STRIPPING OF DESCEMET'S MEMBRANE
`IN CATARACT EXTRACTION*
`
`BY Harold G. Scheie, M.D.
`
`THIS PAPER DESCRIBES three eyes in which Descemet's membrane was
`inadvertently stripped from the cornea during cataract extraction. In
`all eyes the mishap passed unnoticed at the time of surgery and was
`recognized only days or weeks later when a corneal opacity was
`noted that simulated the appearance of epithelial downgrowth.
`Stripping of Descemet's membrane to a lesser degree is not rare.
`Strips of Descemet's membrane, which appear as curly tags of trans-
`parent tissue, can often be seen along the inner aspect of corneal
`incisions or perforations of any type. More extensive separation of
`Descemet's membrane frequently occurs with cyclodialysis. The author
`has seen several patients with permanent localized corneal edema and
`small epithelial blebs overlying areas where Descemet's membrane had
`been stripped by a cyclodialysis spatula during cyclodialysis. The
`edema can progress to painful bullous keratopathy with discomfort
`and loss of vision. Separation of Descemet's membrane from the
`cornea occurs rarely following rupture of Descemet's membrane with
`contusion of the eyeball. It may be seen associated with ruptures of
`Descemet's membrane in infantile glaucoma. Descemet's membrane
`may separate from the cornea at the rupture sites to form a shelf in
`the anterior chamber, and occasionally it may separate completely
`from the cornea between two parallel ruptures forming a ribbon-like
`bridge or reduplication across the anterior chamber. Reduplication of
`Descemet's membrane has been seen during keratoplasty for scarring
`due to severe chemical burns of the cornea. It is possible that corneal
`edema and changes in corneal metabolism allow retraction
`of
`Descemet's membrane from the corneal stroma.
`Extensive stripping of Descemet's membrane with cataract extrac-
`tion has been mentioned in the literature only twice. Weve1 reported
`'From the Department of Ophthalmology, Hospital of the University of Penn-
`sylvania, Philadelphia General Hospital, Veterans Administration Hospital, and
`the Children's Hospital of Philadelphia.
`TR. AM. OPHTH. SOC., vol. 62, 1964
`
`Petitioner - New World Medical
`Ex. 1038, p. 1 of 13
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`Stripping of Descemet's Membrane in Cataract Extraction
`141
`two eyes. Wright2 discussed the complication but reported no eyes
`himself, only referring to the paper of Weve. Since becoming interested
`in the subject, I have learned that several other ophthalmic surgeons
`have encountered the condition. It may be much more common than
`is realized because it closely resembles epithelial downgrowth and
`could be mistaken for it.
`
`CASE REPORTS
`
`CASE ONE
`Mrs. J.P., a 71-year-old patient with bilateral cataracts, was first seen on
`July 7, 1961. Her vision was 6/15 in each eye and she was having great
`difficulty reading. Her eyes otherwise were healthy. The intraocular pressure
`was 17 mm. Hg (Schiotz) in each eye. An intracapsular cataract extraction
`was done, apparently uneventfully, on her left eye on January 4, 1962.
`Using a keratome incision, peripheral iridectomy was done and four
`interrupted sutures placed. One-tenth cc. of 1:10,000 alpha-chymotrypsin
`was injected behind the iris at the six o'clock meridian, and later irrigated
`from the anterior and posterior chambers. The lens was delivered by
`tumbling using the Arruga cross-action forceps. The iris replaced itself
`with the help of pilocarpine. An iris repositor was not used. The sutures
`were tied, the conjunctival flap closed, and the eye covered. Considerable
`striate keratitis was present at the first dressing and a horizontal line of
`opacity was noted, which extended diagonally across the cornea from the
`limbus at 1:30 o'clock to the opposite side at 8:00 o'clock.
`Examination with a slit-lamp revealed Descemet's membrane to have
`been stripped from the cornea over the entire area above this line. The
`upper edge had fallen away from the cornea downward and backward so
`that it was in contact with the iris temporally near the lower pupillary
`border. Considerable postoperative reaction occurred, and her convalescence
`was slow. Atropine and local steroids were used for ten weeks postopera-
`tively before the eye became white and irritation ceased. Her cornea
`became edematous over the area of separation of Descemet's membrane
`where it was at least one-third thicker than the lower half (Figure 1).
