Ординатура / Офтальмология / Английские материалы / Master's Guide to Manual Small Incision Cataract Surgery (MSICS)_Garg_2009

depending on the size of the nucleus should be made. A 6.5 to 7 mm wide tunnel will still be self-sealing if it is well constructed. A large capsulorhexis should be made to facilitate easy prolapse of nucleus into the anterior chamber. Since the nucleus is hard and non mouldable, prolapsing out the nucleus through a small capsulorhexis can result in either zonulodialysis or accidental intra capsular cataract extraction. Once the nucleus is in the anterior chamber then it can be prolapsed out through the tunnel by any of the preferred technique of the surgeon.

Our preferred technique of nucleus expulsion through the tunnel in cases of hard cataract is by hydroexpulsion. Anterior chamber maintainer is not used in our technique. Once the nucleus is in the anterior chamber, viscoelastic is injected all around the nucleus. A Sheet’s glide is introduced under the nucleus to guide it towards the tunnel and to avoid mal engagement of the nucleus into the anterior chamber angle.9 Now a paracentesis is made with the help of 26 G bent needle, mounted on a 2 cc syringe which is filled with BSS. When the needle is inside the anterior chamber, BSS is injected through the 26 G needle as a result the nucleus is pushed towards the tunnel. Once the nucleus has been engaged in the tunnel more fluid is injected to raise the pressure inside the anterior chamber and simultaneously posterior lip of the tunnel is pressed backwards. With the increasing pressure of the fluid inside the anterior chamber, the nucleus is pushed out through the tunnel in a very controlled manner. The advantage of this procedure is that it gives the surgeon full control of the situation and the surgeon can actually control the pressure inside the anterior chamber.

The hard nucleuses are slightly difficult to crack inside the anterior chamber. Trying to divide them inside the anterior chamber by an inexperienced surgeon can lead to anterior chamber trauma.

Alternatively they can be chipped off to reduce the size of the nucleus before taking out. The nucleus is prolapsed into the tunnel and a part of the nucleus is projected out of tunnel, the part of the nucleus which is projecting out of the tunnel is chipped off and the nucleus is then pushed back into the anterior chamber and rotated so that the adjacent site of the nucleus presents out of tunnel for chipping. In this way the size of the nucleus is reduced until it can come out through the tunnel comfortably.

Once the nucleus is out the rest of the surgery can be completed in the usual manner.

If at the end of surgery the surgeon feels the selfsealing nature of the tunnel has been compromised or the tunnel is slipping then one should apply a suture to make the tunnel more stable.

Cases with hard brown to black nucleus are slightly difficult to mange but with proper technique good results can be obtained even in cases of hard nucleus with small incision non phacoemulsification cataract extraction technique.

SUBLUXATED CATARACTS

Small incision non phacoemulsification surgery can safely be performed in cases of subluxated cataracts. Subluxated cataracts are to be dealt very cautiously and the general principles which apply to subluxated cataract surgery apply to this technique also. The decision to perform a small incision non phacoemulsification cataract extraction along with intraocular lens implantation depends upon the amount of subluxation of the lens and the surgical skills of the surgeon. The decision on the technique to be used should be taken on merits of individual case.

The anterior chamber is gently entered with keratome to avoid sudden collapse of the anterior chamber. Sudden collapse of anterior chamber can lead to further subluxation of the lens. A capsulorhexis should always be aimed at in all cases of subluxated cataract and an endocapsular ring should be inserted into the capsular bag as soon as possible. Once the endocapsular tension ring is secure in its place then the management becomes relatively easy. In cases of greater degree of subluxation, Cionni’s ring can be used to anchor the capsular bag to the sclera.10 One has to be very gentle in all the maneuvers when dealing with a case of subluxated cataract.

CATARACTS WITH PSEUDOEXFOLIATION

Cataracts with pseudoexfoliation pose a problem because of weak zonules and non dilating pupil and they are associated with statistically significant increased risk of intraoperative complications during cataract surgery.11 Non dilating pupil can be dealt with as mentioned previously by stretching the pupil. The capsulorhexis opening should be sufficient enough to allow the nucleus to pass out without any stress on the capsule as the slightest stress on the capsule can lead to zonulodialysis and subluxation. The weak zonules can be managed with the help of endocapsular tension ring. Stripping of cortical matter from the capsule

should be done in a tangential way rather then in a radial fashion in order to preserve the integrity of the zonules. The surgeon should be prepared for alternative methods of IOL implantation in case the capsular bag cannot be secured.

