma from the rest of the retina.
|1||Lesberg, D.O. and Schepens, C.L. 1961, Arch. Ophthalmol. 35 : 163.|
|2||Lincoff, H. and Gieser, R., 1971, A.M.A. Arch. Ophthalmol. 85: 565.|