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Corneal surgery for severe phacoemulsification burns
Corneal Surgery for Severe Phacoemulsification Burns A. James Khodabakhsh, MD,1,2 Gerald Zaidman, MD,1,2 Goeffrey Tabin, MD3 Objective: To evaluate the outcome of corneal surgery for the treatment of severe corneal phacoemulsification burns. Design: Interventional case series. Participants: Four patients with severe intraoperative phacoemulsification burns. Intervention: One patient underwent penetrating keratoplasty and 3 underwent lamellar keratoplasties for the treatment of their corneal burns. Main Outcome Measures: Preoperative and postoperative visual acuities, preoperative and postoperative corneal topographies, and clinical observation. Results: The visual acuity (VA) after the phacoemulsification burn was counting fingers in all patients. One patient had a penetrating keratoplasty, whereas the other 3 had lamellar grafts. After the corneal surgery, the corrected postoperative VA was 20/30 to 20/50 in all patients, with astigmatism ranging from 2.5 to 5.5 diopters. Conclusion: Severe phacoemulsification burns can be safely treated with corneal surgery, with acceptable postoperative visual acuities. Ophthalmology 2004;111:332–334 © 2004 by the American Academy of Ophthalmology.
Phacoemulsification is now the primary method of cataract extraction in the United States. During phacoemulsification, ultrasonic energy is used to emulsify the lens nucleus. A portion of this energy is converted to heat, and is in turn cooled by the irrigation and aspiration portion of the unit.1 Many factors can influence this cooling process. If cooling is inadequate, one can develop thermal burns in the cornea or sclera within 1 to 3 seconds.1,2 These factors include overly tight wounds that compress the phacoemulsification handpiece, kinks or bends in the tubing, unrecognized tears in the phacoemulsification sleeve, and viscoelastic plugging or occlusion that prevents fluid flow around the phacoemulsification tip.1,3,4 Relatively little has been published about severe corneoscleral phacoemulsification burn treatment. We report 4 cases of severe phacoemulsification burns and their outcomes.
Case 1 A 77-year-old female with a history of diabetes mellitus underwent clear corneal phacoemulsification of the right eye. The surgeon
Originally received: December 20, 2002. Accepted: June 11, 2003. Manuscript no. 220977. 1 Westchester Medical Center, Valhalla, New York. 2 New York Medical College, Valhalla, New York. 3 University of Vermont Medical Center, Burlington, Vermont. Originally presented in part at: American Academy of Ophthalmology Annual Meeting, October 22–25, 2000; Dallas. Reprint requests to Gerald Zaidman, MD, Westchester Medical Center, Department of Ophthalmology, Valhalla, NY 10595.
332
© 2004 by the American Academy of Ophthalmology Published by Elsevier Inc.
noted that the “machine overheated” during surgery, and “the cornea melted.” On the first postoperative day, the patient was noted to have a visual acuity (VA) of counting fingers in the operated eye. The eye was inflamed, with severe corneal edema at the incision site. There were several iris holes and 2-o’clock to 3-o’clock iridodialysis. The posterior chamber lens was centered. The patient was reoperated on to close the leaking wound. Three months later the patient was referred to our service for management. We found that she had counting fingers vision. There were severe corneal thinning, scarring, and neovascularization at the incision site (Fig 1). There were staining and pooling of fluorescein secondary to a dellen, and there were multiple stromal striae present. The wound was Seidel negative. The remainder of the anterior segment examination showed no changes. A bandage contact lens was placed on the eye. During the subsequent 3 months, there was no improvement in vision or the cornea. She developed central and peripheral corneal thinning and scarring, with approximately 10 diopters (D) of irregular astigmatism (Fig 2). The patient subsequently underwent a penetrating keratoplasty, iridoplasty, and synechiolysis. She had an uneventful postoperative course. Currently (3 years postoperatively), the graft is clear, and the VA is 20/30, with ⫺4.25 ⫹400 ⫻160 D.
