|Year : 1976 | Volume
| Issue : 4 | Page : 9-12
Ophthalmic use of a new synthetic suture-Dexon
P Siva Reddy
Institute of Ophthalmology and Sarojini Devi Eye Hospital, Hyderabad, India
P Siva Reddy
Institute of Ophthalmology and Sarojini Devi Eye Hospital, Hyderabad
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Reddy P S. Ophthalmic use of a new synthetic suture-Dexon. Indian J Ophthalmol 1976;24:9-12
There is a continuing search for an ideal suture specially suited to the delicacies of ophthalmic surgery. Eilert et al considered an ideal suture to be one which could be used throughout any operation, the only variable being the suture's size and tensile strength in the presence of infection. The suture should not persist for prolonged periods or predispose to sinus formation or extrusion, it should be stable and dependably sterilizable and storable.
This clinical study described below was undertaken at the Institute of Ophthalmology and Sarojini Devi Eye Hospital, Hyderabad, to test the efficacy of Polyglycolic acid DEXON, a new synthetic absorbable suture in ophthalmic surgery,
DEXON is a linear homopolymer of glycolic acid (hydroxyacetic acid). It is sterile, inert, non-collagenuous, non-antigenic, nonpyrogenic, flexible and is braided. It is uniform in size and tensile strength. The suture is absorbed by simple hydrolysis. Clinical experience and animal studies have revealed no absorption at 7 days, minimal absorption at 15 days, maximum absorption at 30 days, and essentially complete resorption after 60-90 days. It has features of both silk and catgut. Lilly et al have postulated that polyglycolic acid (PGA) can even inhibit penetration of bacteria. Glycolic acid concentration between the interestices of PGA is sufficient to result in a pH incompatible with bacterial growth.
Use of PGA has been recommended as safe and advantageous in other fields of surgery from intestinal anastamoses to skin sutures. The human eye is one place where one can assess the reaction to a suture by direct observation. The sutures supplied to us were dyed green. The colour of this suture used ensured good visibility in operative fields and for proper observation in subsequent follow-up examinations.
| Materials and Methods|| |
Polyglycolic acid sutures were used in 100 patients who were to undergo a variety of opthalmic surgical procedures. Among these surgical procedures were 54 cases of cataract surgery, 17 of strabismus surgery, four of irideneclesis, 23 of dacrocystectomy, and one each of excision of pterygium and tarsorrhaphy.
The age group ranged from eight to 82 years. Preoperative and post-operative blood pictures and urine analysis were done in all cases and no significant differences were noted. Patients were examined daily during the hospital stay (7 to 10 days) and thereafter every 15 days for a period of eight to 10 weeks. Direct and slit lamp examination were undertaken to study the reaction of the suture material.
There were 54 cases of cataract, 30 of whom were males and 24 females, ranging in the age group of 40 to 82 years. These cases included 3 diabetic, 4 hypertensive and 3 complicated cataract cases. In all cases, a limbus - based conjunctival flap was used. Six-0 PGA (DEXON) on a CE-20 needle was used. DEXON sutures were post-placed prior to lens extraction. In 50 cases, only one sclero-corneal suture placed in the 12 o-clock position was used: in two other cases both sclerocorneal and conjunctival sutures (one suture for each case) were used, while in the remaining 2 cases only conjunctival sutures were used. A peripheral buttonhole iridectomy or a broad iridectomy was performed in all the cases. Post-operatively, topical medicines. one or more combinations of penicillin, soframycin, terramycin or chloromycetine and cortisone were used. Patients were hospitalised for one week and after discharge were advised to continue the antibiotic and cortisone drops for six weeks.
There were 17 cases of strabismus between the ages of eight to 30 years. 5-0 PGA on a DO-1 needle was used for resection and 5-0 terylene for recession; a comparative study was thus made. The conjunctiva over the PGA suture was closed using 6-0 PGA on CE20 needle and that over the terylene suture with 5-0 black silk sutures (the routine procedure at our Institute). Tissue reactions to the new suture (redness, oedema and elevation) were noted in each case. Postoperatively, antibiotics and steroids were used in every case. Conjunctival sutures were removed on seventh post-operative day.
In four cases of iridencleisis ranging in age from 50 to 63 years, 6-0 PGA on a CE-20 needle was used for continuous conjuctival sutures. The sutures were removed on the ninth day. Adverse reactions to the suture if any were noted.
For the 23 dacrocystectomy cases ranging in age from 25 to 75 years, 4-0 PGA on DG-1 needle was used. Except for one male, all the other cases were female. In bilateral cases, 5-0 linen was used in one eye, and 4-0 PGA in the other. Both interrupted and subcutaneous skin sutures were used. In 13 cases, sutures were removed on sixth day; in the remaining 10 cases, sutures were retained to study the absorption.
In the case of bilateral pterygium 6-0 PGA was used in one eye, and 6-0 black silk sutures was used in the other eye. The silk suture was removed after six days, while PGA was retained.
In the one case of tarsorrhaphy, 4-0 PGA was used.
| Discussion|| |
In this clinical trial observations were made of the tolerance of the delicate ocular structures and any untoward reaction to the new suture material were noted.
According to theoretical postulates and practical observations, DEXON is a good ophthalmic suture. It has good tensile strength and is easy to handle, but tends to grab loose tissue. White et al and Sugar et al have reported the same findings. The suture is quite stiff, but this can be reduced by wetting it in normal saline before surgery. Sugar in a clinical trial has observed that 7-0 PGA could eliminate both stiffness and tissue drag. The various types of atraumatic needles attached to the sutures. i.e. CE-20 and DO-l, the first reverse traingular and the second scleral spatula, are superior to what we ordinarily use. The knot is very secure, does not slip and showed no tendency to unravel. Direct visualisation of absorption of material in the anterior chamber revealed that absorption proceeds without fragmentation of suture, occuring superficially and concentrically in the full length of the strand.
