WET-PACK VS. DRY-PACK To the Editor: Through February of 1978, I used only wet-pack lenses manufactured by Medical Workshop, Kurt Morcher or Rayner. Cases of early post-op uveitis were few and most of the time were attributable to surgically induced trauma. Since the February 1978 mandate for use of dry-pack lenses, I have used only dry-pack lenses supplied by Rayner or Medical Workshop. With these lenses I have noticed a markedly increased incidence of early post-op uveitis, even when surgery has been atraumatic. In all cases, these lenses were soaked for ten to fifteen minu tes in. filtered balanced salt solution prior to implantation, and the implant surgery was performed with constant irrigation. I have had several patients who received a wet-pack lens implant in one eye followed by a dry-pack lens in the other eye many months or years later. The marked difference between the response of the eye which received the wet-pack lens and that which received the dry-pack lens soaked in balanced salt solution leads me to believe that some factors, known or unknown, create a greater inflammatory response in eyes which have been implanted with dry-pack lenses from the same manufacturer. If other physicians have reporteq. similar resul ts, I think it would be prudent to call for a very careful investigation of the sterilization method currently mandated by the FDA. Among the questions needing to be answered are: Do all manufacturers use the same ethylene oxide gas manufactured by the same company? What is the quality control of the manufacturing and distribution of ethylene oxide? Do some plastics respond to ethylene oxide differently than others? Do some lenses need to be aired longer than others? Is soaking the lens in balanced salt solution sufficient, or should other soaking material be used? What is the effect of ethylene oxide on ocular tissue? Of course, if soaking the dry-pack lens in salt solution is essential to reduce postoperative reaction, then the greatest argument for eliminating wet-pack lenses, namely the problem of neutralizing solution as a potential source of infection, is reintroduced. This fact with all its implications should be carefully kept in mind. John J. Alpar, M.D. Amarillo, TX
Dr. Hoffer replies: This clinical problem has been reported by many experienced AIOIS members. An investigative 40
task force was formed following a joint meeting of AIOIS's Executive Committee and the Intraocular Lens Manufacturers Association. Mr. Robert Hubbell (President, ILMA) is chairman of the committee which is now considering research contracts with private labs for investigation of this annoying problem. Kenneth J. Hoffer, M.D. Managing Editor Secretary, AIOIS
To the Editor: Care must be used in deciding whether a wetpack or a dry-pack lens causes more anterior chamber reaction and pigmentary dispersion because, in many cases, the switch from a wet-pack to a dry-pack lens also accompanies a switch to a slightly different intraocular lens style. I used mainly Medical Workshop's platinum clip 2-100p lenses in late 1975 and in 1976. In 1977 I switched to CILCO's Prolene (polypropylene) clip 2-100p lens and IOLAB's Prolene clip 2-100p lens. I felt that there was increased pigmentary dispersion with these lenses which I first attributed to the dry packaging technique. Since 1978 I have been using a number of 5.5-mm platinum clip 2-100p lenses from Intermedics and pigmentary dispersion has been minimal. I now feel that the dry packaging of an intraocular lens does not increase anterior chamber reaction or pigmentary dispersion. Instead I think that the spring effect of the Prolene clip causes the iris to be pinched between the posterior loop and the Prolene clip. Subsequent mechanical rubbing of the pigment epithelium causes the increased pigmentary dispersion. The platinum clip 2-100p lens, either wet or dry packed, causes no pressure against the iris and consequently no significant pigmentary dispersion. H.T. Youens, Jr., M.D. Columbus, TX
INFORMED CONSENT To the Editor: I have some inqumes regarding the final revision of the Minimum Standard Informed Consent, dated September 7, 1977. There are ophthalmologists (approved investigators) implanting lenses without having this consent form signed. These physicians feel that they are losing cases when the patients are required to read and sign the consent form. (After reading page three, this is easily understandable.)
