Journal of Pediatric Ophthalmology and Strabismus

Original Article 

Pars Plana Lensectomy for the Management of Ectopia Lentis in Children

Alex J. Shortt, MSc, MB, BCh; Bernie Lanigan, RN

Abstract

Background:

Nontraumatic ectopia lentis arises from a variety of inherited disorders. It may also occur as an isolated abnormality in an otherwise healthy individual. Surgical intervention is necessary when lens subluxation causes a significant refractive error resulting in amblyopia.

Patients and Methods:

We report the results of pars plana lensectomy for nontraumatic ectopia lentis in 24 eyes of 13 patients and provide data on the merits of this surgical approach.

Results:

Postoperative visual acuity was 6/9 or better in 17 of 22 eyes and 6/12 or better in 19 of 22 eyes. Other than contact lens–related problems, there were no perioperative or postoperative complications.

Conclusions:

Pars plana lensectomy is a safe, effective procedure for the management of ectopia lentis. Visual outcomes are excellent. These findings should encourage earlier surgery when indicated to prevent amblyopia and improve visual acuity.

J Pediatr Ophthalmol Strabismus 2004;41:289–294.

The authors are from the National Children’s Eye Centre, Children’s University Hospital, Dublin, Ireland.

Address reprint requests to Professor Michael O’Keefe, FRCS, National Children’s Eye Centre, Children’s University Hospital, Temple Street, Dublin 1, Ireland.

Received: August 05, 2003
Accepted: October 30, 2003

Abstract

Background:

Nontraumatic ectopia lentis arises from a variety of inherited disorders. It may also occur as an isolated abnormality in an otherwise healthy individual. Surgical intervention is necessary when lens subluxation causes a significant refractive error resulting in amblyopia.

Patients and Methods:

We report the results of pars plana lensectomy for nontraumatic ectopia lentis in 24 eyes of 13 patients and provide data on the merits of this surgical approach.

Results:

Postoperative visual acuity was 6/9 or better in 17 of 22 eyes and 6/12 or better in 19 of 22 eyes. Other than contact lens–related problems, there were no perioperative or postoperative complications.

Conclusions:

Pars plana lensectomy is a safe, effective procedure for the management of ectopia lentis. Visual outcomes are excellent. These findings should encourage earlier surgery when indicated to prevent amblyopia and improve visual acuity.

J Pediatr Ophthalmol Strabismus 2004;41:289–294.

The authors are from the National Children’s Eye Centre, Children’s University Hospital, Dublin, Ireland.

Address reprint requests to Professor Michael O’Keefe, FRCS, National Children’s Eye Centre, Children’s University Hospital, Temple Street, Dublin 1, Ireland.

Received: August 05, 2003
Accepted: October 30, 2003

Introduction

Nontraumatic ectopia lentis refers to the partial displacement (subluxation) or complete dislocation of the crystalline lens from its normal position, arising from a variety of inherited disorders. It can occur as a manifestation of Marfan syndrome, homocystinuria, Weill–Marchesani syndrome, hyperlysinemia, and sulfite oxidase deficiency. It may also occur as an isolated abnormality in otherwise healthy individuals such as in essential familial ectopia lentis or isolated idiopathic ectopia lentis.

Whereas trauma is the most common cause of ectopia lentis, the group of patients referred to above represents a well-defined pediatric cohort, and their treatment has caused considerable controversy in the past. Several studies have demonstrated that with the use of modern microsurgical techniques, intervention is successful and safe.1–7 The two procedures commonly performed are limbal lensectomy and anterior vitrectomy or pars plana lensectomy and anterior vitrectomy.

We report the results of pars plana lensectomy for nontraumatic ectopia lentis in 24 eyes of 13 patients and provide data regarding the relative merits of this approach.

Patients and Methods

Patients

Thirteen patients (12 boys and 1 girl) underwent surgery for nontraumatic ectopia lentis between November 1988 and September 2002. Twenty-four eyes were operated on by one surgeon with extensive experience in pediatric cataract surgery and vitrectomy.