It was observed that ocular tissues can tolerate PGA extremely well. In majority of the cases of cataract surgery, minimal conjunctival hyperameia was found to persist around the suture upto the fourth post-operative week. From the fifth to sixth week, the eye was found to be very quiet with almost complete absorption of the suture except for a greenish hue at the site of the suture. By the eighth week no trace of the suture was found. One case showed a relatively quicker absorption in 23 days. In another case of cataract surgery, a mucus flake was found to be adherent to the suture material which showed signs of extrusion, with associated chemosis of conjunctival flap. As observed by Furgiuele adherence of the mucus flake may be due to the braided structure of the suture. The oedema gradually subsided, the suture was intact and absorbed completely. There was one case of lid oedema on the sixth post-operative day; this was due to penicillin allergy and was totally unrelated to the suture. One disadvantage observed was the formation of comparatively large knots as regards the sclero-corneal sutures. A finer gauge, i.e. 7-0 is preferable for sclero-corneal surgery. The initial tight tying of the first knot may cause folds in cornea leading to astigmatism. This inconvenience could be quickly overcome once familiarity with the suture is attained. White et al  have also made the same observation. Removal of sclero-corneal sutures is followed by complications of hyperamia, suture leak, wound gaping and flattening of anterior chamber. Leaving behind very fine gauges of silk or nylon (8-0, 9-0) which is a routine procedure at our Institute, can sometimes cause foreign body reaction or suture extrusion, weeks or months after surgery. With the new absorbable DEXON, these disadvantages could be overcome. During our practical observation, none of the patients complained of any foreign body sensation or feeling of the stitches.
In muscle surgery, one of the disadvantages in using synthetic sutures is the formation of granuloma. Walker found 4-0 DEXON very useful for muscle surgery especially for patients who were allergic to catgut. In each case, redness, oedema and granuloma formation were observed. In our clinical study, there was no appreciable difference in the conjunctival reaction at the suture site between DEXON and the non-absorbable synthetic terylene. The eye was found to be quiet during eighth to 10th post-operative week. In one case, congestion was found to persist even after 12 weeks, but this was also present at the terylene suture site. Foreign body granuloma was observed in one case where terylene was used: none were observed with DEXON. Stein" reported minimal granuloma formation with PGA compared to other sutures. In one case where conjunctival PGA suture was retained to study the absorption, chemosis around the suture was observed on seventh post-operative day. Chemosis did not subside, hence on 12th day the suture was removed and chemosis rapidly subsided. Blau et al who tried PGA sutures in 70 cases of muscle surgery, observed that PGA produced less conjunctival reaction than gut. Walker in his observation of 25 cases, found equal conjunctival reaction for both PGA and collagen. Merritt et al used 4-0 PGA for muscle surgery. They found no difference in reaction during the first post-operative week; however during the third week, gut showed more reaction than PGA. The period three to four weeks post-operatively is important because decreased inflammatory response may indicate less scar tissue and hence more chance for the re-operation.
There was no adverse reaction in any of the cases of iridencleisis.
The skin sutures (interrupted) in dacryocystectomy remained even after the sixth post-operative week, but when pulled the sutures broke off easily. Two cases where subcutaneous sutures were used showed complete absorption by eight to 10 weeks. Since it was observed that skin sutures required more time for absoption, thereby creating inconvenience to the patient, the sutures for the remaining cases were removed on sixth post-operative day. Sugar observed that absorption time of the suture depends on the tissue and size of suture. Soares et al commented that sutures heavier than 5-0 and 6-0 should not be used, because the large sized sutures ccnlain a greater number of strands which prolong absorption time and this may be a drawback where routine removal of sutures between the sixth and eighth day are done in common operations. They used 6-0 for skin sutures and obtained good results.
PGA used in the conjunctiva in cases of pterygium showed spontaneous absorption. No adverse reactions were observed in tarsorrhaphy.
DEXON, in our clinical trial, proved to be a very safe and good material for ophthalmic surgical procedures. A finer gauge than 6-0 is preferred for sclero-corneal surgery. The atraumatic needles attached to the sutures are excellent. Dexon is non-toxic and well tolerated by ocular tissues. The knot is secure and the absorption of the material covers a period which allows complete healing of the surgical wound. The nature of its absorbability would have ideally suited the use of FGA in keratoplasty, but since a gauge finer than 6-0 was not available, this suture could not be evaluated.
| Summary|| |
This report deals with our experience with DEXON polyglycolic acid sutures in 100 patients requiring opthalmic surgery at Institute of Ophthalmology and Sarojini Devi Eye Hospital, Hyderabad. 4-0, 5-0 and 6-0 DEXON, dyed green, were used for various ophthalmic surgical procedures. The operations performed were 54 cataracts, 17 strabismus, 4 iridencleisis, 23 dacryocystectomies, 1 pterygium, and 1 tarsorrhaphy.
The tensile strength of DEXON, the security of its knot, tolerance of the ocular tissues, excellent properties of the needle, easy visibility in the operative fields, combined with absorbability proved that DEXON is a good suture, greatly useful for ophthalmic surgery. A finer gauge than 6-0 is advised for sclerocorneal surgery. Granuloma formation is less likely to occur with PGA for muscle sutures. Skin sutures with 4-0 PGA take a longer time for absorption.
| Acknowledgement|| |
Suture materials were made available to the author through the courtesy of Dr. F. A. Nazareth, Medical Director, Lederle Division, Cyanamid India Limited.
| References|| |
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