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Anaesthetic Techniques in Cataract Surgery: General Anaesthesia, Local Infiltrative Anaesthesia, or Topical Anaesthesia?
DISCUSSION SECTION
Anaesthetic Techniques in Cataract Surgery: General Anaesthesia, Local Infiltrative Anaesthesia, or Topical Anaesthesia? Edited by MICHAEL LAVIN
New developments in cataract surgical techniques have allowed the widespread acceptance of a great range of anaesthetic techniques, ranging from general anaesthesia, infiltrative local anaesthetic techniques combined with monitored continuous intravenous sedation anaesthesia, and isolated infiltrative local anaesthetic techniques (including retrobulbar injection, peribulbar injection, or subconjunctival injection alone) to topical anaesthesia. The object of any anaesthetic technique is to allow the surgeon the maximal degree of surgical control, while at the same time rendering the experience pain-free for the patient, with low ocular and systemic morbidity (and mortality!). More recently, these goals have been extended to include achievement of the shortest recovery period possible, allowing rapid functional recovery. We asked a number of leading cataract surgeons across the world for their views regarding different anaesthetic techniques, and for their requirements, in order to compare and contrast different approaches, and so that we have sufficient information in order to develop a structured approach to anaesthesia and cataract surgery.
Question: anaesthesia for cataract surgery what are the minimum requirements? We asked our contributors to address the following iS3ues in their discussion of anaesthetic choices for cataract surgery. 1. What do you think are the minimum standards for monitoring patients during cataract surgery? Should patients undergoing local anaesthetic (infiltrative or topical) procedures have intravenous cannulae placed as a precaution? 2. What is the minimum number of nursing and technical staff you think are needed to manage a cataract surgical theatre efficiently and safely? 3. Do you use topical anaesthesia (alone), infiltrative local anaesthesia or general anaesthesia in cataract surgery and how frequently do you use these modalities? What is your anaesthetic choice, and why? When do you specifically avoid certain modalities? 0955-3681/94/020113+04 $08.0010
4. Is general anaesthesia an unnecessary systemic risk in the elderly individual aged over 80 years? 5. Is there a place for local anaesthetics in the young (under 45 years) cataractous adult? 6. Is topical anaesthetic justified, or are the benefits outweighed by the disadvantages (poor iris analgesia, no akinesia, short duration, corneal epithelial changes during surgery)? KIMIYA SHIMUZU
Dr Shimuzu is Director of the Department of Ophthalmology at the Musashino Red Cross Hospital, in Tokyo, and has substantial experience with topical anaesthesia in phacoemulsification cataract surgery. 1. Minimum requirements Blood pressure and ECG are two minimal requirements in my view. Patients undergoing local anaesthetic (infiltrative or topical) procedures should have intravenous cannulae placed in case of shock, heart disease, hyperventilation and so on. 2. Staffing There are four persons in all as follows: one operating surgeon, one assistant-surgeon, one scrub nurse and one running nurse. 3. Anaesthetic technique Approximately 20-30% of my patients will receive topical anaesthesia (4% xylocaine), which is instilled three times, 5 minutes pre-operatively. The following are all candidates for topical anaesthesia, but those that are nervous, or can't follow doctor's directions, are excluded: (a) patients with axial length over 28.0 mm;
© 1994 W.B. Saunders Company Limited
Eur J Implant Ref Surg, Vol 6, April 1994
M. Lavin
114
(b) patients with tendency to bleeding; (c) patients with abnormal orbits; Cd) patients with low vision in the fellow eye.
in the operating room for these procedures any more. 2. Staffing
4. Is general anaesthesia an unnecessary systemic risk?
In cataract surgery, I have never employed general anaesthesia in any of my aged patients, though children under 10 years old may receive general anaesthesia. 5. The place of local anaesthesia in those under 45 years
As to your question about the number of nursing and technical staff you think are needed to manage a cataract surgical theatre efficiently and safely, I feel that a minimum of four people efficiently employed using topical anaesthesia are more than adequate and we are currently doing nine phacoemulsification procedures with lens implants in a three hour session in our theatre here. 3. Anaesthetic technique
Many patients under 45 years old are found to have a high vitreous pressure and in addition, topical anaesthesia works less effectively, so that retrobulbar anaesthesia of 5 ml 2% xylocaine is used. A McKintyre's mercury bag is then placed on the eye for 2-3 minutes longer to achieve a soft eye for surgery.
