- Email: [email protected]
AIOIS Fellowship
To the Editor: In answer to Dr. Shapiro's question concerning anticoagulants and implantation of intraocular lenses, we have had some experience in that area. We routinely do not stop warfarin sodium (Coumadin) before our cataract surgery, and since February of 1977 have done ten intracapsular cataract extractions coupled with medallion-style intraocular lens implantation in patients on warfarin. We have experienced no greater than the usual amount of operative bleeding, and one patient had a small hyphema which readily cleared. Donald L. Hall, M.D. Shreveport, LA
To the Editor: To respond to the question on inserting intraocular lenses in patients that are on anticoagulation therapy, we have inserted lenses in 68 patients. The same procedure was performed in each case. Anticoagulation therapy was stopped at least five days prior to surgery. The prothrombin time was checked prior to surgery. All patients received either iris plane or iris clip lenses; none had anterior chamber lenses. Anticoagulation therapy was usually resumed one week after surgery. The maximum follow-up period has been nine years. We have seen no post-op complications related to anticoagulation therapy in these cases. Stephen M. Kulvin, M.D. Miami Beach, FL
IRIS EROSION AND EDGE FINISHING To the Editor: After reading articles on iris erosion resulting from contact with uneven lens edges, I wonder whether there is an objective way to gauge the quality of edge finish for artificial lenses. Although I have never seen this with my own iris suture Medallion (Medical Workshop) lenses, these lenses are lightly supported by the iris and are not forced against the mobile surface of the iris. However, I am concerned about those lens designs which require more iris surface contact than the standard Medallion lens. I would like to see the edges of lenses which have been removed following development of Ellingson's uveitis-glaucoma-hyphema syndrome. I am writing to ask if anyone could show me a Choyce-style lens which has been removed for this
reason so that I could compare its obviously unphysiological edge finish with the edge finish of other lenses and thereby determine whether some standard of edge finish could be set. I recently saw a patient who had a Ridley anterior chamber lens (Rayner) implanted 20 years ago. Although one edge of this lens is constantly rubbing against the iris, there is not the slightest sign of atrophy. The implication is that prolonged chafing of the iris surface with a lens edge will not lead to iris atrophy if the edge of the lens has been properly polished. Edge finishing of intraocular lenses demands a degree of skill and care which is not compatible with assembly line manufacturing procedures. It is imperative to the best interests of our patients that we find an objective means of gauging the quality of edge finishing. Jan G.F. Worst, M.D. Haren, Holland
AIOIS FELLOWSHIP To the Editor: The Binkhorst Medal Lecture delivered at the joint meeting of the AIOIS and Academy was a milestone in American intraocular implant history. It marked the first time the theme of this prestigious lecture emphasized basic research. This departure from previous lectures reflects our increasing curiosity about the basic mechanisms in implantation. The work presented on the endothelium represents the culmination of 16 months of laboratory-oriented animal experimentation. A prodigious effort was required to accumulate the data and it is significant that the work was, in large measure, produced by the AIOIS fellow, Dr. Edward Fetherolf. It was distressing to learn, therefore, that the Scientific Advisory Board of the AIOIS recently decided to withhold future funding of this fellowship. The pioneers in this field established a rationale for implantation. Almost three decades of clinical experience and observation nurtured lens implantation from a mere notion to an accepted surgical procedure. At this moment in our development we are seeking answers to some of those questions posed by clinicians. This is a logical step in the sequence for attaining new information. Since 1974 AIOIS has served as the voice of implant surgeons in this country. Its publication, AIOIS], is designed to present new developments with the needs of the surgeon in mind. But this is not sufficient. This Society must expand its influence and
AM INTRA-OCULAR IMPLANT SOC J-VOL. V, JANUARY 1979
37
be the forum for clinical and scientific advances in implantation. Implicit in this plea is the need for scientific and clinical investigation. If we do not support our own research, why should an outside agency which does not share our interest support it? We are at a crossroads. We can be complacent and ' permit events to evolve haphazardly. Should this occur we are dependent upon extramural, uncontrollable sources. Alternatively, we can strive to make AIOIS function fully in all aspects of implantation. An implant fellowship is an important component in this formulation and must be continued. The financial considerations are small in comparison to the rewards. We cannot afford to be passive observers. We must seize rhe initiative and use the resources available to us. A rational assessmentof alternatives should direct us to one conclusion: long-term viability of this Society mandates our participation in the full scope of implantation. Stephen A. Obstbaum, M.D . New York, NY
AIR TRAVEL &: IOLs To the Editor: I would like to know how soon after cataract extraction and lehs implantation it is reasonably prudent for 'a patient to take an airplane trip in a commerical, pressurized airliner and whether the type of lens implanted makes a significant difference 'in this determination. Also, does this time differ for 'cataract extraction without lens implantation? Apart from the obvious trauma due to a collision or accident, what kinds of post-op complications occur from an airline ' flight-is flying altitude a factor? John J. McGroarty, M.D. North Hollywood, CA
Editor's Note: Readers?
