Ординатура / Офтальмология / Английские материалы / Small Incision Cataract Surgery (Manual Phaco)_Singh_2002

The anterior epithelium This is a single layer of cubical cells beneath the anterior capsule (There is no corresponding posterior epithelium). This layer is responsible for all the metabolic and mitotic activity of the lens. This layer produces the lens fibres.

The cubical cells of the anterior epithelium gradually become columnar and elongate towards the equator and are eventually converted into lens fibres.

As these cells elongate into lens fibres, the part, which is in contact with the capsule becomes the posterior part of lens fibres, while the opposite end grows into the anterior portion of the lens fibre.

The cement substance of amorphous material The various elements forming the lens are bound together by an amorphous substance. The cement substance glues the various fibres to each other.

It is found at following sites:

1.Beneath the capsule both in front and behind.

2.A thin layer deep to the anterior epithelium.

3.The central strand.

The central strand occupies the axis of the lens from anterior to posterior pole. Extending towards the equator from this axial collection the amorphous material is collected in the form of Y. The anterior Y is vertical and posterior is inverted (λ). The lens fibres get inserted into these.

The lens fibres Each lens fibre is a long, prismatic sixsided band. Lens fibre is a collection of albuminoid material enclosed in a pseudo-membrane. The membrane is called pseudo because it is composed of the same material as its contents but is denser.

During embryonic development the first lens fibres arise from posterior epithelium, which run from the back to the front of the vesicle. The later fibres are derived from the equatorial portion of the anterior epithelium. The newer fibres are laid external to the deep older fibres and this give the lens a laminated structure.

New lens fibres are laid on throughout life and as the central portion, which corresponds to the keratin layer of the skin cannot be shed, the lens keeps on growing. However, the growth is not proportional to the number of fibres, because the deeper older fibres get shrunken. The lens at the age of 65 years is one-third larger than at the age of 25 years. Hence, we can anticipate bigger nucleus and may need bigger incision while performing surgery in older persons.

The consistency of the lens varies and superficial cortex is softer than central part of nucleus. The nucleus increases in size with age and this becomes flatter with age. However, the refractive power of lens is retained by an increase in the refractive index of the nucleus.

The colour of the lens also changes with age. In the infant and young, it is quite colourless. After about 35 years the central portion develops yellow tinge and gradually becomes darker and more extensive with age. In the older people the lens has amber colour.

Sometimes the lens appears gray in old people when seen by indirect illumination and can be mistaken as cataract by the beginners.

Ciliary Zonule The ciliary zonules consist of fibres arising from the ciliary body to the lens. It holds the lens in position and enables the ciliary muscles to act on it. The zonular fibres are attached at the equator and the anterior and posterior capsule near the equator.

The zonular fibres can be classified in two groups: Main and Auxillary fibres.

A.Main fibres consists of following fibres:

i.Orbiculoposterior capsular They originate from the ora serrata and are inserted into the posterior capsule.

ii.Orbiculoanterior capsular They are the thickest and strongest of the zonular fibres. They originate from the pars plana of ciliary body and inserted into the anterior capsule of the lens.

iii.The cilio-posterior capsular fibres They are the most numerous fibres. They arise from the valleys and sides of the ciliary processes. They are directed posteriorly and cross the anteriorly directed fibres and are inserted into the posterior capsule.

iv.The cilio-equatorial fibres They are present only in youthful eyes, originate from ciliary valleys and inserted to the equator of the lens. With age these fibres disappear.

B.The auxillary fibres Some of these fibres strengthen the main fibres and help to anchor the individual portions of the zonule, while others hold the ciliary body together. These are very fine and run from without inwards and forward.

It is noteworthy that in old age a large number of zonular fibres disappear but some fibres also get thickened.

Surgical Anatomy of the Lens

For the purpose of cataract surgery lens can be anatomically divided into:

i.Capsular bag with sub-capsular epithelium.

ii.Superficial cortex, i.e. soft lens matter that can be aspirated.

iii.Immediate epinucleus with semi-soft lens matter that can be expressed out.

iv.Deep nucleus or a hard core that can be expressed fractured, fragmented or phacoemulsified.

The capsular bag encapsulates the lens substance. It is highly elastic and hence a big nucleus can be expressed out from a comparatively small capsulotomy or capsulorhexis.