As far as I know I was the first person in these islands to go over to peribulbar anaesthesia and orbital compression with the many varied devices which I began using almost 8 years ago. My interest in the topic evolved as a result of two patients who collapsed on me and almost died following retrobulbar anaesthesia and believe it or not last year I had a patient who ended up with an optic atrophy and perception of light vision following a perfectly 6. Topical anaesthesia: benefits and normal cataract and implant operation following disadvantages retrobulbar injection. I was therefore naturally Selected patients may receive benefit from topical interested to read the joint report of the College of anaesthesia, but the surgeon must have a high Ophthalmology and the College of Anaesthetists degree of skill in order to prevent complications such which Emanuel Rosen helped to produce recently as posterior capsule tears and to manage them if and I would agree completely with the content in they occur. that an anaesthetist should be available and the patient fully monitored if giving anaesthetics by the retrobulbar and peribulbar method. PATRICK CONDON However I think that the report has been rendered totally out of date by what has happened in Dr Patrick Condon practices in Waterford, Ireland, the last year in the United States and will have to be where he practises cataract and refractive surgery, upgraded to take into account the recent developand is also active in teaching both locally and over- ments in topical anaesthesia for cataract surgery which I have just recently started to do following my seas. return from the ASCRS meeting recently in Seattle where I attended a number of courses and listened 1. Minimum requirements to a number of papers on the subject. During the last 6 weeks (before August 1993) I have carried out In my experience I would agree that you need full about 100 cataract procedures using topical anaesscale monitoring and the presence of an anaesthetist thesia combined with a ~ cc of local anaesthesia if you are going to carry out peribulbar or retro- injected subconjunctivally under the upper lid and bulbar anaesthesia because of the possible side have found this to be most effective for phakoemulsieffects that you can get from the anaesthetics. How- fication and lens implant surgery from the analgesic ever, in relation to topical anaesthesia with or with- point of view. I have now got completely used to the out small amounts of subconjunctival regional infil- lack of akinesia and in fact would prefer that the tration, I feel that monitoring of the pulse and blood patients eyelids and globe moved freely during the pressure and serum oxygen are possibly useful. I surgery and also after their surgery. It was also now do not think that an anaesthetist is necessary comforting to find that in none ofthese patients did I Eur J Implant Ref Surg, Vol 6, April 1994
Discussion Section
115
find any increase in intra-ocular pressure or bulging of the vitreous interface during the course of the surgery which I presume was due to the raised intra-orbital pressure attained by injecting the local intra-orbitally. I am also completely amazed at how well these patients perform on the table without any toxic effects whatsoever. I have operated on patients with accelerated hypertension, totally unstable diabetics and patients with many types of abnormal pulse and heart rhythms without any side effects whatever. Both the patients and the nurses are also absolutely delighted with the procedure and as far as I am concerned it has transformed the whole of the cataract operation. Also there is no need as you can gather from my comments for ocular compression and the whole procedure is speeded up most dramatically. 4. Is general anaesthesia an unnecessary systemic risk? 5. The place of local anaesthesia in those under 45 years?
or who may require scleral pocket incision due to corneal disease, a low pre-operative endothelial cell count or a 4+ dense brunescent nucleus that may require ECCE. With either form of anaesthesia, we continue to provide nasal oxygen for out patients underneath their sterile drape and we monitor their oxygen saturation with digital pulse oxymetry. An EKG monitor is in place as well as an automated blood pressure cuff, to monitor the effects of topical and systemic medications, as well as the patient's own medical conditions. An open intravenous line is available on all patients surgery. A nurse anaesthetist is present during the entire procedure. Patients occasionally need medications due to cardiac dysrhythmias or transient hypertension. Patients under topical anaesthesia require more intravenous medication support intra-operatively compared to patients with needle block anaesthesia, who require more intravenous sedation pre-operatively during the needle injection and less sedative medication intra-operatively. The occasional topical anaesthesia patient will receive intra-venous propofol (Diprivan) in 10 mg increments to produce a few minutes of pharmacologic hypnosis and amnesia.
I feel that general anaesthetic is an unnecessary systemic risk in an elderly patient over 80 years. 2. Staffing
Having carried out trabeculectomy in a glaucomatous eye in a 30-year-od patient recently using topical anaesthesia I do think that topical and local subconjunctival infiltration anaesthetic can be carried out quite successfully in the young, under 45 years, cataractous adult.