SOLAR RETINITIS; IOL POWER To the Editor: Two mattets drew my attention upon reading the July issue of AIOIS]. The first concerns Dr. Mainster's cogent article on solar retinitis, wherein he establishes the argument that the pseudophake may be subjected to twice the · retinal ultraviolet exposure experienced by a normal person with an intatt crystalline lens (Am Intra-Ocular Implant 38
Soc] 4:84-86, 1978). I have no criticism of this argument, but I wonder at its significance. The steadystate retinal light level is not regulated by the iris; the iris only functions to regulate abrupt changes in ambient illumination. Human vision adapts to a range of illumination far beyond the range that can be controlled by the iris. My point is that the twofold increase in retinal UV exposure seems insignificant in the face of the thousandfold range of exposure experienced in daily life. I should think that an admonition for the pseudophake to avoid strong sunlight would be an adequate prophylactic against exceeding the maximum UV exposure normally tolerated by the eye. Being a native of the overcast Puget Sound area, I find myself dazzled by light levels considered commonplace in places like Southern California-a matter involving at least a twofold difference in average illumination. Would it not be more significant to consider what geographic region the pseudophake resides in, rather than whether he is or is not a pseudophake per se? The second matter concerns Dr. McClelland's technique of lens power examination (Am IntraOcular Implant Soc] 4:130-131,1978). On the whole, his technique is reasonable for the purposes for which it is intended. I would like to point out, however, that this method is not optically exacting (one would actually be assessing a refractive combination that is not obtained within the eye). Doubtless it will demonstrate that good lenses are good lenses and bad lenses are bad lenses. The problem of defining a reasonable minimum of "goodness" remains to be solved . . . and I am reluctant to believe this will be easy.
M.J. Dunn, M.Sc., M.A.A. Federal Way, WA
Dr. Mainster replies: While Mr. Dunn's confusion of glare with maculopathy and of "steady-state retinal light level" with localized solar retinal irradiance are both merely puzzling, it must be emphasized that it is retinal temperature increase from solar observation in the pseudophakic eye that is twice as great as that in the normal eye, not "retinal ultraviolet exposure" as Mr. Dunn has stated erroneously. Ultraviolet retinal irradiance in the pseudophakic eye is many times greater than that in a normal eye whose retina is protected by a crystalline lens (indeed, in the 355 to 381-nm band the ratio is 88:1), and thus the pseudophakic retina is particularly susceptible to photic maculopathy whose action spectrum increases in the near-ultraviolet. The twofold
AM INTRA-OCULAR IMPLANT SOC J-VOL. V, JANUARY 1979
To the Editor: To respond to the question on inserting intraocular lenses in patients that are on anticoagulation therapy, we have inserted lenses in 68 patients. The same procedure was performed in each case. Anticoagulation therapy was stopped at least five days prior to surgery. The prothrombin time was checked prior to surgery. All patients received either iris plane or iris clip lenses; none had anterior chamber lenses. Anticoagulation therapy was usually resumed one week after surgery. The maximum follow-up period has been nine years. We have seen no post-op complications related to anticoagulation therapy in these cases. Stephen M. Kulvin, M.D. Miami Beach, FL
IRIS EROSION AND EDGE FINISHING To the Editor: After reading articles on iris erosion resulting from contact with uneven lens edges, I wonder whether there is an objective way to gauge the quality of edge finish for artificial lenses. Although I have never seen this with my own iris suture Medallion (Medical Workshop) lenses, these lenses are lightly supported by the iris and are not forced against the mobile surface of the iris. However, I am concerned about those lens designs which require more iris surface contact than the standard Medallion lens. I would like to see the edges of lenses which have been removed following development of Ellingson's uveitis-glaucoma-hyphema syndrome. I am writing to ask if anyone could show me a Choyce-style lens which has been removed for this
reason so that I could compare its obviously unphysiological edge finish with the edge finish of other lenses and thereby determine whether some standard of edge finish could be set. I recently saw a patient who had a Ridley anterior chamber lens (Rayner) implanted 20 years ago. Although one edge of this lens is constantly rubbing against the iris, there is not the slightest sign of atrophy. The implication is that prolonged chafing of the iris surface with a lens edge will not lead to iris atrophy if the edge of the lens has been properly polished. Edge finishing of intraocular lenses demands a degree of skill and care which is not compatible with assembly line manufacturing procedures. It is imperative to the best interests of our patients that we find an objective means of gauging the quality of edge finishing. Jan G.F. Worst, M.D. Haren, Holland
