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Experience with the russian made fyodorov intraocular lens
experience with the russian made fyodorov intraocular lens Marvin L. Kwitko M.D. Montreal Canada The Binkhorst lens l provided the most reliable lens implant for me when I began performing this operation in 1966. 2 In those days two loop lenses were unavailable, at least in Canada. When such a lens was required the anterior loops were amputated. Fig. 1 illustrates my first implant. Since pupil
portion of the anterior loop came dangerously close to the posterior cornea at the limbus. In two instances corneal edema developed in this area and the offending loops had to be amputated. For this reason a modification of the Binkhorst lens was produced. (Fig. 3). Ten of these lenses were used
"
"OOIA
.'0
. 'J i
x AU. DlJot(NSlONS IN Io411.. l.IMETE"S
SECTION ON XX
Fig. 1 (Kwitko, M.L.) Two Loop Binkhorst intraocular lens, extracapsular cataract extraction , sector iridectomy.
block was feared a sector iridectomy was performed with extracapsular extraction. 3 Because of the problems associated with the extracapsular technique, I later turned to the four loop lens with intracapsular technique. (Fig. 2). Unfortunately the terminal
Fig. 3 A,B (Kwitko, M.L.) Binkhorst-Kwitko intraocular lens.
with uniformly good results. 4 The Fyodorov Type 2 lens,s was made available in 1974 which provided all of the advantages of the Binkhorst lens but with the absence of the potentially dangerous anterior loops, (Fig. 4).
Fig. 2 (Kwitko, M.L.) Binkhorst four loop intraocular lens.
32
Complications I have now implanted 100 Russian manufactured Fyodorov lenses. The following complications have been observed. 1. Dislocation. One lens was observed to have two struts dislocated behind the iris on the first post-operative day. The patient was taken to the operation room within the next two hours. By this time all three struts were behind the iris so that the lens rested on the vitreous face in the optical axis. Using a narrow spatula the three struts were repositioned. The patient now enjoys 20125 vision with no other complications. Miotics have not been used. This
E
Loops and Antenna
7.5
1
5 .0
1
7.5
RAD 2
I
I 1
RAD 1
Fig. 4 A,B (Kwitko, M.L.) Fyodorov intraocular lens.
good result was possible because the vitreous face was intact and the lens used was so light. A second case had dislocated one loop in front of the iris. This has not been repositioned and the lens remains centered in the optical axis fixated by the remaining two loops and three struts. A third case had one strut dislocated behind the iris. This was repositioned with dilatation. 2. Retrolental membrane formation. In the early cases when the pupil was not dilated postoperatively with a weak mydriatic (e.g. 0.5% tropicamide)excessive pigment deposition was observed with associated reduction of visual acuity. One case required surgical disruption of the resulting membrane. Since the beginning of 1976, the pupil has been minimally dilated daily beginning on the second post operative day. There has been a marked reduction in this complication. Using this technique no membrane has occurred dense enough to affect the final visual result. This is now the standard post operative treatment. 3. Corneal Edema. There has been only one case of .corneal edema using this lens, when pilocarpine 2% was dropped directly onto the exposed iris. Edema involving the superior one third of the cornea resulted but this was probably due to the toxic effect of the pilocarpine or its preservative. In all other cases only
balanced salt and Miochol solutions have been used to irrigate the anterior chamber. 4. Secondary Glaucoma. Alpha chymotrypsin is not used when a lens implant is installed in order to avoid the elevated intraocular pressure frequently associated with this drug. Two cases in which extracapsular cataract surgery was performed with the Fyodorov lens, developed transient elevated pressures. Both were controlled with acetazolamide. A third case developed pupil block glaucoma two days following the cataract extraction. Further surgery was required : another iridectomy was performed through the original limbal incision. Fluid vitreous was aspirated through the new iridectomy site and the condition was cured. 