Secondary Intraocular Lens Implantation During or After

Corneal Transplantation

Perry S. Binder, M.D.

An analysis of the effects of secondary intraocularlens implantation on the clinical results of cornealtransplantation in four groups of eyes showed thatthe mean visual acuity in 27 eyes undergoing intra­ocular lens implant at the time of aphakic kerato­plasty and in 12 eyes undergoing intraocular lensimplantation after corneal transplant was approxi­mately 20/40; the visual acuity in 24 eyes undergoingintraocular lens exchange at the time of transplantfor pseudophakic bullous keratopathy and in 18eyes undergoing intraocular lens removal at thetime of transplant for pseudophakic bullous kera­topathy was poorer. The techniques used were sim­ple and did not increase the incidence of transplantcomplications. Intraocular lens implantation com­bined with corneal transplants should be consid­ered in aphakic eyes requiring corneal transplants,in eyes requiring simultaneous cataract extractionand corneal transplants, and in eyes in which cata­racts have developed after corneal transplant.

PSEUDOPHAKIC BULLOUS KERATOPATHY is the mostcommon indication for corneal transplantation. I Insuch cases, the corneal surgeon is faced with thequestion of removing or exchanging the lens."" Tomake such a determination, we need to know theeffects of intraocular lens implantation on the cornealgraft in eyes with good visual potential.

Secondary intraocular lens implantation at thetime of aphakic keratoplasty (or in aphakic eyes thathave had a previous corneal transplant) became sim­pler with the development of the flexible anteriorchamber lens." Because recent evidence suggestscontinued endothelial cell loss with certain iris­fixated lenses, II there has been an increased tenden­cy to implant flexible lenses in aphakic eyes during orafter corneal transplantation. The posterior chamber

Accepted for publication March 7, 1985.From the Ophthalmic Research Laboratory, Sharp Cabrillo

Hospital, San Diego, California. This study was supported inpart by a grant from the San Diego Eye Foundation.

Reprint requests to Perry S. Binder, M.D., 9834 GeneseeAvenue, Suite 200, La Jolla, CA 92037.

lens, extracapsular surgery, and sodium hyaluronatehave all simplified the triple procedure (combinedcorneal transplant, cataract extraction, and lens im­plant)12.24 (Table 1) and significantly reduced cornealcomplications.

There are several categories of secondary intraocu­lar lens implantation associated with corneal trans­plantation: implantation at the time of corneal trans­plant in aphakic eyes, implantation in aphakic eyeswith previous corneal transplants, implantation atthe time of cataract extraction in eyes with previouscorneal transplants, and exchange of intraocularlenses at the time of transplant for pseudophakicbullous keratopathy. There are little data availableon the visual results after such procedures. Thepurpose of this study was to evaluate the resultsfrom all four categories of secondary implantationcombined with corneal transplantation.

SUbjects and Methods

This prospective study evaluated all corneal trans­plants I performed from Feb. 1, 1977, through Sept.30, 1984. Each patient received similar preoperativeexaminations and postoperative medical treatmentbut two separate corneal transplant techniques wereused.

Technique I-From February 1977 to February1979, donor corneal buttons were the same size or0.25 mm or 0.5 mm greater in diameter than therecipient hole. All donor corneas were punched fromthe endothelial side over a Teflon block with a Polackcorneal punch. I removed the recipient cornea byentering the anterior chamber with a disposabletrephine rotated clockwise. The wound was complet­ed with curved microcornea1 scissors to produce aposterior wound bevel. Recipient diameters were 7.5to 8.75 mm in diameter. The transplants were su­tured with 16 interrupted 10-0 monofilament nylonsutures or a 16-bite, continuous 10-0 monofilamentnylon suture. Intraocular lens powers were calculat­ed with the fellow eye or previously known recipienteye keratometric readings for the ultrasonographic

©AMERICAN JOURNAL OF OPHTHALMOLOGY 99:515-520, MAY, 1985 515

516 AMERICAN JOURNAL OF OPHTHALMOLOGY May, 1985

TABLE 1

RESULTS OF KERATOPLASTY AND PRIMARY INTRAOCULAR LENS IMPLANTATION (TRIPLE PROCEDURE)

STUDY

Aquavella, Shaw, & Rao"

Lee & Dohlrnan'"

Alpar"

Taylor, Khalig, & Maxwell'"

Gould"

Buxton"

Lindstrom, Harris, & Douqhrnarr"

Hunckler & Hyde21

Crawford & associates'