`Numerous fine epithelial blebs were also seen over this area. Subsequently,
`the edges of Descemet's membrane became adherent to the iris temporally
`and including the upper and lower pupillary border. Corneal edema has
`slowly increased during the past two years with bleb formation. Pain and
`probable loss of the eye can be predicted.
`
`CASE TWO
`Mrs. H.S., a 55-year-old white woman was seen in consultation on
`November 6, 1961. Her vision was 6/60 in the right eye, and counting
`fingers in the left. She had had an intracapsular cataract extraction on the
`
`Petitioner - New World Medical
`Ex. 1038, p. 2 of 13
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`142
`
`Harold G. Scheie
`
`A
`
`B
`
`FIGURE 1
`A, Photograph (patient 1 ) eight months postoperatively showing stripped edge of
`Descemet's membrane in anterior chamber and attached to iris temporally. Hazy
`edematous portion of cornea sharply outlined at site of attachment of Descemet's
`membrane. B, Drawing of above through slit-lamp microscope.
`
`Petitioner - New World Medical
`Ex. 1038, p. 3 of 13
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`A
`
`B
`
`FIGURE 2
`A, Photograph (patient 2) taken two weeks postoperatively showing edema upper
`half of cornea. B, Photograph taken two years postoperatively showing increasing
`corneal edema and optical iridectomy.
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`Petitioner - New World Medical
`Ex. 1038, p. 4 of 13
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`144
`Harold G. Scheie
`right eye two weeks previously. Alpha-chymotrypsin had been used. The
`referring physician had noticed haze over the upper part of her cornea on
`the twelfth postoperative day and had suspected epithelial downgrowth.
`On examination of her eyes, the right eye was healthy except for an
`incipient senile cataract. The upper half of the cornea was hazy and
`terminated near the center of the cornea on a horizontal, slightly curved
`line, which crossed the limbus at 3:30 o'clock and 9:00 o'clock, and extended
`downward nearly to the lower pupillary border (Figure 2). With the slit-
`lamp microscope the hazy area of the cornea was found to be edematous and
`thickened. Bedewing of the epithelium was present. The inner aspect of the
`cornea showed what appeared to be separation of Descemet's membrane,
`which terminated
`at the horizontal
`the
`line running across
`cornea.
`Descemet's membrane was in contact here and there throughout the area
`that had been stripped, and had not fallen backward into the anterior
`chamber. The appearance somewhat resembled large, but very flat, epithelial
`bullas. It was impossible to tell whether the areas of contact with the cornea
`represented re-attachment, or simply incomplete detachment. She has been
`observed from time to time since. An optical iridectomy at 6:00 o'clock was
`done on September 21, 1962 (Figure 2). Her vision could then be improved
`to 6/20. It has diminished since because of a very slow increase in the
`edema and haze of the upper half of the cornea.
`
`CASE THREE
`Mrs. E.L., a 77-year-old white lady was seen in consultation on July 16,
`1963. She had had a cataract extraction performed on her right eye on
`August 21, 1962. Information given by the referring physician stated
`that the operation had been done under local anesthesia. A Graefe knife
`limbal section had been done with a fornix-based conjunctival flap. The
`wound was closed with 6-0 mild chromic sutures. Three peripheral iridec-
`tomies were performed. The lens was delivered by tumbling using a Kalt
`forceps with traction and counterpressure at the lower limbus. As the
`lens was delivered, the capsule ruptured and tore. The entire capsule was
`removed, using a capsule forceps, before tying the sutures. Alpha-chymo-
`trysin was not employed. Marked striate keratitis was seen immediately
`postoperatively. This cleared somewhat during the next few days, but the
`cornea remained hazy. A horizontal line of opacity was noted across the
`pupillary space. Her visual acuity on October 30, 1962 was 6/15 (20/50).