AM INTRA-OCULAR IMPLANT SOC J-VOL. V, JANUARY 1979
Prior to this informed consent it was my experience that patients seemed very comfortable signing the routine hospital consent form for ocular surgery. Therefore I would like to know just how mandatory is it for patients to sign this informed consent? Is there any violation of a Federal rule by not having this signed? Briefly stated, does an investigator have to use this consent form, or is it up to his own discretion? Warren F. Smith, M.D . Oak Park, IL
Dr. Hoffer replies: Regarding informed consent for intraocular lens implant patients: 1) It is against the law not to have the Minimum Standard Informed Consent signed prior to surgery. 2) Not having this consent signed violates the provisions of your Hospital Institutional Review Committee approval. 3) Lack of signed consent jeopardizes your status as an investigator and leaves you open to being disqualified as an investigator, with this fact being communicated to Medicare, your local university and your state licensing board. 4) The signed Informed Consent (HEW consent form) is the greatest protection and defense for malpractice that a surgeon has. All lens implant surgeons that I know comply with the law and have this consent form signed. 5) No other consent form can substitute for the HEW form. Kenneth J. Hoffer, M.D. Managing Editor
IOL TERMINOLOGY To the Editor: I am concerned with the widespread imprecise use of our language and terminology. Cataract surgery and intraocular lens implantation are in a state of rapid technological evolution. That, I am sure, is the major disruptive influence in our communication. We are constantly bombarded with misused terminology such as "iridocapsular," "posterior chamber," " fixation" or "Medallion," and are now blessed with a new and unnecessary anatomical term, "ciliary sulcus." It would seem appropriate for AIOIS] to take the initiative in maintaining clear definition and consistent usage of terminology.
The term "posterior chamber" is clearly defined and used for that space posterior to the iris, anterior to the lens and peripherally limited by the ciliary body. I propose that intraocular lenses be identified by three major factors: (1) mechanism of support (capsule, posterior chamber, iris, anterior chamber angle); (2) location of the optics (postpupillary, iris plane, prepupillary); and (3) lens designer's name and/or lens configuration (Binkhorst 2-loop, Binkhorst-Federov 4-loop, Choyce Mark VIII, etc.). In addition, for statistical purposes, we must very clearly identify the type of surgical procedure used as intracapsular or as extracapsular with or without ultrasonic fragmentation and with either an intact or an open posterior capsule. David
J.
Mcintyre, M.D.
Bellevue, W A
POLYPROPYLENE To the Editor: I was quite interested in the Newsletter's comments on Prolene (polypropylene) as a substance for intraocular lens (lOL) loop designs (AIOIS Newsletter, No.1, July 1978). I have been somewhat concerned about Prolene since my first lens removal approximately six months ago. This IOLAB lens with Prolene loops was removed because of chronic secondary foreign body reaction in the anterior chamber. Recently I removed my second IOL. This was also an IOLAB lens with Prolene loops, and again was associated with anterior chamber reaction. Prolene-Iooped IOLs constitute approximately 10% of the 200 lenses I have implanted but 100% of those I have removed. The indication for removal of both of those IOLs was a chronic anterior chamber reaction with secondary corneal changes. I have since abandoned Prolene-looped IOLs. William Z. Bridges, M.D. Thomasville, GA
IOL DESIGN To the Editor: Because of the recent FDA ruling I sent my iris clip and iridocapsular lenses manufactured by Morcher back to Germany, despite the fact that I never had any trouble with them (including the metal loop iridocapsular model which worked
AM INTRA-OCULAR IMPLANT SOC J-VOL. V, JANUARY 1979
41
Dr. Hoffer replies: This clinical problem has been reported by many experienced AIOIS members. An investigative 40
task force was formed following a joint meeting of AIOIS's Executive Committee and the Intraocular Lens Manufacturers Association. Mr. Robert Hubbell (President, ILMA) is chairman of the committee which is now considering research contracts with private labs for investigation of this annoying problem. Kenneth J. Hoffer, M.D. Managing Editor Secretary, AIOIS
To the Editor: Care must be used in deciding whether a wetpack or a dry-pack lens causes more anterior chamber reaction and pigmentary dispersion because, in many cases, the switch from a wet-pack to a dry-pack lens also accompanies a switch to a slightly different intraocular lens style. I used mainly Medical Workshop's platinum clip 2-100p lenses in late 1975 and in 1976. In 1977 I switched to CILCO's Prolene (polypropylene) clip 2-100p lens and IOLAB's Prolene clip 2-100p lens. I felt that there was increased pigmentary dispersion with these lenses which I first attributed to the dry packaging technique. Since 1978 I have been using a number of 5.5-mm platinum clip 2-100p lenses from Intermedics and pigmentary dispersion has been minimal. I now feel that the dry packaging of an intraocular lens does not increase anterior chamber reaction or pigmentary dispersion. Instead I think that the spring effect of the Prolene clip causes the iris to be pinched between the posterior loop and the Prolene clip. Subsequent mechanical rubbing of the pigment epithelium causes the increased pigmentary dispersion. The platinum clip 2-100p lens, either wet or dry packed, causes no pressure against the iris and consequently no significant pigmentary dispersion. H.T. Youens, Jr., M.D. Columbus, TX
INFORMED CONSENT To the Editor: I have some inqumes regarding the final revision of the Minimum Standard Informed Consent, dated September 7, 1977. There are ophthalmologists (approved investigators) implanting lenses without having this consent form signed. These physicians feel that they are losing cases when the patients are required to read and sign the consent form. (After reading page three, this is easily understandable.)