Present study

NO. OF EYES

5

10

18

22

11

23

18

177

56

60

VISUAL ACUITY (%)'MEAN FOLLOW·UP CLEAR GRAFTS

(MOS) {'Yo} 20/20 TO 20150TO20/40 20/100

15.0 80.0 Not given Not given

15.9 60.0 50.0 30.0

21.0 94.0 77.7 22.2

Unknown 77.0 36.3 27.2

Not given 72.0 54.5 016.9 79.3 43.4 8.6

21.0 89.0 55.5 27.7

>6.0 94.0 88.7 9.0

15.8 90.0 65.2 21.2

24.5 91.6 61.6 21.6

'Visual acuity results from previous studies do not differentiate between best and latest visual acuities.

'G. J. Crawford, R. D. Stulting, G. O. Waring, W. S. VanMeter, and L. A. Wilson, unpublished data.

calculations. The powers selected were intended toprovide the patient with refractive errors of -1.00sphere.

Technique 2-From March 1979 to September 1984,I used eight interrupted 10-0 monofilament nylonsutures followed by a continuous, 16-bite, 16-lJ.mmonofilament nylon suture. 25 Donor corneal buttonswere 0.5 mm greater in diameter than the recipient. Iused the Polack corneal punch and later a polycar­bonate cutting block with three curves in the well toprepare the donor corneal buttons." The recipientcorneal buttons were removed in the same fashion asthey were in Technique 1. Removal of the interrupted10-0 sutures was based on central and peripheralkeratometric readings." Intraocular lens power cal­culations were made using the SRK regression for­mula based upon postkeratoplasty steep and flatkeratometric readings from the most recent cases"(and Crawford and associates, unpublished data)were selected for emmetropia.

In all cases 20 mg of subconjunctival gentamicinsulfate and 32 mg of methylprednisolone were inject­ed at the termination of surgery. Postoperatively, alleyes received topical prednisolone acetate 1% andhydrocortisone eyedrops administered at variousfrequencies depending on the degree of postopera­tive inflammation. Artificial tears and lubricatingointments were routinely prescribed.

Group 1: Implantation into previously aphakiceyes at the time of keratoplasty-After removal ofthe donor corneal button, lysis of synechiae, neces­sary iris suturing with 10-0 polypropylene, and (ifnecessary) anterior vitrectomy, I inserted a Bink­horst four-loop lens in the vertical meridian (whenpossible); I sutured one or both anterior loops to the

iris with a 10-0 polypropylene suture." The corneawas sewn in place over the intraocular lens with acushion of air by a needle-pinning technique." Sodi­um hyaluronate, used routinely since June 1981, hasfacilitated this step. More recently, I have usedflexible loop anterior chamber lenses. 10

Group 2: Implantation into aphakic eyes withprevious corneal transplants-I made an incision inthe flat corneal meridian at the posterior corneoscler­al limbus with a razor blade after creating a fornix­based conjunctival flap. If an intact vitreous face waspresent in the anterior chamber, air injected throughthe entry site forced the vitreous through the pupil,after which the pupil was constricted with acetylcho­line. Initially, I implanted four-loop iris-fixed lenses.The anterior loop was sutured to the iris with onepolypropylene suture under an air bubble. Later, Iused flexible loop anterior chamber lenses under acushion of sodium hyaluronate. The wounds wereclosed with a running, cross-tied 10-0 monofilamentnylon suture with the goal of steepening the flatmeridian to the point of making it the steepermeridian. 29

Group 3: Implantation at the time of cataractextraction in eyes with corneal transplants-All pro­cedures were performed using the same plannedextracapsular cataract extraction technique with pos­terior chamber lens implantation and wound closurewith a double-continuous, cross-tied suture tech­nique." Sodium hyaluronate was used in every case.

Group 4: Intraocular lens exchange at the time ofcorneal transplant for pseudophakic bullous kera­topathy-After removing the previous intraocularlens (which was usually a Copeland, Binkhorst four­loop, or rigid anterior chamber lens),30 I implanted a

Vol. 99, No.5 Intraocular Lenses and Corneal Transplants 517

Binkhorst four-loop lens or, later, a flexible loopedanterior chamber lens. Sodium hyaluronate wasused in each case. The results in this group werecompared with those in a group of 18 eyes withpseudophakic bullous keratopathy that underwentintraocular lens removal at transplant (Group 5).

Collection of data-Central keratometric readings,visual acuity, and complications were recorded post­operatively and the data stored in a data base soft­ware program. Statistical analysis was done with astatistics package designed for the data base system.