5. Flat Chamber. Two cases developed fl at chambers, one case four weeks following surgery and one case on the first post-operative day. In both instances the end knobs of the three struts came up against the corneal endothelium. Since the struts come out of the lens body in an almost parallel fashion, the struts kept the lens body itself away from the cornea so that touch occurred at only three places with the lens body separated from the endothelium by aqueous humor. In the first case it was felt that the chamber had been flat for at least several days with the lens body straddling but separated from the cornea by the struts. The eye was treated with dilatation (0.5% tropicamide) and pressure patching for four days. There was no improvement. The wound was inspected in the operating room and four leaks were discovered. The entire cataract wound was resutured with a running 10-0 nylon suture after the chamber was deepened with balanced salt solution. The remaining course was uneventful. Because of this experience, the second case was treated with daily dilatation (0.5% tropicanide) and pressure patching. The chamber deepened on the third day and the remaining course was uneventful. In each case the cornea was not affected except for three dots which were observed by slit lamp examination where the knobs of the struts touched the endothelium. The first case now has 20/25 vision and the second 20/30. Because of the design of other lenses ,the lens body would come into contact with the corneal endothelium should the chamber flatten and surgery would be required as quickly as possible. Surgical Technique The patient is administered a local, general or "local with general standby" anesthesia. The cataractous eye is prepped and drapped in the usual manner for intraocular surgery. The pupil is not dilated preoperatively. A limbal section is made in the surgeon's usual manner for intra capsular cataract extraction preferably with a 160-170° section to give 33
adequate exposure. Absorable sutres should not be used. Silk (8-0 or 9-0) or monofilament nylon (9-0 or 10-0) are preferred since adequate wound closure must be maintained for at least eight weeks. Absorbable sutures cannot be relied upon to last that long. The sterile lens is inspected with the microscope prior to surgery, to insure that the lens is perfect in all details i.e. the loops are sufficiently separated from the lens body to allow adequate space for the iris and the struts are well fixed. The dioptric power of the intraocular lens to be used is determined by the simple graph method suggested by Shepard 6 or the more precise A-scan ultrasonographic method as modified by Hoffer' or Binkhorst.8 If there is any doubt as to the required dioptric power for a given patient, a +18.00 diopter lens may be used for approximating emmetropia. A + 19.50 diopter lens may be used to produce a myopic eye, approximately -1.50 diopters postoperatively. The cataract is extracted. The iris should be floated up off the vitreous face with balanced salt solution if the eye is very soft and the iris diaphram bows backward. Care must be taken in this case not to trap air in the posterior cavity. If the chamber flattens after removal of the cataract, air should be injected into the anterior chamber. If the air is not retained and there is evidence of positive vitreous pressure, the implantation should be aborted and the case carried on as a routine cataract operation. In any event an intraocular lens should only be implanted if it can be separated from the corneal endothelium with air at all times during the operation. If vitreous is lost as the cataract is removed the implantation of an intraocular lens should not be done. The standard treatment for handling this complication should be employed. The iridectomy should not be done before implanting the lens since a loop may enter the iridectomy and disinsert the iris root. In addition an intact iris plane protects to some degree against vitreous loss that can occur during lens insertion. The lens is grasped with the direct lens implantation hplder made by Katena 9 with one posterior loop positioned at 6 o'clock. The lens is inserted downward (meaning from forehead to chin) placing the inferior lens loop posterior to iris at 6 0' clock and making sure that the two inferior oblique struts at 4: 30 and 7: 30 are anterior to the iris. The lens is moved sideways to the surgeons left to drop the right superior loop beneath the iris and the lens is moved to the right to position the left superior lens loop. On occasion it may be necessary to lift the iris over the superior loop with a wide mouthed blunt hook made by Katena 10 or an iris forceps. At this time careful observation must be made with the microscope to insure that the struts are anterior and the loops are all posterior to the iris. If not they must be positioned 34
