- Email: [email protected]
Retrobulbar Block Revised
LEITERS
first point is the author seems to feel that induction of general anesthesia will lead to a significantly elevated intraocular pressure (lOP). It should be noted that rapid sequence induction with the newer nondepolarizing agents has very little, if any, effect on lOP. It should also be noted that using 10 cc to give a peribulbar block will most certainly cause a significant lOP increase. Another point that should be noted is that 5 hours after a light breakfast, the patient's gastric contents would be minimal and thus this patient probably had an empty stomach. Sedating the patient with midazolam and propofol without an airway in place put the patient at higher risk for aspiration than he would have been while having rapid sequence induction and placement of an endotracheal tube. Thus, I feel that the ophthalmologist's reasoning about the use of anesthesia was faulty and that general anesthesia remains the anesthetic of choice in the treatment of ruptured globes. JAMES D. HAYASHI, MD
cation is desirable from the patient's standpoint.-Richard
J. Eggleston, MD
Retrobulbar Block Revised
I
was taught Dr. Robert Hamilton's technique of retrobulbar block l in 1950 by Professor W.]. Kapuscinski in Poznan, Poland. He indicated then that the original Atkinson's approach can result in an engagement of the extraocular muscles and also presents a risk of perforation. Another excellent piece of advice that I received then, as a beginning ophthalmic surgeon, was to position myself behind the patient's head, as during routine surgery, and perform the injection with the patient's eye open. I would not call it luck that in tens of thousands of procedures, I did not experience a perforation. On a few occasions, transient postoperative diplopia could be registered. Dr. Hamilton should be congratulated for bringing his approach to our attention. K.
Quincy, Illinois, USA Reference 1. Eggleston RJ. Surgical repair of multiple ruptures of radial and transverse incisions under topical anesthesia (letter). J Cataract Refract Surg 1996; 22: 1394
Reply: The letter from Dr. Hayashi makes some valid points. I and the anesthesia personnel involved with this case are aware of the advantages of the nondepolarizing agents, including that of the lOP problem. However, I think it is still preferable to avoid the risk of intratracheal tube irritation causing a bucking response that could have extruded orbital contents. It should also be recalled that whenever there is any significant injury or stress, gastric function can almost come to a standstill. We felt there was still a significant possibility of the patient's having a full stomach and that this could have caused regurgitation and aspiration pneumonitis. The amount of midazolam (Versed®) and propofol that were appropriate for this patient's size did not cause any problem with his breathing. The anesthesia department felt very comfortable in giving this amount without having intubation present. It should be noted that this was used only while the facial block was performed. The anesthesiologists and anesthetists whom I have spoken to agree that they would be very relieved, even with modern agents, not to have to give a patient with an open eye and a full stomach a general anesthetic if it could be avoided. They felt, though, that this was dependent on their degree of confidence in the skill of the surgeon with whom they would be working. I still feel that the concept of intraocular topical anesthesia with some supplementation with intravenous medi-
EDMUND SPAK,
MD, PHD
Houston, Texas, USA Reference 1. Hamilton RC. Retrobulbar block revisited and revised. J Cataract Refract Surg 1996; 22:1147-1150
Demonstrating Glare to the Surgical Patient
T
he article by Maguen and coauthors l about photorefractive keratectomy (PRK) in an aircraft pilot mentions the importance of using contact lenses to demonstrate monovision to patients prior to their surgery. In the related editorial by Mader,2 he mentions the night vision problems, such as glare and ghost images, potentially associated with refractive surgery. Having worn soft bifocal contact lenses for many years and experienced the glare and ghost images at night, I suggest that the soft bifocal contact lens can provide a means to demonstrate these phenomena to a potential surgical patient. This may be helpful in obtaining a more informed consent. F. BIGGER, MD Augusta, Georgia, USA
JOHN
References 1. Maguen E, Nesburn AB, Salz J] . Bilateral photorefractive keratectomy with intentional unilateral undercorrection in an aircraft pilot. J Cataract Refract Surg 1997; 23:294-296 2. Mader TH. Bilateral photorefractive keratectomy with intentional unilateral undercorrection performed on an aircraft pilot. J Cataract Refract Surg 1997; 23:145-147