Axial length was measured with the pupil dilated.The speed of the sound was adjusted for aphakic andpseudophakic eyes. The final manifest refractionexpressed in spherical equivalent was performed bythe operating surgeon or by a corneal fellow. Bestcorrected visual acuity was measured on a Snellenchart in a ten-foot lane. A clear graft was one with acompact «0.54 mm) central stroma without cornealabnormalities and that permitted a clear view of theiris and intraocular lens detail. Macular disease wasconfirmed by fluorescein angiography. Patients wereroutinely examined every six weeks for the first yearand then at six-month intervals.

Results

Group I-Of the 29 aphakic eyes that underwentsecondary intraocular lens implantation at the timeof keratoplasty, 17 received Binkhorst four-loop lens­es and 12 received flexible looped anterior chamberlenses. Ten eyes had macular degeneration or cystoidmacular edema (Table 2). Transplants failed becauseof recurrent herpes simplex (one eye), early graftfailure (one eye), late graft failure (one eye), andirregular astigmatism (one eye).

The mean best visual acuity decreased with timebecause of late-onset cystoid macular edema. The

mean spherical equivalent was myopic (Table 3).Fourteen of the 29 eyes had final visual acuities of20/40 or better. Table 4 shows the clinical results insimilar, previously reported cases.

Groups 2 and 3-A total of 12 eyes with previouscorneal transplants underwent secondary intraocu­lar lens implantation. Eight eyes were previouslyaphakic (Group 2) and four were phakic (Group 3).Because of the small numbers involved, I combinedthese two groups for analysis. The conditions forwhich the corneal transplants were originally per­formed were Fuchs' endothelial dystrophy (foureyes), herpes simplex keratitis (one eye), keratoco­nus (one eye), corneal leukoma (two eyes), andpreviously failed transplants (four eyes). Transplantssubsequently failed because of recurrent herpes sim­plex (one eye), corneal ulcer (one eye), and late graftfailure (one eye) (Table 2).

The best corrected visual acuity exceeded 20/40 inseven of the 12 eyes (Table 3). The mean sphericalequivalent was reduced to -1.59 diopters. Table 5compares these results with those in similar, previ­ously published cases.

Group 4-Twenty-four eyes with pseudophakicbullous keratopathy or with failed grafts for pseudo­phakic keratopathy underwent intraocular lens ex­change. Of these 24 grafts, 22 remained clear. Eleveneyes had clinically significant cystoid macular edemaor macular degeneration (Table 2), accounting for thepoor visual acuities. The mean spherical equivalentwas reduced compared with those in Groups 1, 2,and 3 (Table 3). Five eyes had anterior vitrectomyduring surgery. These results were similar to thosepreviously reported for pseudophakic bullous kera­topathy (Table 6).

To determine whether the clinical results and com­plications were affected by the presence of an intra­ocular lens, I studied the results in a group of 18 eyeswith pseudophakic bullous keratopathy that under­went intraocular lens removal (Group 5). Limited

TABLE 2

INDICATIONS, FOLLOW-UP, AND COMPLICATIONS

CLINICAL DATA GROUP 1 GROUPS 2 GROUP 4 GROUP 5

(NO,) AND 3 (NO.) (NO.) (NO.)

Preoperative diagnosis

Aphakic bullous keratopathy 18 1 0 0

Failed transplant 9 3 7 3

Pseudophakic bullous keratopathy 0 0 17 15

Other 2 8 0 0

Mean tollow-up (mos) 23.0 10.7 8.8 29.3

Cystoid macular edema or macular

degeneration 10 1 11 11

Failed grafts 4 3 2 3

518 AMERICAN JOURNAL OF OPHTHALMOLOGY

TABLE 3VISUAL ACUITY AND REFRACTIVE RESULTS

May, 1985

CLINICAL DATA

Mean visual acuity with spectacles

Best

Latest

Mean spherical equivalent (dlopters)

Mean corneal astigmatism (diopters)*

Mean keratometric values'

Flat

Steep

GROUP 1

(NO. = 29)

0.430.31

-2.05

3.39

41.34

44.64

GROUPS 2 AND 3(NO. = 12)

0.56

0.43

-1.59

2.51

43.88

46.48

GROUP 4

(NO. = 24)

0.34

0.29

-1.06

3.10

44.20

47.46

GROUP S

(NO. ~ 18)

0.41

0.28

+8.40

4.58

44.02

48.58

'Eyes with pseudophakic bullous keratopathy had significantly (P = .01) more astigmatism.