Case 2 A 73-year-old female with a history of diabetes mellitus and hypertension had phacoemulsification of the right eye. At the time of surgery, a severe corneal burn was noted. The wound was sutured closed. A few months later she was referred to the cornea service for management. On referral, the VA was counting fingers. There were temporal corneal thinning and scarring. There were iris atrophy and 3 clock hours of iridocorneal adhesions present. The pupil was irregular. Seven diopters of astigmatism were present on refraction. Keratometry measurements were 42.6/55.5 at 35. ISSN 0161-6420/04/$–see front matter doi:10.1016/j.ophtha.2003.06.004
Khodabakhsh et al 䡠 Phacoemulsification Burns
Figure 1. Slit-lamp photograph (case 1) demonstrates phacoemulsification burns at the incision site. A bandage contact lens is in place.
Figure 3. Slit-lamp photograph (case 3) demonstrates a temporal lamellar patch graft in position over the area of the corneal burn.
The patient received a lamellar patch graft and underwent iridoplasty, synechiolysis, and compression suturing. Now, 3 years after surgery, she has a corrected VA of 20/50 (due to mild macular degeneration), with a clear graft and minimal astigmatism.
Case 4
Case 3 A 77-year-old female underwent phacoemulsification in the right eye. The patient had a history of hypertension and angina. During surgery it was noted that the irrigation bottle emptied and a severe corneal burn occurred. The wound was sutured, but the surgeon could not obtain a watertight closure. The patient developed iris prolapse, hypotony, and a flat anterior chamber. On referral, the VA was finger counting at 6 feet. There was a 1⫻2-mm area of corneal melting, with a surrounding corneal edema. The anterior chamber was shallow, with an atrophic iris that was plugging the wound. The eye was hypotonous. The posterior chamber intraocular lens was in good position. The next day, the patient underwent surgical repair consisting of a lamellar keratoplasty and synechiolysis (Fig 3). The postoperative course was uneventful. Currently, 3 years after surgery, the VA is 20/25, with a minimal correction.
An 83-year-old had phacoemulsification of the right eye. The patient had a medical history of diabetes mellitus and heart disease. A corneal burn was noted during the procedure. The wound was sutured, but a watertight closure could not be accomplished. On referral, the VA was finger counting, and a severe corneal melt with a shallow anterior chamber was noted. An atrophic iris was plugging the wound. The intraocular pressure was 11 mmHg. A surgical repair consisting of a lamellar patch graft and synechiolysis was performed. The patient’s eye healed, with a corrected VA of 20/40 (with ⫺2.00 ⫹4.25 ⫻137 D). She died 6 months after surgery.
Results We retrospectively identified 4 patients who had severe corneal burns and were treated with corneal surgery. The mean age was 77.5 years (range ⫽ 72– 83). Three of the 4 patients had diabetes mellitus. The patient data, including preoperative and postoperative visual acuities and astigmatisms, are summarized in Table 1. All patients had a Snellen VA of counting fingers after the phacoemulsification burn. Three patients underwent lamellar keratoplasties, whereas 1 (patient 1) underwent a penetrating keratoplasty. In the 2 patients who were measured before their corneal surgery, keratometric astigmatisms were 10 and 14 D. The postoperative Snellen VA was 20/25 to 20/50. The mean postoperative astigmatism (in all 4 patients) was 2.75 D (range ⫽ 1.25– 4.00). Table 1. Patient Data Preoperative
Figure 2. Slit-lamp photograph (case 1) of central and peripheral corneal scarring and neovascularization.
Postoperative
Patient
Visual Acuity
Astigmatism (D)
Visual Acuity
Astigmatism (D)
1 2 3 4
CF CF CF CF
10 12 NA NA
20/30 20/50 20/25 20/40
4.00 1.25 1.50 4.25
CF ⫽ counting fingers; D ⫽ diopters; NA ⫽ not available.