The capsular bag provides support to the IOL within the bag allowing for good haptic placement. The anterior epithelium consisting of cubical cells beneath the anterior capsule is responsible for all the metabolic and mitotic activity of the lens. The cells migrate and elongate towards equator and produce lens fibres. After extra-capsular cataract extraction the remaining lens epithelium especially those in the equator region undergo metaplasia and migrate towards posterior capsule and lead to posterior capsule opacification.

The zonules are inserted into the capsule in a continuous fashion at the equator, anteriorly 2-2.5 mm into the capsule and 1-1.25 mm into the posterior capsule. Hence only a 5-6 mm of zonular free zone of capsule is left for capsulorhexis or capsulotomy.

The lens nucleus has a configuration with a welldefined hard inner nucleus surrounded by semi-soft epinucleus and soft cortical matter. During hydrodelineation the nucleus is separated from epinucleus and this reduces the size of the overall nucleus which can be expressed out from a smaller incision. The epinucleus also forms a cushion beneath the nucleus during phacoemulsification.

Surgical Anatomy of the Limbus

Limbus is an important structure from surgical point of view as all the surgery for cataract and glaucoma is performed at the limbus. The external landmarks of the surgical limbus are (Fig. 1.2):

i.The anterior limbal border It is identified by the insertion of conjunctiva and Tenon’s capsule into

the cornea, which creates a prominent ridge. This ridge overlies the termination of Bowman’s membrane.

ii.The midlimbal line When the conjunctiva is separated from the limbus a bluish transluscent zone 1 to 1.2 mm wide is seen posterior to the anterior limbal border. Posterior to this bluish zone is the white sclera. The line formed at the junction of bluish zone and white sclera is called midlimbal line and it overlies the Schwalbe’s line (which is the termination of Descemet’s membrane).

iii.Posterior limbal border It lies 1 mm behind the midlimbal line and can be seen only with the use of sclerotic scatter illumination. Posterior limbal border

lies approximately over the scleral spur.

The width of the blue limbal zone varies in different quadrants. Maximum width is in the superior quadrant about 1mm. In the temporal and nasal quadrant it is 0.4 mm and in the inferior quadrant 0.8 mm wide. The width of the white limbal zone remains constant throughout.

The midlimbal line is a very important landmark, which overlies the Schwalbe’s line and we can remember this by the phrase, “where the white meets the blue Schwalbe’s line waits for you.”

But the difficulty is that this landmark is frequently indistinct. Anterior limbal line can be easily distinguished in a limbus based conjunctival flap, but in a fornix-based flap it is frequently irregular and is not a helpful landmark.

FURTHER READING

2.Gholam Peyman (Ed): Principles of Ophthalmology Jaypee Brothers; 489-91, 532-33, 1987.

1. Wolf’s Anatomy of the Eye 5: 138-42, 1961.

3.Yanoff M, Duker JS (Ed): Ophthalmology Mosby International Ltd: 4-(1.1-1.4), 1999.

History of 2

Cataract Surgery

Kamaljeet Singh

KS Kathait

Historians suggest that Egyptians, Greeks and Romans performed operations. Sushruta is considered to be the father of cataract surgery, who used to push the lens towards the retina, by a needle.

This technique, called couching was mastered by Indians and is still being practiced at some remote areas.

With certainty only this can be said that Arabians performed cataract surgery by reclination or depression. Daviel extracted the lens in recent times in 1745. He made a section in the limbus with a triangular knife. The cut was enlarged with a scissors or small knife having a dull point. The cornea was then raised and cataract removed with a Lancet, which pierced the pupil. The surgery remained in abeyance since infections used to occur and eyes were lost due to this. It was only after 1870, when the antisepsis was discovered, that cataract surgery became popular and all the ophthalmologists started performing this technique. von Graefe (1865) used a knife for making the cornea scleral incision. This knife has been used till eighties by many surgeons especially in camp surgery. Graefe also advocated iridectomy for the first time. Till this time, interestingly the surgery was extracapsular and sutureless, Williams started sutures in 1967.

The technique remained extracapsular for long. Pagenstecher (1877) tried intracapsular surgery by pressing the lower corneal limbus with a fixation forceps and depressing the scleral border by introducing a spatula behind the lens through the incision. Stoever in 1902, presented technique of removing the lens by creating a vacuum through a cupping device joined to a rubber bulb, called erisophake. This technique gained popularity only when Barraquer (1917) presented his cannula cup and suction apparatus. Forceps removal of lens was first time advocated by Staneuleann but became popular only after publication of his results by Elschnig (1924).