Our operating room staff consists of one surgeon (myself), one surgical scrub technician, one circulating nurse and one certified nurse anaesthetist. This is minimal and adequate staff to carry out our routine daily procedures for cataract surgery.
HARRY GRABOW
3. Anaesthetic technique
Dr Harry Grabow is an Assistant Professor in Ophthalmology at the University of South Florida, and is based at the Sarasota Cataract Institute, where he has developed an international reputation as a cataract surgeon and teacher of cataract surgery.
For topical anaesthesia our anaesthetic choice is lidocaine that is packaged in breakable glass ampoules. The solution is drawn into a sterile syringe; the needle is removed; and the solution is administered as topical drops directly from the syringe. We do not use preserved lidocaine in multidose vials and also do not use the lidocaine manufactured as a topical solution, as this form is not labelled 'sterile'. The latter form oftopical solution is for use in the contaminated cavities such as the oral cavity for mucous membrane surgery. The anaesthetic eye drops are administered in the pre-operative surgical area by a nurse in sequence with the patient's dilating drops. The patients lidocaine syringe accompanies the patient to the operating room and prior to prepping, the circulating nurse administers one final drop to the operated eye and an additional drop to the unoperated eye. The drop
1. Minimum requirements
During our cataract procedure, 85% of which are performed under topical anaesthesia with temporal clear-corneal incisions, we continue to monitor our patients as we always have when we were routinely using needled injection anaesthesia of the orbit. Fifteen percent of our patients receive a peribulbar block with short-acting lidocaine. These are patients who may be deaf, dysphasic, dysfunctional mentally, £ur J Implant Ref Surg, Vol 6, April 1994
M. Lavin
116
in the unoperated eye serves to blunt the corneal blink reflex and allows the patient to keep both eyes open for 15 or 20 minutes. Peribulbar needle block anaesthesia is performed in approximately 15% of our cases, also using lidocaine 4% plain solution. We do not add epinephrine to this. However, we do add hyaluronidase (Wydase). As we do not place a patch or shield on these eyes post-operatively we prefer the short action of lidocaine in order to have the transient ptosis and diplopia disappear within the first few hours of surgery. The retrobulbar route is no longer used. 4. Is general anaesthetic an unnecessary systemic risk?
General anaesthesia is occasionally used when a patient cannot be made comfortable or sedated with intravenous medication following peribulbar block. 5. The place of local anaesthesia in those under 45 years
Patients who are under the age of 60 seem to be more anxious and have much better innervation of their intra-ocular structures than elderly patients. These patients require more intravenous medication when performed under topical anaesthetic and might be more comfortable at surgery under a peribulbar block. 6. Topical anaesthesia: benefits and disadvantages
I believe that topical anaesthesia is the next logical step in our evolution toward attempting to reduce the risk of cataract surgery. Certainly, eliminating the needle from the orbit and all of its possible attendant complications is a step in this direction. With the topical anaesthetics that are available at the present time, we are not able to achieve absolute
anaesthesia of the iris or the ciliary nerves. This is why some of these patients require analgesic and hypnotic medications under topical anaesthesia. Performing diamond blade incisions in the cornea and capsulorhexis without akinesia requires a learning curve on the part of the surgeon. An increased level of verbal communication with the patient is required to encourage ongoing voluntary patient fixation of the globe on the microscope light during these manoeuvres. To date, we have observed no topical anaesthetic pharmacologic complications to the eye or the patient systemically following our first year and 700 cases of topical anaesthesia. Seeing these patients sitting up minutes after surgery without subconjunctival haemorrhage, periorbital ecchymosis, ptosis or diplopia, with full sensory and motor function of the operated eye provides a level of personal gratification for both eye patient and the surgeon that have not been appreciated with earlier techniques. These patients could actually drive themselves home or to work following this form of cataract surgery and anaesthesia if it were not for the medico-legal ramifications associated with the intravenous sedation. CONCLUSIONS
The comments of these experienced cataract surgeons, from Europe, the Far East and United States, reflect the continued evolution of approaches to anaesthesia in cataract surgery. It is instructive to see how readily these successful surgeons have incorporated topical anaesthetic techniques into their practice. While topical anaesthesia is attractive and must reduce anaesthetic morbidity, concerns regarding ocular motility and patient cooperation exist. Cataract anaesthetic techniques will continue to develop and will offer specific advantages to selected categories of patients. Experienced and skilled support staff are needed, both to assist with the surgical procedure, and more importantly, to ensure the patients' well-being.