333
Ophthalmology Volume 111, Number 2, February 2004
Discussion Thermal burns to the cornea and sclera were recognized as a severe and catastrophic complication of phacoemulsification cataract surgery, shortly after Kelman first introduced the procedure in 1967.5 Phacoemulsification burns during cataract surgery are due to the buildup of heat, in and around the phacoemulsification tip, which is not dissipated by the irrigation fluid.1,4 Severe burns can acutely lead to corneal or scleral melting, wound gape, aqueous leakage, iris atrophy, iris holes, and synechiae.1– 4,6 Direct measurement of wound temperatures during phacoemulsification has been performed. These temperatures have been reported to be as high as 81° to 100° C.7,8 Ernest et al showed that under equal conditions, if the irrigation/aspiration flow has been compromised or plugged with either dispersive or cohesive viscoelastics, then comparable elevations in temperature were recorded.9 Also, because viscoelastics are sugars, when heated sufficiently, they can cause a burn. If the cornea is subjected to these temperatures, even for a few seconds, then all the layers of the cornea will be disrupted. In these severe corneal burns, the necrosis of the corneal layers leads to sloughing and melting of the cornea, ocular hypotony, and possible extrusion of the intraocular contents.10 After the burn, as the cornea heals, it causes scarring and shrinkage, which in turn leads to high irregular astigmatism. The corneal heat tolerance has been tested in the past. Goldsblatt heated the rabbit cornea to 45° C for 15 minutes, without observing any significant changes on light microscopy.11 After a temperature of 59° C was applied for 5 minutes, the result was a cloudy cornea with stromal edema and disorganization. It has been shown, histologically, that localized hyperthermia of 70° C or higher for a period of a few seconds can cause necrosis of all human tissues. At the histologic level, the tissue is carbonized, and all cellular structures are lost.12 Polack and Sugar have reported cases of phacoemulsification burns that have required penetrating keratoplasty in the past.6 Their report did not note either the postoperative VA or clinical outcome of the patient. In a second report, Sugar noted astigmatism of 6 to 15 prism diopters in 3 patients with phacoemulsification burns.3 One patient underwent penetrating keratoplasty, then attained a VA of 20/200 before dying. The other patient’s astigmatism decreased over time with the removal of the corneal sutures. In our series, all patients had severe corneal burns, and at least 2 had documented preoperative high irregular astigmatism. Three patients had corneal melts. The fourth patient had severe scarring and thinning of the cornea. All patients had iris damage and synechiae formation. Three patients underwent lamellar patch grafts, whereas the fourth patient had a penetrating keratoplasty. Postoperatively, all of the patients had significant reduction in their astigmatism. All patients had a final VA of ⱖ20/50 in the operated eye.
334
Of note is the finding in our study that 3 of our 4 patients had diabetes mellitus. We concede that our sample size is far too small to make any significant conclusions from this, except that the surgeon should proceed with extra caution in a diabetic patient. It is extremely important for all surgeons to start each cataract extraction by checking the tubing for kinks or bends. Overly tight phacoemulsification wounds should be monitored for compression of the silicone sleeve. A dispersive and/or adhesive viscoelastic that prevents fluid flow around the phacoemulsification tip should be used cautiously. Clinical experience indicates that when a mild corneal burn occurs, the tissue will heal over time, and the resulting astigmatism may decrease. However, for very severe burns, our series of patients indicates that corneal surgery, including full thickness penetrating grafts and lamellar patch grafts, can be used (when necessary) to successfully restore integrity to the globe. These procedures can be used with few complications to decrease astigmatism, eliminate corneal scarring, and improve vision in patients with phacoemulsification burns.
References 1. Cionni RJ, Osher RH. Intraoperative complications of phacoemulsification surgery. In: Steinert RF, ed. Cataract Surgery: Techniques, Complications and Management. Philadelphia: WB Saunders; 1995:327– 40. 2. Scleral and corneal burns during phacoemulsification with viscoelastic materials. Health Devices 1988;17:377–9. 3. Sugar A, Schertzer RM. Clinical course of phacoemulsification wound burns. J Cataract Refract Surg 1999;25:688 –92. 4. Majid MA, Sharma MK, Harding SP. Corneoscleral burn during phacoemulsification surgery. J Cataract Refract Surg 1998;24:1413–5. 5. Kelman CD. Phaco-emulsification and aspiration: a new technique of cataract removal. A preliminary report. Am J Ophthalmol 1967;64:23–35. 6. Polack FM, Sugar A. The phacoemulsification procedure. III. Corneal complications. Invest Ophthalmol Vis Sci 1977;16: 39 – 46. 7. Yamagami S, Yamagami H. Direct measurement of wound temperature during phacoemulsification. Ophthalmologia 1998;212:50 –2. 8. Benolken RM, Emery JM, Landis DJ. Temperature profiles in the anterior chamber during phaco-emulsification. Invest Ophthalmol 1974;13:71– 4. 9. Ernest P, Rhem M, McDermott M, et al. Phacoemulsification conditions resulting in thermal wound injury. J Cataract Refract Surg 2001;27:1829 –39. 10. Duke-Elder S, MacFaul PA. Non-mechanical injuries. In: Duke-Elder S, ed. System of Ophthalmology. Vol. 14. Part 2. St. Louis: CV Mosby; 1972:747–76. 11. Goldsblatt WS, Finger PT, Perry HD, et al. Hyperthermic treatment of rabbit corneas. Invest Ophthalmol Vis Sci 1989; 30:1778 – 83. 12. Rubin E, Farber JL, eds. Pathology. Vol. 1. 3rd ed. Philadelphia: Lippincott-Raven; 1994:315–7.
