Indian Journal of Ophthalmology

ORIGINAL ARTICLE
Year
: 1990  |  Volume : 38  |  Issue : 2  |  Page : 81--84

Trabeculocyclostomy-A new modified filtering surgery for primary simple glaucoma


Gurdeep Singh1, Jagmeet Kaur2,  
1 Ex.lecturer in Ophthalmology, G.R. Medical College, Gwalior. Lecturer in Ophthalmology, Gandhi Medical College, Bhopal, India
2 Research Officer, Indian Council of Medical Research. Dept. of Ophthalmology, Gandhi Medical College, Bhopal, India

Correspondence Address:
Gurdeep Singh
E-1/100 Arera Colony, BHOPAL M.P. INDIA, Pin: 462 016.
India

Abstract

A new modified «SQ»INTERNAL«SQ» filtering surgery, Trabeculocyclostomy (TC) is described in 24 eyes of Primary open angle glaucoma. The importance of controlled drainage of aqueous into the suprachoroidal space and its absorption by the well vascularised choroidal tissue is highlighted. Out of the 24 eyes operated by this technique, in 20 eyes (83.3%) no further treatment was required for a mean follow up period of 18 months. In majority of the cases i.e. 19 eyes the anterior chamber reformed from the first day itself and remained so throughout the follow up period. With this in mind Trabeculocyclostomy may be a valuable procedure in cases of pseudophakic glaucoma (usually pre-existent) especially where an anterior chamber intraocular lens implantation has been done or is being done as a combined procedure. Minimum complications have been encountered to date.



How to cite this article:
Singh G, Kaur J. Trabeculocyclostomy-A new modified filtering surgery for primary simple glaucoma.Indian J Ophthalmol 1990;38:81-84


How to cite this URL:
Singh G, Kaur J. Trabeculocyclostomy-A new modified filtering surgery for primary simple glaucoma. Indian J Ophthalmol [serial online] 1990 [cited 2020 Apr 9 ];38:81-84
Available from: http://www.ijo.in/text.asp?1990/38/2/81/24531


Full Text

 INTRODUCTION



Glaucoma is one of the major blinding conditions not only in India but even in economically developed countries.

Despite the introduction of effective medications there are certain problems with this mode of treatment like lack of effective responses to drugs like miotics and beta blockers, non compliance to medical therapy in some people and lack of follow up of cases especially in rural areas.

Recent years have witnessed an increasing use of LASER procedures but some of these procedures are still in an experimental stage and require a large capital outlay for the surgeon.

Currently the most popular surgical technique which is performed throughout the world is Trabeculectomy. Cairns and Watson who originated this technique in 1968-72 expected that an opening made in the Schlemm's canal wouk9 provide a pathway for the aqueous outflow [1],[2],[3]

It is now understood however that an opening in Schlemm's canal closed after the surgery and that the aqueous is absorbed into the scleral flap tissues cover­ing the trabeculectomy hole or is drained into the Tenon's capsule and sub-conjunctival tissue as the main source of drainage.

For this reason many surgeons today close the scleral flap loose to allow drainage out of the eyeball. This could lead to excessive drainage, shallow anterior chamber post operatively and bullous keratopathy espe­cially in cases of pseudophakic glaucoma.

With these considerations in mind, the authors believe that the ideal mode of aqueous drainage is 'IN­TRAOCULAR DRAINAGE' itself in which the water produced in the eyeball would be absorbed within the eyeball.

 MATERIAL AND METHODS



24 eyes comprising Primary open angle glaucoma with good visual functions were subjected to Trabeculocyclostomy(TC).

This work was done in the Dept. of Ophthalmology Medi­cal College, Gwalior as well as partly in the Dept. of Ophthalmology, Gandhi Medical College, Bhopal.

The criteria for surgery were- Progressive visual field defects inspite of control of intraocular pressure or an I.O.P. more than 25 mm Hg Schiotz inspite of maximal medical treatment.

The evaluation of (TC) was based on:

1. Ease of performance/problems during surgery.

2. Reliable and permanent effect in maintaining the IOP within safe limits.

3. Lack of immediate and late complications.

4. Nature and type of post operative bleb formation.

Preoperative examination in all cases included a thorough external ocular examination with slit lamp, Schiotz tonometry, gonioscopy, fundus examination and Goldmann perimetry, if possible.