`Her eye remained irritable. The corneal haze increased and reduced the
`visual acuity to 6/60 by February, 1963. When she was seen in consultation
`by me on July 16, 1963, her visual acuity was counting fingers in the left
`eye, and 6/15 in the right, which was healthy except for an incipient
`nuclear cataract. The cornea of the left eye was diffusely hazy, more so
`over the upper half (Figure 3). A horizontal line could be seen with the
`naked eye running across the cornea from 2:30 o'clock to 9:00 o'clock,
`which simulated an epithelial downgrowth. A slit-lamp examination revealed
`
`Petitioner - New World Medical
`Ex. 1038, p. 5 of 13
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`Stripping of Descemet's Membrane in Cataract Extraction
`
`145
`
`FIGURE 3
`Photograph (patient 3) taken sixteen months postoperatively showing line of
`opacity across pupillary space and corneal haze.
`
`diffuse corneal edema, much more marked over the upper half of the
`cornea. Epithelial blebs were present. Descemet's membrane, stripped from
`the upper half of the cornea, was rolled downward. The horizontal line
`seen on external examination proved to be the line of attached Descemet's
`membrane to the cornea. The intraocular pressure was 15 mm. Hg (Schiotz)
`in each eye. The eye has since shown progressive corneal opacity. In
`February, 1964, she developed a corneal ulcer that was cleared by anti-
`biotic therapy. Her vision remains counting fingers.
`
`DISCUSSION
`Three eyes have been described with extensive separation of
`Descemet's membrane from the comeal stroma during cataract extrac-
`tion. One of the patients had been operated by me and two were seen
`in consultation. The visual result was poor in all of the eyes. No
`difficulty had been recognized during cataract extraction, nor had
`any corneal complication been suspected. The difficulty was noticed in
`the immediate postoperative period in two patients, and on the
`twelfth postoperative day in the third. The appearance of the corneas
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`Petitioner - New World Medical
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`Harold G. Scheie
`146
`of the three eyes simulated epithelial downgrowth. Grossly, the upper
`portion of the cornea was hazy. The cloudy portion of the cornea was
`delineated inferiorly by an opaque line suggestive of epithelial down-
`growth. Slit-lamp examination, however, revealed Descemet's mem-
`brane to have been peeled off in a sheet-like manner in two eyes. In
`the other, it had remained attached or had re-attached to the cornea
`here and there. The picture somewhat suggested large bullae of
`Descemet's membrane. The cornea was edematous and considerably
`thickened over the area from which Descemet's membrane had been
`stripped. Diffuse fine epithelial bullae shortly appeared. The aqueous
`was clear, whereas a flare and floaters are usually seen in the aqueous
`of epithelial downgrowth. The intraocular pressure was normal in all
`eyes.
`Appearance of the corneal opacity during the first few days after
`surgery should help exclude epithelial downgrowth. The differential
`diagnosis must include almost any condition that results in corneal
`edema after cataract extraction. There has been no indication in any
`of the eyes reported that the endothelial defect caused by this
`accident will correct itself. The three eyes reported here, and the
`two by Weve,' described persistent corneal edema and bullous
`keratitis. The edema has increased with time in all of the eyes, and the
`visual acuity has become poorer. Large bleb formation with resulting
`painful eyes can be anticipated. An optical iridectomy was done with
`some improvement in vision in one of the eyes. The suggestion has
`been made that the sheet of loosened membrane should be excised., 2
`This would seem feasible only if it
`is recognized at the time of
`operation.
`The mechanism of stripping of Descemet's membrane is obscure.
`Weve1 speculated that it had been cut by a cystotome allowing the
`edges to retract and roll away from the cornea. It seems more likely
`in the eyes reported herein that stripping might have been caused
`by the sweep of an iris spatula or an irrigator that had been inserted
`beneath Descemet's membrane accidentally. This could explain the
`sharp delineation of the detachment. Conceivably a scissors used to
`enlarge the section could cause the same accident, or even a capsule
`forceps. In two of the three eyes, alpha-chymotrypsin was used to
`soften the zonule. It is possible that the enzyme might have predis-
`posed to the accident by softening the attachment of Descemet's
`membrane to the stroma.