CATARACTS WITH EXISTING FILTRATION BLEBS

Selected patients who have already been operated for trabeculectomy and who have now developed visually significant cataract can be operated with the technique of small incision non phacoemulsification cataract surgery. A patient having well dilating pupil with soft cataract and intact zonules can be safely operated with this technique. Presence of posterior synechiae leading to small pupil, hard cataracts or cataracts with subluxation in the presence of filtering bleb should be operated very cautiously. A temporal incision is to be made as most of the time a trabeculectomy has been performed at 12 o’clock position.

DO’S AND DON’TS

Performing cataract surgery using small incision non phacoemulsification technique in difficult situations requires the understanding of the basic principles of the technique along with the complications of the technique employed. Approaching these difficult situations in a systematic manner will help the surgeon to surmount over these situations.

REFERENCES

1.Stewart R, Grosserode R, Cheetham JK, Rosenthal A. Efficacy and safety profile of ketorolac 0.5% ophthalmic

solution in the prevention of surgically induced miosis during cataract surgery. Clin Ther 1999;21(4):723-32.

2.Srinivasan R, Madhavaranga: Topical ketorolac tromethamine 0.5% versus diclofenac sodium 0.1% to inhibit miosis during cataract surgery. J Cataract Refract Surg 2002;28(3):517-20.

3.Shepherd DM. The pupil stretch technique for miotic pupils in cataract surgery. Ophthalmic Surg 1993;24(12): 851-2.

4.Dinsmore SC. Modified stretch technique for small pupil phacoemulsification with topical anesthesia. J Cataract Refract Surg 1996;22(1):27-30.

5.Graether JM. Graether pupil expander for managing the small pupil during surgery. J Cataract Refract Surg 1996; 22(5):530-5.

6.Jacob S, Agarwal A, Agarwal A, Agarwal S, Chowdhary S, Chowdhary R, et al. Trypan blue as an adjunct for safe phacoemulsification in eyes with white cataract. J Cataract Refract Surg 2002;28(10):1819-25.

7.Horiguchi M, Miyake K, Ohta I, Ito Y. Staining of the lens capsule for circular continuous capsulorhexis in eyes with white cataract. Arch Ophthalmol 1998;116(4): 535-7.

8.Pandey SK, Werner L, Escobar-Gomez M, Roig-Melo EA, Apple DJ. Dye-enhanced cataract surgery. Part 1: Anterior capsule staining for capsulorhexis in advanced/white cataract. J Cataract Refract Surg 2000;26(7): 1052-9.

9.Blumenthal M, Ashkenazi I, Fogel R, Assia EI. The gliding nucleus. J Cataract Refract Surg 1993;19(3):435-7.

10.Moreno-Montanes J, Sainz C, Maldonado MJ. Intraoperative and postoperative complications of Cionni endocapsular ring implantation. J Cataract Refract Surg 2003;29(3):492-7.

11.Scorolli L, Campos EC, Bassein L, Meduri RA. Pseudoexfoliation syndrome: A cohort study on intraoperative complications in cataract surgery. Ophthalmologica 1998;212(4):278-80.

INTRODUCTION

With the advancing age there is an increased incidence of both cataract and glaucoma and both of them cause a decrease in vision. Both these disease are preventable cause of blindness. Cataract and glaucoma may be found to coexist in one eye and sometimes cataract can lead to glaucoma or long-term miotic therapy for glaucoma can lead to cataract formation. As the life expectancy is increasing so is the incidence of coexisting cataract with glaucoma is increasing and the challenge of managing coexisting glaucoma and cataract is becoming ever more frequent.1 Beside the difficulty in diagnosis of glaucoma in the presence of cataract there are many other problems to be considered in the surgical management of glaucoma such as compliance of the patient, side effects and cost etc.

