Aseptic technique
Aseptic technique in the office or hospital is an attempt to prevent infection by the elimination of microorganisms. Ophthalmic surgery demands maximum asepsis, particularly in operations involving the globe itself. Microorganisms that gain access to the interior of the eye can multiply and cause irreparable damage, often resulting in blindness. Aseptic technique demands:
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Proper sterilization of all instruments
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Sterilization of the skin adjacent to the operative site
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Sterilization of the hands of both the operator and the assistant
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Use of sterile solutions and ointments during and after the operation
For the most part, the following discussion of aseptic technique will be oriented toward ophthalmic surgery in the office.
Disinfection of eyelid skin
Office surgery for conditions involving eyelid skin requires carefully applied skin antiseptics ( Table 30.1 ; spray packs of antiseptics are contraindicated.) Care must be taken that none of the antiseptic material enters the eye. This may be done with careful application by cotton applicators soaked in such solutions as tincture of iodine 2%, povidone-iodine (Betadine), Ioprep, alcohol, and cetrimonium bromide. It also may be done by scrupulous scrubbing of the area with hexachlorophene (Phisohex) or green soap. Betadine and alcohol are available in large, presoaked swabs.
| Classification | Manufacturer | Type of bactericide |
|---|---|---|
| Tinctures | ||
| Tincture of iodine 2% | Iodine-alcohol | |
| Alcohol 70% | Alcohol | |
| Zephiran chloride | Winthrop | Quaternary ammonium compound + alcohol |
| Merthiolate | Eli Lilly & Co | Sodium ethylmercurithiosalicylate + alcohol |
| Aqueous preparations | ||
| Merthiolate | Eli Lilly & Co | Sodium ethylmercurithiosalicylate |
| Zephiran chloride | Winthrop | Quaternary ammonium compound |
| Hexachlorophene scrubs | ||
| Gamophen | Arwood | Hexachlorophene |
| Septisol | Vestal | Hexachlorophene |
| Phisohex | Winthrop | Hexachlorophene |
| Iodophors | ||
| Ioprep | Johnson & Johnson | Iodophor |
| Wescodyne | West | Iodophor |
| Betadine | British Drug Houses | Iodophor |
Scrubbing (degerming of hands)
For many minor office procedures, scrubbing may be unnecessary if both the operator and the assistant adhere to a “no-touch” technique. In this technique, the tops of the sterile instruments are never touched by hands or laid down in a nonsterile area.
The skin of the hands contains normal bacterial inha-bitants, as well as many transient microorganisms with which the individual may recently have come into contact. It is virtually impossible to scrub the hands sufficiently to get rid of all normal inhabitants, but the use of gloves overcomes this handicap. We tend to use powderless gloves, because particulate matter (e.g., starches) of powder can have a damaging effect in the eye.
Scrubbing with a brush degerms the hands by the removal of bacteria, and the dilution of the bacteria content is achieved by rinses and the use of antiseptic skin agents that are bactericidal. Before scrubbing, the fingernails should be cleansed with an orangewood stick. The various antiseptic agents available have their own scrubbing time, which should be followed rigidly. The fingers and nails should be carefully scrubbed and all hidden recesses of the hands scrupulously cleansed.
Instillation of eye medication
Eye medication can easily become contaminated by incorrect instillation. There is a right and a wrong way to instill eye medication both before and after minor office surgery ( Fig. 30.1 ). With the patient’s head tilted back, the dropper, dropper bottle, or ointment tube should be held about half an inch (1.25 cm) from the eye before the release of medication. When corneal anesthesia is required, the patient should be asked to look down so that the cornea will be completely covered by the medication. It is important that the tip of the dropper or dropper bottle never touches the eye or eyelid. Contamination will result, in which case the dropper and medication should be discarded. Alcohol and alcohol-type solutions must never enter the eye. They are damaging to the corneal epithelium.
Sterility of ophthalmic solutions
The sterility of eye solutions is desirable not only because of the obvious danger of ocular infection, but also because contaminated solutions may prove toxic and irritating to the eye. The sterilization of ophthalmic solutions may be performed effectively by pouring through bacterial filters. The addition of a preservative, such as chlorobutanol or benzalkonium chloride, aids in preventing contamination.
The ophthalmologist’s office should have solutions that are well prepared and contain an added preservative. They should be kept in small bottles, never in large stock sizes. Individual-dose sizes are commercially available in disposable plastic containers. In addition, one must be careful about contamination of the eyedropper, particularly if it has touched an infected eye. If contamination is suspected, the solution should be discarded. One solution notorious for harboring microorganisms, particularly Pseudomonas aeruginosa , is fluorescein. However, fluorescein is available in dried sterile strips that are safe to use.
All solutions that enter the eye should be of the nonpreserved type (e.g., lidocaine 1% [Xylocaine], vancomycin). All solutions that are applied to an open wound should be made up fresh through micropore filters (e.g., mitomycin).
Disinfection of tonometer prism
Every tonometer prism should be cleaned and disinfected before use. The main purpose of this is to prevent the spread of infection from patient to patient, especially of the viruses that cause epidemic keratoconjunctivitis and acquired immunodeficiency syndrome (AIDS).
