Preliminary visual results of pediatric epikeratophakia

Epikeratoplasty for adult and pediatric aphakia, myopia, and keratoconus: the Massachusetts Eye and Ear Infirmary experience

Between February, 1985 and February, 1987, 49 eyes of 47 patients underwent epikeratoplasty for one of the following indications: adult aphakia (21 eyes; 20 patients), pediatric aphakia (10 eyes; 10 patients), myopia (7 eyes; 6 patients), and keratoconus (11 eyes; 11 patients). Follow-up at least 12 months (average = 18 months) is available for all 49 eyes. Of 49 eyes, 44 (90%) were anatomically successful with an intact, clear lenticule at least 12 months post-operatively, with no significant difference between the four groups (adult aphakia = 90%, pediatric aphakia = 90%, myopia = 86%, and keratoconus = 91%). The functional success rate, however, was 91% for keratoconus, 81% for adult aphakia, 80% for pediatric aphakia, and only 43% for myopia. We conclude that epikeratoplasty can be an effective tool in the treatment of carefully selected patients with adult or pediatric aphakia and keratoconus, but has only limited applicability in the management of myopia.

Long-term results of myopic epikeratoplasty

Twenty-three eyes of 20 patients who had had myopic epikeratoplasty were evaluated and the mean 21-month postoperative results (range: 12 to 47 months) tabulated. Average preoperative myopia was -16.7 diopters (D) spherical equivalent (range: -10 to -33 D), and average postoperative refractive correction was 13 D. Of 22 eyes, 17 eyes (77%) were within 4 D of emmetropia. Preoperative visual acuities without correction were between 2/200 and 20/100 (average = 2/40); postoperative acuities were between 2/200 and 20/20 (average = 20/40). Average preoperative best corrected visual acuity was 20/30. Best corrected visual acuities were unchanged or improved in 82% of cases. Re-epithelialization was complete within an average of seven days (range: three to 16 days) postoperatively except in one case in which the lenticule was removed because re-epithelialization did not occur. Five cases showed progressive loss of lenticular power.

Implantation in children

With the development of posterior chamber lenses and continuous curvilinear capsulorhexis, and with the availability of viscoelastic agents, the use of intraocular lenses (IOLs) in children is becoming more popular. Since 1982, we have implanted posterior chamber IOLs (PC-IOLs) in the capsular bags of 61 cataractous eyes of 46 children and adolescents. The goal was in-the-bag placement facilitated by the use of a small capsulectomy, and, since 1984, by the use of the continuous curvilinear capsulorhexis. Forty-four cataracts were congenital, 13 were traumatic, and 4 were developmental. Cataract extraction with IOL implantation was performed in 16 (26%) preschool cases (ages 2 through 5), in 31 (51%) child cases (ages 6 through 12), and 14 (23%) adolescent cases (ages 13 through 18). Surgical and postoperative complications were minimal. Visual results were good. Fifty-six percent of preschoolers, 87% of children, and 86% of adolescents achieved 20/40 or better best corrected vision, with 79% of the total cohort achieving 20/40 or better. Overall, 35% achieved an uncorrected visual acuity of 20/40 or better. All but two cases had improvement in best corrected vision; if 20/20 was not attained, the cause was mainly due to deprivation amblyopia. Forty-eight percent of patients were within a diopter of emmetropia.

Risk factors for complications following pediatric epikeratoplasty

We studied the prevalence and types of complications that occurred in children treated with epikeratoplasty to identify risk factors. A review of the clinical records of 88 consecutive patients (106 eyes; 114 procedures) revealed that no complications occurred in 58 grafts (54%). Refractive complications (refractive error greater than 3.00 diopters spherical equivalent from emmetropia or astigmatism greater than 3.00 diopters) occurred in 30 eyes (28%). Medical complications occurred in 22 eyes (19%); these included epithelial defects (14 grafts), interface opacities (six grafts), graft vascularization (eight grafts), graft infection (two grafts), graft necrosis (five grafts), graft haziness (four grafts) or opacification (11 grafts), and graft dehiscence (three grafts). Eleven grafts (10%) were removed and five eyes received new grafts. Epikeratoplasty in children will be more successful if risk factors such as patient age less than one year, microcornea, corneal endothelial cell dysfunction, mental retardation, and combining the procedure with cataract surgery are avoided.