using a narrow spatula with or without a blunt hook. This technique is referred to as the open eye technique. The author's preferred technique is the closed eye system as follows. After the intraocular lens is inserted with the inferior lens loop posterior to iris at 6 o'clock, the globe is closed and the safety sutures tied. Additional air may now be injected to further deepen the anterior chamber to insure adequate separation between lens and cornea during the following manipulations. A fine iris spatula is inserted via the limbal wound at 11 o'clock. The blade is kept parallel to the iris plane and the spatula blade is used to push the left-hand superior posterior loop downward obliquely 1: 30 toward 7: 30 by pushing against the posts of the posterior lens loop. Just as the tip of the posterior loop clears the iris margin, slight posterior pressure is applied to the spatula such that the loop drops posterior to iris. The spatula direction is then reversed and is brought out toward 11 :00. The spatula is now inserted at 1 o'clock with its blade parallel again to the plane of the iris. The spatula blade is inserted between the posterior loop (which is still anterior to the iris) and the optical portion of the lens pushing against the two posterior pegs (where the loop comes off the back side of the lens). Pressure is applied downward (from forehead to chin) in an oblique direction from 10:30 towards 4:30. Just as the tip of the posterior loop clears the iris margin, the iris spatula blade is again pushed slightly posterior such that the posterior loop is now behind iris. The spatula is now withdrawn in the same direction, that it entered. Two or three peripheral iridectomies are now performed at 10:00, 12:00 and 2:00 o'clock. Several iridotomies or one iridectomy is insufficient to guard against pupil-block glaucoma. The anterior chamber is reconstituted with acetylcholine solution. Most of the air is removed and the position of the intraocular lens is checked. It can now be rotated or repositioned (if necessary) with hooks and fine spatulas. The remaining corneoscleral suturing is completed and the wound is tested for watertight integrity with Week-eel sponges. Additional suturing is performed if required. An antibiotic ointment is instilled and an injection of Icc chloromycetin succinate is made in the subtenon's space. If the cornea exhibits a clear luster at this point no further medications are used. If the corneal luster is dull and there was more than the usual manipulations, 1cc of subconjunctival Kenalog is injected. The eye is bandaged using 2 oval eyepads and a protective metal or plastic shield. For the first three days a steroid drop is used every three hours during the day with an antibiotic four times a day. While at home after the fourth day antibiotic and steroid drops are used only at bed time. The patient is
refracted on the eighth week and appropriate glasses prescribed. Some sutures may be removed after the tenth week if the superior limbus remains injected from suture irritation. Dislocation When a intraocular lens loop becomes dislocated an attempt should be made to reposition it medically. The dislocation usually occurs because synechiae develop around one set of loop posts. As the pupil dilates the lens is drawn in the direction of the iris-loop adhesion. This causes the opposite loop to clear the pupil margin and dislocate anteriorly. In the same way a strut may dislocate posteriorly. If the LOOP cannot be positioned medically no further treatment is indicated. A dislocated STRUT must be repositioned otherwise the lens may drop into the vitreous. The presence of loop-iris synechiae will however keep the lens in the iris plane. Positioning may be accomplished as follows. One drop of 10% phenylephrine is instilled and the pupil observed for appropriate dilatation. The patient is positioned in the supine position (loop dislocation) or in the prone position (strut dislocation). A cotton tipped applicator dipped in 10% phenylephrine may be applied at the limbus in the exact location of the dislocated loop or strut. This gives a slight degree of added eccentric dilatation at that specific point which may be just enough to allow the pupil to clear the offending loop or strut. Pressure may now be applied at the topically anesthetized limbus with a glass rod or using the two index fingers to push the offending loop into position behind the iris. This cannot be done with the strut .. With the lens in position an indirect ophthalmoscope light is directed into the patient's eye. This causes enough miosis to hold the lens in place until the pilocarpine 6% (1 drop every 5 minutes for 6 doses) takes effect. Usually no further local treatment is required. If the patient's lens subluxates a second time, carbachol 3% drops twice a day are used. 12 Chronic dislocation of this lens can be treated or prevented by the use of a McCannel suture. 13 If the anterior 12 o'clock strut comes forward (due to peripheral anterior synechiae, etc.) it can touch the corneal endothelium and give rise to focal bullous keratopathy. Correction is made by amputation of the offending strut either via an adjacent limbal approach, or through clear cornea over the strut in question.