`Hoping to gain some information, the corneas from three donor
`eyes were, therefore, marinated in 1:5000 alpha-chymotrypsin for 15
`
`Petitioner - New World Medical
`Ex. 1038, p. 7 of 13
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`Stripping of Descemet's Alembrane in Cataract Extraction
`147
`minutes. They were placed in fresh solution every two or three
`minutes. This, however, seemed to have no effect upon the ease with
`Nvlhich Descemet's membrane could be separated. It is possible, never-
`theless, that individual corneas might have different susceptibilities
`to alpha-chymotrypsin.
`It would seem thbat, regardless of the possible effect of alpha-
`chymotrypsin, the actual stripping must have been caused by instru-
`mentation. The operator should be aware of this accident and should
`be very careful that the tip of an instrument is in the anterior chamber,
`and not beneath Descemet's membrane, before moving the instrument
`from side to side. Care should be taken to lift the corneal flap, if
`necessary, to permit free introduiction of instruments. No treatment
`is suggested.
`
`SUNINIARY
`1. Three eyes wvith stripping of Descemet's membrane during cata-
`ract extraction are reported.
`9. Stripping of Descemet's membrane is a rare complication, but
`may be more frequent than suspected since it could be mistaken for
`epithelial downgrowth.
`3. The prognosis is poor because of progressive corneal edema.
`4. Great care is urged in inserting instruments into the anterior
`chamber.
`
`REFERENCES
`1. Weve, H., Separation of the memiibrane of Descemet after extraction of the
`lens. Translatedl from the Duitch journal of Medicine, 71 (No. 2-A) :398, 1927.
`2. Wright, R. E., Lectures on catatract, ILL. Anterior-segment and other com-
`plications in the postoperative period, Am. J. Ophth., 20:240-53, 1937.
`
`DISCUSSION
`De. JOHN H. DUNNINGTON. Strippinig is an appropriate term to differentiate
`the gross injuries to Descemet's membrane with their disastrous conse-
`qiuences from lesser detachments which often heal with little or no residua.
`Miinor defects have beein described after various intraocular operations-
`Vlon Sallmanni in 19241 reported the presence of such lesions in eyes operated
`uipon for glaucoma by trephininlg or bv iridencleisis. In 1928 Samuels,2 in
`his thesis for membership inl this Societv. discussed detachment of Desce-
`met's membraine. He studied the pathological material in E. Fuchs' collection
`and reported, "the sections showed numerous separations after cataract
`extractioni referable to the kknife or spatula." From his findings he concluded
`that the operative separation had "nlo effect on the healing of the incisions
`
`Petitioner - New World Medical
`Ex. 1038, p. 8 of 13
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`Harold G. Scheie
`148
`. and often none on the transparency of the cornea." A. Fuchs, in 1936,3
`referred to the frequency of this complication in cyclodialysis and stated,
`"clinically no great harm is done by detachment of Descemet's membrane."
`Wright4 in speaking of the effects of detachment of Descemet's in cataract
`extraction concluded: "(1) It may go back into place with moderate haze
`and definite folds or, (2) It may not attach so well, in which case, the denser
`opacities associated with exposure of the substantia propria to aqueous are
`produced. (3) Even if Descemet's membrane is removed the cornea may
`clear to a remarkable degree. I have not seen the endothelium grow over
`but believe it does. (4) A synechia with detachment is worse than a simple
`detachment since there may be proliferative changes and organization in the
`deep layers of substantia propria."
`In contrast to the relative harmlessness of these minor injuries to Desce-
`met's membrane, Dr. Scheie has shown us the end results in three cases of
`stripping of this membrane. As additional material, I am reporting two cases
`found in the records of the corneal clinic of the Institute of Ophthalmology,
`Presbyterian Hospital.
`
`CASE REPORTS
`
`CASE 1, Mrs. I.S. Aet: 63
`November 28, 1962: Intracapsular extraction with peripheral iridectomy,
`keratome-scissors section. Immediate convalescence uneventful except for
`persistent edema of the upper half of cornea.
`December 14, 1962: Deep folds at center of cornea. Slight edema of
`epithelium at upper margin. Something in anterior chamber in front of nasal
`side of pupil that looks like capsule.