Visual performance after aphakic epikeratoplasty

While good visual acuity and refractive results after epikeratoplasty for aphakia have been reported, particularly for adults and older children, limited detailed information on the nature of the resulting vision is available. We have evaluated the visual performance of seven aphakic subjects corrected by epikeratoplasty by measuring contrast sensitivity, with and without the presence of glare. These results were compared with those for other aphakic corrections, namely spectacles (n = 5 eyes), contact lenses (n = 5 eyes), or intraocular lens implantation (n = 5 eyes). There were statistically significant differences among these four aphakic correction types (p = 0.0330), with a consistent trend for diminished visual performance after epikeratoplasty. Threshold elevations occurred in the presence of glare, but they were not statistically different between the groups (p = 0.1631). Based on these visual assessments, epikeratoplasty does result in statistically significant visual losses. Despite this, it may still offer an acceptable alternative to other managements of the aphakic patient when those others are contraindicated.

Visual results after early surgical treatment of unilateral congenital cataracts

The authors reviewed the records of 25 consecutive patients who had been operated on for unilateral congenital cataracts at 1 year of age or younger and who had been followed for a period of 5 years or longer. Excluded were patients who demonstrated retinal and optic nerve anomalies. Five eyes achieved 20/40 or better Snellen visual acuity, 5 eyes achieved 20/50 to 20/100 visual acuity, and 15 eyes had 20/200 or less visual acuity. All patients with visual acuity of 20/40 or better had cataract surgery performed before 17 weeks of age, the critical period, and surgery was scattered within this time frame. For surgery performed between 17 weeks and 1 year of age, the best achieved visual acuity in children with surgically significant unilateral congenital cataracts was between 20/50 and 20/100. There was no correlation between the age at the time of surgery and the attainment of these visual levels in this patient subset.

National outcomes of cataract extraction. I. Retinal detachment after inpatient surgery

Rehospitalization for retinal detachment (RD) was studied in 338,141 Medicare beneficiaries older than 65 years of age who were undergoing inpatient cataract extraction in 1984. Extracapsular cataract extraction (ECCE) was performed in 60% of patients, intracapsular cataract extraction (ICCE) in 31%, and phacoemulsification in 9%. The risk of rehospitalization for RD within 4 years of ICCE was 1.55% over 1.5 times the risk associated with ECCE (0.9%). The risk of RD after phacoemulsification was 1.17%. Cataract surgery accompanied by anterior vitrectomy was associated with a 5.0%, likelihood of RD at 4 years, which is 4.5 times greater than that for cataract surgery alone (1.12%). White patients were 1.7 times more likely to be rehospitalized for RD than were black patients (1.15% versus 0.67%; P less than 0.001). In both races, younger patients were more likely to be rehospitalized for RD than were older patients (P less than 0.001). While the increased rate of RD after ICCE versus ECCE confirms previously held clinical beliefs, the increase in the risk following phacoemulsification (P less than 0.0001) has not been reported previously.

Epikeratoplasty with nonlyophilized tissue in children with aphakia

We studied 75 epikeratoplasty procedures using nonlyophilized tissue performed by eight ophthalmic surgeons in 70 eyes (47 patients) to correct for aphakia in children less than 8 years of age (mean age, 3.4 +/- 2.1 years). Of the 47 patients in the study, 24 were girls and 23 were boys; 23 patients had bilateral surgery. Seven of the epigrafts required removal; two were not replaced, and five underwent successful repeat epikeratoplasty. Overall, the success rate (that is, the percentage of epigrafts that remained optically and functionally clear throughout the course of this study) for the epikeratoplasty procedure was 89% (62 of 70 eyes) for initial surgery and 96% (67 of 70 eyes) for repeat surgery. The average spherical equivalent was +14.4 +/- 3.7 diopters preoperatively and +0.3 +/- 2.9 diopters one year after the operation. One year after the final surgical procedure, 42 of 56 eyes (75%) were within 3 diopters of emmetropia. In the 29 verbal patients, best-corrected visual acuity was 20/100 or better in 25 (86.2%) one year after the operation.

