AIOIS survey of intraocular lenses in children—1978

AlDIS survey of intraocular lenses in children-1978 David A. Hiles, M.D. Pittsburgh, Pennsylvania

articles

The implantation of intraocular lenses (IOLs) in children remains a controversial subject for many ophthalmologists. There are few guidelines for IOL implantation in these patients or for the results obtainable following this procedure since Binkhorst first implanted an IOL in a child in 1959. 1 Recently, it has become necessary to identify the number of patients in the United States in whom IOLs have been implanted. It is also necessary to recognize the preoperative, operative and postoperative complications as well as the visual and fusional results obtained from these same patients. This information is necessary to the clinician when he is advising parents about the prognosis for their child with a cataract who harbors a similar series of findings or complications. A child's visual results following cataract surgery are known to be markedly different from those obtained following senile cataract and IOL implantation surgery.2 These variations in results are based upon the complications peculiar to children. This information may also provide guidelines for both federal regulatory agencies and IOL manufacturers. The survey compiles results from a cross section of pediatric IOL implant surgeries up to the institution of the Federal Food and Drug Administration's investigation of the IOL in February of 1978. IOL manufacturers need to be aware of the same information to better substantiate their protocols for IOL implantation in children before they apply for their investigational device exemption numbers. It is the purpose of this paper to present the data derived from the 1978 AIOIS survey of IOL implants in children. Since the Food and Drug Administration has decreed that separate implantation protocols be maintained for infantile and traumatic cataracts, the material presented here is also divided in this manner.

MATERIALS AND METHODS In March 1978, the American Intra-Ocular Implant Society'S (AIOIS) Scientific Advisory Board authorized a post card survey of its membership to Reprint requests to David A. Hiles, M.D., 3518 Fifth Avenue, Pittsburgh, PA 15213. 166

AM INTRA-OCULAR IMPLANT SOC J-VOL. IV, OCTOBER 1978

determine the numbers and types of IOLs implanted in children. As the inquiry cards were returned to AIOIS by the membership, detailed data sheets requesting additional information about each patient who had undergone an IOL implant were returned to each responding ophthalmologist. This aspect of the survey concluded on July 1, 1978, and the following results were tabulated. RESULTS One hundred and forty six (7.7%) of the then 1,855 American members of AIOIS responded positively to the post card survey. They reported 484 IOL implants in children: 183 (38%) lenses were implanted in patients with infantile cataracts and 301 (62%) lenses were implanted in traumatic cataract patients. The number of IOL implants that each surgeon had performed were tabulated from the post card survey (Table 1). Only five surgeons implanted 11 or more IOLs. traumatic cataract patients and also by the total number of implants performed by each surgeon. Only five surgeons implanted 11 or more IOLs.

one third of these children had received other aphakic optical therapy prior to the decision to implant an IOL.

Table 2. Primary and secondary IOL implantations. Number of Patients With Infantile With Traumatic Cataracts Cataracts

Total

Primary implants

89 (69%)

95 (57%)

184 (62%)

Secondary implants

38 (29%)

59 (36%)

97 (33%)

Unknown

3 (2%)

12 (7%)

15 (5%)

130 (44%)

166 (56%)

296 (100%)

Total

Most surgeons preferred the iris suture medallion-style IOL (34%) or the Binkhorst 2-loop IOL

Table 1. Number of surgeons performing implants in children and responding to AIOIS post card survey.

1-2 Implants

3-6 Implants

99 (68%)

35 (24%)

Number of Surgeons 7-10 11-20 Implants Implants

7 (5%)

Detailed data sheets were completed and returned by 100 (68.5%) of the 146 ophthalmologists who responded to the post card survey. The remainder of this study will relate only to those patients for whom the detailed data sheets were available. This series includes 130 infantile and 166 traumatic implant patients. Two hundred and eighty-eight patients received unilateral implants while only four patients (eight eyes) received bilateral implants. The current trend in the United States is towards unilateral implantation in children until such time as IOL implants are demonstrated to be totally safe for a "life-time". The distribution of primary and secondary implantations is shown in Table 2. While technically it is often easier to implant an IOL as a combined primary cataract extraction and IOL implantation,