Phacoemulsification is now the primary method of cataract extraction in the United States. During phacoemulsification, ultrasonic energy is used to emulsify the lens nucleus. A portion of this energy is converted to heat, and is in turn cooled by the irrigation and aspiration portion of the unit.1 Many factors can influence this cooling process. If cooling is inadequate, one can develop thermal burns in the cornea or sclera within 1 to 3 seconds.1,2 These factors include overly tight wounds that compress the phacoemulsification handpiece, kinks or bends in the tubing, unrecognized tears in the phacoemulsification sleeve, and viscoelastic plugging or occlusion that prevents fluid flow around the phacoemulsification tip.1,3,4 Relatively little has been published about severe corneoscleral phacoemulsification burn treatment. We report 4 cases of severe phacoemulsification burns and their outcomes.
Case 1 A 77-year-old female with a history of diabetes mellitus underwent clear corneal phacoemulsification of the right eye. The surgeon
Originally received: December 20, 2002. Accepted: June 11, 2003. Manuscript no. 220977. 1 Westchester Medical Center, Valhalla, New York. 2 New York Medical College, Valhalla, New York. 3 University of Vermont Medical Center, Burlington, Vermont. Originally presented in part at: American Academy of Ophthalmology Annual Meeting, October 22–25, 2000; Dallas. Reprint requests to Gerald Zaidman, MD, Westchester Medical Center, Department of Ophthalmology, Valhalla, NY 10595.
332
© 2004 by the American Academy of Ophthalmology Published by Elsevier Inc.
noted that the “machine overheated” during surgery, and “the cornea melted.” On the first postoperative day, the patient was noted to have a visual acuity (VA) of counting fingers in the operated eye. The eye was inflamed, with severe corneal edema at the incision site. There were several iris holes and 2-o’clock to 3-o’clock iridodialysis. The posterior chamber lens was centered. The patient was reoperated on to close the leaking wound. Three months later the patient was referred to our service for management. We found that she had counting fingers vision. There were severe corneal thinning, scarring, and neovascularization at the incision site (Fig 1). There were staining and pooling of fluorescein secondary to a dellen, and there were multiple stromal striae present. The wound was Seidel negative. The remainder of the anterior segment examination showed no changes. A bandage contact lens was placed on the eye. During the subsequent 3 months, there was no improvement in vision or the cornea. She developed central and peripheral corneal thinning and scarring, with approximately 10 diopters (D) of irregular astigmatism (Fig 2). The patient subsequently underwent a penetrating keratoplasty, iridoplasty, and synechiolysis. She had an uneventful postoperative course. Currently (3 years postoperatively), the graft is clear, and the VA is 20/30, with ⫺4.25 ⫹400 ⫻160 D.
Case 2 A 73-year-old female with a history of diabetes mellitus and hypertension had phacoemulsification of the right eye. At the time of surgery, a severe corneal burn was noted. The wound was sutured closed. A few months later she was referred to the cornea service for management. On referral, the VA was counting fingers. There were temporal corneal thinning and scarring. There were iris atrophy and 3 clock hours of iridocorneal adhesions present. The pupil was irregular. Seven diopters of astigmatism were present on refraction. Keratometry measurements were 42.6/55.5 at 35. ISSN 0161-6420/04/$–see front matter doi:10.1016/j.ophtha.2003.06.004
Khodabakhsh et al 䡠 Phacoemulsification Burns
Figure 1. Slit-lamp photograph (case 1) demonstrates phacoemulsification burns at the incision site. A bandage contact lens is in place.
Figure 3. Slit-lamp photograph (case 3) demonstrates a temporal lamellar patch graft in position over the area of the corneal burn.