`December 20, 1962: Edema of epithelium more extensive. Deep folds
`present. The capsule-like material is probably touching the cornea.
`January 30, 1963: Area of edema and folds less. Curled up tissue is not
`touching cornea.
`February 13, 1963: Cornea unchanged. Membrane is adherent to vitreous.
`April 22, 1963: No change except for many small bullae above.
`July 10, 1963: Tissue removed through keratome incision.
`October 10, 1963: Cornea uniformly hazy and thickened above.
`October 31, 1963: Rather marked bullous keratopathy. Abnormal or
`absent endothelium noted after clearing cornea with glycerin.
`January 24, 1964: Condition unchanged.
`PATHOLOGICAL REPORT. Specimen consists of a small fragment of tissue
`that has been placed on a slide. The tissue is a thin sheet which has been
`folded on itself. On one surface of the specimen there are endothelial cells
`which appear to be numerous and normal in size. The remainder of the tissue
`is a clear pink-staining structureless material consistent with that found in
`Descemet's membrane.
`DIAGNOSIS: cornea: Descemet's membrane, detachment.
`
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`149
`
`Stripping of Descemet's Membrane in Cataract Extraction
`CASE 2, Mrs. M.S., Aet: 62
`October 22, 1962: Intracapsular extraction with complete iridectomy, left
`eye. Keratome and scissors section. Immediate convalescence uneventful
`except for clouding of upper part of cornea and presence of membrane on
`posterior surface of cornea. Consultation requested because of possibility of
`epithelization. First seen in corneal clinic, December 12, 1962, with cor-
`rected vision 20/60+. Epithelial edema over line delineating separation of
`Descemet's-some epithelial edema below. Vitreous in anterior chamber not
`touching cornea.
`March 9, 1964: Corrected vision 20/20. Cornea clear except for some
`diffuse clouding above.
`Weve5 has suggested early removal of the torn fragment. I doubt the
`advisability of such a procedure as the corneal changes are the result of
`exposure of substantia propria to the aqueous humor. Furthermore, in one of
`the cases herein reported, complete removal of the separated piece did not
`arrest the bullous keratopathy. Since bullous keratopathy from other causes
`is often benefited by the use of the so-called Gundersen conjunctival flap,6
`I suggest that this operation be tried in these cases. If this procedure is done
`before the edema extends to the pupillary area, a partial covering may be
`sufficient.
`Dr. Scheie has enumerated other conditions characterized by corneal
`edema and membrane formation on the posterior surface of the cornea with
`which stripping of Descemet's can be confused. In the first case I reported,
`the surgeon originally considered the tissue to be retained capsule whereas
`in the second epithelization was suspected. In the latter instance careful
`slit-lamp study after clearing the cornea with glycerin revealed the torn
`Descemet's membrane. The relatively clear cornea and good visual acuity
`18 months after the operation in this case makes one wonder how often such
`an accident does occur without subsequent development of bullous kerato-
`pathy. Dr. Scheie's presentation should stimulate all of us not only to strive
`anew to prevent such a mishap, but also to recognize it when it does occur.
`I thank him for the privilege of opening the discussion on his interesting
`presentation.
`
`REFERENCES
`1. Von Sallmann, L., (Ophth. Gesellsch. Wien. Sitzg. 15 Dec. 1924), Ztschr. f.
`Augenh., 55:200-2, 1925.
`2. Samuels, Bernard, Tr. Am. Ophth. Soc., 26:437, 1928.
`3. Fuchs, A., A.M.A. Arch. Ophth., 16:341, 1936.
`4. Wright, R. E., Am. J. Ophth., 20:247, 1937.
`5. Weve, H., translated from the Dutch Journal of Medicine, 71 (No. 2-A):398,
`1927.
`6. Gundersen, Trygve, A.M.A. Arch. Ophth., 64:260, 1960.