References 1. Binkhorst C.D. Iris supported artificial pseudophakia Ophthalmol. Soc., U.K. 79:569, 1959. 2. Kwitko., M.L. Intraocular lens implantation after cataract surgery-five year follow up report. Univ. of Western Ontario Medical Seminar. 1971. London, Ont. 1971. 3. Kwitko M.L. PrecautlOns in lens implantation-eight year follow up report. Amer.]. Ophthal. 78:547, 1974. 4. Kwitko M.L. Intraocular lens. Fixation Devices. Contact and Intraocular Lens Med.]. 2:12, 1976. 5. Fyodorov. S.N. Apphcation of intraocular pupillary lenses for aphakia correction. Vestn. Oftal. (Mosk) 78:76, 1965. 6. Shepard D.O. The Intraocular Lens Instructional Manual 1975 p. 24. 7. Hoffer K. The Intraocular Lens Instructional Manual 1975, 1975,p.25,26. 8. Binkhorst R. The optical design of intraocular lens implants Ophth. Surg. 6:17, 1975. 9. Kwitko M.L. Direct intraocular lens holder, manufactured by Katena, New Jersey. 10. Kwitko M.L. Wide mouthed blunt iris hook for iris manupulation and lens positioning, made by Katena, New Jersey. 11. Galin M.A. Barasch, K. Wills Eye Meeting Philadelphia 1975. 12. Havener, W.H.: Ocular Pharmacology C.V. Mosby St. Louis, Ed. 3, p. 260. 13. McCannel, M.: A retrievable suture idea for anterior uveal problems. Ophth. Surg. 7 :98, 1976.
Summary One hundred cases have been operated using the Fyodorov Russian made lens. The installation and the postoperative course have been no more difficult that that experienced with other lens styles. 35
portion of the anterior loop came dangerously close to the posterior cornea at the limbus. In two instances corneal edema developed in this area and the offending loops had to be amputated. For this reason a modification of the Binkhorst lens was produced. (Fig. 3). Ten of these lenses were used
"
"OOIA
.'0
. 'J i
x AU. DlJot(NSlONS IN Io411.. l.IMETE"S
SECTION ON XX
Fig. 1 (Kwitko, M.L.) Two Loop Binkhorst intraocular lens, extracapsular cataract extraction , sector iridectomy.
block was feared a sector iridectomy was performed with extracapsular extraction. 3 Because of the problems associated with the extracapsular technique, I later turned to the four loop lens with intracapsular technique. (Fig. 2). Unfortunately the terminal
Fig. 3 A,B (Kwitko, M.L.) Binkhorst-Kwitko intraocular lens.
with uniformly good results. 4 The Fyodorov Type 2 lens,s was made available in 1974 which provided all of the advantages of the Binkhorst lens but with the absence of the potentially dangerous anterior loops, (Fig. 4).
Fig. 2 (Kwitko, M.L.) Binkhorst four loop intraocular lens.
32
Complications I have now implanted 100 Russian manufactured Fyodorov lenses. The following complications have been observed. 1. Dislocation. One lens was observed to have two struts dislocated behind the iris on the first post-operative day. The patient was taken to the operation room within the next two hours. By this time all three struts were behind the iris so that the lens rested on the vitreous face in the optical axis. Using a narrow spatula the three struts were repositioned. The patient now enjoys 20125 vision with no other complications. Miotics have not been used. This
E
Loops and Antenna
7.5
1
5 .0
1
7.5
RAD 2
I
I 1
RAD 1
Fig. 4 A,B (Kwitko, M.L.) Fyodorov intraocular lens.