Smith’s technique was published in 1910 for performing the intracapsular cataract operation. He did the

surgery by making a corneal incision and pressing the lower limbus with the end of a strabismus hook.

Despite these techniques, most of the ophthalmologists performed extracapsular technique. Intracapsular technique was fraught with complications due to non-avail- ability of anaesthesia. It was only in 1919 that Willard for the first time described the akinesia of orbicularis, later Tochat in 1920 published his work. Later Van Lint’s (1920) and O’Brien’s (1929) facial block techniques became popular and are being still practiced world over. In 1930, Elschnig and Arruga advocated the retrobulbar anaesthesia.

Jacquina Barraaquer used alphachymotrypsin in 1958 for destroying the zonules for removing the cataract by intracapsular technique to avoid undue pressure by the zonules. This enzyme remained in use for long dissolving the zonules for intracapsular surgery especially in the young patients.

IOL Implantation

Casanova has mentioned in his memoirs that he met Tadini in 1766, who showed him a box with small spheres that were well-polished and looked like beautiful crystals. The oculist then had remarked, “One may put such globes under the cornea in place of crystalline lens.” Casanova although doubted that Tadini used to perform such operations, but he can be said to be the first person, who probably mentioned the possibility of lens implantation.

Casaamata, the Count Eye Doctor of Dresden, in 1795 used to perform cataract operations and also implanted an artificial lens. Münchow (1964) cited a book, named Schiferli (1797) in his study “About the History of Intraocular Correction of Aphakia.” It states, ‘Casaamata performed the procedure by inserting a glass lens through the wound of the cornea into the eye. He realised, however, that the glass lens could not substitute for the natural

lens because during the experiment, the glass fell into the bottom of the eye. Therefore, Casaamata can be said to be first surgeon to attempt an intraocular correction of aphakia.

But so far as the history of modern lens implantation goes Harold Ridley of London is considered as father of intraocular lens implantation. Ridley (1952) mentions in

British Journal of Ophthalmology that while he was performing a cataract operation in 1949 a medical student asked why he did not replace the sick lens with a new one. This initiated Ridley to implant the first lens. Thus, the first lens was implanted into the capsular bag following extracapsular cataract extraction at St. Thomas Hospital in London on November 28, 1949 and the second on August 23, 1950 (Ridley, 1951). Both of these lenses had too high a refractive power and patients had high myopic error (– 20.0D and – 15.0D). This gave an idea to Ridley to measure the radius of curvature. He operated 750 patients with new lenses. But later in 1959 gave up implantation because there were lots of complications. These lenses, weighed 110 mg, were made of acrylic. Acrylic was used because it was found that during World War II, some members of the British Air Force sustained perforating eye injuries from airplane canopies. Those were made of acrylic glass, it was noticed by the ophthalmologists, that it did not cause any irritation to the eyes.

Second generation lenses, which were supported in the angle of anterior chamber. These were called, second generation lenses (Strampelli, 1954). Many ophthalmologists around the world implanted these intraocular lenses with their own designs, but they produced complications like corneal decompensation, glaucoma and iritis and fell into disrepute. The problem was basically of the manufacturing designs and sterilization. Amongst these second generation lenses Choyce produced several designs, ultimately Choyce Mark VIII lens was perfectly designed and was used by several surgeons from 1963 until 1978.

Third generation lenses Epstein and Binkhorst produced the iris fixed lenses, which caused iritis in many patients. Later they produced iris plane lenses or pupillary lenses. These lenses were used in USA for quite a long period from 1968 until 1980s, but these implants used to cause chronic irritation and cystoid macular oedema. During this time Binkhorst produced four-loop iris clip lenses. It had two clips anterior to iris and two behind the iris and they did not reach the angle. These lenses

produced the iritis, glaucoma and hyphaema due to its designs. Later several modifications by these two ophthalmologists and by Fyodorov also appeared. Fyodorov’s sputnik lens became quite popular.

Fourth generation lenses Since the Binkhorst’s lenses loops were tying in front and back of iris he was not too happy and produced a design in which posterior loops would be placed in the capsular bag. These lenses were called Binkhorst’s iridocapsular lenses. Worst, came up with another idea of fixing lens with iris by applying sutures. These lenses were called Worst’s Madallion lenses. Worst used steel sutures for fixing these lenses. In India, Dr Daljit Singh is the pioneer, who used iris-claw lenses in thousands with excellent results.