Visual acuity in monocular pediatric aphakia: does epikeratophakia facilitate occlusion therapy in children intolerant of contact lens or spectacle wear?

Twenty-two children had a monocular cataract extracted between 1981 and 1986. Twelve of these patients eventually tolerated a monocular contact lens or anisometropic spectacle wear. Eleven patients initially would not tolerate conventional therapy, and epikeratophakia was performed. Of the 12 patients tolerating a contact lens or spectacles, eight (67%) now see 20/60 or better, and six (50%) see 20/40 or better. Only one (10%) of the patients maintaining the epikeratophakia graft developed vision as good as 20/70. Epikeratophakia did not facilitate occlusion therapy for amblyopia. The critical factor in the development of good vision following monocular cataract extraction was the patient's willingness to patch the better eye, not the method of correcting the refractive error.

The nationwide study of epikeratophakia for aphakia in older children

A nationwide study of epikeratophakia for aphakia in older children was conducted from March 1984 to March 1986. Sixty-three patients, 8 to 18 years of age, underwent this procedure in 65 eyes. Twenty-eight patients had congenital cataracts and 35 had traumatic cataracts. Fifty-one of the 65 eyes were aphakic at the time of surgery (secondary procedures). All surgeries were successful; no tissue lenses were lost or removed. Postoperatively, 73% of the patients were within 3 diopters (D) of emmetropia. The patients with congenital cataracts gained an average of one Snellen line of best-corrected visual acuity; patients with traumatic cataracts lost an average of one Snellen line of best-corrected visual acuity. In older pediatric patients, epikeratophakia appears to be a safe and effective procedure for the correction of aphakia.

Traumatic cataracts in young children. Correction of aphakia by intraocular lens implantation

Thirty-seven children aged two to ten years old sustained unilateral traumatic cataract. Aspiration of the traumatic lens was followed by intraocular lens implantation in these 37 eyes. In 23 eyes an IOL was inserted during the initial surgical setting; in 14 eyes a secondary implantation was performed. In 34 eyes posterior capsulotomy and anterior vitrectomy was performed before insertion of the lens. No major post-operative complications were observed during the period of follow-up ranging from six to 24 months. In three cases, posterior capsulotomy was not carried out. Secondary surgical intervention was needed and the final visual outcome was poor in these three eyes. Visual acuity of 6/12 or better was achieved in 77% and 69% of the cases after primary or secondary IOL implantation, respectively. Best visual results were recorded in most cases four to ten months after the surgery. These results demonstrate that IOL implantation is a practical approach even in children of the younger age groups.

Epikeratoplasty. The surgical correction of aphakia, myopia, and keratoconus

Thirty-five patients have had 39 consecutive epikeratoplasty procedures (12 adult aphakic, 9 pediatric aphakic, 12 myopic, and 6 keratoconic eyes) by the same surgeon, using commercially prepared lenticules. The lenticule remained totally clear in 85% of eyes. Two lenticules were removed due to infection and scarring; four lenticules had minimal scarring and did not require removal. Spectacle-corrected acuity was worse than one line from the preoperative spectacle-corrected acuity in 58% of the adult aphakic eyes; however, 75% were 20/50 or better postoperatively. Fifty percent were within 2 diopters (D) of emmetropia and 92% within 3 D. All pediatric aphakic patients showed an improvement in best-corrected acuity, and 83% of eyes at 6 months were within 2 D of emmetropia; by 1 year a 3.4-D average myopic shift had occurred. Two of the six eyes (33%) using the original myopia technique were within 2 D of emmetropia, whereas five of the six eyes (83%) with the current technique are within this range. Spectacle-corrected acuity in the entire current myopia group has either improved by one or more lines or has remained unchanged. Five of the six keratoconic eyes had 20/40 or better spectacle-corrected and 20/25 contact lens-corrected acuity postoperatively; average corneal flattening was 6 D. Persistent epithelial defect and irregular astigmatism were the principal factors in delay in visual recovery.