good result was possible because the vitreous face was intact and the lens used was so light. A second case had dislocated one loop in front of the iris. This has not been repositioned and the lens remains centered in the optical axis fixated by the remaining two loops and three struts. A third case had one strut dislocated behind the iris. This was repositioned with dilatation. 2. Retrolental membrane formation. In the early cases when the pupil was not dilated postoperatively with a weak mydriatic (e.g. 0.5% tropicamide)excessive pigment deposition was observed with associated reduction of visual acuity. One case required surgical disruption of the resulting membrane. Since the beginning of 1976, the pupil has been minimally dilated daily beginning on the second post operative day. There has been a marked reduction in this complication. Using this technique no membrane has occurred dense enough to affect the final visual result. This is now the standard post operative treatment. 3. Corneal Edema. There has been only one case of .corneal edema using this lens, when pilocarpine 2% was dropped directly onto the exposed iris. Edema involving the superior one third of the cornea resulted but this was probably due to the toxic effect of the pilocarpine or its preservative. In all other cases only
balanced salt and Miochol solutions have been used to irrigate the anterior chamber. 4. Secondary Glaucoma. Alpha chymotrypsin is not used when a lens implant is installed in order to avoid the elevated intraocular pressure frequently associated with this drug. Two cases in which extracapsular cataract surgery was performed with the Fyodorov lens, developed transient elevated pressures. Both were controlled with acetazolamide. A third case developed pupil block glaucoma two days following the cataract extraction. Further surgery was required : another iridectomy was performed through the original limbal incision. Fluid vitreous was aspirated through the new iridectomy site and the condition was cured. 5. Flat Chamber. Two cases developed fl at chambers, one case four weeks following surgery and one case on the first post-operative day. In both instances the end knobs of the three struts came up against the corneal endothelium. Since the struts come out of the lens body in an almost parallel fashion, the struts kept the lens body itself away from the cornea so that touch occurred at only three places with the lens body separated from the endothelium by aqueous humor. In the first case it was felt that the chamber had been flat for at least several days with the lens body straddling but separated from the cornea by the struts. The eye was treated with dilatation (0.5% tropicamide) and pressure patching for four days. There was no improvement. The wound was inspected in the operating room and four leaks were discovered. The entire cataract wound was resutured with a running 10-0 nylon suture after the chamber was deepened with balanced salt solution. The remaining course was uneventful. Because of this experience, the second case was treated with daily dilatation (0.5% tropicanide) and pressure patching. The chamber deepened on the third day and the remaining course was uneventful. In each case the cornea was not affected except for three dots which were observed by slit lamp examination where the knobs of the struts touched the endothelium. The first case now has 20/25 vision and the second 20/30. Because of the design of other lenses ,the lens body would come into contact with the corneal endothelium should the chamber flatten and surgery would be required as quickly as possible. Surgical Technique The patient is administered a local, general or "local with general standby" anesthesia. The cataractous eye is prepped and drapped in the usual manner for intraocular surgery. The pupil is not dilated preoperatively. A limbal section is made in the surgeon's usual manner for intra capsular cataract extraction preferably with a 160-170° section to give 33