'The flatter values for Group 1 resulted from a different suturing technique.

vitrectomies were performed in eight of these eyes.Eleven of the eyes were later found to have signifi­cant macular disease. Three of the 18 transplantsfailed; one was a late graft failure (36 months postop­eratively), one was an early graft failure, and theother failed because of bacterial corneal infection.There was no significant difference in the visualresults for Groups 4 and 5. In a separate group of 41eyes with pseudophakic bullous keratopathy inwhich intraocular lenses were left in situ, the meanbest visual acuity was 20/45, and the latest visualacuity was 20/60; in 60.9%, visual acuity was 20/40 orbetter 0. R. Samples and P. S. Binder, unpublisheddata). In contrast, in the 42 eyes in Groups 4 and 5combined, the best visual acuity was 20/55" and thelatest visual acuity was 20/70; 18 eyes (42.8%) hadvisual acuities of 20/40 or better. The difference invisual acuity results for Groups 4 and 5 compared tothose for eyes with intraocular lenses left in situ wasnot significant.

The use of sodium hyaluronate made all proce­dures simpler. Only two cases of corneal failurecould be attributed to secondary intraocular lensimplantation (Group 2). Both eyes had previouslyhad transplants for Fuchs' endothelial dystrophy, 25

and 42 months before intraocular lens insertion. Oneadditional case was lost to follow-up in the firstpostoperative year.

Discussion

Previous studies have shown a high incidence oftransplant failure in patients who underwent subse­quent cataract extraction." Corneal surgeons nowperform simultaneous corneal transplant and cata­ract extraction to obviate a second operation andeliminate potential graft failures associated withposttransplant cataract extractiort." The eliminationof the need for contact lens care, insertion, andremoval, coupled with the potential and actual com­plications of contact lenses." especially in cornealtransplant patients, stimulated the use of intraocularlenses in corneal transplantation (Table 1). Excellentclinical and visual results have been documented ineyes undergoing simultaneous transplant, cataractextraction, and intraocular lens implant-the so­called "triple procedure" (Table 1).2.12.13.15,24.27.28

The initial treatment for pseudophakic bullous

TABLE 4RESULTS OF INTRAOCULAR LENS IMPLANTATION AT TIME OF APHAKIC KERATOPLASTY

STUDY NO. OF EYES MEAN FOLLOW·UP CLEAR GRAFTS VISUAL ACUITY (%)

(MOS) (%)20;20 TO 20/40 20/50 TO 20/100

Aquavella, Shaw, & Rao" 8 15.0 50 Not given Not givenLee & Dohlman" 5 19.0 80 0 0Alpar" 10 28.0 100 60.0 40.0Taylor, Khalig, & Maxwell" 18 Not given 83 22.2 33.3Gould" 22 Not given 91 50.0 22.7

Present study 29 23.4 86.2 48.3 27.6

Vol. 99, No.5 Intraocular Lenses and Corneal Transplants 519

TABLE 5RESULTS OF INTRAOCULAR LENS IMPLANTATION IN PREVIOUSLY APHAKIC EYES WITH TRANSPLANTS OR IN

PREVIOUSLY PHAKIC EYES WITH TRANSPLANTS UNDERGOING CATARACT EXTRACTION

STUDY NO. OF EYES MEAN FOLLOW-UP CLEAR GRAFTS VISUAL ACUITY (%)(MOS) (%)

20/20 TO 20/40 20/50 TO 20/100

Aquavella, Shaw, & Rao" 3 15.0 0 Not given Not given

Taylor, Khalig, & Maxwell'· 9 Not given 89.0 44.4 44.4

Gould" 4 Not given 75.0 50.0 25.0

Present study 12 10.7 72.7 58.3 41.7

keratopathy was to remove the intraocular lens at thetime of keratoplasty. 2-5.8.9 The large number of trans­plant patients who had undergone simultaneoustransplant and cataract extraction and the growingnumber of patients with pseudophakic bullous ker­atopathy who underwent intraocular lens removal attransplant were subsequently fitted with contactlenses. Unfortunately, despite good technique andexcellent contact lenses, many of these patients areunable to function visually with contact lenses. Forall of these reasons, corneal surgeons implant intra­ocular lenses in aphakic eyes undergoing kerato­plasty.