DIAGNOSIS OF GLAUCOMA

The diagnosis of glaucoma in the presence of cataract is slightly difficult as out of the three cardinal points in diagnosis of glaucoma, that is raised IOP, optic disc cupping and visual field defect; it becomes difficult to evaluate the latter two. The problem can be overcome by looking at the past records of the patient and evaluating the other eye.

DECISION

The decision as to how to operate and when to operate on a case of coexisting visually significant cataract and glaucoma lies entirely on the merits of individual case. There are various options available for surgical management of coexisting cataract and glaucoma. The surgeon

Arun Kshetrapal. Ramesh Kshetrapal (India)

can either go in for a sequential approach; that is to perform trabeculectomy before proceeding for cataract extraction with IOL implantation at a later date or can opt for combined cataract extraction and IOL implantation with trabeculectomy in a single sitting.

COMBINED SURGERY

Combined trabeculectomy with small incision (< 6 mm) cataract extraction often succeeds in reducing IOP2 and the results are promising.3 The combined surgery can control IOP effectively and can improve visual acuity rapidly.4 There is strong evidence for better long-term control of IOP with combined glaucoma and cataract operations compared with cataract surgery alone.5 Combined surgery has the advantages for the patient with visually significant cataract and uncontrolled glaucoma. When the two procedures are performed together in a single sitting it becomes very convenient for the patient as he has to undergo the mental trauma of a surgical procedure only once. The patient saves lot of time in terms of rehabilitation and cost. The visual rehabilitation is faster. The most important advantage of combined procedure is the prevention of postoperative spike of IOP seen after cataract surgery alone. This postoperative spike of IOP can be detrimental in a case of glaucoma.

Having decided to perform surgery in a single sitting the surgeon has two options, either to perform trabeculectomy and cataract extraction at two different sites or to perform both the procedures at a single site. In this chapter we will discuss about single site technique of combined trabeculectomy and cataract extraction through a small incision without the use of phacoemulsification.

INDICATIONS

The main indication for performing combined trabeculectomy with cataract extraction is when the patient is having both a visually significant cataract that requires extraction and IOL implantation along with uncontrolled glaucoma. It seems justified to extend the indication for combined surgery in cataract patients with coexisting open angle glaucoma in case of poor compliance, inability of sufficient medical care, or unacceptable medication.6

PREOPERATIVE EVALUATION

Evaluating a case preoperatively not only gives us a chance to confirm the diagnosis but also to uncover the problems that may arise during the surgery. A detailed history along with a good clinical examination should be performed using a slit lamp.

The condition of cornea is to be taken into consideration during preoperative evaluation. The cornea could be very hazy and edematous especially in cases of lens induced glaucoma. Operating upon such a case with corneal haze or edema can lead to difficulty in visualization of capsule and cortical material during surgery. Lowering of IOP with oral acetazolamide or with intravenous mannitol can help in clearing up the corneal haze and edema which will facilitate visualization of cortex and capsule per operatively. Administration of glycerin drop can also facilitate clearing of corneal edema.

Sometimes, especially in cases of lens induced glaucoma there could be cells and aqueous flare in the anterior chamber. This should be taken care of with steroids preoperatively for few days till the cells disappear from the anterior chamber. This will also help in reducing postoperative inflammation.

The status of the pupil and the extent of pupillary dilatation should be assessed preoperatively. Presences of any amorphous deposits on the pupillary margin are suggestive of pseudoexfoliation. If patient is on miotic therapy then they should preferably be stopped at least a week before surgery and oral acetazolamide can be added to control the IOP.

Fundus examination if possible should be carried to determine the status of the optic nerve head.

The surgeon should also determine as to what proportion of visual loss is due to cataract and what proportion of visual loss is due to glaucoma. This should be brought into the patient’s knowledge before operating and to inform him or her about the vision likely to be gained after the surgery.

THE TECHNIQUE

Many techniques have been described in the literature for performing combined trabeculectomy and cataract extraction through a small self-sealing tunnel without the use of phacoemulsification. The basic principle in all the procedures is to achieve sclerectomy of the posterior lip of the sclerocorneal tunnel which is covered by anterior lip of the tunnel. This can be achieved either with the help of a blade knife or a scleral punch.