The nationwide study of epikeratophakia for myopia

In the nationwide study of epikeratophakia, 116 ophthalmic surgeons performed 352 procedures for the correction of myopia; 256 of the eyes had 30 or more days of follow-up after suture removal. Of 204 eyes, 153 (75%) were within 30% of emmetropia after surgery. Of 208 eyes, 202 (97%) had postoperative best corrected visual acuity within two Snellen lines or better of their preoperative visual acuity. All but one patient improved uncorrected visual acuity. Of the 120 patients who equaled or improved their preoperative best corrected visual acuity, 116 (97%) were within two Snellen lines of their preoperative measurement between 30 and 60 days after suture removal. Corneal astigmatism changed from a preoperative mean (+/- S.D.) of 1.4 +/- 0.8 diopters to a postoperative mean of 2.6 +/- 2.1 diopters. Of 352 tissue lenses, 36 (10%) were removed, largely as a result of inaccurate power, decay, or failure to reepithelialize, and 17 of these eyes underwent a second successful epikeratophakia procedure.

The nationwide study of epikeratophakia for aphakia in children

In the nationwide study of epikeratophakia, 97 surgeons performed a total of 335 procedures in 314 eyes for the correction of aphakia in children under the age of 8 years 1 month. Fifteen children underwent bilateral surgery. Thirty-six tissue lenses were removed and 21 of these eyes underwent a second epikeratophakia procedure. Overall, the success rate for procedures was 89%, and with repeated surgery it was 95% for eyes. Seventy-three percent of the patients were within 3 diopters of emmetropia after surgery. Visual acuity results in patients able to provide verbal responses to the illiterate E, Allen card, or Snellen line chart testing showed improvement in most cases. The safety of epikeratophakia makes it a desirable option for the correction of aphakia in children who are spectacle or contact-lens intolerant, and the permanence of the correction eliminates the problem of optical noncompliance.

The nationwide study of epikeratophakia for aphakia in adults

In the nationwide study of epikeratophakia, 154 ophthalmic surgeons who had attended a training course performed 519 procedures for the correction of aphakia in adults: 310 of the eyes had 30 or more days of follow-up after suture removal. Of 229 eyes, 172 (75%) were within 3 diopters of emmetropia after surgery. Of 259 eyes, 245 (95%) demonstrated improved uncorrected visual acuity; 138 (53%) improved by four or more Snellen lines. Of 265 eyes, 209 (78%) achieved within two lines or improved their best corrected visual acuity. Of the 119 patients who achieved or improved their preoperative best corrected visual acuity, 110 (92%) were within two Snellen lines or better by 30 to 60 days after suture removal. Of the 127 patients with more than three months of follow-up after suture removal, 124 (98%) of those between 18 and 70 years of age but only 13 of 23 (54%) of those between 81 and 87 years of age achieved within two lines or better of their best corrected visual acuity. Corneal astigmatism measured by keratometry changed from a preoperative mean (+/- S.D.) of 2.1 +/- 1.8 diopters to a postoperative mean of 2.7 +/- 2.6 diopters. Of the 519 tissue lenses, 22 (4%) were removed, and one third of these patients underwent a second, successful epikeratophakia procedure.

Nonfreeze epikeratophakia for the correction of myopia

We developed a procedure for preparing epikeratophakia tissue lenses for the correction of myopia from unfrozen tissue using a newly developed artificial anterior chamber and the BKS-1000 (Barraquer-Krumeich-Swinger) refractive set. The results of 23 clinical cases involving tissue that was not frozen or lyophilized demonstrate a correlation coefficient of 0.90 in terms of accuracy of correction and good visual acuity results.