Fifth generation lenses Pearce and Simocoe in 1977 used the posterior chamber lenses by modifying the Binkhorst’s four-loop lenses. They sacrificed the posterior loops of these lenses and placed in the back after during ECCE. He sutured these lenses with the iris or capsule in the superior position.

These lenses gave an idea to Shearing who introduced J-loop lenses, which was basically the lens, being used by Barraquer also. Barraquer used to place these lenses in the anterior chamber, whereas Shearing placed them behind the iris after ECCE. The haptic made its own place on the ciliary body, which he called ciliary lenses. This was, in fact, the beginning of true PCIOLs, which were excellent and reduced the incidence of corneal decompensation, iritis and glaucoma. Later came the Simcoe’s ‘C’ α modified ‘C’ lenses.

generation VI lenses In the early nineties the era of PC-IOLs through can-opener technique started ending. The main drawbacks of canopener technique with ciliary sulcus fixated lenses are IOL instability and decentration. Posterior capsular opacification was another problem seen in 50% of the cases. Now came the era of surgery within in the bag implantation through envelope or capsulorhexis. The extracapsular surgery with long incision and in the bag placement of one piece IOLs is included in Generation VIA. When the same surgery is done by phacoemulsification technique with capsulorhexis and in the bag placement of single piece or foldable IOL it is included in Generation VIB (Table 2.1).

Evolution of Small Incisions

With the advent of phacoemulsification, Kelman predicted that incisions 3 mm wide be astigmatism-neutral

because of their reduced size. However, within a very short time after the introduction of phacoemulsification, intraocular lens (IOL) implants became more common place. This necessitated enlargement of the phacoemulsification incision to 6.5 to 7 mm for lens implantation.

Kratz is generally credited as the first surgeon to move from the limbus posteriorly to the sclera, increasing appositional surfaces to enhance wound healing and attempt to exert less traction on the cornea, thereby controlling surgically induced astigmatism. Girard and Hoffman were the first to call the posterior incision a ‘scleral tunnel incision’ and were perhaps the first to make a point of actually entering the anterior chamber from a slightly corneal location.

With the availability of small incision lenses that could be introduced through incisions of 4 mm or less; the stage was set for the development of technique that resulted in the achievement of both relative astigmatism neutrality and self-sealing incisions. In 1989, Shepherd introduced the single horizontal suture, which was actually a vertical mattress suture, for the closure of 4 mm scleral tunnel incisions in phacoemulsification and foldable lens

implantation. The achievement of astigmatism neutrality was impressive. Others rapidly recognized that the compressive force of the single horizontal suture was tangential to the limbus and therefore exerted no force on the cornea, which would alter its curvature. As a result variations of the Shepherd single stitches were soon developed for closure of incision 5 to 7 mm wide, including the fine infinity suture, Masket’s horizontal anchor suture and Fishkind’s horizontal overlap suture.

In 1989, McFarland in Pine Bluff, Arkansas introduced an incision architecture that allowed the phacoemulsification and implantation of lenses without the need for suturing. This involved lengthening the scleral tunnel and in his early attempts, creating partial thickness grooves in the floor of the scleral tunnel parallel to the long axis of the tunnel so that the incision could be reversibly stretched to admit a foldable lens.

Ernest observed McFarland’s surgery and recognized that McFarland’s long scleral tunnel incision terminated in a decidedly corneal entrance and that the posterior lip of the incision, the so called corneal lip, acted as a one way valve imparting to this incision its self-sealing

characteristic. Koch in Warwick, Rhode island described what he called the incisional tunnel, indicating that there were certain characteristics of self-sealing incisions with respect to length and configuration that imparted not only self-sealability but also astigmatism neutrality to these incisions.

Self-sealing scleral tunnel incisions have varied with respect to width and the configuration of the groove (which represents the external or scleral incision as opposed to the internal or corneal portion of the incision). The groove has varied from circumlimbal to straight to frown or chevron-shaped.

The rebirth of extracapsular cataract extraction in its modern, refined microsurgical version has brought with it the need for an adequate technique for anterior capsulectomy. That’s why in 1984, Gimbel in Calgary, Alberta and Neuhann in Munich developed a technique that essentially consisted of tearing rather than cutting out, a central anterior capsular window. Neuhann termed it capsulorhexis.