3 (2%)

>20 Implants

Total

2 (1%)

146 (100%)

Table 3. IOL types. Number of Patients With Infantile With Traumatic Cataracts Cataracts

Total

Binkhorst 2-loop

35 (27%)

45 (27%)

Binkhorst 4-loop

9 (7%)

13 (8%)

22 (7%)

80 (27%)

Medallion-style

54 (42%)

48 (29%)

102 (34%)

Choyce-style

12 (9%)

31 (19%)

43 (15%)

Other

20 (15%)

27 (16%)

47 (16%)

2 (1%)

2 «1%)

166 (56%)

296 (100%)

Unknown Total

130 (44%)

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(27%) for implantation in both infantile and traumatic cataract patients (Table 3). The Choyce-style lens (15%) and the 4-loop Binkhorst lens (7%) as well as a variety of unspecified IOLs (16%) were also implanted. The latter category often reHected earlier prototypes of the present day IOLs which were randomly used for clinical trials as they became available to surgeons.

Preoperative Complications. Preoperatively, many of these patients were found to have congenitally malformed or traumatized eyes (Table 4). These factors often adversely affected the visual results of cataract surgery and IOL implantation. It should be noted that some patients may have had several defects. Table 4. Preoperative complications.

with increased incision size (2%) and iris complications (3%) were also encountered infrequently. Iris complications have been significantly reduced by the use of the Sheets lens glide. 3 Table 5. Operative complications. Number of Patients With Infantile With Traumatic Cataracts Cataracts Posterior capsule rupture

Total

7 (5%)

16 (10%)

23 (8%)

13 (10%)

17 (10%)

30 (10%)

Hyphema

2 (2%)

7 (4%)

9 (3%)

Globe collapse

1«1%)

4 (2%)

5 (2%)

Iris complication

2 (2%)

6 (4%)

8 (3%)

Vitreous loss

Number of Patients With Infantile With Traumatic Cataracts Cataracts

Total

Early Postoperative Complications. The most frequent early postoperative complications, those occurring during the first two postoperative weeks, were striate keratitis, corneal edema and operative iridocyclitis (Table 6). On the other hand anticipated wound closure problems of Hat chamber (2%), prolapsed iris (0%) and wound dehiscence (0.3%) did not occur in the numbers which had been expected, based on past experiences with the larger incisions utilized for linear extraction.

Corneal scar

1«1%)

88 (53%)

89 (30%)

Adherent leukoma

4 (3%)

28(17%)

32(11%)

Micro eye

7 (5%)

Atonic pupil

4 (3%)

16 (10%)

20 (7%)

Iris atrophy

0

26 (16%)

26 (9%)

Iridodialysis

0

13 (8%)

13 (4%)

Congenital coloboma

6 (5%)

Traumatic coloboma

0

40 (24%)

40 (14%)

Number of Patients

Dislocated lens

0

8 (5%)

8 (3%)

Persistent hyperplastic plastoid vitreous

With Infantile With Traumatic Cataracts Cataracts

5 (4%)

0

5 (2%)

Glaucoma

I «1%)

3 (2%)

4 (1%)

Vitreous opacities

0

7 (4%)

7 (2%)

Macular scars

1«1%)

11 (7%)

12 (4%)

Optic nerve defects

5 (4%)

I «1%)

6 (2%)

Other

I «1%)

4 (2%)

4 (1%)

0

0

7 (2%)

6 (2%)

Operative Complications. The most significant operative complications were posterior capsule rupture (8%) and vitreous loss (10%) (Table 5). As expected, these complications were more frequent in patients following penetrating trauma. Hyphema (3%), collapse of the globe 168

Table 6. Early postoperative complications occurring within the first two weeks.