Anesthesia

This surgery is most safely performed under a peribulbar anesthesia. The technique of anesthesia is the same as given for any other ocular surgery. A mixture of 2.5 ml of lignocaine 2% and 1.5 ml of bupivicaine 0.5% along with hyaluronidase is used and is injected in the peribulbar space along the inferior orbital rim at the junction of lateral one third and medial two third. Addition of sodium bicarbonate instead of hyaluronidase in lignocaine can make this procedure painless. Topical 2% lidocaine hydrochloride jelly without systemic sedation may be a safe and effective alternative anesthetic method in combined surgery.7

Conjunctival Flap

The conjunctival flap can either be a limbus or a fornix based. The use of either flap in combined surgery achieves the same IOP lowering.8 A fornix based conjunctival flap is preferred when considering a combined surgery as it has the advantage of better exposure of the surgical site. Conjunctiva is lifted up in the superior quadrant with the help of a non traumatizing forceps about 1 to 1.5 mm away from the limbus and a radial nick is given with the help of a Wescot’s scissors (Figure 33.1). The conjunctiva along with tenon is undermined (Figure 33.2) and cut along the limbus (Figure 33.3) to give a fornix based triangular conjunctival flap. A rim of 1 mm of conjunctiva can be left at the limbus so as to facilitate suturing if the surgeon desires. The exposed sclera is then scrapped clean for the remnants of tenons capsule if present with the help of BP blade and if required minimum cauterization of the scleral site is done to achieve haemostasis. Excess cauterization is avoided as it makes the sclera stiff and later on it can lead to excess fibrosis which can be detrimental for the surgery.

Scleral Tunnel

The three plane scleral tunnel is constructed very meticulously when performing a combined surgery. A

Figure 33.2: Conjunctiva is undermined

5.5 mm or 6 mm wide partial thickness frown scleral incision is made with the help of blade knife or with the help of depth-preset knife (300 microns). The center of the frown incision is placed about 2.5 to 3 mm posterior to the limbus which 0.5 to 1 mm more posterior to the usual incision when performing cataract extraction alone. The scleral tunnel is constructed with the help of a crescent blade. It is of utmost importance to enter at correct depth and to maintain the same depth throughout the tunnel. The scleral tunnel is carried forward for about 1.5 to 2 mm into the cornea. The dissection at the corneal end of the tunnel has to be 2 mm wider then the scleral end. Now anterior chamber

is entered with a suitable sized keratome. Once the anterior chamber is entered it should be reformed with the viscoelastic and then the sides of the tunnel is enlarged to make it funnel shaped.

Capsulorhexis

Every attempt should be made to achieve a continuous curvilinear capsulorhexis however in certain cases of lens induced glaucoma it becomes very difficult to perform a capsulorhexis. Adequate amount of viscoelastic should be used in such cases to counter balance the intra lenticular up thrust. Staining of capsule with trypan blue dye is a very good tool when performing capsulorhexis in mature and hypermature cataracts. An appropriate sized capsulorhexis should be made keeping the size of nucleus in mind so that the nucleus can be prolapsed easily into the AC. In cases of lens induced glaucoma the nucleus in most of the cases is not very big, it is the hydration of the cortex which has caused the lens to swell up and increase in size. In cases when the pupil is not dilating which is frequently seen in cases with long standing miotic therapy, the capsulorhexis can be made under the iris, even without visualization of the capsulorhexis margin if the surgeon has sufficient amount of proficiency. Alternatively the pupil can be enlarged with various techniques as described elsewhere in this book. In cases of psedoexfoliation, when combined surgery is being performed the size of capsulorhexis should be adequate as slightest pressure on the capsulorhexis margin during proplapse of the nucleus into the anterior chamber can lead to zonulodialysis.

Hydrodissection

The technique of hydrodissection does not differ significantly in a case where a combined surgery is being performed. It is performed in the usual way except in cases where the posterior capsule is not visible. When the posterior capsule is not visible the hydrodissection has to be very slow and minimal fluid is to be used. In cases of mature and hypermature cataract, hydrodissection can be avoided and the nucleus can be easily mobilized by engaging it with the help of Sinskey’s hook.