While SICS is certainly possible with linear and canopener type capsulotomy, it is the continuous curvilinear capsulorhexis (CCC) that has made modern techniques of endolenticular phacoemulsification possible. Capsulorhexis leaves a capsular bag with mechanical and structural integrity, in spite of an opening large enough to deliver the lens.

The ‘hydrodissection method’ was first described by Micheal Blumenthal but the term ‘hydrodissection’ was given by Faust.

In hydrodissection the infusion fluid is injected exactly between the anterior capsule and the cortex so that the fluid wave dissects all around the capsular bag and separates it. This facilitates nucleus rotation and manipulation during phaco and non-phaco techniques.

Hydrodelineation was a concept introduced by Aziz Y Anis. In hydrodelineation, the infusion fluid is injected between the epinucleus and nucleus. This fluid wave appears as a golden ring under the surgical microscope. A reliable classification of nuclear hardness based on the diameter of the smallest circle delineated is listed in Table 2.2.

Measuring the diameter of the delineated circle is reasonable by comparing it to the measured limbal incision.

Nuclear Extraction in

Manual Small Incision Techniques

Table 2.2: Classification of nucleus hardness

forceps to crack the nucleus. For safety reasons, this technique was abandoned is favour of the nuclear prolopse method.

Blumenthal Technique

Blumenthal technique is an ingenious method of cataract surgery introduced by Blumenthal of lsrael, and is the preferred form of manual SICS. Its essential feature is hydrodissection and hydrodelineation of the core nucleus followed by its dislocation into the anterior chamber. The nucleus delivery is by hydrodynamic expression.

The advantages of this technique are that the AC is formed at all times, it is not viscoelastic dependent and there are no instruments used within the AC for nucleus delivery. Moreover, no sophisticated instrumentation is required; it can be used with all tyes of nuclei and with all types of capsulotomies, thus, increasing its universal appeal.

Phacosandwich Technique

Luther Fry et al introduced Phacosandwich technique. He discovered that nucleus can be captured between two instruments and moulded through a 7.5 mm incision with ease.

Luther Fry first attempted to cut the nucleus in two and remove the pieces separately through the same incision in 1985 (unaware that Gerald Keener had developed a nucleus bisection technique two years ago). He found it difficult to do what he attempted but in the process discovered that by squeezing the nucleus between a lens spatula and lens loop, it could be extracted through a smaller incision, leaving the softer peripheral nuclear and cortical matter to be aspirated. Today, almost a decade later, Luther Fry uses this technique in almost 70 per cent of his planned ECCE cases with an incision of 7.5 mm size. Gills a few years later, described a similar method where a lens loop alone is used to extract the nucleus.

Phacofracture Technique

The concept of fracturing or cracking the nucleus is not new. As far back as 1967, Kelman used Ringberg

This technique pioneered by Kansas and designed by Francisco J, Gutierrez C accomplishes nucleus removal

in the following way. After CCC or can-opener capsulotomy, hydrodelineation of the nucleus is performed and the nucleus is prolapsed into the AC. Viscoelastic was used to protect the endothelium and needs to be replenished as liberally as required. A solid curved vectis is introduced under the nucleus and a special instrument called the nucleotome is introduced above the nucleus. The nucleus is sandwiched between these two instruments. The nucleotome is manoeuvred towards the nucleus till it comes in contant with the vectis. Keping nucleotome in place, a spatula is introduced, and using it and the nucleotome the cleavage is confirmed and the pieces of the nucleus separated. Viscoelastic is replenished and a special nucleus forceps with 9 mm jaws, each with a double row of teeth, is introduced into the AC. Nuclear fragments were then positioned in the axis of the wound and removed. Removal of cortical debris mixed with viscoelastic (viscoelastic sludge) with a lagre bore irrigation aspiration tip is the next important step prior to insertion of an intraocular lens. The wound is checked for integrity, and the conjunctiva replaced in position.

A 3-4 mm incision can be used in this technuqe. The instrumentation is relatively simple. Howeve, this technique is very viscoelastic dependent. There is potential for corneal damage. Moerover, it is a difficult technique to master, probably not suited for hard brunescent nuclei which are dealt with standard ECCE.

Nucleus Division with Snare

Dr Getrald Keener et al discovered a Nucleus division technique, according to which nucleus can be divided and conquered. Instead of using a cutting blade, he used a fine wire that bisects the nucleus and expresses each piece separately.

Welsch Rovert C et al reported that nucleus trisection inside anterior chamber make the removal of lens pieces very easy through less than 5 mm scleral tunnel incision.