`DR. TRYGVE GUNDERSEN. The title of Dr. Scheie's paper is "Stripping of
`Descemet's Membrane in Cataract Extraction." He mentions in his list of
`changes that occur in Descemet's membrane after a number of other
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`Petitioner - New World Medical
`Ex. 1038, p. 10 of 13
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`Harold G. Scheie
`150
`conditions, endophthalmus and other situations, but he failed to mention
`one that we see fairly commonly, and that is the obstetrical forceps injury
`we see in the cornea. I am sorry I did not bring any photographs of this, but
`I think you all know the condition. There are two points about this which
`I think are worth mentioning. First, even though the infant has an obstetrical
`forceps injury and one or several tears in Descemet's membrane, and
`reduplications and falsiform ligaments in the anterior chamber, bullous
`keratopathy does not usually come on until age 30 or thereabouts. This is
`strange. I do not believe you could cause a similar injury in an adult cornea
`-at least I have never seen it. In an injury which I think is comparable to
`"laying on the obstetrical hands," so to speak, it might occur.
`Therein must lie the answer to this problem, and there must be a vast
`difference between Descemet's membrane of the newborn and that of the
`adult.
`DR. FREDERICK W. STOCKER. I believe it is necessary to differentiate between
`two things in the appearance of a cuticular membrane in the anterior
`chamber after a cataract operation. In the first and last cases shown by
`Dr. Scheie I believe it was stripping of Descemet's membrane. However, in
`the middle case, I believe it was not.
`In 1962, in a discussion at the meeting of the Southern Medical Associa-
`I pointed out that we had noticed recently the appearance of a
`tion,
`cuticular membrane in the anterior chamber after cataract extraction,
`usually rolled up like a scroll. I have now seen seven such cases, and recently
`my associates have seen them too. Dr. McPherson has seen two and Dr.
`Kerns, Jr., one.
`Here are our ideas about this: in some cases these membranes may be a
`stripping of Descemet's membrane, but in other cases, this is very improb-
`able. The cornea is perfectly clear and the scroll remains inert. In two cases
`we have found that the membrane was plastered against the cornea. After
`we decided it was not part of the cornea, we removed it, and then the cornea
`cleared completely. So, if the membrane obviously could not be Descemet's
`membrane, what could it be?
`The cataract extractions were all intracapsular. Only one case was done
`without alpha-chymotrypsin; all the others were with alpha-chymotrypsin.
`We think that, since the lens capsule is enveloped by the extension of the
`zonular material, the zonular lamella of the lens capsule, it could be that the
`alpha-chymotrypsin which is used to dissolve the zonule might also have an
`effect on the zonular lamella of the lens capsule, and during the extraction
`of the lens some of it may peel off.
`[Slide] This is the membrane we removed. It was a perfectly clear
`membrane with no cellular elements on it. Then I took an eye-bank eye,
`removed the cornea for keratoplasty, and without touching the lens in any
`way we injected alpha-chymotrypsin. The lens was not handled with any
`instruments. It was immediately fixed and then stained with periodic acid-
`
`Petitioner - New World Medical
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`Stripping of Descemiiet's Alembrane in Cataract Extraction
`151
`Schliff stainl. First, I wanit to slhowt vou a normal lents to demonstrate the lenis
`capsule.
`[Slide] You canl see the lens capstule proper is shown in dark red. Then
`there is an outer laver which is pink, and this is the zonular lamella.
`[Slide] This slide shows how the zonular lamella extends gradually over the
`lens capsule from the upper pole of the lens. [Slide] This shows the posterior
`lens capsule, anid againl wvith this differential stain the dark red is the capsule
`proper, whereas the piink is the zonular lamella.
`[Slide] This showNs a lens that has been treated with alpha-chvmotrypsin,
`and vou can see how this material is peeling off.
`[Slide] This is from the last case Dr. McPherson saw. This membrane
`shows cells on the membrane, therefore it cannot be the zonular lamella. It
`must be either Descemet's membrane or lens capsule proper. It has been
`only about a week since this patient was operated on, so we cannot be sure
`yet whether there is a defect in Descemet's membraine.
`Unless one uses a microscope durinig the operation, one is not aware of
`the development of this membranie. In his case, Dr. McPherson had seen
`that piece of materiial coming off, and he removed it at the time of operation.