J CATARACT REFRACT SURG-VOL 23, JUNE 1997
697
first point is the author seems to feel that induction of general anesthesia will lead to a significantly elevated intraocular pressure (lOP). It should be noted that rapid sequence induction with the newer nondepolarizing agents has very little, if any, effect on lOP. It should also be noted that using 10 cc to give a peribulbar block will most certainly cause a significant lOP increase. Another point that should be noted is that 5 hours after a light breakfast, the patient's gastric contents would be minimal and thus this patient probably had an empty stomach. Sedating the patient with midazolam and propofol without an airway in place put the patient at higher risk for aspiration than he would have been while having rapid sequence induction and placement of an endotracheal tube. Thus, I feel that the ophthalmologist's reasoning about the use of anesthesia was faulty and that general anesthesia remains the anesthetic of choice in the treatment of ruptured globes. JAMES D. HAYASHI, MD
cation is desirable from the patient's standpoint.-Richard
J. Eggleston, MD
Retrobulbar Block Revised
I
was taught Dr. Robert Hamilton's technique of retrobulbar block l in 1950 by Professor W.]. Kapuscinski in Poznan, Poland. He indicated then that the original Atkinson's approach can result in an engagement of the extraocular muscles and also presents a risk of perforation. Another excellent piece of advice that I received then, as a beginning ophthalmic surgeon, was to position myself behind the patient's head, as during routine surgery, and perform the injection with the patient's eye open. I would not call it luck that in tens of thousands of procedures, I did not experience a perforation. On a few occasions, transient postoperative diplopia could be registered. Dr. Hamilton should be congratulated for bringing his approach to our attention. K.
Quincy, Illinois, USA Reference 1. Eggleston RJ. Surgical repair of multiple ruptures of radial and transverse incisions under topical anesthesia (letter). J Cataract Refract Surg 1996; 22: 1394
Reply: The letter from Dr. Hayashi makes some valid points. I and the anesthesia personnel involved with this case are aware of the advantages of the nondepolarizing agents, including that of the lOP problem. However, I think it is still preferable to avoid the risk of intratracheal tube irritation causing a bucking response that could have extruded orbital contents. It should also be recalled that whenever there is any significant injury or stress, gastric function can almost come to a standstill. We felt there was still a significant possibility of the patient's having a full stomach and that this could have caused regurgitation and aspiration pneumonitis. The amount of midazolam (Versed®) and propofol that were appropriate for this patient's size did not cause any problem with his breathing. The anesthesia department felt very comfortable in giving this amount without having intubation present. It should be noted that this was used only while the facial block was performed. The anesthesiologists and anesthetists whom I have spoken to agree that they would be very relieved, even with modern agents, not to have to give a patient with an open eye and a full stomach a general anesthetic if it could be avoided. They felt, though, that this was dependent on their degree of confidence in the skill of the surgeon with whom they would be working. I still feel that the concept of intraocular topical anesthesia with some supplementation with intravenous medi-
EDMUND SPAK,
MD, PHD
Houston, Texas, USA Reference 1. Hamilton RC. Retrobulbar block revisited and revised. J Cataract Refract Surg 1996; 22:1147-1150
Demonstrating Glare to the Surgical Patient
T
he article by Maguen and coauthors l about photorefractive keratectomy (PRK) in an aircraft pilot mentions the importance of using contact lenses to demonstrate monovision to patients prior to their surgery. In the related editorial by Mader,2 he mentions the night vision problems, such as glare and ghost images, potentially associated with refractive surgery. Having worn soft bifocal contact lenses for many years and experienced the glare and ghost images at night, I suggest that the soft bifocal contact lens can provide a means to demonstrate these phenomena to a potential surgical patient. This may be helpful in obtaining a more informed consent. F. BIGGER, MD Augusta, Georgia, USA
JOHN
References 1. Maguen E, Nesburn AB, Salz J] . Bilateral photorefractive keratectomy with intentional unilateral undercorrection in an aircraft pilot. J Cataract Refract Surg 1997; 23:294-296 2. Mader TH. Bilateral photorefractive keratectomy with intentional unilateral undercorrection performed on an aircraft pilot. J Cataract Refract Surg 1997; 23:145-147
J CATARACT REFRACT SURG-VOL 23, JUNE 1997
697