FURTHER READING

1.Arruga’s Olcular surgery: Mcgraw Hill Book Co.: 4: 109-15, 1962.

2.John J Alpar, Paul U Fechner: In Fechner’s Intraocular Lenses:

Jaypee Brothers (Indian Edn) 6-22, 1988.

3.Apple DJ, Ram Jagat, Foster A et al: Elimination of cataract blindness: A global perspective: Entering the new millenium.

Surv of Ophthalmol 45(Suppl): 570-99, 2000.

4.Aziz Y Anis: A methodical approach to small incision cataract surgery. In Cataract Surgery: Alternative Small Incision Technique (1st Indian edn) Slack Inc. 139-62, 1995.

5.Blumenthal Michael: Mini Nuc Manual extra capsular technique Highlights of ophthalmology letter, 21(5): 1993.

6.Daviels Jacques: Cited in Duke Elder, XI: 253, 1748.

7.Epstein E: History of intraocular lens implant surgery, In: Mazzocico TR, Rajacich GH, Epstein E (Eds): Soft Implant Lenses in Cataract Surgery, Thorogare NJ, Slock Inc: 1-10, 1986.

8.Fine IH: Infinity suture: Modified horizontal suture for 6.5 mm incisions. In Gills JP, Sanders DR (Eds): Small Incision Cataract Surgery, Foldolde Lenses, One-stich Surgery, Suturless Surgery, Astigmatic Keratomy. Thorofare NJ Slack Inc: 191-96, 1990.

9.Fine IH: Architecture and construction of a self-sealing incision for cataract surgery. J Cataract Refract Surg 17 (Suppl): 672-73, 1991.

10.Harold Ridley A: Implantation PMMA IOL in human-current therapy. In Ophth Surg, Spaeth and Katz 135.

11.Luther L Fry: Phacosandwitch technique. In Cataract Surgery: Alternative Small Incision Technique (1st Indian Edn) Slack Inc: 71-110, 1995.

12.Masket S: Origin of scleral tunnel methods (letter to the Editor)

J Cataract Refract Surg 19: 812-13, 1993.

13.Peter Kansas: Phacofracture technique. In Cataract Surgery Alternative Small Incision Technique (1st Indian Edn.) Slack Inc: 44-70, 1995.

INTRODUCTION

When viewed upon from the broader angle however good a surgery may have been performed should it be complicated with infection, the result is fraught with peril. The patient suffers ultimately and the surgeon goes through hell. We have all had our share of infection and its disastrous effects.

Should a surgeon say they have never had infection spoiling their case, either they have never done surgery or the truth lies hidden elsewhere.

Be that as it may we need to understand microorganisms in a much better manner. We need to give this topic full attention in our hospitals and continue to give it the importance it requires by continuing quality checks at every interval regularly every day and in every case.

Some basic facts of postsurgical infection in human eyes whether cataract surgery or any intraocular surgery is concerned, are that we need to regard all infections to arise from the operation theatre unless proved otherwise. The operating room is certainly the most guilty in providing the microorganism for post-surgical infection.

It may be very easy to complain about patient compliance and dirtiness to be the cause of infection, and sometimes that may be true, however in our hearts it is safer and better for us to accept that this infection has come from the operating room and then work ourselves backwards in removing the source of the disease.

We may be able to shift blame to a tooth infection or septic foci in the sinus, however, should we be able to first accept the operating room to be at fault, our energies would be directed in improving our facilities, thus averting further mishaps from occurring.

The first rule in sterilization at least where developing countries are concerned is not to believe any manufacturer when they claim to have sterilized their wares. To be taken as guilty of infection unless proved otherwise. This is true of not only suture material, disposable needles and syringes but also of intravenous and intraocular fluids. Many cases have been reported in India where

bacteria have grown from the Ringer lactate used. A startling study was carried out in the early 90s where several eyes were lost due to balanced salt solution (BSS) not being of pH 7.4, because the last rinse did not wash of the remnant soap from the glass bottle.

What we all need to remember is that when everything is going fine nobody complains, but as soon as there is a complication the surgeon is the first and often the last person to be held totally responsible for all misdemeanors on anybody’s part. Thus as captain of the ship the surgeon has to sink with his or her ship. However, all this can be avoided by taking precautions before entering the operating room.