Nucleus Management

The prolapse of the nucleus from the bag into the anterior chamber and then through the tunnel out the anterior chamber is on the same principles as is done for cataract extraction alone. The nucleus can be prolapsed into the anterior chamber by any of the preferred techniques of the surgeon and then the nucleus is prolapsed out through the tunnel with a technique with which the surgeon is most comfortable. Once the nucleus is removed, a careful cortical clean up is done and the capsule is well polished and an IOL is implanted after filling the anterior chamber with viscoelastic.

Sclerectomy

Sclerectomy is done after the IOL has been implanted and before the viscoelastic is removed. Various techniques of performing sclerectomy are available. Here in this chapter we will discuss one technique of performing posterior lip sclerectomy using a scleral punch and one technique without the use of scleral punch.

Scleral Punch Technique

A Holth scleral punch (Figure 33.4) is used in this technique to perform sclerectomy of the posterior lip of the scleral tunnel. After the IOL has been implanted, the anterior chamber is replenished with viscoelastic which has escaped during IOL implantation.

The posterior lip of the scleral tunnel is held at the corneal end with the help of a Pierse Hoskins forceps and it is pulled out beyond the posterior margin of the anterior lip (Figure 33.5). To hold the corneal end of posterior lip, lift up the anterior lip with Pierse Hoskins forceps held in right hand and with another Pierse Hoskins forceps held in the left hand reach for the anterior end of the posterior lip. Press lightly with one

Figure 33.4: Holth scleral punch

Figure 33.5: Inner lip of tunnel is held with a forceps

limb of the forceps at the corneal end of the lip so that the lip becomes slightly everted which can now be easily grasped with the forceps in the left hand.

Once the posterior lip has been grasped by the forceps in left hand, the sclera is engaged between the limbs of scleral punch held in right hand (Figure 33.6) and a portion of the sclera is punched out by closing the punch and the piece of the sclera is removed Figure 33.7). The extent of the sclera to be punched out should be continuously monitored through the punch from where the surgeon can visualize the area being punched out. It should not cross the line of incision, as the punched out area will be more then what the anterior lip can cover.

An iridectomy is performed in the area of sclerectomy to complete the procedure. Care should be taken while punching the sclera. Sometimes if the surgeon is

Figure 33.6: Sclera is punched out with Holth punch

Figure 33.7: Punched out posterior lip of tunnel

not careful enough, the iris can be caught in between the punch which then will be punched out along with the sclera. The area of the punched out sclera should be barely enough so that it is covered by the anterior lip of the tunnel.

Sclerectomy without the Help of Scleral Punch

Various techniques of performing sclerectomy of the posterior lip without the use of scleral punch have been described. The posterior lip of the scleral tunnel is held with the help of a forceps as described earlier or the lip is exposed by pulling on to the anterior lip towards the cornea by an assistant. The surgeon then with the help of a blade breaker knife makes two radial incisions, parallel to each other and about 1.5 mm apart extending about 2 mm from the corneolimbal junction towards the sclera. A third incision is made at the corneolimbal junction that is parallel to the limbus and connects the two radial incisions. Once these two radial incisions and corneolimbal incision have been made, a hinged flap of the corenosclera is obtained which is excised horizontally with the help of vannas scissors. In this manner a portion of sclera is removed from the posterior lip.

After completion of sclerectomy, if the self sealing nature and the integrity of the scleral tunnel are in doubt, then the tunnel should be sutured to prevent any complication.

Once the sclerectomy has been performed, the viscoelastic is removed and anterior chamber is formed with ringer lactate or if needed then it can be filled with air.

Conjunctival Closure

The conjunctival flap is sutured at one or both ends to the limbus with 8-0 or 10-0 nylon sutures to obtain tight limbal closure. If the conjunctival flap had been initially fashioned leaving a 1 mm rim of conjunctiva at the limbus then the conjunctiva to conjunctiva can be sutured by a running 10-0 nylon suture. Alternatively the conjunctiva can be cauterized back to cover the incision site and it works equally well.

ANTIMETABOLITES

Antimetabolites such as 5-flurouracil (5-FU) or mito- mycin-C when used in conjunction with combined surgery can be beneficial. The antimetabolites are indicated for intractable glaucoma and high risk patients where the chances of failure are more. Application of 3 mg/ml of mitomycin-C for 2 minutes on the sclera, at the site of scleral tunnel has been found to be beneficial in combined surgery. After application the excess drug has to be washed out with copious amount of fluid to prevent complications such as scleral melting,

bleb leak and hypotony. Contact of mitomycin-C to the conjunctiva should be avoided as it may cause conjunctival necrosis.