The patient received a lamellar patch graft and underwent iridoplasty, synechiolysis, and compression suturing. Now, 3 years after surgery, she has a corrected VA of 20/50 (due to mild macular degeneration), with a clear graft and minimal astigmatism.
Case 4
Case 3 A 77-year-old female underwent phacoemulsification in the right eye. The patient had a history of hypertension and angina. During surgery it was noted that the irrigation bottle emptied and a severe corneal burn occurred. The wound was sutured, but the surgeon could not obtain a watertight closure. The patient developed iris prolapse, hypotony, and a flat anterior chamber. On referral, the VA was finger counting at 6 feet. There was a 1⫻2-mm area of corneal melting, with a surrounding corneal edema. The anterior chamber was shallow, with an atrophic iris that was plugging the wound. The eye was hypotonous. The posterior chamber intraocular lens was in good position. The next day, the patient underwent surgical repair consisting of a lamellar keratoplasty and synechiolysis (Fig 3). The postoperative course was uneventful. Currently, 3 years after surgery, the VA is 20/25, with a minimal correction.
An 83-year-old had phacoemulsification of the right eye. The patient had a medical history of diabetes mellitus and heart disease. A corneal burn was noted during the procedure. The wound was sutured, but a watertight closure could not be accomplished. On referral, the VA was finger counting, and a severe corneal melt with a shallow anterior chamber was noted. An atrophic iris was plugging the wound. The intraocular pressure was 11 mmHg. A surgical repair consisting of a lamellar patch graft and synechiolysis was performed. The patient’s eye healed, with a corrected VA of 20/40 (with ⫺2.00 ⫹4.25 ⫻137 D). She died 6 months after surgery.
Results We retrospectively identified 4 patients who had severe corneal burns and were treated with corneal surgery. The mean age was 77.5 years (range ⫽ 72– 83). Three of the 4 patients had diabetes mellitus. The patient data, including preoperative and postoperative visual acuities and astigmatisms, are summarized in Table 1. All patients had a Snellen VA of counting fingers after the phacoemulsification burn. Three patients underwent lamellar keratoplasties, whereas 1 (patient 1) underwent a penetrating keratoplasty. In the 2 patients who were measured before their corneal surgery, keratometric astigmatisms were 10 and 14 D. The postoperative Snellen VA was 20/25 to 20/50. The mean postoperative astigmatism (in all 4 patients) was 2.75 D (range ⫽ 1.25– 4.00). Table 1. Patient Data Preoperative
Figure 2. Slit-lamp photograph (case 1) of central and peripheral corneal scarring and neovascularization.
Postoperative
Patient
Visual Acuity
Astigmatism (D)
Visual Acuity
Astigmatism (D)
1 2 3 4
CF CF CF CF
10 12 NA NA
20/30 20/50 20/25 20/40
4.00 1.25 1.50 4.25
CF ⫽ counting fingers; D ⫽ diopters; NA ⫽ not available.
333
Ophthalmology Volume 111, Number 2, February 2004
Discussion Thermal burns to the cornea and sclera were recognized as a severe and catastrophic complication of phacoemulsification cataract surgery, shortly after Kelman first introduced the procedure in 1967.5 Phacoemulsification burns during cataract surgery are due to the buildup of heat, in and around the phacoemulsification tip, which is not dissipated by the irrigation fluid.1,4 Severe burns can acutely lead to corneal or scleral melting, wound gape, aqueous leakage, iris atrophy, iris holes, and synechiae.1– 4,6 Direct measurement of wound temperatures during phacoemulsification has been performed. These temperatures have been reported to be as high as 81° to 100° C.7,8 Ernest et al showed that under equal conditions, if the irrigation/aspiration flow has been compromised or plugged with either dispersive or cohesive viscoelastics, then comparable elevations in temperature were recorded.9 Also, because viscoelastics are sugars, when heated sufficiently, they can cause a burn. If the cornea is subjected to these temperatures, even for a few seconds, then all the layers of the cornea will be disrupted. In these severe corneal burns, the necrosis of the corneal layers leads to sloughing and melting of the cornea, ocular hypotony, and possible extrusion of the intraocular contents.10 After the burn, as the cornea heals, it causes scarring and shrinkage, which in turn leads to high irregular