The most common presenting complaint was reduced visual acuity, and many of the patients had a family history of dislocated lenses or systemic disease. Some patients had been initially treated in other units and were referred for a surgical opinion. The average age at presentation was 3 years and 10 months (range, 6 months to 9 years). Eight of the 13 patients presented at or before the age of 3 years. Other than ectopia lentis, no significant ocular pathology was identified in any patient.

The direction of lens subluxation along with other significant preoperative and postoperative findings are summarized in Table 1. Subluxation progressed in 4 (30.7%) of 13 eyes in patients with Marfan syndrome and 3 (100%) of 3 eyes in patients with homocystinuria. Progression of subluxation was not seen in any of the 8 patients with familial or isolated idiopathic ectopia lentis.

Patient Data

Table 1:

Patient Data

Of the 13 patients, 7 were diagnosed as having Marfan syndrome, 2 as having homocystinuria, 3 as having familial idiopathic subluxation, and 1 as having primary idiopathic ectopia lentis.

A complete ophthalmic examination was performed in all cases. This comprised assessment of visual acuity, orthoptic assessment, refraction (both automated and by retinoscopy), Goldmann tonometry where possible, and slit-lamp and dilated fundal examination. Visual acuity was measured using Snellen testing where possible; otherwise, forced choice preferential looking or Sheridan–Gardner tests were employed as appropriate. All children were referred for pediatric assessment and appropriate investigation.

In all patients, the indication for surgery was lens subluxation causing a reduction of visual acuity or a refractive error that could not be corrected using either contact lenses or spectacles.

Surgical Technique

Surgery comprised pars plana lensectomy and anterior vitrectomy. Eleven patients had bilateral surgery. One patient underwent only unilateral surgery because the visual acuity in his other eye did not meet the criteria for surgery.

Pupils were dilated preoperatively with cyclopentolate 1% (0.5% if younger than 1 year) and phenylephrine 2.5%. Surgery was performed with general anesthesia in all cases, and appropriate additional perioperative precautions were taken for those patients with homocystinuria.

A limbal conjunctival flap was created to allow us to perform a sclerotomy 2 to 2.5 mm from the limbus. A corneal tunnel was made for the insertion of an infusion cannula into the anterior chamber. A small opening was made in the posterior surface of the capsule of the lens using a Ziegler knife through the sclerotomy site. The vitrectomy probe was passed through the sclerotomy and into the capsular bag. Aspiration alone was sufficient to remove the lens. After all of the lenticular material had been removed, the capsular bag was removed using the cutting mode of the vitrectomy probe. This was followed by a core anterior vitrectomy. The sclera was then closed with 7-0 Vicryl (Ethicon, Somerville, NJ) and the conjunctiva with 6-0 Vicryl. All of the patients received subconjunctival dexamethasone and tobramycin.

Postoperative Care

Eye drops were administered 12 to 18 hours following completion of the surgery. All patients received atropine 1% once daily, prednisolone 1% four times daily initially tapering during 1 month, and chloramphenicol 0.5% four times daily for 2 weeks.

Refraction was performed 1 to 2 weeks following surgery, and appropriate spectacles or contact lenses were prescribed. Occlusion therapy for amblyopia was initiated where indicated.

Results

Pars plana lensectomy and anterior vitrectomy were performed on 24 eyes (12 left and 12 right) of 13 patients. The age at surgery ranged from 1 to 13 years. The mean age was 5 years. The figure illustrates the distribution of age at the time of surgery. Eleven patients underwent bilateral lensectomy. The mean interval between the surgeries was 2.8 months (range, 2 weeks to 16 months).

Postoperative correction of aphakia included the use of glasses in 5 (38.4%) of 13 patients and contact lenses in the remaining patients. Of the two patients undergoing unilateral surgery, one had previously been rendered aphakic in the other eye, and the other with unilateral aphakia was treated with contact lenses. Two patients developed contact lens–related complications. One developed microbial keratitis, and the other developed a noninfectious epithelial defect. Both resumed contact lens wear after appropriate treatment. No intraocular lenses were inserted in any patient in this group.