Eur J Implant Ref Surg, Vol 6, April 1994
Anaesthetic Techniques in Cataract Surgery: General Anaesthesia, Local Infiltrative Anaesthesia, or Topical Anaesthesia? Edited by MICHAEL LAVIN
New developments in cataract surgical techniques have allowed the widespread acceptance of a great range of anaesthetic techniques, ranging from general anaesthesia, infiltrative local anaesthetic techniques combined with monitored continuous intravenous sedation anaesthesia, and isolated infiltrative local anaesthetic techniques (including retrobulbar injection, peribulbar injection, or subconjunctival injection alone) to topical anaesthesia. The object of any anaesthetic technique is to allow the surgeon the maximal degree of surgical control, while at the same time rendering the experience pain-free for the patient, with low ocular and systemic morbidity (and mortality!). More recently, these goals have been extended to include achievement of the shortest recovery period possible, allowing rapid functional recovery. We asked a number of leading cataract surgeons across the world for their views regarding different anaesthetic techniques, and for their requirements, in order to compare and contrast different approaches, and so that we have sufficient information in order to develop a structured approach to anaesthesia and cataract surgery.
Question: anaesthesia for cataract surgery what are the minimum requirements? We asked our contributors to address the following iS3ues in their discussion of anaesthetic choices for cataract surgery. 1. What do you think are the minimum standards for monitoring patients during cataract surgery? Should patients undergoing local anaesthetic (infiltrative or topical) procedures have intravenous cannulae placed as a precaution? 2. What is the minimum number of nursing and technical staff you think are needed to manage a cataract surgical theatre efficiently and safely? 3. Do you use topical anaesthesia (alone), infiltrative local anaesthesia or general anaesthesia in cataract surgery and how frequently do you use these modalities? What is your anaesthetic choice, and why? When do you specifically avoid certain modalities? 0955-3681/94/020113+04 $08.0010
4. Is general anaesthesia an unnecessary systemic risk in the elderly individual aged over 80 years? 5. Is there a place for local anaesthetics in the young (under 45 years) cataractous adult? 6. Is topical anaesthetic justified, or are the benefits outweighed by the disadvantages (poor iris analgesia, no akinesia, short duration, corneal epithelial changes during surgery)? KIMIYA SHIMUZU
Dr Shimuzu is Director of the Department of Ophthalmology at the Musashino Red Cross Hospital, in Tokyo, and has substantial experience with topical anaesthesia in phacoemulsification cataract surgery. 1. Minimum requirements Blood pressure and ECG are two minimal requirements in my view. Patients undergoing local anaesthetic (infiltrative or topical) procedures should have intravenous cannulae placed in case of shock, heart disease, hyperventilation and so on. 2. Staffing There are four persons in all as follows: one operating surgeon, one assistant-surgeon, one scrub nurse and one running nurse. 3. Anaesthetic technique Approximately 20-30% of my patients will receive topical anaesthesia (4% xylocaine), which is instilled three times, 5 minutes pre-operatively. The following are all candidates for topical anaesthesia, but those that are nervous, or can't follow doctor's directions, are excluded: (a) patients with axial length over 28.0 mm;
© 1994 W.B. Saunders Company Limited
Eur J Implant Ref Surg, Vol 6, April 1994
M. Lavin
114
(b) patients with tendency to bleeding; (c) patients with abnormal orbits; Cd) patients with low vision in the fellow eye.
in the operating room for these procedures any more. 2. Staffing
4. Is general anaesthesia an unnecessary systemic risk?
In cataract surgery, I have never employed general anaesthesia in any of my aged patients, though children under 10 years old may receive general anaesthesia. 5. The place of local anaesthesia in those under 45 years
As to your question about the number of nursing and technical staff you think are needed to manage a cataract surgical theatre efficiently and safely, I feel that a minimum of four people efficiently employed using topical anaesthesia are more than adequate and we are currently doing nine phacoemulsification procedures with lens implants in a three hour session in our theatre here. 3. Anaesthetic technique
Many patients under 45 years old are found to have a high vitreous pressure and in addition, topical anaesthesia works less effectively, so that retrobulbar anaesthesia of 5 ml 2% xylocaine is used. A McKintyre's mercury bag is then placed on the eye for 2-3 minutes longer to achieve a soft eye for surgery.