astigmatism. The corneal heat tolerance has been tested in the past. Goldsblatt heated the rabbit cornea to 45° C for 15 minutes, without observing any significant changes on light microscopy.11 After a temperature of 59° C was applied for 5 minutes, the result was a cloudy cornea with stromal edema and disorganization. It has been shown, histologically, that localized hyperthermia of 70° C or higher for a period of a few seconds can cause necrosis of all human tissues. At the histologic level, the tissue is carbonized, and all cellular structures are lost.12 Polack and Sugar have reported cases of phacoemulsification burns that have required penetrating keratoplasty in the past.6 Their report did not note either the postoperative VA or clinical outcome of the patient. In a second report, Sugar noted astigmatism of 6 to 15 prism diopters in 3 patients with phacoemulsification burns.3 One patient underwent penetrating keratoplasty, then attained a VA of 20/200 before dying. The other patient’s astigmatism decreased over time with the removal of the corneal sutures. In our series, all patients had severe corneal burns, and at least 2 had documented preoperative high irregular astigmatism. Three patients had corneal melts. The fourth patient had severe scarring and thinning of the cornea. All patients had iris damage and synechiae formation. Three patients underwent lamellar patch grafts, whereas the fourth patient had a penetrating keratoplasty. Postoperatively, all of the patients had significant reduction in their astigmatism. All patients had a final VA of ⱖ20/50 in the operated eye.
334
Of note is the finding in our study that 3 of our 4 patients had diabetes mellitus. We concede that our sample size is far too small to make any significant conclusions from this, except that the surgeon should proceed with extra caution in a diabetic patient. It is extremely important for all surgeons to start each cataract extraction by checking the tubing for kinks or bends. Overly tight phacoemulsification wounds should be monitored for compression of the silicone sleeve. A dispersive and/or adhesive viscoelastic that prevents fluid flow around the phacoemulsification tip should be used cautiously. Clinical experience indicates that when a mild corneal burn occurs, the tissue will heal over time, and the resulting astigmatism may decrease. However, for very severe burns, our series of patients indicates that corneal surgery, including full thickness penetrating grafts and lamellar patch grafts, can be used (when necessary) to successfully restore integrity to the globe. These procedures can be used with few complications to decrease astigmatism, eliminate corneal scarring, and improve vision in patients with phacoemulsification burns.
References 1. Cionni RJ, Osher RH. Intraoperative complications of phacoemulsification surgery. In: Steinert RF, ed. Cataract Surgery: Techniques, Complications and Management. Philadelphia: WB Saunders; 1995:327– 40. 2. Scleral and corneal burns during phacoemulsification with viscoelastic materials. Health Devices 1988;17:377–9. 3. Sugar A, Schertzer RM. Clinical course of phacoemulsification wound burns. J Cataract Refract Surg 1999;25:688 –92. 4. Majid MA, Sharma MK, Harding SP. Corneoscleral burn during phacoemulsification surgery. J Cataract Refract Surg 1998;24:1413–5. 5. Kelman CD. Phaco-emulsification and aspiration: a new technique of cataract removal. A preliminary report. Am J Ophthalmol 1967;64:23–35. 6. Polack FM, Sugar A. The phacoemulsification procedure. III. Corneal complications. Invest Ophthalmol Vis Sci 1977;16: 39 – 46. 7. Yamagami S, Yamagami H. Direct measurement of wound temperature during phacoemulsification. Ophthalmologia 1998;212:50 –2. 8. Benolken RM, Emery JM, Landis DJ. Temperature profiles in the anterior chamber during phaco-emulsification. Invest Ophthalmol 1974;13:71– 4. 9. Ernest P, Rhem M, McDermott M, et al. Phacoemulsification conditions resulting in thermal wound injury. J Cataract Refract Surg 2001;27:1829 –39. 10. Duke-Elder S, MacFaul PA. Non-mechanical injuries. In: Duke-Elder S, ed. System of Ophthalmology. Vol. 14. Part 2. St. Louis: CV Mosby; 1972:747–76. 11. Goldsblatt WS, Finger PT, Perry HD, et al. Hyperthermic treatment of rabbit corneas. Invest Ophthalmol Vis Sci 1989; 30:1778 – 83. 12. Rubin E, Farber JL, eds. Pathology. Vol. 1. 3rd ed. Philadelphia: Lippincott-Raven; 1994:315–7.