Secondary capsule-supported intraocular lens implantation in children

Secondary capsule-supported intraocular lens implantation in children Ashok Sharma, MD, Surendra Basti, DNB, Satish Gupta, MD

ABSTRACT Purpose: To evaluate surgical problems, postoperative complications, and visual results of secondary posterior chamber intraocular lens (IOL) implantation in children. Setting: L.V. Prasad Eye Institute, Hyderabad, India. Methods: A retrospective study was done of secondary IOL implantation in 27 children (35 eyes) who were not satisfied with aphakic glasses and were intolerant of or reluctant to use contact lenses. The extent of posterior capsular support was assessed prior to surgery. Additional surgical procedures were posterior synechiolysis (11 eyes), anterior vitrectomy (8 eyes), pupilloplasty (2 eyes), and membranectomy (2 eyes). Results: Postoperative complications included wound leak (1 eye), uveitis (5 eyes), peripheral anterior synechias (2 eyes), and retinal detachment (1 eye). Visual acuity improved or remained at the preoperative level in 34 eyes. Conclusion: Secondary posterior chamber IOL implantation is an effective optical modality for managing pediatric aphakia. Observation must continue to determine the long-term safety of the procedure. J Cataract Refract Surg 1997; 23:675-680

O

ptical correction of pediatric aphakia is challenging. Aphakic glasses offer an imperfect solution because of visual field restriction and induced prismatic effects. 1 Contact lenses, although useful, are associated with the risk of infection. Repeated insertion and removal of a contact lens can be psychologically traumatic to the child. 2 ,3 Increased cost, epithelial healing problems, interface scarring, and nonavailability oflenticules have restricted the use of epikeratophakia for correcting pediatric aphakia. 4 ,5 Optical correction with an intraoc6 ular lens (IOL) provides good quality vision. Although From Sight Savers' Cornea Training Centre (Sharma) and Cornea Service (Basti, Gupta), L. V. Prasad Eye Imtitute. Reprint requests to Satish Gupta, MD, L. V. Prasad Eye Institute, Road #2, Banjara Hills, Hyderabad-500 034, India.

initial reports indicated an increased rate of complications with the use of IOLs in children? recent reports have shown encouraging results. 8 ,9 Intraocular lens implantation is, however, suboptimal in children below 2 years of age because of significant alterations in IOL power from a rapid increase in the axial length. 10 A recent surveyll indicates that IOL implantation was the preferred modality for correcting pediatric aphakia among 27% of the responding members of the American Society of Cataract and Refractive Surgery and 46% of the responding members of the American Association of Pediatric Ophthalmology and Strabismus. Secondary IOL implantation is a safe option for adult aphakes; it has been recommended for patients having difficulty with aphakic glasses, unilateral . . Ierant to contact Ienses. 12-14 ap hakes, an d patlents mto

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The only reports of secondary posterior chamber IOLs in children have been combined with secondary IOL implantation in adults or with primary IOL implantation in children. 6 ,15,16 There have been no reports dedicated to secondary IOL implantation in children. In this paper, we report the surgical technique, intraoperative problems, postoperative complications, and visual results of secondary IOL implantation in children.

Patients and Methods Thirty-five secondary IOL implantations were performed in 27 children between January 1991 and December 1994. Patients were selected for secondary IOL implantation on the basis of parental or patient dissatisfaction with aphakic glasses, reluctance to use or intolerance to contact lenses, or both. After the risks and benefits of secondary IOL implantation were explained to each child's parents, informed consent was obtained. A complete ophthalmic examination including visual acuity, slitlamp biomicroscopy, and fundus examination after mydriasis was performed prior to surgery. Presence of posterior synechias, extent of the posterior capsule, and presence of vitreous in the anterior chamber were documented. Associated ocular structural abnormalities were recorded. In children who did not permit reliable examination, examination was performed under general anesthesia. If the posterior capsule was not visible in the pupillary area during examination under anesthesia, depression was performed posterior to the limbus using a blunt-tipped forceps while simultaneously rotating the globe in the direction of the forceps (Figure O. This was performed 360 degrees to assess the extent of posterior capsular support. In cases in which dense posterior synechias precluded visualization of posterior capsular support superiorly, examination through peripheral iridectomy was done to look for evidence of posterior capsular remnants (Figure 2). Axial length was measured, keratometry performed; IOL power was calculated using the SRK II formula. When children did not cooperate for axial length measurement, it was done under general anesthesia just before surgery. For children in whom keratometry could not be performed, the standard-for-age K-readings were used. 17 Children between 2 and 4 years of age were corrected to achieve 2.0 diopters (D) of hypermetropia; children above 4 years were corrected to achieve emmetropia. In chil676

Figure 1. (Sharma) Evaluating posterior capsular support using a blunt-tipped forceps. It depresses the globe just posterior to the limbus while rotating the globe in the opposite direction. The rim of posterior capsule is visualized at the 6 o'clock position behind the iris.