Total

Striate keratitis

59 (45%)

34 (20%)

93 (31%)

Corneal edema

59 (45%)

20 (18%)

79 (27%)

Iridocyclitis

64 (49%)

32 (19%)

96 (32%)

Pupillary block glaucoma

5 (4%)

2 (1%)

7 (2%)

Flat chamber

3 (2%)

'3 (2%)

6 (2%)

Wound dehiscence

0

I (0.6%)

I (0.3%)

Prolapsed iris

0

0

0

Endophthalmitis

0

0

0

Vitritis

I (0.8%)

9 (5%)

10 (3%)

Dislocated IOL

4 (3%)

7 (4%)

II (4%)

Other

2 (2%)

0

AM INTRA-OCULAR IMPLANT SOC J-VOL. IV, OCTOBER 1978

2 (0.6%)

Better wound closure techniques utilizing the operating microscope, finer sutures and sharper needles are partly responsible for these results.

Late Postoperative Complications. The late postoperative complications are tabulated in Table 7. The necessity for secondary membrane discission was the most frequent complication encountered. Most posterior capsules in children become opaque and it is therefore better to open them early to produce a clear visual axis.4 Table 7. Late postoperative complications. Number of Patients With Infantile With Traumatic Cataracts Cataracts Endothelial dystrophy

Total

also noted with medallion-style lenses (four patients), 4-100p lenses (three patients), Choyce-style lenses (three patients) and unspecified IOLs (two patients). Iris sphincter erosion was noted in 10 (3%) patients. This complication is frequently related to metal loop lenses. 5 Eleven (4%) IOLs were removed: two lenses from infantile cataract patients (one patient had had a fungus keratitis) and nine lenses following implantation in patients with traumatic cataracts. Four of these latter IOLs were removed because of corneal complications. Three IOLs were removed following secondary additional trauma to a previously traumatized eye. Five patients with traumatic cataracts had keratoplasties. Four of these were performed in combination with cataract extraction and IOL implantation.

7 (5%)

6 (4%)

13 (4%)

IOL precipitates

10 (8%)

16 (10%)

26 (9%)

IOL dislocations

4 (3%)

17 (10%)

21 (7%)

Secondary membranes

89 (68%)

80 (48%)

169 (57%)

Discission

81 (62%)

72 (43%)

153 (52%)

Pseudo membranes

II (8%)

9 (5%)

20 (7%)

Glaucoma

2 (2%)

2 (1%)

4 (1%)

Glaucoma surgery

1 (0.8%)

2 (1%)

3 (1%)

Iris sphinctererosion

5 (4%)

5 (3%)

10 (3%)

Occluded pupil

5 (4%)

6 (4%)

II (4%)

Iris atrophy

2 (2%)

7 (4%)

9 (3%)

Uveitis

6 (5%)

10 (6%)

16 (5%)

Number of Patients

Cystoid macular edema

0

3 (2%)

3 (1%)

With Infantile With Traumatic Cataracts Cataracts

Optic atrophy

0

I (0.6%)

1 (0.3%)

Detached retina

0

5 (3%)

5 (2%)

Phthisis bulbi

0

2 (2%)

2 (1%)

IOL removal

2 (2%)

9 (5%)

II (4%)

Enucleation

2 (2%)

0

2 (1%)

Keratoplasty

0

5 (3%)

5 (2%)

IOL precipitates were noted in 26 (9%) patients. Most of these disappear with time and generally do not require therapy.4 Late dislocations occurred in 21 (7%) patients and were either loop dislocations or total dislocations of unfixed IOLs. They occurred most frequently with the 2-100p IOL (9 patients), but were

DISCUSSION The number of patients with complications (excluding secondary membranes necessitating discission) occurring in the preoperative, operative, early postoperative or late postoperative periods are tabulated in Table 8. Of significance is the fact that 52% of the patients had preoperative defects and 32% had late postoperative complications. While many of these complications were of little significance, others were vision threatening, and, in some instances, resulted in the removal of the IOL, the loss of vision or the loss of the eye. Table 8. Summary of complications.

Total

Preoperative

32 (25%)

121 (73%)

153 (52%)

Operative

24 (18%)

36 (22%)

50 (16%)

Early postoperative

22 (17%)

66 (40%)

88 (30%)

Late postoperative

38 (29%)

56 (34%)

94 (32%)

There is no apparent difference in the late complication rate for different age groups or for the subgroups with infantile or traumatic cataracts. The numbers of infantile and traumatic cataract patients receiving specific IOL types were compared separately with the occurrence of late postoperative complications (Tables 9 and 10). Overall, the medal-

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lion-style iris suture lens had a lower complication rate (25%) than any of the other varieties of lenses implanted (Table 11). The reason for this reduced rate may be the greater stability of the secured IOL as compared to the more mobile 2-100p or 4-100p IOLs or to other types of IOLs. The Choyce-style IOL has its own series of complications peculiar to anterior chamber IOLs. Table 9. IOL type and late complication rate for infantile cataract patients.