Combined surgery augmented with mitomycin-C achieves a lower IOP than combined surgery alone without the use of mitomycin-C. The use of 5-fluoro- uracil is not as effective as mitomycin-C and has a variable influence on the results.9

COMPLICATIONS

Besides the usual complications of small incision non phacoemulsification cataract extraction certain specific complications are seen with combined surgery.

Intraoperative Complications

The most dreaded intra operative complication is making of an oversized sclerectomy which cannot be covered by the anterior lip of the scleral tunnel. Once an oversized sclerectomy is made then every attempt should be made to suture the incision as watertight as possible without pulling on to the lips of the scleral tunnel and closing the conjunctiva with sutures and making it as watertight as possible. The other common complication could be intra operative hyphema. The bleeding vessel should be identified and if possible should be cauterized. If the bleeding vessel cannot be seen or is at a location where the cautery cannot be performed then the surgeon should wait for the bleeding to stop on its own and then wash out all the blood from the anterior chamber and then the conjunctiva is closed. Alternatively adrenaline can be used to achieve haemostasis if the patient is having normal blood pressure and there is no contraindication to its use.

Postoperative Complications

The most common complication seen postoperatively is severe fibrinous reaction with or without hyphema. The anterior chamber reaction along with exudates clears in 2 to 3 days time after frequent use of topical steroids. Postoperative shallow anterior chamber is seen in cases when the anterior chamber was not well formed on the table. If the anterior chamber is shallow along with low IOP, over filtration should be suspected and the patient should either be pad and bandaged until the anterior chamber deepens or the patient should be taken into operating room and anterior chamber reformed with the help of air and the incision closed watertight with sutures.

If the anterior chamber is shallow along with raised IOP then a pupillary block should be suspected and instillation of topical mydriatics can relieve the pupillary block.

CONCLUSION

Each case of coexistent visually significant cataract and glaucoma has to be managed on its own merits. The surgeon should decide the course of management of a case on the surgical capability of the surgeon and no generalization should be made. The techniques described in this chapter should only serve as guide for individual surgeon’s preferences in management of cataract and glaucoma. However if the combined surgery is performed with appropriate technique, excellent results can be expected with high rate of success.

REFRENCES

1.Heffelfinger BL, Berman MN, Krupin T, Rosenberg LF, Ruderman JM. Surgical management of coexisting glaucoma and cataract. Ophthalmol Clin North Am 2000;13(3):545-52. Review.

2.Lyle WA, Jin C. Comparison of 3- and 6-mm incision in combined Phacoemulsification and trabeculectomy. Am J Ophthalmol 1991;111:189.

3.Kubota T, Touguri I, Onizuka N, Matsuura T. Phacoemulsification and intraocular lens implantation combined with trabeculotomy for open-angle glaucoma and coexisting cataract. Ophthalmologica 2003;217(3): 204-7.

4.Chen H, Ge J, Liu X, Lu F. The clinical analysis of 260 combined surgery of glaucoma and cataract. Yan Ke Xue Bao 2000;16(2):102-5.

5.Friedman DS, Jampel HD, Lubomski LH, Kempen JH, Quigley H, Congdon N, et al. Surgical strategies for coexisting glaucoma and cataract: An evidence-based update. Ophthalmology 2002;109(10):1902-13. Review.

6.Storr-Paulsen A, Perriard A, Vangsted P. Indications and efficacy of combined trabeculectomy and extracapsular cataract extraction with intraocular lens implantation in cataract patients with coexisting open angle glaucoma. Acta Ophthalmol Scand 1995;73(3):273-6.

7.Lai JS, Tham CC, Lam DS. Topical anesthesia in phacotrabeculectomy. J Glaucoma 2002;11(3):271-4.

8.Simmons ST, Litoff D, Nicholas DA, et al. Extracapsular cataract extraction and posterior chamber intraocular lens implantation combined with trabeculectomy in patients with glaucoma. Am J Ophthalmol 1987;104:465.