The 29 aphakic Lyes in Group 1 achieved excellentvisual acuities. For the 12 eyes in Groups 2 and 3combined the visual results were similar. The poor­est results were obtained in Groups 4 and 5. Theseconfirmed the previously reported finding of poorvisual outcome after corneal transplantation forpseudophakic bullous keratopathy. 2-5,8 In a prelimi­nary study of similar cases, analysis of visual acuity

data suggested a better visual prognosis for eyes inwhich intraocular lenses were left in situ at kerato­plasty.2 The results of this study, combined with arecent analysis of transplants performed for pseudo­phakic bullous keratopathy (Samples and Binder,unpublished data), again suggest that eyes that un­dergo intraocular lens removal (or exchange) have apoorer visual prognosis than eyes in which the intra­ocular lenses are left in situ.

The use of intraocular lenses combined with corne­al transplants permits patients to recover visual acu­ity much faster than if they had to wait for sutureremoval before being fitted with contact lenses. Theimplant eliminates potential corneal injury, infec­tion, or neovascularization that may occur with con­tact lens wear. 33 It has been my impression thattransplant patients with intraocular lenses achieveexcellent peripheral vision and clinically appear tohave greater functional vision even in the presenceof macular disease than patients who wear aphakicspectacles or contact lenses.

STUDY

TABLE 6RESULTS IN PSEUDOPHAKIC BULLOUS KERATOPATHY

STATUS OF INTRAOCULARLENS (%)

NO. OF MEAN CLEAR

EYES FOLLOW-UP GRAFTS

(MOS) (%)

20/20 TO 20/40 20/50 TO 20/100

REMOVED RETAINED UNKNOWN REMOVED RETAINED UNKNOWN

Aquavella, Shaw, & Rao" 19 15.0 72

Fine'· 17 Not given 100 35.3

Taylor, Khalig, & Maxwell'· 11 Not given 82 0

Gould" 5 Not given 80 80.0

Meyer & Sugar< 25 20.0 88 24.0

Charlton, Binder, &Perl' 19 13.1 15.0

Waltman' 26 12.0 91 50.0

Waring & associates' 35 14.8 91 0

Taylor & assoctates" 42 14.8 88 30.9

Arentsen & Laibson' 36 18.0 94 13.9

Schanzlin &associatess 34 21.0 88 40.0

Samples & Binder" 76 21.0 83 42.8

*J. R. Samples and P. S. Binder, unpublished data.

28.0

19.4

60.9

8.0

30.5

9.7

520 AMERICAN JOURNAL OF OPHTHALMOLOGY May, 1985

The refractive errors obtained after implantationand corneal transplant permit patients to function atnear without spectacles (Tables 2 and 3). Using meanflat and steep keratometric readings when calculat­ing intraocular lens powers has further reduced themean spherical equivalent."

In summary, when intraocular lens implants arecombined with corneal transplants, there is no in­creased risk to the transplant. Intraocular lensesprovide the patients with better visual rehabilitation.The procedures are not technically difficult. Knowl­edge of potential postoperative keratometric read­ings has helped reduce the postoperative refractiveerrors (Crawford and associates, unpublished data).The results of this study further confirmed the poorresults obtained in patients with pseudophakic bul­lous keratopathy. Nevertheless, even such patientsbenefit from intraocular lenses.

References

1. Smith, R. E., McDonald, H. R., Nesburn, A. B., andMinckler, D. 5.: Penetrating keratoplasty. Changing indica­tions, 1947 to 1978. Arch. Ophthalmol. 98:1226, 1980.

2. Charlton, K. H., Binder, P. S., and Perl, T.: Visualprognosis in pseudophakic corneal transplants. OphthalmicSurg. 12:411, 1981.

3. Arentsen, j. L. and Laibson, P. R.: Surgical manage­ment of pseudophakic corneal edema. Complications andvisual results following penetrating keratoplasty. Ophthal­mic Surg. 12:371, 1982.

4. Meyer, R. F., and Sugar, A.: Penetrating keratoplastyin pseudophakic bullous keratopathy. Am. J. Ophthalmol.90:677,1980.

5. Polack, F. M.: Management of anterior segment com­plications with intraocular lenses. Ophthalmology 87:881,1980.

6. Waltman, S. R.: Penetrating keratoplasty for pseudo­phakic bullous keratopathy. Visual results. Arch. Ophthal­mol. 99:415, 1981.

7. Waring, G. 0., Welch, S. N., Cavanagh, H. D., andWilson, L. A.: Results of penetrating keratoplasty in 123eyes with pseudophakic or aphakic corneal edema. Oph­thalmology 90:25, 1983.

8. Schanzlin, D. j.. Robin, j. B., Gomez, D. S., Gindi,J. J., and Smith, R. E.: Results of penetrating keratoplastyfor aphakic and pseudophakic bullous keratopathy, Am. J.Ophthalmol. 98:302, 1984.