AM INTRA-OCULAR IMPLANT SOC J-VOL. V, JANUARY 1979
Prior to this informed consent it was my experience that patients seemed very comfortable signing the routine hospital consent form for ocular surgery. Therefore I would like to know just how mandatory is it for patients to sign this informed consent? Is there any violation of a Federal rule by not having this signed? Briefly stated, does an investigator have to use this consent form, or is it up to his own discretion? Warren F. Smith, M.D . Oak Park, IL
Dr. Hoffer replies: Regarding informed consent for intraocular lens implant patients: 1) It is against the law not to have the Minimum Standard Informed Consent signed prior to surgery. 2) Not having this consent signed violates the provisions of your Hospital Institutional Review Committee approval. 3) Lack of signed consent jeopardizes your status as an investigator and leaves you open to being disqualified as an investigator, with this fact being communicated to Medicare, your local university and your state licensing board. 4) The signed Informed Consent (HEW consent form) is the greatest protection and defense for malpractice that a surgeon has. All lens implant surgeons that I know comply with the law and have this consent form signed. 5) No other consent form can substitute for the HEW form. Kenneth J. Hoffer, M.D. Managing Editor
IOL TERMINOLOGY To the Editor: I am concerned with the widespread imprecise use of our language and terminology. Cataract surgery and intraocular lens implantation are in a state of rapid technological evolution. That, I am sure, is the major disruptive influence in our communication. We are constantly bombarded with misused terminology such as "iridocapsular," "posterior chamber," " fixation" or "Medallion," and are now blessed with a new and unnecessary anatomical term, "ciliary sulcus." It would seem appropriate for AIOIS] to take the initiative in maintaining clear definition and consistent usage of terminology.
The term "posterior chamber" is clearly defined and used for that space posterior to the iris, anterior to the lens and peripherally limited by the ciliary body. I propose that intraocular lenses be identified by three major factors: (1) mechanism of support (capsule, posterior chamber, iris, anterior chamber angle); (2) location of the optics (postpupillary, iris plane, prepupillary); and (3) lens designer's name and/or lens configuration (Binkhorst 2-loop, Binkhorst-Federov 4-loop, Choyce Mark VIII, etc.). In addition, for statistical purposes, we must very clearly identify the type of surgical procedure used as intracapsular or as extracapsular with or without ultrasonic fragmentation and with either an intact or an open posterior capsule. David
J.
Mcintyre, M.D.
Bellevue, W A
POLYPROPYLENE To the Editor: I was quite interested in the Newsletter's comments on Prolene (polypropylene) as a substance for intraocular lens (lOL) loop designs (AIOIS Newsletter, No.1, July 1978). I have been somewhat concerned about Prolene since my first lens removal approximately six months ago. This IOLAB lens with Prolene loops was removed because of chronic secondary foreign body reaction in the anterior chamber. Recently I removed my second IOL. This was also an IOLAB lens with Prolene loops, and again was associated with anterior chamber reaction. Prolene-Iooped IOLs constitute approximately 10% of the 200 lenses I have implanted but 100% of those I have removed. The indication for removal of both of those IOLs was a chronic anterior chamber reaction with secondary corneal changes. I have since abandoned Prolene-looped IOLs. William Z. Bridges, M.D. Thomasville, GA
IOL DESIGN To the Editor: Because of the recent FDA ruling I sent my iris clip and iridocapsular lenses manufactured by Morcher back to Germany, despite the fact that I never had any trouble with them (including the metal loop iridocapsular model which worked
AM INTRA-OCULAR IMPLANT SOC J-VOL. V, JANUARY 1979
41
