|Year : 1979 | Volume
| Issue : 4 | Page : 66-70
Combined surgery for cataract and glaucoma
Daljit Singh, Mohinder Singh, Arun Verma
Medical College, Amritsar, India
Professor of Ophthalmology, Department of Ophthalmology, Medical College, Amritsar
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Singh D, Singh M, Verma A. Combined surgery for cataract and glaucoma. Indian J Ophthalmol 1979;27:66-70
Cataract and glaucoma often coexist. The glaucoma may be primary open-angle type or lens-induced one.
There are three ways to manage these cases:
1. One stage operation for both cataract and glaucoma. 2. Surgery for glaucoma, followed by cataract extraction after some weeks. 3. Removal of cataract, followed by control of ocular tension by medicines or surgery.
The one stage operation for glaucoma and cataract is favoured by many surgeons,,,,, on the following grounds: 1. The patient needs to be operated only once. 2 Shortening the period of stay in the hospital. 3. The insult of a second operation with all its associated risks to a chronically ill eye is avoided. 4. The risk and annoyance of prolonged medication is terminated. 5. Cataract extraction as a secondary procedure may cause loss of tendon control, which may have been achieved by the first antiglaucoma operation. 6. Early restoration of vision. 7. The surgeon operates in a standard manner, under familiar circumstances.
A new technique of "pretrabecular filtration" for the management of glaucoma has been developed by us. The following report concerns a series of 70 consecutive cases in which cataract extraction was combined with pretrabecular filtration.
| Material and methods|| |
70 cases have been operated and followed. They include 8 cases of primary wide angle glaucoma with cataract and 62 cases of lens-induced glaucoma. The duration of acute attack in the latter cases varied between 2 to 20 days, with an average of 7 days.
The intraocular pressure was controlled with miotics, acetazolamide, oral glycerine or intravenous mannitol. Broad spectrum antibiotic drops were put frequently.
Anaesthesia: Local I/v diazepam 10 mgm when needed.
Steps of operation
1. A limbal based conjunctival flap is made from 3 to 9 O'clock in such a way that its width at 12 O'clock is about 8-10 mm, which decreases gradually to 3 mm at the ends and is reflected on the cornea [Figure - 4]. The blood. vessels are lightly cauterized.
2. Incision: Half thickness incisions are made along the limbus perpendicular to the surface from 9 to 11.30 h, and 12.30 to 3 h., the intervening distance between these two incisions is about 4 mm. Starting from the upper ends of these incisions, two half thickness converging scleral incisions are made to meet about 4 to 5 mm above the limbus. [Figure - 1].
3. The cornea is split horizontally for about 1 mm in the area of the two limbal incisions. One preplaced stitch is passed on either side and loops made [Figure - 2].
4. Half thickness triangular scleral flap is raised, the splitting is continued beyond the limbus into the clear cornea for about 1-1/2 mm [Figure - 2].
5. A 1 to 1-1/2 mm square opening is made in the deeper layers of the cornea, under the triangular flap. This opening is anterior to the corneoscleral trabeculae [Figure - 2].
6. An iris repositor is passed through the pretrabecular opening and the peripheral irido-corneal adhesions are separated on either side.
7. A corneal scissors is introduced through the pretrabecular opening and a flange incision is completed on either side [Figure - 3]. The flange incision comprises of the first vertical cut, the second horizontal splitting and the third vertical cut 3/4 mm anterior to the first vertical incision.
8. Peripheral iridectomy is done in the area of the pretrabecular opening [Figure - 3]. Complete iridectomy is done when cryoprobe has to be applied.
10. The apex of the triangular scleral flap is stitched hack to the original place and the preplaced corneoscleral stitches are tied [Figure - 4].
11. Sterile air is introduced into the anterior chamber and the conjunctival flap is stitched with three interrupted sutures.
The patient is allowed to move about as and when he can. Solid food is permitted from second day onwards. Capsules chloramphenicol 250 mgm are given every 6 hrs. for the first three days. Analgesics are given when needed.
Observation and discussion
In our cases of lens-induced glaucoma, 44 patients (70%) were females, a great majority being in the agegroup of 51 to (0 years. The high incidence of lensinduced glaucoma in the females may possibly be attributed to the smaller size of the cornea, shallow anterior chamber and excessive vaso-motor instability in them.