As far as I know I was the first person in these islands to go over to peribulbar anaesthesia and orbital compression with the many varied devices which I began using almost 8 years ago. My interest in the topic evolved as a result of two patients who collapsed on me and almost died following retrobulbar anaesthesia and believe it or not last year I had a patient who ended up with an optic atrophy and perception of light vision following a perfectly 6. Topical anaesthesia: benefits and normal cataract and implant operation following disadvantages retrobulbar injection. I was therefore naturally Selected patients may receive benefit from topical interested to read the joint report of the College of anaesthesia, but the surgeon must have a high Ophthalmology and the College of Anaesthetists degree of skill in order to prevent complications such which Emanuel Rosen helped to produce recently as posterior capsule tears and to manage them if and I would agree completely with the content in they occur. that an anaesthetist should be available and the patient fully monitored if giving anaesthetics by the retrobulbar and peribulbar method. PATRICK CONDON However I think that the report has been rendered totally out of date by what has happened in Dr Patrick Condon practices in Waterford, Ireland, the last year in the United States and will have to be where he practises cataract and refractive surgery, upgraded to take into account the recent developand is also active in teaching both locally and over- ments in topical anaesthesia for cataract surgery which I have just recently started to do following my seas. return from the ASCRS meeting recently in Seattle where I attended a number of courses and listened 1. Minimum requirements to a number of papers on the subject. During the last 6 weeks (before August 1993) I have carried out In my experience I would agree that you need full about 100 cataract procedures using topical anaesscale monitoring and the presence of an anaesthetist thesia combined with a ~ cc of local anaesthesia if you are going to carry out peribulbar or retro- injected subconjunctivally under the upper lid and bulbar anaesthesia because of the possible side have found this to be most effective for phakoemulsieffects that you can get from the anaesthetics. How- fication and lens implant surgery from the analgesic ever, in relation to topical anaesthesia with or with- point of view. I have now got completely used to the out small amounts of subconjunctival regional infil- lack of akinesia and in fact would prefer that the tration, I feel that monitoring of the pulse and blood patients eyelids and globe moved freely during the pressure and serum oxygen are possibly useful. I surgery and also after their surgery. It was also now do not think that an anaesthetist is necessary comforting to find that in none ofthese patients did I Eur J Implant Ref Surg, Vol 6, April 1994
Discussion Section
115
find any increase in intra-ocular pressure or bulging of the vitreous interface during the course of the surgery which I presume was due to the raised intra-orbital pressure attained by injecting the local intra-orbitally. I am also completely amazed at how well these patients perform on the table without any toxic effects whatsoever. I have operated on patients with accelerated hypertension, totally unstable diabetics and patients with many types of abnormal pulse and heart rhythms without any side effects whatever. Both the patients and the nurses are also absolutely delighted with the procedure and as far as I am concerned it has transformed the whole of the cataract operation. Also there is no need as you can gather from my comments for ocular compression and the whole procedure is speeded up most dramatically. 4. Is general anaesthesia an unnecessary systemic risk? 5. The place of local anaesthesia in those under 45 years?
or who may require scleral pocket incision due to corneal disease, a low pre-operative endothelial cell count or a 4+ dense brunescent nucleus that may require ECCE. With either form of anaesthesia, we continue to provide nasal oxygen for out patients underneath their sterile drape and we monitor their oxygen saturation with digital pulse oxymetry. An EKG monitor is in place as well as an automated blood pressure cuff, to monitor the effects of topical and systemic medications, as well as the patient's own medical conditions. An open intravenous line is available on all patients surgery. A nurse anaesthetist is present during the entire procedure. Patients occasionally need medications due to cardiac dysrhythmias or transient hypertension. Patients under topical anaesthesia require more intravenous medication support intra-operatively compared to patients with needle block anaesthesia, who require more intravenous sedation pre-operatively during the needle injection and less sedative medication intra-operatively. The occasional topical anaesthesia patient will receive intra-venous propofol (Diprivan) in 10 mg increments to produce a few minutes of pharmacologic hypnosis and amnesia.
I feel that general anaesthetic is an unnecessary systemic risk in an elderly patient over 80 years. 2. Staffing
Having carried out trabeculectomy in a glaucomatous eye in a 30-year-od patient recently using topical anaesthesia I do think that topical and local subconjunctival infiltration anaesthetic can be carried out quite successfully in the young, under 45 years, cataractous adult.
Our operating room staff consists of one surgeon (myself), one surgical scrub technician, one circulating nurse and one certified nurse anaesthetist. This is minimal and adequate staff to carry out our routine daily procedures for cataract surgery.
