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Drugs and Instruments Used in Cataract Surgery
CORRESPONDENCE
184
The patient, a 38-year-old Negro, is pres ently a resident of Buenaventura on the Pacific Coast of Colombia. He has lived on the Pacific versant but he states that he has never been out of Colombia. It follows, therefore, that the infection must have been contracted in Colombia. As onchocerciasis has not previously been reported from this country, and is only known in the Americas in southern Mexico, Guatemala and (a lim ited focus) Venezuela, it seemed worthwhile to call attention to the present case. A team from the Universidad del Valle and the International Center for Medical Research and Training of Tulane Univer sity is currently investigating the source and epidemiology of the infection. Georges Assis M. M. D. Little Cali, Colombia, S.A.
DRUGS AND INSTRUMENTS USED IN CATARACT SURGERY
Editor, American Journal of Ophthalmology : In response to your request, it is a plea sure to reply to your questions concerning the drugs and instruments which we use in cataract surgery. 1. DRUGS
a. Mydriatics. To obtain a pupillary dila tation of about seven mm before surgery we instill one drop of cyclopentolate HC1 (Cyclogyl) three hours before the operation. Phenylephrine HC1 (Neo-Synephrine) 10%, supplied by Crookes-Barnes Laborato ries as sterile plastic "Iso-Sol Dropperettes" containing one ml, is instilled at a dose of one drop two hours preoperatively. If the pupillary diameter is less than seven mm one hour prior to the operation another drop of Neo-Synephrine is instilled. b. Zonulolytic agents. We use alpha chymotrypsin exclusively for enzymatic zonulolysis. The enzyme is supplied in the United
States by Smith, Miller & Patch (Quinotrase, Ophthalmic) in packages containing 750 PEYVA units of alpha chymotrypsin and a vial of 10-ml sterile isotonic diluent. The solution is injected into the posterior chamber in a concentration of 1 :5000 and a volume of 0.5 ml to facilitate rupture of the zonule. c. Irrigating solution. We prefer artificial aqueous humor which is less cytotoxic than physiologic saline solution. It is supplied in a plastic bag as commonly used for intrave nous infusion (Flec-Flac) by PEYVA Lab oratories, Barcelona, Spain. The bag is sus pended within reach of the nurse and the plastic tube can be cut to any length to facil itate direct irrigation of the eye. The stream of artificial aqueous can be opened, closed and directed with a cross-action clamp. A built-in filter retains any particulate matter and the entire set is supplied sterile but may be autoclaved again. The composition of this artificial aqueous humor is: Sodium chloride 3.445 gm Anhydrous calcium chloride 0.043 gm Potassium sulfate 0.110 gm Water, twice distilled 500 ml d. Miotics. At the end of the operation 0.5 ml of a 1% acetylcholine chloride solution (Mecholyl) (Smith, Miller & Patch) is in stilled in the anterior chamber. Acetylcho line is supplied in a two-chamber vial. The lower chamber contains sterile, stable, lyophilized acetylcholine chloride. The upper chamber contains a sterile diluent. The solu tion is prepared immediately before use and the excess is discarded because the aqueous solution is unstable. 2. GLOVES
We use special gray nylon gloves which neither leave fibrils nor "catch," supplied by El Guante de Oro, Barcelona (Boqueria 16), Spain. They do not cause numbing of the fingers as do rubber gloves. Instruments can therefore be held securely with little pressure and do not slip. No talc or its sub stitutes are put on the gloves and the intro-
CORRESPONDENCE duction of foreign particles into the open eye is prevented. The gloves are sterilized in the autoclave. 3. INSTRUMENTS
a. The marten-hair brush (supplied by N. Di Mauro, Barcelona (Valencia 96) Spain) is useful to dry and clean the wound edges and indispensable for certain manipu lations in the anterior chamber. In contrast with moist cotton swabs which tend to leave fibrils, the marten-hair brush does not shed. It is most suitable for removing particles that adhere to the iris, the endothelium or the hyaloid, to expose the iris in iridectomy, for dilating the sphincter and for repositing the iris. It is useful in places within the eye which are otherwise inaccessible. The marten-hair brushes should be stored in distilled water, protecting the hair with a little white petrolatum. For sterilization the brushes are boiled in distilled water for five minutes. b. A galvanocautery is preferred to a flame-heated cautery because of its instant, continuous heating, and because it is less dangerous in the presence of inflammable gas. The cautery is connected to a trans former with a rheostat to regulate the cur rent to maintain a constant temperature at the tip. A foot switch provides perfect