Figure 2. (Sharma) Posterior capsular rim seen through the peripheral iridectomy.

dren below 5 years, preoperative mydriasis was obtained using atropine sulfate 1% eye ointment twice daily starting 3 days before surgery. In children 5 years and older, six applications of phenylephrine 10% and homatropine hydro bromide 1% were used starting 3 hours prior to surgery. All children were operated on using general anesthesia. The surgical procedure for secondary posterior chamber IOL implantation was as follows: A fornixbased conjunctival flap was raised and a 6 mm, posterior limbal, two-plane incision made. Synechiolysis was done by injecting viscoelastic material (2% methylcellulose) through the peripheral iridectomy. In patients with dense peripheral anterior synechias, synechiolysis was

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performed with an iris spatula; if this was not successful, synechiotomy was performed with Vannas scissors. lridoplasty and pupilloplastywere performed to repair preexisting iris defects using 10-0 polypropylene sutures. In cases with Elshnig-pearl-type posterior capsule opacification (PCO), the posterior capsule was polished by vacuuming with a Simcoe cannula. In eyes that had a densely fibrotic PCO, the PCO was first cut into strips with Vannas scissors. Membranectomy was then performed with a guillotine-type vitreous cutter, using a low cutting rate (50 cuts/minute) and high vacuum (300 mm Hg). The vitreous cutter was also used to clear the corneoscleral wound and anterior chamber of vitreous. The anterior chamber was then deepened with 2% methylcellulose and a one-piece, all-poly(methyl methacrylate), posterior chamber IOL with modified C-loops and a 13.5 mm haptic spread was inserted into the ciliary sulcus. The corneoscleral wound was sutured using 10-0 polyamide sutures. A Simcoe cannula was used to meticulously remove viscoelastic from the anterior chamber at the conclusion of surgery. A subconjunctival injection of gentamicin sulfate (10 mg) and dexamethasone (2 mg) was given and the eye was patched. The day after surgery a slitlamp biomicroscopic examination was performed and the patients were prescribed topical betamethasone sulfate 0.1% every 2 hours, cyclopentolate hydrochloride 1% twice a day, gentamicin eyedrops 0.3% every 6 hours, and gentamicin-dexamethasone eye ointment at bedtime. These medications were tapered and then stopped 6 weeks postoperatively. Retinoscopy was done 2 weeks after surgery. In children less than 8 years of age who had amblyopia, the good eye was completely occluded with a suction occluder. Standard occlusion regimen was fol10wed. 18 In bilateral cases with asymmetric fixation, amblyopia therapy was continued in the first eye until fixation in the two eyes was comparable. Surgery was then performed in the second eye. In cases with bilateral aphakia and symmetric fixation, surgery was performed in the second eye within a week after surgery in the first eye. Both eyes were refracted 2 weeks after the second surgery and the refractive correction prescribed. A complete ocular examination including refraction, slitlamp biomicroscopy, intraocular pressure measurement, and fundus examination by indirect ophthalmoscopy with scleral depression was performed

6 weeks postoperatively and every 3 months thereafter up to 1 year. Follow-up visits were then scheduled every 4 to 6 months. Posterior capsule opacification was considered significant if the visual axis was obscured on distant direct ophthalmoscopy and a two-line drop in visual acuity was noted.

Results Demographic details are summarized in Table 1. In 16 eyes (46%), both primary surgery and secondary IOL implantation were done at L.V. Prasad Institute; in 19 eyes (56%), primary surgery was performed by the referring physician. The primary surgical procedures were extracapsular cataract extraction (ECCE) in 32 eyes and ECCE with primary posterior capsulotomy and anterior vitrectomy in 3 eyes. Status of the posterior capsule is shown in Table 2. Secondary IOL implantation was performed in all eyes (Figures 3 and 4). Posterior synechiolysis was performed in 11 eyes: in 6 a viscoelastic substance was used, Table 1. Demographic details of patients. Number of Eyes Laterality Unilateral Bilateral

19 16

Type of cataract Infantile Traumatic

20 15

Age at primary surgery (years) Mean Range

7.85 1-14.75

Duration between primary surgery and secondary IOL (years) Mean Range

3.69 0.25-14

Age at secondary IOL implantation (years) Mean Range

11.54 2.50-17

Table 2. Preoperative status of eyes. Status Aphakia with Aphakia with Aphakia with with vitreous

intact posterior capsule open posterior capsule open posterior capsule in anterior chamber

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Figure 3. (Sharma) Postoperative photograph after secondary IOl implantation. The anterior segment structures are well preserved.

Figure 4. (Sharma) Postoperative photograph after secondary IOl implantation. An inferior radial sphincterotomy was performed in this case. Pigments are seen on the inferior part of the posterior capsule following synechiolysis in this area.

in 3 an iris spatula, and in 2 a Vannas scissors. Severe hypotony with scleral collapse occurred in 2 eyes; repeated injections of 2% methylcellulose into the anterior chamber were needed to implant the IOL in these eyes. Additional surgical procedures are shown in Table 3. Postoperative complications are shown in Table 4. The patient with a retinal detachment complained of a sudden diminution in vision 1 month after IOL implantation. He had a three-quadrant dialysis of the ora serrata along with a total detachment. Preoperative fundus examination with indirect ophthalmoscopy and scleral depression was unremarkable. Retinal detachment surgery was unsuccessful, and the patient had no light perception at the last follow-up. Postoperatively, the required cylindrical correction was below 1.0 D in 28 eyes (80%), 1.5 to 2.5 D in 4 (11 %), and 3.0 D or more in 3 (9%). In the latter 3 eyes, the astigmatism was with the rule. Suture removal decreased the astigmatism to below 2.5 D. In 34 eyes

(91 %), visual acuity improved or remained at the preoperative level (Table 5). Significant peo was observed in 3 eyes, and neodymium:YAG capsulotomies were performed successfully. The postoperative course was otherwise unremarkable in all eyes during the mean follow-up of21 weeks (range 6 to 52 weeks). Table 4. Complications following secondary IOl implantation (N = 35).