HARRY GRABOW
3. Anaesthetic technique
Dr Harry Grabow is an Assistant Professor in Ophthalmology at the University of South Florida, and is based at the Sarasota Cataract Institute, where he has developed an international reputation as a cataract surgeon and teacher of cataract surgery.
For topical anaesthesia our anaesthetic choice is lidocaine that is packaged in breakable glass ampoules. The solution is drawn into a sterile syringe; the needle is removed; and the solution is administered as topical drops directly from the syringe. We do not use preserved lidocaine in multidose vials and also do not use the lidocaine manufactured as a topical solution, as this form is not labelled 'sterile'. The latter form oftopical solution is for use in the contaminated cavities such as the oral cavity for mucous membrane surgery. The anaesthetic eye drops are administered in the pre-operative surgical area by a nurse in sequence with the patient's dilating drops. The patients lidocaine syringe accompanies the patient to the operating room and prior to prepping, the circulating nurse administers one final drop to the operated eye and an additional drop to the unoperated eye. The drop
1. Minimum requirements
During our cataract procedure, 85% of which are performed under topical anaesthesia with temporal clear-corneal incisions, we continue to monitor our patients as we always have when we were routinely using needled injection anaesthesia of the orbit. Fifteen percent of our patients receive a peribulbar block with short-acting lidocaine. These are patients who may be deaf, dysphasic, dysfunctional mentally, £ur J Implant Ref Surg, Vol 6, April 1994
M. Lavin
116
in the unoperated eye serves to blunt the corneal blink reflex and allows the patient to keep both eyes open for 15 or 20 minutes. Peribulbar needle block anaesthesia is performed in approximately 15% of our cases, also using lidocaine 4% plain solution. We do not add epinephrine to this. However, we do add hyaluronidase (Wydase). As we do not place a patch or shield on these eyes post-operatively we prefer the short action of lidocaine in order to have the transient ptosis and diplopia disappear within the first few hours of surgery. The retrobulbar route is no longer used. 4. Is general anaesthetic an unnecessary systemic risk?
General anaesthesia is occasionally used when a patient cannot be made comfortable or sedated with intravenous medication following peribulbar block. 5. The place of local anaesthesia in those under 45 years
Patients who are under the age of 60 seem to be more anxious and have much better innervation of their intra-ocular structures than elderly patients. These patients require more intravenous medication when performed under topical anaesthetic and might be more comfortable at surgery under a peribulbar block. 6. Topical anaesthesia: benefits and disadvantages
I believe that topical anaesthesia is the next logical step in our evolution toward attempting to reduce the risk of cataract surgery. Certainly, eliminating the needle from the orbit and all of its possible attendant complications is a step in this direction. With the topical anaesthetics that are available at the present time, we are not able to achieve absolute
anaesthesia of the iris or the ciliary nerves. This is why some of these patients require analgesic and hypnotic medications under topical anaesthesia. Performing diamond blade incisions in the cornea and capsulorhexis without akinesia requires a learning curve on the part of the surgeon. An increased level of verbal communication with the patient is required to encourage ongoing voluntary patient fixation of the globe on the microscope light during these manoeuvres. To date, we have observed no topical anaesthetic pharmacologic complications to the eye or the patient systemically following our first year and 700 cases of topical anaesthesia. Seeing these patients sitting up minutes after surgery without subconjunctival haemorrhage, periorbital ecchymosis, ptosis or diplopia, with full sensory and motor function of the operated eye provides a level of personal gratification for both eye patient and the surgeon that have not been appreciated with earlier techniques. These patients could actually drive themselves home or to work following this form of cataract surgery and anaesthesia if it were not for the medico-legal ramifications associated with the intravenous sedation. CONCLUSIONS
The comments of these experienced cataract surgeons, from Europe, the Far East and United States, reflect the continued evolution of approaches to anaesthesia in cataract surgery. It is instructive to see how readily these successful surgeons have incorporated topical anaesthetic techniques into their practice. While topical anaesthesia is attractive and must reduce anaesthetic morbidity, concerns regarding ocular motility and patient cooperation exist. Cataract anaesthetic techniques will continue to develop and will offer specific advantages to selected categories of patients. Experienced and skilled support staff are needed, both to assist with the surgical procedure, and more importantly, to ensure the patients' well-being.
Eur J Implant Ref Surg, Vol 6, April 1994