Lens Type

Number of Patients Late Receiving Lens Complication Rate

The best corrected visual acuity must remain the yardstick with which to measure the success of an IOL implantation. The visual acuities were subdivided into categories: 20/ 20 to 20/ 40 (economically useful vision), 20/50 to 20/100 (adequate for standard educational techniques), 20/200 (a level of legal blindness) and those patients with less than 20/200 vision (visual failures). Several patients are listed as having unknown acuities; most of these were young or unresponsive children or patients lost to follow-up (Table 12). Table 12. Visual acuity results. Number of Patients

2-loop

35 (27%)

37% (13 patients)

4-loop

9 (7%)

67% (6 patients)

Medallion-style

54 (42%)

30% (16 patients)

Choyce-style

12 (9%)

8% (I patient)

Other

20 (15%)

20% (4 patients)

Total

130 (100%)

31% (40 patients)

Table 10. IOL type and late complication rate for traumatic cataract patients.

Lens Type

Number of Patients Late Receiving Lens Complication Rate

2-loop

45 (27%)

42% (19 patients)

4-loop

13 (8%)

54% (7 patients)

Medallion-style

48 (29%)

21% (10 patients)

Choyce-style

31 (19%)

39% (12 patients)

Other

27 (16%)

19% (5 patients)

Unknown Total

2 (1%) 166 (100%)

-

(1 patient)

33% (54 patients)

Table II. IOL type and late complication rate for all pediatric patients. Number of Lenses Implanted

Late Complication Rate

2-loop

80

40% (32 patients)

4-loop

22

59% (13 patients)

Lens Type

Medallion-style

102

25% (26 patients)

Choyce-style

43

30% (13 patients)

Other

47

19% (9 patients)

Unknown Total 170

2 296

-

(I patient)

32% (94 patients)

With Infantile With Traumatic Cataracts Cataracts

Total

20/ 20 to 20/40

30 (23%)

77 (46%)

107 (36%)

20/ 50 to 20/ 100

23 (18%)

29 (18%)

52 (18%)

20/ 200

13 (10%)

9 (5%)

22 (7%)

<20/ 200

42 (32%)

20 (12%)

62 (21 %)

Unknown

22 (17%)

31 (19%)

53 (18%)

Total

130

166

296 (100%)

Older cataract patients receiving implants often displayed better postoperative vision than did younger age groups if the patients had had good vision prior to the cataract's onset (Table 13). This differentiation is based upon the fact that patients with dense cataracts from birth have severe deprivation amblyopia prior to cataract surgery/ IOL implantation which may not respond to optical or occlusive therapy. Traumatic cataract patients also fare better in the older age groups than in the younger age groups (Table 14). Many of the visual decreases in these patients are due to severe injuries which induce organic as well as deprivational amblyopias not always remediable by optical, surgical or occlusive therapy techniques. Amblyopia was reported in 90 (69%) of the patients with infantile cataracts undergoing IOL implantation. Fifty-five (33%) patients suffering traumatic cataracts also had amblyopia. A total of 145 (49%) patients from the total series were am bl yopic at some time. Many of these patients do respond to occlusion and its use should be emphasized.· Strabismus is a frequent complication in children with cataracts; 122 (41 %) patients demonstrated an ocular malalignment at some time during the observation period. The strabismic deviations and other pre- and post-IOL implantation occurrences are compared by cataract subtypes (Table 15).