HISTORY

Dating back to the time that Sushruta from 500 BC explained the importance of washing hands and draping wounds with clean cloth, as well as having a clean environment for surgical procedures, Indian medicine has always kept this part of medical practice in good stead. Practicing principles of Dhanvantri medicine a Hindu physician-oculist wrote that surgeons should clean their nails prior to operating, wear fresh clothing, and spray sweet smelling vapors around the operating room. Little did he know the importance of these instructions. However, these were carried down through the ages by the Vaids (Hindu physicians), now with better knowledge there is more understanding of the topic on infection and sterilization control.

The middle ages saw European medicine catching ground however, sterilization tactics were still very rudimentary. Most surgeons thought it to be fashionable not to wash hands, mayhap due to the cold climate of the temperate zones. Thus centuries of unknown prevailed with thousands being lost to infection and disease even inside the operating room. It was considered hazardous to lay a surgeons hand in the fear of losing the patient to “fever” as it was called then.

However, Hieronymus Fracastorus in 1546 published a landmark book that may have led to the discovery of

bacteria. His theory of contagious diseases and their treatment sparked off the original microbe hunter, to identify bacteria with his own saliva in 1675, using his microscope screwed together with some lenses, Anton van Leeuwenhoek had set about 2 centuries of hot debate amongst the European scientists.

In 1840 Jakob Henle postulated the theory of the contagion. This was further specified by Robert Koch in 1876 where he showed that by isolating the anthrax bacillus and was able to infect a normal animal with the same that the theory of contagion was true. This work won him the Nobel Prize for medicine and physiology in 1905.

It took Louis Pasteur to bring out the emphasis of the “little beings” as those responsible for disease. His paper on the importance of washing hands before starting a obstetrical delivery shows the utmost significance of this one act towards a sterile atmosphere.

Throughout the 1800s pioneering technologies of Pasteur, Nizer, Klebs, Escherich, Cohn and Ehrlich played major roles in the evolution of discovery of pathological germs. Today the science of microbiology and medicine are occupied by their names forming important landmarks in the discovery of the importance of sterilization techniques.

Where hospital wards are concerned, making surgery safe and banishing sepsis from hospital wards, an era of pre-Lister and post-Lister can be demarcated. This was the importance of Joseph Lister on surgical outcome. He based a lot of his studies however, on Ignaz Semmelweiss (1818-1865)—who was cruelly maligned for his theory of the origins of child-bed fever that led him to be institutionalized and die an unhappy man. The irony of the situation was his studies brought about a revolution in hospital wards and the prevention of infection by antiseptics and cleanliness reiterated by Joseph Lister.

By the time Daimler brought out his first motor cycle in 1884, scientists round the globe had devised the autoclave deriving from the fact that boiling did away with microbes. This revolutionized hospital wards and operation theatre sepsis to a great extent. So much so that till date some contraption of the autoclave is still used in every operation theatre in existence in the modem world.

By 1899 a century was going by and scientists believed this was the ultimate and that internal sepsis was not going to be much more advanced beyond theory and that the field was not likely to advance further. Today with much more information and knowledge we think

contrary, that we still know only a drop in this ocean of knowledge against disease and infection.

Change is the spice of life and just as today changes to another day, of more discovery and more scientific achievements so to these pioneers were to discover much more. Sulfanilamide first discovered by Paul Gelmo in 1908 was found to be effective on surgical wounds, by Gerhard Domagk who first used the drug on humans in 1935. This won Domagk the Nobel Prize for Medicine and Physiology in 1939.

Paul Ehrlich and Toju Hata discovered Salvarsan, the arsenic derivative for the treatment of syphilis, it heralded yet another era, that of the antibiotic.

In 1929, Alexander Fleming published his classical work on Penicillin from London and history followed his every achievement. Through the World Wars his medicine was of immense use in the control of infection and weeding out of disease. He showed first through invitro studies that a contaminant of Staphylococcus medium, Penicillium notatum had a destructive effect on the Staphylococcus bacteria that was growing on the agar plate. In further experiments he showed that this mold also had strong antibacterial activity against other pathogenic gram-positive bacteria as well as gramnegative cocci and bacilli but was not effective against organisms such as Escherichia coli.

While the world raged with War, yet another kind of war was being fought for mankind inside the laboratories of HW FIorey at Oxford University. By 1940 Ernst Chain showed the curative effects of penicillin in vivo. In 1945 by the end of the World War II, these three men were awarded the Nobel Prize for Medicine and Physiology. Selman Waksman discovered spates of antibiotics in succession with streptomycin in 1944 for tuberculosis and neomycin in 1949.