func tioning of the contact. Finger switches on the handle of the cautery are easily damaged during sterilization and may fail to work because of the low voltage. Carbonized blood must be removed from the tip periodi cally with a wire brush or a file or it may act as a thermal insulator and interfere with cautery. Diathermy coagulation cannot be used for hemostasis in cataract surgery be cause it is only effective on dry tissues. c. The colibri forceps is used to hold the wound edges, to lift the iris for peripheral iridectomy and to exert external pressure during lens extraction and in all kinds of delicate surgery. It has extremely fine teeth set at an angle of 100 degrees which permit a firm but practically atraumatic grasp. It
18S
has a small tying platform which is useful for suturing. The curved shaft and angulation near the tip allow the surgeon's hand to rest on the patient's forehead without ob structing the view of the operative field. d. The motor-driven erisophake creates a continuous vacuum. The pump is operated by a foot switch and is connected to the handle of the erisophake by a rubber tube. The handle is made of the lightweight metal, Dur alumin. It has a tip for connecting to the pump, a separate regulator on one end and the suction cup on the other. The suction cup is made of platinum. It has a diameter of 5.5 to 6.0 mm and the curvature of its rim is similar to that of the anterior capsule of the lens. The cup must be deep enough to allow the capsule to expand without ob structing the internal opening of the tube. e. The mosquito needle holder can be manipulated most accurately because of its smooth spring action without a lock and the cylindric form of the knurled handle which permits delicate rotation between the fingers. The Grieshaber model has extremely fine jaws with a longitudinal groove on the in side. This groove increases the stability of the needle and lengthens the life of the same. f. For the removal of very fine sutures we have designed a special forceps which has the same handle as the colibri forceps but with a modified tip. Joaquin Barraquer Barcelona, Spain CORRFXTION
Editor, American Journal of
Ophthalmology:
The second sentence of "Myopia in adults" (Am. J. Ophth., 60:738 [Oct.l 1965) should read as follows: "The Air Force has recommended that +0.5D of cycloplegic hyperopia in the least hyperopic meridian be required upon entrance for flight training." Stanley Diamond San Francisco, California
184
The patient, a 38-year-old Negro, is pres ently a resident of Buenaventura on the Pacific Coast of Colombia. He has lived on the Pacific versant but he states that he has never been out of Colombia. It follows, therefore, that the infection must have been contracted in Colombia. As onchocerciasis has not previously been reported from this country, and is only known in the Americas in southern Mexico, Guatemala and (a lim ited focus) Venezuela, it seemed worthwhile to call attention to the present case. A team from the Universidad del Valle and the International Center for Medical Research and Training of Tulane Univer sity is currently investigating the source and epidemiology of the infection. Georges Assis M. M. D. Little Cali, Colombia, S.A.
DRUGS AND INSTRUMENTS USED IN CATARACT SURGERY
Editor, American Journal of Ophthalmology : In response to your request, it is a plea sure to reply to your questions concerning the drugs and instruments which we use in cataract surgery. 1. DRUGS
a. Mydriatics. To obtain a pupillary dila tation of about seven mm before surgery we instill one drop of cyclopentolate HC1 (Cyclogyl) three hours before the operation. Phenylephrine HC1 (Neo-Synephrine) 10%, supplied by Crookes-Barnes Laborato ries as sterile plastic "Iso-Sol Dropperettes" containing one ml, is instilled at a dose of one drop two hours preoperatively. If the pupillary diameter is less than seven mm one hour prior to the operation another drop of Neo-Synephrine is instilled. b. Zonulolytic agents. We use alpha chymotrypsin exclusively for enzymatic zonulolysis. The enzyme is supplied in the United
States by Smith, Miller & Patch (Quinotrase, Ophthalmic) in packages containing 750 PEYVA units of alpha chymotrypsin and a vial of 10-ml sterile isotonic diluent. The solution is injected into the posterior chamber in a concentration of 1 :5000 and a volume of 0.5 ml to facilitate rupture of the zonule. c. Irrigating solution. We prefer artificial aqueous humor which is less cytotoxic than physiologic saline solution. It is supplied in a plastic bag as commonly used for intrave nous infusion (Flec-Flac) by PEYVA Lab oratories, Barcelona, Spain. The bag is sus pended within reach of the nurse and the plastic tube can be cut to any length to facil itate direct irrigation of the eye. The stream of artificial aqueous can be