`DR. ALGERNON B. REESE. The fact that Schwalbe's ring may be quite large
`is well known. It is possible that anI instrument may be inserted into the
`an-terior chamber posterior
`the
`ring and thus detach Descemet's
`to
`membrane.
`DR. JOHN M. MCLEAN. I have two observations to make on this rather rare
`condition which might add some information to Dr. Scheie's presentation.
`We have seen two eves with this condition after cataract extraction; both
`of them were in the same patient, which perhaps is slight evidence suggest-
`ing support of his idea of predisposition. Both of these eyes were operated
`on by Dr. McGruder, who is now in Florida, when he was a resident at
`New York Hospital, and some of you have seen this patient. She was
`presented before the New York Ophthalmological Society.
`Instead of excising this membrane, he replaced it and, interestingly
`enough, it stayed. He made a tiny opening near the limbus, took a very
`narrow cyclodialysis spatula, unrolled the rolled-up diploma-like membrane,
`forced it back in place, inflated the anterior chamber very strongly up to
`high tension with air, and much to my amazement (he was confident, and
`I was not) the thing has stuck ever since, and the edema has disappeared
`in both eyes of the same patient.
`DR. C. DWIGHT TOwVNES. Bearing out the observation that Dr. Stocker
`menitioned, I have seen two such cases in which a curled-up membrane was
`present in the anterior chamber. Both of these were done about ten years
`ago, without any corneal edema or other disturbance in the cornea and no
`diminution of visioIn. The eves are still good, but in the anterior chamber
`there is a little semi-transparent, curled-up piece of tissue looking like
`
`Petitioner - New World Medical
`Ex. 1038, p. 12 of 13
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`Harold G. Scheie
`152
`cellophane which may be, as Dr. Stocker points out, a remnant of the
`lamella of the lens capsule. Both were intracapsular extractions with no
`complications.
`DR. HAROLD GIFFORD. The zonular lamella can come off without alpha-
`chymotrypsin. The chymotrypsin has nothing to do with this zonular
`stripping. This is a mechanical thing that happens every so often. It is
`entirely different. Dr. Stocker is right: this is the zonular lamella. It is not
`capsule and not Descemet's membrane.
`DR. SCHEIE. I wish to thank the discussers for adding so greatly to my
`presentation. I am delighted that my report of accidental stripping of
`Descemet's elicited so many comments.
`I am sure Dr. Dunnington is correct. This complication is caused by
`maladroit instrumentation. Whether or not a predisposition exists, as sug-
`gested by Dr. McLean, I do not know. As a precaution, the corneal flap
`should be elevated before inserting the instrument in each case. Unfor-
`tunately, at times the flap must be secured as quickly as possible and
`instruments such as an iris spatula inserted as best one can. Ever since my
`first patient, I have been concerned about causing the accident under such
`circumstances.
`Dr. Gundersen mentioned ruptures of Descemet's membrane following
`forceps injury. Indeed I have been aware of them and I have one such
`patient with corneal edema occurring in later years as a late complication.
`However, I have not seen, nor have I been aware of, a separation of
`Descemet's membrane following forceps injury, but it would very possibly
`occur as in buphthalmos.
`Dr. Stocker's suggestion is certainly interesting. However, the eye of the
`second patient that I was fortunate enough to observe in consultation showed
`the same horizontal line, as if a spatula had been swept across the cornea.
`The cornea was considerably thickened above the line.
`Initially, the
`epithelial edema was limited to the area of supposed separation but
`Descemet's membrane had re-attached, at least partially.
`After hearing Dr. McLean's comments about replacing the membrane, I
`am more convinced than ever that this patient did actually have stripping
`which partially re-attached while the membrane was in contact at the time
`the anterior chamber was shallow.
`In closing, I would emphasize the need for prevention rather than attempts
`at cure. One should certainly take great care, as Dr. Dunnington said, to
`insert one's instruments so that they will not catch the cornea ledge, and
`thereby possibly avoid Schwalbe's line.
`
`Petitioner - New World Medical
`Ex. 1038, p. 13 of 13
`New World Medical, Inc. v. MicroSurgical Tech., Inc., IPR2020-01573
`
`