The Goldmann application tonometer prism is best cleaned and disinfected by soaking in 1:10 sodium hypo-chlorite solution (bleach) or 3% hydrogen peroxide. Some practices use 70% isopropyl alcohol soaks or wipe with an alcohol pad. After disinfecting, the prism should be rinsed in running water and dried. Detailed instructions are available on the manufacturer’s website.
Several handheld applanation tonometers are available (e.g., TonoPen). These require a special sterile rubber cover for each individual.
Minor office surgery
Ophthalmologists vary in the amount and type of office surgery they perform. Such factors as the availability of outpatient facilities in a nearby hospital, the time spent at the hospital by the physician, the physical layout of the physician’s office, and the presence of a trained and efficient ophthalmic assistant influence the decision whether to perform surgical procedures in the office or in the hospital outpatient department. When adequate physical facilities and a trained assistant are available, many minor procedures can be performed in the ophthalmic office in a special sterile operating room. Age may be a consideration for choice of patient.
Of fundamental importance is the general sterility of the area in which the surgical procedure is to be performed. Main-tenance of adequate cleanliness and dusting of the surgical area should be performed regularly. The area should be segregated from the routine patient flow as much as possible. An office operating room will not achieve the same high standard of sterility that is found in a hospital operating room. Such factors as a separate scrub area, elimination of all street clothing, shoe covers, air filtration, and positive-pressure operating rooms are not generally found in an office minor-procedure operating room. In an office that one enters without a mask, airborne bacteria may remain active for hours. In all offices, emphasis must be placed on adequate sterilization of instruments, combined with personal measures to ensure that there is reasonable cleanliness and sterility in the surgical area.
Careful and complete cleanliness of instruments must precede all efforts at sterilization. It is useless to place a blood-stained curet into an antiseptic solution, heat oven, or autoclave because these dirty instruments can never be thoroughly sterilized. Scrupulous cleansing with a fine nailbrush or toothbrush and careful inspection of the instruments are essential. This inspection is done most efficiently with magnifying lenses or loupes. The cleansing may be done in soapy water or with one of the many detergents available. Protein enzyme solutions are available to remove blood and tissue debris from the instruments. Instruments with moving parts should be lubricated periodically or dipped into surgical instrument milk. After these instruments are carefully rinsed, they are sterilized ( Fig. 30.2 ).
Sterilization of the instruments may be performed by one of the methods outlined previously. Small autoclaves are available for office use. They have their own timing device and will sterilize within 5 minutes. Disinfection of the patient’s skin is performed for many lid procedures by applying an antiseptic solution, such as iodine, povidone-iodine (Betadine), or benzalkonium chloride.
The surgeon and the ophthalmic assistant should observe all rules of cleanliness, particularly for the more advanced procedures that may be performed in the office. Before handling sterilized instruments, the ophthalmic assistant should scrub, preferably with hexachlorophene soap. Gloves may be required for some of the minor operations. Powderless gloves are preferred. Assistants should not use nail polish or wear hand or wrist jewelry when assisting during minor office procedures. Masks and caps are often not necessary for most minor office procedures. More extensive operations, however, such as pterygium removal and plastic surgery on the eyelid, may require surgical care comparable to the standards used in a first-class hospital operating room. Minor surgery is often performed under magnification with loupes ( Fig. 30.3 ).
Safety considerations
Defibrillator apparatus should be available in a conspicuous place ( Fig. 30.4 ). All staff should be trained on this in association with regular cardiopulmonary resuscitation (CPR) courses.
Instruments and surgical materials for ophthalmic procedures
The following surgical instruments may be required in minor office surgery: forceps, scissors, needle holders, clamps, curets, scalpels and blades, and lacrimal instruments and cannulas. The numerous individual variations of these instruments depend on the surgeon’s choice.
Forceps
Forceps are used to grasp small tissues for either removal or suture insertion. The teeth of these instruments vary from 0.12 to 0.5 mm. The jaws may be rounded, flat, or serrated. Some forceps, called tying forceps, have no teeth. Others, called epilation forceps, also have no teeth and are used to remove eyelashes. Thus both tooth and nontooth forceps often are available in the office ( Fig. 30.5 ).
Scissors
Scissors may be blunt or sharp, curved or straight. They may have spring action or direct action.
Needle holders
Needle holders hold suture needles and provide good control for inserting needles. Some of these instruments are nonlocking, some locking; some handles are spring-loaded. Some needle holders for larger-size needles have a thumb release ( Fig. 30.6 ).
Clamps
Clamps used in ophthalmic surgery may be round, with a guarded plate behind to provide hemostasis during removal of chalazia. Other clamps are used to hold eyelids during surgery, as well as to create hemostasis.
Curets
Curets are slim-handled and have a bowl-shaped end. The ends are either round or serrated and are used to remove chalazia and other small cystic material.
Scalpels, keratomes, and blades
Scalpels used by the physician depend on preference. Commonly used instruments are often disposable small blades, some angled blades, some keratomes for incising into the cornea, and the Bard-Parker scalpel used for skin cutting. Some tips are of gem quality (e.g., sapphire, diamond). Smaller and smaller keratomes are used to accommodate the newer foldable lenses.
Lacrimal instruments
A lacrimal set consists of a punctum dilator, which enlarges the punctum; a sterile medicine glass to hold sterile saline solution or an antibiotic solution; and a disposable syringe with a blunt lacrimal cannula. The last introduces a solution into the canaliculus ( Fig. 30.7 ).