[Table - 1] shows the operative complications:
1. Rupture of the lens: In our series the lens ruptured in 14 cases (20%). The incidence of lens rupture by other authors is: 20% (Wenaas and Stertzbach 1956), 5% (Hughse et al 1963), 28% (Nagpaul et al 1966), 5% (Maumenne et al 1970). The higher figures of lens rupture by certain authors are probably related to the higher percentage of lens-induced glaucoma in their series. Rupture of the lens in lens-induced glaucoma is more frequent probably for the following reasons:
a. Very shallow anterior chamber predisposes the lens to easy injury by the tip of the blade when opening the anterior chamber or when completing the incision with scissors, or by the iris forceps, when doing iridectomy before lens delivery.
b. The very nature of the swollen lens with stretched thin capsule, also favours more frequent rupture during delivery.
[Table - 2] shows the post-operative complications.
Post-operative intraocular tension
[Table - 3] shows the post-operative intraocular tension.
After an average follow up of 195 days the intraocular pressure in 57 cases (81.6%) was found to be below 20 mm Hg. 9 cases (12.8%) had pressure between 21 and 30 mm Hg, and 4 cases (5.6%) above 30 mm Hg. Intraocular tension above 20 mm Hg. was controlled with 2% pllocarpine three times a day in 9 cases (12.8%). Thus the overall control of intraocular pressure was achieved in 94.4% of cases in our series. Overall control of ocular tension as reported by other authors is: 96% (Wenaas and stretzbach 1955), 100% (Hughe et al 1963), 94% (Nagpaul et al 1966), 90% (Gablin et al 1969), 90% (Nath and Shukla 1966) and 65% (Maumenne et al 1970).
Types of filtering blebs
The filtering bleb was absent in 8 cases (11.5%). 7 of these cases bad an abnormal rise of tension later on. 17 cases (24.3%) had a non-prominent bleb and 45 cases (64.2%) bad a prominent bleb. Thus a great majority of the patients had a filtering bleb. It is evident that for the tension to be kept under control, certain amount of filtration under the conjunctiva through the pretrabecular opening is essential.
Types of anterior vitreous face
Type I: The anterior vitreous face lies entirely behind the pupillary plane.
Type II: The vitreous face has a slight convexity showing through the pupil.
It will be seen that cases of lens induced glaucoma ended up with much better vision as compared to cases of wide angle glaucoma associated with cataract.
Gonioscopy was done in 63 cases. In a great majority (93.7%) the opening was situated totally anterior to the Schwalbe's line. In four cases (6.3%) the anterior part of the trabeculum was also inadvertently involved in the excision. In 9 cases (14.2%) the opening was partially closed by the iris (7) and vitreous (1). One pretrabecular opening appeared to be scarred.
Type III: There is a herniation of the vitreous into the anterior chamber.
Type IV: The vitreous actually touches the back of the cornea.
In this series only 48.5% of the cases fall in type I and type II . In comparison 90% of our routine cases of cataract extraction show anterior vitreous face belonging to type I and type II Singh et a1. The incidence of vitreous touch syndrome in our routine cataract extractions reported earlier was 0.4% Singh et al, whereas in this series it is very high (4.3%).
[Table - 4] shows the corrected vision.
Advantages of pretrabecular filtration with cataract extraction
1. The operation can be done without an operating microscope.
2. The opening is anterior to the diseased canal of Schlemm, corneoscleral trabeculae and peripheral synechiae. Thus it offers better chances of filtration.
3. The opening being anteriorly situated, the vitreous has lesser chances of blocking it.
4. The opening being covered with a scleral flap, results in a thick walled bleb. Tho chances of its late perforation and infection are minimized.
5. The operation is easy to perform and gives consistent results.
| References|| |
Callahan, A, 1956, "Surgery of the eye-diseases" p. 287, Charles C. Thoman Publishers U.S.A.
Dellaporta, 1976, Highlights of Ophthal., 14,
Dutta, L.C. and Bora, S., 1977, Proceedings of All India Ophthalmological Conference (under publication).
Stocker, F.W., 1964, Arch. Ophthal., 72,
Singh, D., Nirankari, M.S. and Singh, M., 1977, Proceedings of All India Ophthalmological Conference (under publication).
Thyer, H.W., and Wilson, P., 1972, Brit. J. Ophthal., 56,
Wright, R.E., 1937, Amer J. Ophthal.,
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4]
[Table - 1], [Table - 2], [Table - 3], [Table - 4]