Secondary cataracts in infants after lensectomies

Three infants, one who was two weeks old, and two who were two months old, underwent lensectomy and vitrectomy in a total of four eyes for congenital cataracts by means of an automated suction cutter. Two patients with unilateral opacities underwent combined cataract extraction and epikeratophakia, and one with bilateral congenital cataracts underwent cataract extractions and was fit with extended wear contact lenses. In all cases, the surgery involved at least a 5-mm posterior capsulotomy with a shallow anterior vitrectomy, and was uneventful. Three of the four eyes developed new opacities that required surgical removal three to five months after the original surgery. Cytological evaluation of the specimen obtained from one patient showed this material to be lens epithelium. In all three cases, the material grew without the support of the posterior capsule; in one patient the material appeared to have seeded onto the iris. This previously unreported complication in infants with congenital cataracts who have undergone posterior capsulotomy and anterior vitrectomy emphasizes the need for frequent retinoscopies on such patients. The absence of the posterior capsule does not guarantee that these children will not develop secondary growth of lens epithelium which may obstruct the visual axis.

Five year follow-up of epikeratophakia in children

Epikeratophakia alters the anterior curvature of the cornea by the addition of a machine-carved donor lenticule. Since March 1980, 88 patients under eight years of age have had epikeratophakia, with at least six months of follow-up. Eighty percent of the original surgeries were successful; some failed grafts were replaced successfully, so that in all, 89% of the patients had successful grafts. The average increase in curvature of the cornea was 14.7 diopters, and the average spectacle overcorrection was +0.56 diopters. In these growing eyes, we documented a myopic shift of 1.5 diopters per year. Visual acuity results varied with the timing of refractive surgery, density of the amblyopia, and the parents' ability to maintain the patching schedule. The largest group of children were those who had unilateral traumatic cataracts. In this group, 7 of 15 patients who had surgery under 4 years of age had final verbal acuities of 20/40 or better. Long-term follow-up has demonstrated that epikeratophakia safely and successfully corrects refractive errors in aphakic children either as a primary procedure, or as a secondary procedure after cataract extraction.

Epikeratophakia in children with corneal lacerations

Epikeratophakia grafts were used to optically correct aphakia in six children who suffered traumatic cataracts and corneal lacerations which were greater than 3 mm in length. The ages of the patients at the time of corneal laceration ranged from nine months to 3 3/12 years. Five of the six grafts were successful. The average increase in corneal curvature was 16.11 diopters with an average over-refraction of -0.73 diopters. The deprivation interval in the five children with successful grafts ranged from two months to two years, and the average visual acuity for the four verbal patients with successful grafts was 20/60. This series demonstrates that epikeratophakia grafts can be successfully applied to scarred and irregular corneas and may be superior to penetrating keratoplasty in some cases, because epikeratophakia allows for a prompt restoration of visual function.

Epikeratophakia in children

Epikeratophakia was performed in 61 children for the correction of aphakia after the removal of unilateral congenital or traumatic cataracts; 51 patients (54 grafts) have more than 6 months follow-up. In the first 27 grafts, 8 (30%) failed, but in the last 27 grafts, only 2 (7%) failed, largely due to improved surgical and tissue handling techniques. The average increase in corneal refractive power for the early patients was 12.68 +/- 4.63 D with an average overrefraction of +0.45 +/- 5.60 D. The last half of the patients showed an average increase of 14.83 +/- 4.83 D, with an average overrefraction of -0.00 +/- 5.20 D. Visual acuity results in patients with traumatic cataracts have been the most satisfactory, with the majority of patients obtaining useful vision. It also appears that in patients with congenital cataracts, the younger the patient at the time of surgery, the greater the chance for a good visual result. Some improvement in vision has been seen in all of the children with successful grafts, even those beyond the age when amblyopia therapy would be considered to have some potential for therapeutic effect. By attaching the correction permanently on the eye, epikeratophakia facilitates the vigorous occlusion therapy required after cataract extraction in these children.