General Anesthesia and AISH

the 15 cases of AISH that is in accord with his newer management in the two cases reported. I have recommended simply applying direct pressure to the incision with a Q-tip. This transmits pressure to the suprachoroidal space and tamponades the suprachoroidal effusion or hemorrhage. This maneuver is perhaps distinct from what Dr. Davison describes as "massage," which I fear would cause more shear. This direct pressure is maintained for five to 15 minutes until the intraocular pressure is stabilized. Surgery can then be completed. Dr. Davison expresses concern about the "health of the retinal vasculature." This is an essential concern. As I pointed out in my paper, Hayreh and Weingeist4 have shown experimentally that occlusion of the central retinal artery does not lead to irreversible axonal damage if present for fewer than 90 minutes. Paul N. Arnold, M.D. Springfield, Missouri

REFERENCES 1. Davison JA. Acute intraoperative suprachoroidal hemorrhage in capsular bag phacoemulsification. J Cataract Refract Surg 1993; 19:534-537 2. Arnold PN. Study of acute intraoperative suprachoroidal hemorrhage. J Cataract Refract Surg 1992; 18:489-494 3. Arnold PN. One handed, posterior chamber phacoemulsification. J Cataract Refract Surg 1990; 18:157-161 4. Hayreh SS, Weingeist T A. Experimental occlusion of the central artery of the retina. IV: Retinal tolerance time to acute ischaemia. Br J Ophthalmol 1980; 64:818-825

James A. Davison, M.D., replies: I would like to congratulate Dr. Arnold for his fine paper on acute intraoperative suprachoroidal hemorrhage. We have had similar experiences and share most viewpoints. Had his paper been published earlier, I would not have felt the need to report my own experiences and recommendations with capsular bag phacoemulsification. I finished my manuscript and submitted it in March 1992. I was on record in my 1986 paper as recommending next-day completion of surgery but because of the contrast of my more recent experience, I felt obligated to update to same-day, same-operating-session completion and point out the improvements offered by capsular bag phacoemulsification through the selfsealing wound. The final revision of this manuscript was accepted by the Journal in September 1992, coincident with the publication of Dr. Arnold's paper in the September issue. Drs. Hans and Thierry Wilbrandt have recently published a paper on transducer-measured intraocular pressure fluctuations during various phacoemulsification strategies, which I did not have the opportunity to cite. 1 I highly recommend it as well as Dr. Arnold's to all ophthalmologists. Dr. Arnold and I seem to differ in one of our recommendations. While neither of us endorses intraoperative vitreous taps or drainage of suprachoroidal blood, I 814

would attempt intraoperative pars plana vitrectomy and drainage of suprachoroidal hemorrhage or effusion in a situation where retinal blood flow appeared to be completely obstructed for more than a few minutes. Hayreh and Weingeist's research was conducted on healthy monkeys, not cataract-age humans who commonly have fragile circulations and aged tissue. Fortunately this disasterous circulatory dynamic remains a hypothetical situation in my experience. James A. Davison, M.D. Marshalltown, Iowa

REFERENCE I. Wilbrandt HR, Wilbrandt TH. Evaluation of intraocular pressure fluctuations with differing phacoemulsification approaches. J Cataract Refract Surg 1993; 19:223-231

General Anesthesia and AISH To the Editor: I read with interest Dr. Davison's article describing two cases of acute intraoperative suprachoroidal hemorrhage (AISH) using modern phacoemulsification techniques. I have handled one case of AISH while performing in-the-bag phacoemulsification. After a short pause for ocular compression and a dilated funduscopic examination, I was able to conclude the case uneventfully. While making the procedure more difficult, this complication did not preclude successful completion of the case. In case number two, Dr. Davison described a patient who had also experienced AISH in her other eye. In light of the fact that this patient suffered the same complication when the other eye was operated on (presumably both were done under local anesthesia), would he now recommend doing the second eye under general anesthesia? The previously reported incidence of AISH in other operative situations is lower in patients who have had surgery using general anesthesia. While the incidence of AISH is so low that the benefit/risk ratio for routine use of general anesthesia is generally not favorable, it might be prudent to use it when a patient has experienced this complication in the first eye. Randy J. Epstein, M.D. Chicago, Illinois

James A. Davison, M.D., replies: I would like to thank Randy Epstein for his letter. He is correct; there is evidence of a lower incidence of expulsive choroidal hemorrhage with the use of general anesthesia during penetrating keratoplasty. Intraocular venous congestion from increased resistance in episcleral venous outflow caused by retrobulbar injection has been suspected as a risk factor for development of expUlsive hemorrhage early in the operation. 1,2 For local

J CATARACT REFRACT SURG-VOL 19, NOVEMBER 1993