opened, closed and directed with a cross-action clamp. A built-in filter retains any particulate matter and the entire set is supplied sterile but may be autoclaved again. The composition of this artificial aqueous humor is: Sodium chloride 3.445 gm Anhydrous calcium chloride 0.043 gm Potassium sulfate 0.110 gm Water, twice distilled 500 ml d. Miotics. At the end of the operation 0.5 ml of a 1% acetylcholine chloride solution (Mecholyl) (Smith, Miller & Patch) is in stilled in the anterior chamber. Acetylcho line is supplied in a two-chamber vial. The lower chamber contains sterile, stable, lyophilized acetylcholine chloride. The upper chamber contains a sterile diluent. The solu tion is prepared immediately before use and the excess is discarded because the aqueous solution is unstable. 2. GLOVES
We use special gray nylon gloves which neither leave fibrils nor "catch," supplied by El Guante de Oro, Barcelona (Boqueria 16), Spain. They do not cause numbing of the fingers as do rubber gloves. Instruments can therefore be held securely with little pressure and do not slip. No talc or its sub stitutes are put on the gloves and the intro-
CORRESPONDENCE duction of foreign particles into the open eye is prevented. The gloves are sterilized in the autoclave. 3. INSTRUMENTS
a. The marten-hair brush (supplied by N. Di Mauro, Barcelona (Valencia 96) Spain) is useful to dry and clean the wound edges and indispensable for certain manipu lations in the anterior chamber. In contrast with moist cotton swabs which tend to leave fibrils, the marten-hair brush does not shed. It is most suitable for removing particles that adhere to the iris, the endothelium or the hyaloid, to expose the iris in iridectomy, for dilating the sphincter and for repositing the iris. It is useful in places within the eye which are otherwise inaccessible. The marten-hair brushes should be stored in distilled water, protecting the hair with a little white petrolatum. For sterilization the brushes are boiled in distilled water for five minutes. b. A galvanocautery is preferred to a flame-heated cautery because of its instant, continuous heating, and because it is less dangerous in the presence of inflammable gas. The cautery is connected to a trans former with a rheostat to regulate the cur rent to maintain a constant temperature at the tip. A foot switch provides perfect func tioning of the contact. Finger switches on the handle of the cautery are easily damaged during sterilization and may fail to work because of the low voltage. Carbonized blood must be removed from the tip periodi cally with a wire brush or a file or it may act as a thermal insulator and interfere with cautery. Diathermy coagulation cannot be used for hemostasis in cataract surgery be cause it is only effective on dry tissues. c. The colibri forceps is used to hold the wound edges, to lift the iris for peripheral iridectomy and to exert external pressure during lens extraction and in all kinds of delicate surgery. It has extremely fine teeth set at an angle of 100 degrees which permit a firm but practically atraumatic grasp. It
18S
has a small tying platform which is useful for suturing. The curved shaft and angulation near the tip allow the surgeon's hand to rest on the patient's forehead without ob structing the view of the operative field. d. The motor-driven erisophake creates a continuous vacuum. The pump is operated by a foot switch and is connected to the handle of the erisophake by a rubber tube. The handle is made of the lightweight metal, Dur alumin. It has a tip for connecting to the pump, a separate regulator on one end and the suction cup on the other. The suction cup is made of platinum. It has a diameter of 5.5 to 6.0 mm and the curvature of its rim is similar to that of the anterior capsule of the lens. The cup must be deep enough to allow the capsule to expand without ob structing the internal opening of the tube. e. The mosquito needle holder can be manipulated most accurately because of its smooth spring action without a lock and the cylindric form of the knurled handle which permits delicate rotation between the fingers. The Grieshaber model has extremely fine jaws with a longitudinal groove on the in side. This groove increases the stability of the needle and lengthens the life of the same. f. For the removal of very fine sutures we have designed a special forceps which has the same handle as the colibri forceps but with a modified tip. Joaquin Barraquer Barcelona, Spain CORRFXTION
Editor, American Journal of
Ophthalmology:
The second sentence of "Myopia in adults" (Am. J. Ophth., 60:738 [Oct.l 1965) should read as follows: "The Air Force has recommended that +0.5D of cycloplegic hyperopia in the least hyperopic meridian be required upon entrance for flight training." Stanley Diamond San Francisco, California