 TECHNIQUE



A limbal based conjunctival flap with half thickness sceral flap of 5x4 mm is prepared. Two ab externo incisions one along the surgical limbus and another approx. 1 mm towards the scleral side are made. A spatula is then introduced under the scleral bridge created by the two incisions and the adhesions between the sclera and the ciliary body i.e. pars plicata to be precise are then separated. A peripheral iridectomy is performed through the incision along the limbus. The spatula is also introduced a few millimeters into the suprachoroidal space to confirm the absence of any adhesions. The scleral bridge is then cut from one end and is then placed under the deep scleral bed to provide pathway for aqueous drainage into the suprachoroidal space. The scleral bed is sutured watertight with five interrupted 8-0 virgin silk and the conjunctival incision is closed by 6-0 silk. At the end of the operation a sub tenon injection of 0.25 cc each of Garamycin and Decadron is given in the lower fornix.

Post operative care was essentially the same for all the patients and consisted of topical steroids, cycloplegics and antibiotics. The patients on an average was kept in the hospital for 3-4 days and a record of post operative IOP, examination of anterior and posterior segment of the eye and visual acuity was maintained.

The first follow up was after one week and them monthly follow up was done for approximately 1 1/2 years. In all these examinations particular attention was paid to the visual recovery, condition of anterior chamber, post operative IOP and the nature of filtering blebs.

 RESULTS



Trabeculocyclostomy (TC) was performed in 24 eyes of Primary Open Angle Glaucoma. [Table 1][Table 2] shows the sex and age distribution of the patients in this study.

In majority of the patients this surgery was performed in one eye only while in 4 patients bilateral surgery was done. These patients were mostly those cases who presented late. Age-wise, maximum number of cases belonged to the elderly age group in both the sexes.

Visual acuity measured preoperatively and at the end of the follow up period remained unchanged in 22 eyes (91.6%) while it decreased by one Snellen line in one case and improved by two Snellen line in one case. [Table 3]. The cause of fall in the visual acuity in this case was probably due to an increase in the len­ticular opacity while the patient in which it improved the cause was clearing of the mild corneal oedema after control of Intra ocular pressure.

An intra ocular pressure of 20 mm Hg Schiotz or less was considered controlled in this series. This was achieved in 20 eyes(83.3%) as shown in [Table 4]. In 2 eyes the pressure ranged from 21-35 mm Hg. Schiotz These patients were prescribed local antiglaucoma medications for maintenance of the I.O.P Only in 2 eyes the pressure ranged between 8-13 mm Hg Schiotz, but in both the eyes no adverse effects were observed during the follow up period.

The mean value of I.O.P. before operation calculated by the 'formulae M=E fx/Ef came out to be 44.0 mm Hg. Schi φtz while the same of the post operative cases was 17.3 mm Hg. Schi φtz thus showing a mean fall of 60.7% by this technique in this series.(Ref. [Table 5])

Reformation of anterior chamber was seen from the first day in majority of the eyes i.e. 19, eyes (79.1%). In the remaining 5 eyes the Anterior chamber was reformed by the third day. (Ref. [Table 6])

It was also clinically observed that this reformation of Anterior chamber started on the operating table itself and was formed more than half by the time the scleral sutures were tied. This observation is highly significant especially in those cases where an anterior chamber intra ocular lens implantation has been already done or is to be done as a combined procedure.

In the present study depending on the nature of the post operative filtering bleb, we classified them into three groups. .

Type I - Bleb extremely small and diffuse.

Type II - Bleb medium sized, thick and diffuse.

Type III - Bleb large raised, cystic and thin.

We found that in majority of the operated eyes by

Trabeculocyclostomy i.e. 17 eyes (70.8%), Type I blebs were seen while in the remaining 7 eyes (29.2%) Type II were observed. This clinical presentation could be explained firstly by the presence of the intervening lamellar scleral flap and secondly by the direction of maximum drainage of aqueous i.e. suprachoroidal drainage in this surgical procedure. (REF. [Table 7])

No serious complication was encountered in the present study but minor problems were observed. Post opera­tive iritis was the most common complication but in all these cases i.e. 6 eyes it was controlled by the local use of Steroids/Cycloplegics within 3 weeks of the post operative period. Hyphaema which was mild in nature was seen in 2 eyes, but was cleared spontaneously within 4 days of the surgery in both the eyes. One case each had an increase in the lenticular haze and conjunctival button holing. (Ref. [Table 8]).