AIOIS FELLOWSHIP To the Editor: The Binkhorst Medal Lecture delivered at the joint meeting of the AIOIS and Academy was a milestone in American intraocular implant history. It marked the first time the theme of this prestigious lecture emphasized basic research. This departure from previous lectures reflects our increasing curiosity about the basic mechanisms in implantation. The work presented on the endothelium represents the culmination of 16 months of laboratory-oriented animal experimentation. A prodigious effort was required to accumulate the data and it is significant that the work was, in large measure, produced by the AIOIS fellow, Dr. Edward Fetherolf. It was distressing to learn, therefore, that the Scientific Advisory Board of the AIOIS recently decided to withhold future funding of this fellowship. The pioneers in this field established a rationale for implantation. Almost three decades of clinical experience and observation nurtured lens implantation from a mere notion to an accepted surgical procedure. At this moment in our development we are seeking answers to some of those questions posed by clinicians. This is a logical step in the sequence for attaining new information. Since 1974 AIOIS has served as the voice of implant surgeons in this country. Its publication, AIOIS], is designed to present new developments with the needs of the surgeon in mind. But this is not sufficient. This Society must expand its influence and
AM INTRA-OCULAR IMPLANT SOC J-VOL. V, JANUARY 1979
37
be the forum for clinical and scientific advances in implantation. Implicit in this plea is the need for scientific and clinical investigation. If we do not support our own research, why should an outside agency which does not share our interest support it? We are at a crossroads. We can be complacent and ' permit events to evolve haphazardly. Should this occur we are dependent upon extramural, uncontrollable sources. Alternatively, we can strive to make AIOIS function fully in all aspects of implantation. An implant fellowship is an important component in this formulation and must be continued. The financial considerations are small in comparison to the rewards. We cannot afford to be passive observers. We must seize rhe initiative and use the resources available to us. A rational assessmentof alternatives should direct us to one conclusion: long-term viability of this Society mandates our participation in the full scope of implantation. Stephen A. Obstbaum, M.D . New York, NY
AIR TRAVEL &: IOLs To the Editor: I would like to know how soon after cataract extraction and lehs implantation it is reasonably prudent for 'a patient to take an airplane trip in a commerical, pressurized airliner and whether the type of lens implanted makes a significant difference 'in this determination. Also, does this time differ for 'cataract extraction without lens implantation? Apart from the obvious trauma due to a collision or accident, what kinds of post-op complications occur from an airline ' flight-is flying altitude a factor? John J. McGroarty, M.D. North Hollywood, CA
Editor's Note: Readers?
SOLAR RETINITIS; IOL POWER To the Editor: Two mattets drew my attention upon reading the July issue of AIOIS]. The first concerns Dr. Mainster's cogent article on solar retinitis, wherein he establishes the argument that the pseudophake may be subjected to twice the · retinal ultraviolet exposure experienced by a normal person with an intatt crystalline lens (Am Intra-Ocular Implant 38
Soc] 4:84-86, 1978). I have no criticism of this argument, but I wonder at its significance. The steadystate retinal light level is not regulated by the iris; the iris only functions to regulate abrupt changes in ambient illumination. Human vision adapts to a range of illumination far beyond the range that can be controlled by the iris. My point is that the twofold increase in retinal UV exposure seems insignificant in the face of the thousandfold range of exposure experienced in daily life. I should think that an admonition for the pseudophake to avoid strong sunlight would be an adequate prophylactic against exceeding the maximum UV exposure normally tolerated by the eye. Being a native of the overcast Puget Sound area, I find myself dazzled by light levels considered commonplace in places like Southern California-a matter involving at least a twofold difference in average illumination. Would it not be more significant to consider what geographic region the pseudophake resides in, rather than whether he is or is not a pseudophake per se? The second matter concerns Dr. McClelland's technique of lens power examination (Am IntraOcular Implant Soc] 4:130-131,1978). On the whole, his technique is reasonable for the purposes for which it is intended. I would like to point out, however, that this method is not optically exacting (one would actually be assessing a refractive combination that is not obtained within the eye). Doubtless it will demonstrate that good lenses are good lenses and bad lenses are bad lenses. The problem of defining a reasonable minimum of "goodness" remains to be solved . . . and I am reluctant to believe this will be easy.
M.J. Dunn, M.Sc., M.A.A. Federal Way, WA
Dr. Mainster replies: While Mr. Dunn's confusion of glare with maculopathy and of "steady-state retinal light level" with localized solar retinal irradiance are both merely puzzling, it must be emphasized that it is retinal temperature increase from solar observation in the pseudophakic eye that is twice as great as that in the normal eye, not "retinal ultraviolet exposure" as Mr. Dunn has stated erroneously. Ultraviolet retinal irradiance in the pseudophakic eye is many times greater than that in a normal eye whose retina is protected by a crystalline lens (indeed, in the 355 to 381-nm band the ratio is 88:1), and thus the pseudophakic retina is particularly susceptible to photic maculopathy whose action spectrum increases in the near-ultraviolet. The twofold
AM INTRA-OCULAR IMPLANT SOC J-VOL. V, JANUARY 1979