Complication

Number of Eyes

Percentage

Uveitis' Posterior synechias pcot Peripheral anterior synechias Wound leak* Retinal detachment

5

14

5 3 2

14 9 6 3 3

'Greater than grade 2, Hogan's classification 19 tPosterior capsule opacification *Required suturing

Table 5. Visual acuity prior to and following secondary IOl implantation (N = 35).

Table 3. Additional surgical procedures performed.

Number of Eyes

Procedure

Number of Eyes

Percentage

Posterior capsule polishing Anterior vitrectomy Posterior synechiotomy Pupilloplasty Membranectomy lens matter aspiration Scleral fixation of haptic

5 8

14 26 31 6 6 6 3

678

11 2 2 2

Visual Acuity

Prior to Surgery

Post Secondary IOL Implantation

<20/300 20/200 to 20/80 20/70 to 20/50 20/40 to 20/30 20/25 to 20/20

14 6 3 6 6

10' 6 4

7 8

'One eye had no light perception following a retinal detachment

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Discussion Although secondary 10L implantation can reduce best corrected visual acuity, the preoperative visual acuity has been maintained in 84 to 100% of adults who had this surgery.12,16,20,21 In our study, preoperative visual acuity improved or remained the same in 34 eyes (97%). Pre-existing amblyopia, nystagmus, and unilateral strabismus were responsible for poor visual outcome in some patients. The procedure is not totally without hazard, as exemplified by 1 patient whose visual acuity dropped from 20/60 preoperatively to no light perception at the last follow-up from a rhegmatogenous retinal detachment. The risks and benefits of the procedure should be clearly explained to and understood by parents prior to surgery. Low ocular rigidity in children usually results in scleral collapse and hypotony during intraocular surgery?2 We encountered this problem in two eyes. In one eye, ECCE with primary posterior capsulotomy with anterior vitrectomy had been performed. The other eye had extensive synechiolysis with anterior vitrectomy at the time of secondary 10L implantation. Open posterior capsule and vitrectomy may have precipitated scleral collapse and hypotony in both these eyes. Endothelial damage and iris trauma should be minimized in such cases. Use of a Flieringa ring has been recommended to avoid endothelial touch from scleral collapse during surgery in children?2 We used repeated injections of methylcellulose 2% to restore globe contour in these eyes. The use of a high-viscosity viscoelastic may be advantageous in managing this condition. A higher incidence of cystoid macular edema (CME) with secondary 10L implantation in adults in whom vitreous loss occurred at the time of initial cataract surgery has been reporte d .1323 ' Other stud'les 21,24 performed on similar patients, however, reported excellent results when a careful and controlled vitrectomy was performed with secondary 10L implantation. Our findings agree with the latter; eight eyes needed anterior vitrectomy, and we did not observe clinical CME in these cases. Bilateral uveitis (possibly sympathetic ophthalmia), resulting in blindness in a child following secondary 10L implantation for unilateral congenital cataract has been reported. 25 Sympathetic ophthalmia is an infrequent but potentially sight-threatening complication

that can occur following any kind of surgical trauma to the eye. We believe the incidence of this complication with secondary 10L implantation in children is the same as with that of any other surgical procedure. Bilateral uveitis was not seen in any of our patients following surgery. Five of our patients developed increased anterior uveitis (>grade 2, Hogan's classification 19) on the first postoperative day. Extensive synechiolysis had been performed in each of these cases; this is likely to have been the cause of the increased uveitis. One eye developed a rhegmatogenous retinal detachment 5 weeks after secondary 10L implantation. An anterior vitrectomy had been performed prior to 10L insertion in this case. Inadvertent vitreous traction during this procedure may have caused a retinal break. Careful and meticulous removal of vitreous during vitrectomy and periodic detailed fundus examination in such cases are important. None of our patients developed corneal edema or glaucoma. Axial length increases in the growing child. Most of the elongation occurs during the first 18 months of life. 17 The eyeball is known to elongate at the rate of 0.5 mm per year between 2 and 4 years of age. The overall increase thereafter until adulthood is 1.0 mm. We therefore aimed at making the eye hypermetropic by 2.0 D in children aged 2 to 4 years and emmetropic in children more than 4 years of age. In all patients, the postoperative refractive errors corresponded to the intended results. Our study shows encouraging results with secondary 10L implantation in children. Observation of these cases must continue, however, to determine the longterm safety of the procedure.

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