9.Casson RJ, Salmon JF. Combined surgery in the treatment of patients with cataract and primary openangle glaucoma. J Cataract Refract Surg 2001;27(11): 1854-63. Review.

INTRODUCTION

Over the past decade or so, we’ve witnessed a phenomenon wherein improved instrumentation and advancements in the science of optics have brought MSICS at par with phacoemulsification surgery as far as visual rehabilitation and ocular morbidity is concerned, so much so that MSICS has been aptly termed as ‘poor man’s phaco’. It is indeed the most appropriate technique wherein a large surgical load has to be overcome in the minimum possible man-hours and with minimal expenditure. In fact, in a developing country like India, MSICS has emerged as the most appropriate technique to counter the huge load of ‘preventable blindness’, to lessen the burden on the society in managing its everincreasing numbers of the aging population, and finally, to empower newly qualified ophthalmologists with a skillful technique, which may be put to good use in terms of community service.

The huge volume of cataract surgeries which can be performed in a single day through MSICS combined with the immediate visual rehabilitation it offers, can bring about a sea-change in the general outlook towards life of the elderly rural populace. All these factors reflect in the development of productive individuals and healthier societies around us. In a heavily populated country like India, the need of the hour is to disseminate the perfected steps and techniques of MSICS—acquired by an ophthalmic surgeon during the course of his training—to far, interior, rural pockets where very few doctors and fewer health services reach.

The operative techniques, instrumentation and sterilization protocols can be re-modelled and adapted to meet local requirements in terms of large volume surgeries and cost effectiveness without compromising

on the final visual outcome. Some of the main adaptive measures thus have been dwelt upon in this chapter.

Disposables

With more and more disposables entering the operating area, there has been less dependence on re-autoclavable material including linen, gowns, etc., thus saving on fuel, time, manpower and storage space. Good quality adhesive eye drapes, replete with side pouches and large, water-proof towels are quite effective in isolating the operative area from eyelashes, expired air, throat secretions and contamination from the surrounding skin. With bulk usage, these are quite cost effective, keep the operative area clean, easy to incinerate and quite environment friendly.

Preoperative Preparation of the Patient

Though eyelash cutting has been a time-tested method of reducing the load of contaminants in the operative area, it is not acceptable to many present day patients from a cosmetic point of view. Also, with a large surgical load, this method is a drain on manpower too. Current evidence suggests that good adhesive eye drapes can isolate the operative area from contaminants equally well. Also, a drop of 5% povidone–iodine solution, applied to the conjunctival cul-de-sac, 5-8 minutes prior to surgery renders the operative field completely sterile.

Conversion to Topical Anesthesia (Figure 34.1)

MSICS involves making a scleral tunnel and conjunctival peritomy and both these structures are quite pain sensitive. With proper case selection, SICS can be done under topical anesthesia by placing cotton-tipped

Figure 34.1

applicator soaked in xylocaine solution over the site of scleral tunnel and injecting intra-cameral, preservativefree 1% lignocaine. The advantages are avoidance of needle prick and the complications associated with it, less pain or apprehension on the part of the patient, less operating time, immediate postoperative visual recovery (no eye patch), good cosmesis and cost effectiveness.

‘No-peritomy’ Scleral Tunnel

In select patients, where the perilimbal congestion is minimum, peritomy and subsequent cauterization of bleeders, can be avoided. The scleral tunnel is made directly through the conjunctiva, without dissecting or undermining the latter (Figure 34.2).

This technique helps to save time, is without any foreign body sensation postoperatively and preserves the limbal zone architecture for any future surgery in that area. This incision is cosmetically good too and avoids all complications related to cautery like scleral shrinkage, wound gape, etc. (Figures 34.3 and 34.4).

For making the initial incision, a razor blade fragment can be used with good effect. It is cheap, very sharp and at least, a dozen fragments can be made from a single razor blade. The initial incision cuts through conjunctiva, tenon’s capsule and superficial layers of the sclera. The tunnel is fashioned with a crescent blade, viewing the depth through the conjunctiva. The assistant should be competent enough to mop-up the bleeding at the operative site.

Side-port Incisions

A 20 or 21 G needle is sharp enough to make good sideport incisions. The problems faced while using the

Figure 34.2

Figure 34.3

Figure 34.4