9. Taylor, D. M., Atlas, B. F., Romanchuk, K. G., andStern, A. L.: Pseudophakic bullous keratopathy, Ophthal­mology 90:19, 1983.

10. Fenzl. R. E., and Hahs. G.: Evaluation of serniflexibleand flexible anterior chamber intraocular lenses. Am. In­traocul. Implant Soc. J. 9:42, 1983.

11. Rao, G. N., Stevens, R. E., Harris, j. K., and Aqua­vella, J. V.: Long-term changes in corneal endotheliumfollowing intraocular lens implantation. Ophthalmology88:386, 1981.

12. Taylor, D. M.: Keratoplasty and intraocular lenses.Ophthalmic Surg. 7:31, 1976.

13. Taylor, D. M., and Khalig, A.: Keratoplasty and intra­ocular lenses. Follow-up study. Ophthalmic Surg. 8:49,1977.

14. Lee, J. R., and Dohlman, C. H.: Intraocular lens im­plantation in combination with keratoplasty. Ann. Ophthal­mol. 9:513, 1977.

15. Aquavella, j. V., Shaw, E. L., and Rao, G. N.: Intra­ocular lens implantation combined with penetrating kerato­plasty. Ophthalmic Surg. 8:113,1977.

16. Buxton, G. N., and Jaffe, M. S.: Combined kerato­plasty, cataract extraction, and intraocular lens implementa­tion. Am. Intraocul. Implant Soc. j. 4:110, 1978.

17. Alpar. j. J.: Keratoplasty with primary and secondarylens implantation. Ophthalmic Surg. 9:58, 1978.

18. Fine, M.: Keratoplasty for bullous keratopathy withintraocular lens. Am. Intraocul. Implant Soc. j. 4:12, 1978.

19. Taylor, D. M., Khalig, R., and Maxwell, R.: Kerato­plasty and intraocular lenses. Current status. Ophthalmolo­gy 86:242, 1979.

20. Hunckler, J. D., and Hyde, L. L.: The triple proce­dure. Combined penetrating keratoplasty, cataract extrac­tion, and lens implantation. Am. Intraocul. Implant Soc. J.5:222, 1979.

21. --: The triple procedure. Combined penetratingkeratoplasty, extracapsular cataract extraction, and lensimplantation-an expanded experience. Am. Intraocul. Im­plant Soc. J. 9:20, 1983.

22. Buxton, G. N.: The "triple" procedure (corneal graft,intracapsular cataract extraction, and intraocular lens).Contact Intraocul. Lens Med. J. 6:409, 1980.

23. Lindstrom, R. L., Harris, W. S., and Doughman,D. L: Combined penetrating keratoplasty, extracapsularcataract extraction, and posterior chamber lens implanta­tion. Am. Intraocul. Implant Soc. j. 7:130, 1981.

24. Gould, H. L.: Keratoplasty and intraocular lenses.Am. Intraocul. Implant Soc. J. 6:42, 1980.

25. Stainer, G. A., Perl, T., and Binder, P. S.: Controlledreduction of postkeratoplasty astigmatism. Ophthalmology89:668, 1982.

26. Tanne, E.: A new donor cutting block for penetratingkeratoplasty. Ophthalmic Surg. 12:371, 1981.

27. Binder, P. S.: Intraocular lens powers used in thetriple procedure. Effect on visual acuity and refractive error.Ophthalmology, in press.

28. Alpar, J. j.: Keratoplasty with primary and secondarylens implantation. Ann. Ophthalmol. 13:1255, 1981.

29. Perl, T., Binder, P. S., and Earl, K.: Postcataractastigmatism with and without a surgical keratometer. Oph­thalmology 91:489,1984.

30. Shaw, E. L.: Removing a square peg through a roundhole or a new technique for the removal of Choyce styleanterior chamber lenses through a keratoplasty incision.Contact Intraocul. Lens Med. J. 5:182, 1979.

31. Stark, W. J., and Maumenee, A. E.: Cataract extrac­tion after successful penetrating keratoplasty. Am. J. Oph­thalmol. 75:751, 1973.

32. Kaufman, H. E.: Combined keratoplasty and cataractextraction. Am. j. Ophthalmol. 77:824, 1975.

33. Mannis, M. j., and Matsumoto, E. R.: Extended wearaphakic soft contact lens after penetrating keratoplasty.Arch. Ophthalmol. 101:1225, 1983.