Much of today’s discoveries have been dependent on the way we see these small “animalcules”’ of Leeuwenhoek, in 1933. Our eyes could see the destruction of the world with Hitler as the Chancellor of Germany, and could see even greater destruction by microbes since the invention of the first transmission electron microscope by Ruska. Further developed to a phase contrast microscope by 1953, by which time the World War had ended and humanity was once again allowed to prosper. So much so that the scanning tunneling microscope could be developed by 1980 and its fast developing clones that are in use today.

However, very soon the side effects of antibiotics were noted with the classic example of chloramphenicol the first broad-spectrum antibiotic, discovered in 1949,

effective against rickettsial infection, typhoid. A link was established between severe bone marrow depression and aplastic anemia with its use. This curtailed the use of these eyedrops and oral regime in USA.

We owe a lot to these forefathers of modern medicine and surgery, and today’s technological advancements have made us more wary of the microbe. It seems to be the more we advance the more microbes we find the cause of disease. Stress and other dietary factors were believed to be the cause for peptic ulcers, though now we know bacteria to be the root. In a similar manner, there are many more diseases that still retain their shroud of mystery.

Let us not rest on previous laurels and with the close of this century believe that we have reached the ultimate. In reality, we have only skimmed the surface there is much more to be unraveled in this body beautiful of the

Homo sapiens.

Tempting to say in the words of Louis Pasteur, “Science knows no country, because knowledge belongs to humanity, and is a torch which illuminates the world.”

AREAS OF STERILIZATION

Once we enter the operating room we expect that everything must be in order, and somebody else is in charge, not me. However much to our utter astonishment seldom does anything go wrong, though when it does, the blame is once again pushed on to somebody else, not me. This is where the first principle of surgery has to be changed and restructured. The first and only person responsible for the whole team at work inside an operating room is the main surgeon.

This is the person who every body in the operation theatre must report to. This is the person who before entering the theatre has to ensure that everything inside this pious area is under strict control of the surgeon. This is the person who must take responsibility if an infection should arise in the patient’s eye within one week of surgery.

After carrying out so many tests and sterilization techniques I would rather believe for the benefit of all future patients that infection in a postsurgical eye arises from the operation theatre facilities. It is very difficult to put infection inside a closed eyeball, though it is easy enough while the eye coats are still open. More often than not infection is carried into the eye by instruments themselves.

There is however a small possibility that this may not be the case and there may be a septic foci residing in some corner of the human body like a tooth abscess or such. Still these occurrences are very rare and far

between. Moreover, it is far more beneficial to all concerned to garner our resources and give a thorough job of the operating room than to be witch hunting on the patients habits and dirtiness. It is my belief that even a dirty patient cannot infect the inside of his or her eye, if he or she has a postsurgical infection for sure it has been carried in through the workings of the operation theatre.

Going in a methodical manner from without to within anything entering the theatre has to be sterile. First the operating room itself has to be sterile.

The Operating Room Air

The air we breathe can be filled with pollutants, viruses, bacteria and irritants such as pollen, chemical gases, odors and smog. In critical situations—military command centers and public arenas—there is also a threat of chemical and biological agents being released into the air. All these air-borne pollutants can be treated by using various technologies.

We forget about the air coming into the operating room, though however we should understand that if this itself is clean it is much easier to retain the cleanliness within. There are many ways of filtering clean air into the operating room. One of the easiest and best is to first make sure the rooms pertaining to the operation theatre complex are sealed shut, with only one entry into the complex. Now we need to bring in clean air into the operating rooms.

Air-Conditioning

Ideally the whole operating area complex must be airconditioned with the units stationed well outside the complex and only ducts bringing in fresh temperaturecontrolled air into the complex. The air-conditioning units could be in the form of towers or split units stationed on the terrace or window firmaments outside.

Filtration of air The ducts bringing in the clean oxygenated air need to have the air passing through filters that can ward off bacteria which means they should be 0.2 micron filters. More often these filters need to be changed and or cleansed on a daily pattern.

Ultraviolet radiation Ultraviolet light bulbs could be placed in the path of the filtered air to make sure the air is disinfected as it enters the operating rooms. Alternately these bulbs could be left in the operating area and kept on throughout the night, this would also ensure clean areas the next morning after 12 hours of exposure to the ultraviolet light.