adequate exposure. Absorable sutres should not be used. Silk (8-0 or 9-0) or monofilament nylon (9-0 or 10-0) are preferred since adequate wound closure must be maintained for at least eight weeks. Absorbable sutures cannot be relied upon to last that long. The sterile lens is inspected with the microscope prior to surgery, to insure that the lens is perfect in all details i.e. the loops are sufficiently separated from the lens body to allow adequate space for the iris and the struts are well fixed. The dioptric power of the intraocular lens to be used is determined by the simple graph method suggested by Shepard 6 or the more precise A-scan ultrasonographic method as modified by Hoffer' or Binkhorst.8 If there is any doubt as to the required dioptric power for a given patient, a +18.00 diopter lens may be used for approximating emmetropia. A + 19.50 diopter lens may be used to produce a myopic eye, approximately -1.50 diopters postoperatively. The cataract is extracted. The iris should be floated up off the vitreous face with balanced salt solution if the eye is very soft and the iris diaphram bows backward. Care must be taken in this case not to trap air in the posterior cavity. If the chamber flattens after removal of the cataract, air should be injected into the anterior chamber. If the air is not retained and there is evidence of positive vitreous pressure, the implantation should be aborted and the case carried on as a routine cataract operation. In any event an intraocular lens should only be implanted if it can be separated from the corneal endothelium with air at all times during the operation. If vitreous is lost as the cataract is removed the implantation of an intraocular lens should not be done. The standard treatment for handling this complication should be employed. The iridectomy should not be done before implanting the lens since a loop may enter the iridectomy and disinsert the iris root. In addition an intact iris plane protects to some degree against vitreous loss that can occur during lens insertion. The lens is grasped with the direct lens implantation hplder made by Katena 9 with one posterior loop positioned at 6 o'clock. The lens is inserted downward (meaning from forehead to chin) placing the inferior lens loop posterior to iris at 6 0' clock and making sure that the two inferior oblique struts at 4: 30 and 7: 30 are anterior to the iris. The lens is moved sideways to the surgeons left to drop the right superior loop beneath the iris and the lens is moved to the right to position the left superior lens loop. On occasion it may be necessary to lift the iris over the superior loop with a wide mouthed blunt hook made by Katena 10 or an iris forceps. At this time careful observation must be made with the microscope to insure that the struts are anterior and the loops are all posterior to the iris. If not they must be positioned 34
using a narrow spatula with or without a blunt hook. This technique is referred to as the open eye technique. The author's preferred technique is the closed eye system as follows. After the intraocular lens is inserted with the inferior lens loop posterior to iris at 6 o'clock, the globe is closed and the safety sutures tied. Additional air may now be injected to further deepen the anterior chamber to insure adequate separation between lens and cornea during the following manipulations. A fine iris spatula is inserted via the limbal wound at 11 o'clock. The blade is kept parallel to the iris plane and the spatula blade is used to push the left-hand superior posterior loop downward obliquely 1: 30 toward 7: 30 by pushing against the posts of the posterior lens loop. Just as the tip of the posterior loop clears the iris margin, slight posterior pressure is applied to the spatula such that the loop drops posterior to iris. The spatula direction is then reversed and is brought out toward 11 :00. The spatula is now inserted at 1 o'clock with its blade parallel again to the plane of the iris. The spatula blade is inserted between the posterior loop (which is still anterior to the iris) and the optical portion of the lens pushing against the two posterior pegs (where the loop comes off the back side of the lens). Pressure is applied downward (from forehead to chin) in an oblique direction from 10:30 towards 4:30. Just as the tip of the posterior loop clears the iris margin, the iris spatula blade is again pushed slightly posterior such that the posterior loop is now behind iris. The spatula is now withdrawn in the same direction, that it entered. Two or three peripheral iridectomies are now performed at 10:00, 12:00 and 2:00 o'clock. Several iridotomies or one iridectomy is insufficient to guard against pupil-block glaucoma. The anterior chamber is reconstituted with acetylcholine solution. Most of the air is removed and the position of the intraocular lens is checked. It can now be rotated or repositioned (if necessary) with hooks and fine spatulas. The remaining corneoscleral suturing is completed and the wound is tested for watertight integrity with