|Year : 1980 | Volume
| Issue : 2 | Page : 81-83
"Evaluation of trabeculectomy"
DL Maria, Vidya Kachole
Department of Ophthalmology Medical College, Aurangabad, India
D L Maria
Deptt. of Ophthalmology Medical College, Aurangabad
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Maria D L, Kachole V. "Evaluation of trabeculectomy". Indian J Ophthalmol 1980;28:81-3
In our patients, majority of whom are illiterate and poor, medical line of treatment for glaucoma becomes impracticable. So in spite of the danger to the inner eye due to surgery in the form of flat anterior chamber, anterior and posterior synechae formation, hypotony, acceleration of cataract formation, infection, haemorrhage, malignant glaucoma, bleb rupture etc., we have to choose a surgical line of treatment to hold the intra ocular tension at levels low enough to protect the optic nerve. In such a situation the operation of trabeculectomy, introduced by Cairns, an operation following which the above mentioned complications are very minimal, is a very satisfactory means to treat the glaucoma. This operation was initially a privilege of the surgeon who had an operating microscope but can be done without magnification with the same results.
| Material and methods|| |
45 eyes (40 cases) having chronic simple glaucoma were selected for the study. The cases were investigated and the intra ocular pressure was recorded on 7th day, at the time of discharge and then after one month, 3 months and 6 months.
| Surgical technique|| |
A limbal bas, i flap of 7-8 mm of conjunctiva with Tenon's capsule was reflected. 5 mm above the corneo-scleral junction a 5 mm long partial thickness incision was made in the sclera, parallel to the limbus. From its ends two radial incision were made converging at 3 mm. distance from each other. A partial thickness scleral flap was made hinging on the cornea. A block of tissue 3 mm x 2 mm. consisting of part of Schlemm's canal, portion of trabecular meshwork and deeper part of cornea and sclera was removed. A peripheral iridectomy was done. The scleral flap was sutured with one suture on either radial incision and three in the horizontal incisions. The conjunctival flap was closed with continuous conjunctival sutures.
| Observation|| |
Forty cases (45 eyes) of 24 females and 16 males suffering from chronic glaucoma were included in this study. The intra ocular pressure pre-operatively varied between 30.4 mm. Hg. to 81 mm. Hg. Maximum number of eyes (33) had intra ocular pressure from 41 to 60 mm. Hg. [Table - 1].
There was no complication during surgery. In the first week after the operation 4 eyes (8.9%) had delayed anterior chamber formation, 3 eyes (6.6%) had iritis, 4 eyes (8.9%) hyphaema, 3 eyes (6.6%) had conjunctival gaping while 3 eyes (6.6%) failed to respond to the surgery [Table - 2]. of these 2 eyes were controlled with pilocarpine 2% drops while the 3rd eye, where the number of scleral sutures was more, was alright after removal of these extra sutures.
The filtering bleb was flat in 16 eyes, diffuse in 27 eyes and very much prominent in 2 eyes only [Table - 3]. Histopathological study of excised scleral block showed Schlemm's canal and trabecular meshwork.
Thus the success rate as far as lowering of intra ocular tension is concerned is 93.3% [Table - 4]. Visual acuity improved in 13 eyes (28.88%) and in 32 eyes it remained the same.
| Discussion|| |
The aim of any type of glaucoma surgery is to lower the intra ocular pressure within the normal range, in order to prevent further damage to inner structures of the eye. Trabeculectomy, introduced by Cairns, consists of removal of trabecular meshwork, with a part of Schlemm's canal, thus enabling the aqueous to reach the canal of Schlemm and flow into the episcleral veins in the normal way. Partly it works like cyclodialysis. It is now thought that the main route of aqueous drainage is subconjunctival like any other fistulizing operation except that the bleb is posterior and diffuse. In our study 27 eyes had diffuse bleb and 2 eyes had a prominent bleb, thus confirming the subconjunctival drainage.
No complication took place during the operation as was also observed by Watson (1975), Singha (1974) and Dutta (1974-75). Post operative complications were minimal, as also observed by others. Flat anterior chamber was seen in 4 eyes, iritis in 3 eyes, hyphaema in 4 eyes and gaping of conjunctival wound in 3 eyes in this study. Incidence of flat anterior chamber was seen in 7 out of 17 eyes
Cairns, 4% in Singha and one in 64 cases in Watson's study.
The next common complication was hyphaema. Cairns saw slight hyphaema in all the seventeen cases, while Dutta and Watson's series showed one case each in 57 and in 80 cases respectively while Mehta had 100% incidence.
In this study iritis was seen in 3 eyes (6.6%) only in the first week after operation while Cairns did not see this complication in his series. Dutta had three cases of iritis out of 57 and Mehta had 3.3% incidence. The incidence of bleb formation shows a wide variation in different studies. Cairns got it in 5 out of 17 cases in the first study while 50% cases showed the bleb formation in the next study. Watson's series showed a diffuse bleb in all cases, Mehta had in 64% cases while our study had in 64.4% of cases.
Though Microscope is preferable it is seen that trabeculectomy without operating microscope can also be done with successful results 93.3% in cases of chronic simple glaucoma in this series. The success rate in Cairns study was 100%, Mehta 85.97%, Maskati 90%, Singha 96% and Watson in 90% . Visual acuity will improve depending upon the condition of the optic nerve head. If the nutrition improves after the control of intra ocular tension the nerve fibres start re-functioning.
The long term results of trabeculectomy are still to be awaited though Watson et al and Ridgeway (1974) followed up their cases from 1-6 years and 3 years respectively with favourable results, while we had followed up our cases upto 6 months.
Another advantage of trabeculectomy operation apart from minimum complication is that it can be repeated in other quadrants.
| Summary|| |
Trabeculectomy operation without operating microscope was done in 45 eyes of chronic simple glaucoma. The success rate as far as lowering of intra ocular tension is concerned was 93.3%.
| References|| |
Cairns J.E., 1968, Amer. J. Ophthalmol. 66: 673.
Watson P.G., and Barnett F., 1975, Amer. J. Ophthalmol. 79 :831.
Singha S.S., 1974, East. Arch. Ophthalmol. 2 : 18.
Dutta L.C., 1974, Proceedings of All India Ophthalmological Society Vol. 31. p.
Mehta K.R., Sathe S.N. and Karyekar S.D., 1974, Indian J. of Ophthalmol 22: III, 9.
Maskati B.T., and Bakshi K.K., 1974-75, Proceedings of All India Ophthalmological Society, Vol. 31 and 32.
Ridgway, Alan E A., 1974, Brit. J. Ophthalmol. 58: 680.
[Table - 1], [Table - 2], [Table - 3], [Table - 4]