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Table 13. Postoperative visual acuity versus age for infantile cataract patients. Number of Patients (separated by degree of visual acuity) Age of patient (in years) at time of implant

20/20-20/40

<1

20/50-20/100

20/200

<20/200

Unknown

Total

0

0

5

8

14

I

0

I

0

3

6

10

2

2

4

4

5

4

19

3

0

4 5

2

6 7

2

0

2

7

II

3

0

0

2

6

2

3

4

4

15

3

0

2

2

8

1

I

0

6

0

4

3

8

3

0

0

>8

14

3

3

3

Unknown

2

3

1

3

4

13

Total

29

23

12

28

28

130

24

Table 14. Postoperative visual acuity acuity versus age for traumatic cataract patients. Number of Patients (separated by degree of visual acuity) Age of patients (in years) at time of implant

20120-20/40

20/50-20/100

20/200

<20/200

Unknown

Total


0

0

0

0

0

0

1

0

0

0

1

2

2

0

2

0

3

6

3

1

0

2

2

6

4

5

2

3

12

5

7

2

1

12

6

6

3

1

2

13

7

3

2

0

2

8

8

6

3

1

0

2

12

>8

37

12

I

10

3

63

II

4

2

4

11

32

30

166

Unknown Total

76

28

9

23

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The post-IOL group consists of those patients who either retained their pre-IOL strabismus or who developed a new strabismus (13 patients) following IOL implantation. Table 15. Strabismic deviations. Before IOL ImElantation

After IOL ImElantation

Infantile Cataract Patients

Traumatic Cataract Patients

Infantile Cataract Patients

Traumatic Cataract Patients

Esotropia

45

18

26

II

Exotropia

21

32

22

15

4

5

0

0

Hypertropia

Esotropia occurred more frequently in the infantile cataract patients both pre- and post-IOL implantation. Strabismus surgery was frequently performed in this group of patients (Table 16). Eighty-one (27%) patients underwent strabismus surgery at some time during this survey .. Since this is an ongoing series, it is expected that additional patients may develop strabismus with time and require additional surgeries for their ocular mal alignment.

satisfactory degree of fusion. However, a total of 112 (38%) patients achieved some fusion results at some time following IOL implantation. CONCLUSION The implantation of intraocular lenses in children has been successfully performed since 1959. The number of implants still remains very small, however, as compared to the number of implants performed in adult patients. Preoperative and postoperative complication rates remain much higher in these younger patients. Fifty-two percent of the patients brought preoperative complications to the implant surgeon. Operative complications arose in 16% of the patients. Early (30%) and late (32%) complications were frequently encountered. Strabismus (41 %) and amblyopia (49%) also distorted the final visual result. Thirty-six percent of all patients achieved 20/20 to 20/40 levels of visual acuity, with a surprisingly high fusion rate of 38%. REFERENCES 1. Binkhorst CD, Gobin MH: Ophthalmologica 148:169, 1964

2. Hiles DA, Wallar PH: Visual results following infantile cataract surgery. Int Ophthalmol Clinics 17 (4):265, 1977 3. Sheets ]H, Maida ]W: Lens glide in implant surgery. Arch Ophthalmol 96: 145, 1978 4. Hiles DA: Intraocular lenses in children. Int Ophthalmol Clinics 17 (4):221, 1977

Table 16. Strabismus surgery. Number of Patients With Infantile With Traumatic Cataracts Cataracts

Total

Before IOL implantation

27 (21%)

29 (17%)

After IOL implantation

20 (15%)

20 (12%)

40 (14%)

Total

47 (16%)

49 (17%)

96 (33%)

3. Sheets ]H, Maida ]W: Lens glide in implant surgery. Arch Ophthalmol 96:145, 1978 4. Hiles DA: Intraocular lenses in children. Int Ophtflalmol Clinics 17:221, 1977 5. Shepard DD: The dangers of metal-loop intraocular lenses. Ophthalmic Surg 8 (5):93, 1977

56 (19%)

The ultimate goal of IOL implant surgeons is not only to achieve normal vision in the implanted eye, but to obtain some degree of binocular awareness or fusion. This goal was achieved in 31 (24%) of the patients with infantile cataracts. Eightyone (49%) patients undergoing implantation following trauma achieved this level. This high percentage is related to the age at which trauma occurred: the older the patient, the more developed and stablilized is his binocular awareness prior to fusion disruption. Many patients in the infantile groups have had their fusion disrupted since birth and may not hope for a 172

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