 DISCUSSION



A large number of surgical procedures which have been introduced for the control of raised tension in glaucoma is testimony to the fact that the ideal operation which should preserve eye function, maintain the I.O.P. within normal limits and retain the integrity of the globe has not yet been developed.

Trabeculectomy has proved itself to be a safe filtering surgery [4], but evaluation of the mechanism of its filtera­tion site has now confirmed that majority of the drainage is external [3] and only part of it is through the two cut ends of the Schlemm's canal.

For this reason many surgeons today close the scleral flap lose [6], or do a partial sclerectomy 7 or even do an intentional cyclodialysis [8], with the routine trabeculec­tomy.

Trabeculocyclostomy aims at producing an 'INTERNAL DRAINGAGE' of aqueous i.e. suprachoroidal and its absorption by the well vascularised choroidal tissue.

This surgery was first introduced by Prof. MM. Krasnov and his associate in Moscow in 1978 [9], [10], but since these articles were written in Russian language, it was not well known in other parts of the world, although it produced excellent results.

In the traditional Trabeculectomy some amount of suprachoroidal drainage has also been demonstrated by Kwitto (1973) in his series of cases [11]. In the present study as is evident from the results a well controlled filteration was observed in majority of the cases through this cul-de-sac space with minimum shallowing of anterior chamber post-operatively.

Trabeculocyclostomy was later re-introduced by Prof. Akira Momose in Japan, who partly modified this tech­nique and did not find any case of choroidal detachment in his series [12]

The authors have used this modified technique in the present study probably for the first time in Indian and obtained excellent results with controlled filteration and minimum complication in approx. 84% of the cases.

 ACKNOWLEDGEMENT



We are grateful to Dr. Akira Momose M.D. F.I.C.S Director, Institute of Clinical Ophthalmology Kiryu Japan, under whose guidance this surgery was learned by the senior author during his fellowship training at his In­stitute by the Momose Afro-Asian Fund of Ophthalmol­ogy offered to him through the Indo-Japanese Ophthalmological foundation.

 CONCLUSIONS



A modified 'INTERNAL FILTERING' surgery­ Trabeculocyclostomy (TC) is evaluated probably for the first time in Indians as a primary surgical procedure for Primary open angle glaucoma.

This study which covers 24 eyes gives a high rate of success with virtual absence of complications. The authors suggest its importance in obtaining a controlled filteration in a cul-de-sac space i.e. suprachoroidal space and its utility as the operation of choice in cases where in association an anterior chamber intro ocular lens implantation has already been done or is being done as a combined procedure.

References

1Cairns J.E. Trabeculectomy: Preliminary report of a new method. Am. J. Ophthalmol 1968,66:673=679.
2Cairns J.E. Symposium: Microsurgery of the outflow channel in Trabeculectomy. Contemporary ophthalmology 1972. The CV Mosby Co. 127-131.
3Watson P.G. : Surgery of Glaucomas. Br.J.of Ophthalmol 1972,56:299=306.
4Ridgway A.E.A : Trabeculectomy a follow up study. Br. J.of ophthalmol 1874 48, 680-686.
5Thyer H.W. and Wilson P: Trabeculectomy Br.J. of ophthalmol. 1972, 56:37-40.
6Freedman J, Shen. E. and Ahren M: Trabeculectomy in a block Ameriacal population. Br.j.ophthalmol 1976, 60:573-574.
7Welsh N.H: Failure of filteration operation in the African:Br. of Ophthalmol 1970, 54:594-596.
8Galin M.A., Bounik V. and Robbins R.m.: Surgical landmarks in Trabecular surgery, Am. J. of ophth. 1975,80:696-701.
9Krasnov M.M.: Trabeculostomy and Trabeculocyclostomy in com­bined form of glaucoma. Vestn ophthalmol, 1978 N-4:9-11
10Krasnov M.M.: Microsurgery of Glaucoma 1979 the CV Mosby Co. St. Louis Pg. 111-116.
11Kwitto M.L.: Glaucoma in infant and children. 1973 Vol .1 pg 82, Appleton Century Crofts, New York.
12Momose A: Control of Pseudophakic glaucoma. trans APAO VIII 1983, 430-437.