Week-eel sponges. Additional suturing is performed if required. An antibiotic ointment is instilled and an injection of Icc chloromycetin succinate is made in the subtenon's space. If the cornea exhibits a clear luster at this point no further medications are used. If the corneal luster is dull and there was more than the usual manipulations, 1cc of subconjunctival Kenalog is injected. The eye is bandaged using 2 oval eyepads and a protective metal or plastic shield. For the first three days a steroid drop is used every three hours during the day with an antibiotic four times a day. While at home after the fourth day antibiotic and steroid drops are used only at bed time. The patient is
refracted on the eighth week and appropriate glasses prescribed. Some sutures may be removed after the tenth week if the superior limbus remains injected from suture irritation. Dislocation When a intraocular lens loop becomes dislocated an attempt should be made to reposition it medically. The dislocation usually occurs because synechiae develop around one set of loop posts. As the pupil dilates the lens is drawn in the direction of the iris-loop adhesion. This causes the opposite loop to clear the pupil margin and dislocate anteriorly. In the same way a strut may dislocate posteriorly. If the LOOP cannot be positioned medically no further treatment is indicated. A dislocated STRUT must be repositioned otherwise the lens may drop into the vitreous. The presence of loop-iris synechiae will however keep the lens in the iris plane. Positioning may be accomplished as follows. One drop of 10% phenylephrine is instilled and the pupil observed for appropriate dilatation. The patient is positioned in the supine position (loop dislocation) or in the prone position (strut dislocation). A cotton tipped applicator dipped in 10% phenylephrine may be applied at the limbus in the exact location of the dislocated loop or strut. This gives a slight degree of added eccentric dilatation at that specific point which may be just enough to allow the pupil to clear the offending loop or strut. Pressure may now be applied at the topically anesthetized limbus with a glass rod or using the two index fingers to push the offending loop into position behind the iris. This cannot be done with the strut .. With the lens in position an indirect ophthalmoscope light is directed into the patient's eye. This causes enough miosis to hold the lens in place until the pilocarpine 6% (1 drop every 5 minutes for 6 doses) takes effect. Usually no further local treatment is required. If the patient's lens subluxates a second time, carbachol 3% drops twice a day are used. 12 Chronic dislocation of this lens can be treated or prevented by the use of a McCannel suture. 13 If the anterior 12 o'clock strut comes forward (due to peripheral anterior synechiae, etc.) it can touch the corneal endothelium and give rise to focal bullous keratopathy. Correction is made by amputation of the offending strut either via an adjacent limbal approach, or through clear cornea over the strut in question.
References 1. Binkhorst C.D. Iris supported artificial pseudophakia Ophthalmol. Soc., U.K. 79:569, 1959. 2. Kwitko., M.L. Intraocular lens implantation after cataract surgery-five year follow up report. Univ. of Western Ontario Medical Seminar. 1971. London, Ont. 1971. 3. Kwitko M.L. PrecautlOns in lens implantation-eight year follow up report. Amer.]. Ophthal. 78:547, 1974. 4. Kwitko M.L. Intraocular lens. Fixation Devices. Contact and Intraocular Lens Med.]. 2:12, 1976. 5. Fyodorov. S.N. Apphcation of intraocular pupillary lenses for aphakia correction. Vestn. Oftal. (Mosk) 78:76, 1965. 6. Shepard D.O. The Intraocular Lens Instructional Manual 1975 p. 24. 7. Hoffer K. The Intraocular Lens Instructional Manual 1975, 1975,p.25,26. 8. Binkhorst R. The optical design of intraocular lens implants Ophth. Surg. 6:17, 1975. 9. Kwitko M.L. Direct intraocular lens holder, manufactured by Katena, New Jersey. 10. Kwitko M.L. Wide mouthed blunt iris hook for iris manupulation and lens positioning, made by Katena, New Jersey. 11. Galin M.A. Barasch, K. Wills Eye Meeting Philadelphia 1975. 12. Havener, W.H.: Ocular Pharmacology C.V. Mosby St. Louis, Ed. 3, p. 260. 13. McCannel, M.: A retrievable suture idea for anterior uveal problems. Ophth. Surg. 7 :98, 1976.
Summary One hundred cases have been operated using the Fyodorov Russian made lens. The installation and the postoperative course have been no more difficult that that experienced with other lens styles. 35