Preoperative visual acuity was 6/18 (20/60) or considerably worse in most patients (Table 1). The postoperative visual acuity is that reached and maintained following appropriate correction of aphakia and occlusion therapy where indicated. Visual acuity improved postoperatively in all except 2 eyes (of 1 patient), in which it remained the same. Postoperative visual acuity was 6/9 (20/30) or better in 17 (77.3%) of 22 eyes and 6/12 (20/40) or better in 19 (86.4%) of 22 eyes. One additional patient who underwent bilateral surgery reads 6/6 (Sheridan–Gardner) with both eyes open; however, data are not available for each eye individually. Only 3 eyes had a postoperative visual acuity of worse than 6/12 (20/40). This was attributed to amblyopia in all cases. Visual acuity did not decrease following surgery in any eye.

The mean duration between surgery and reaching the final postoperative visual acuity was 8 months (range, 1 to 18 months).

No patients required a second surgical procedure or developed a raised intraocular pressure, optic disc cupping, or retinal detachment. The average duration of follow-up was 5 years and 6 months (range, 8 months to 13 years and 4 months). Twelve eyes had a follow-up period of more than 4 years, and 7 eyes had a follow-up period of more than 9 years.

Discussion

The indications for and historical perspective of surgical treatment of nontraumatic ectopia lentis have been discussed in great detail in several previous studies.1–4,8 The common conclusion of these studies is that surgical intervention is now safe and effective for those patients in whom lens subluxation causes a significant refractive error that cannot be managed conservatively. This commonly occurs as the edge of the lens approaches the visual axis.9,10 The other indication for surgery is the development of complications such as raised intraocular pressure and anterior or posterior dislocation of the lens.

Recently published studies have employed modern microsurgical techniques and one of two surgical approaches. Limbal lensectomy and anterior vitrectomy were used in three studies2,3,5; pars plana lensectomy and anterior vitrectomy were used in three studies1,6,7; and one study employed both techniques.4 Details of these studies as well as the results of the current study are summarized in Table 2.

Studies Published Regarding Limbal or Pars Plana Lensectomy

Table 2:

Studies Published Regarding Limbal or Pars Plana Lensectomy

Some authors have speculated about the theoretical advantages of one approach over the other without providing supporting data. Concerns about the pars plana approach include the long-term effects of damage to the vitreous base and retina, especially given that the pars plana has not fully developed until the age of 7 years.2,4 Although the average duration of follow-up in our group of patients was 5 years and 6 months, for 12 eyes follow-up lasted more than 4 years and for 7 eyes more than 9 years. None of these patients developed retinal tears or detachments, and they all reached the age of 7 years. Therefore, presumably, their pars plana continued to develop normally despite the surgical insult. Also, some studies using the pars plana approach have reported dropped lens fragments.1,4 In all but one case, these resolved with nonsurgical management.

Vitreous adhesion to the wound was a relatively frequent complication in several studies using a limbal approach.2,4 This was treated with either YAG laser or, more commonly, secondary vitrectomy and division of vitreous adhesions. In one study by Hakin et al., vitreous adhesions to the wound required a secondary vitrectomy and division of vitreous adhesions in 6 (23%) of 26 eyes.4 Although the final outcome was good in all of these cases, the need for this many secondary intraocular procedures with general anesthesia is less than ideal. This is especially relevant to patients with homocystinuria because they have a higher than normal rate of perioperative complications. In cases where the lens has dislocated into the anterior chamber, a limbal approach is the approach of choice for obvious reasons.

There is no evidence to support claims that the corneal endothelium may be less traumatized by using a pars plana approach because no study using either technique has investigated endothelial cell numbers before and after each procedure. However, some loss of endothelial cells will occur with a limbal approach. The published literature does not report any cases of corneal decompensation as a result of endothelial failure in this group of patients.

Despite the fact that early surgical treatment of nontraumatic ectopia lentis is now safe and effective in improving visual acuity, most cases can be managed medically. In those patients who require surgery, we believe that the lower rate of secondary intraocular procedures using the pars plana approach makes this the approach of choice except for anteriorly dislocated lenses.

To our knowledge, this is the second largest series of patients with nontraumatic ectopia lentis treated by pars plana lensectomy and anterior vitrectomy. Our data suggest that this is the optimal approach in the treatment of these patients. These findings should encourage earlier surgery when indicated to prevent amblyopia and improve visual acuity.

References

  1. Halpert M, BenEzra D. Surgery of the hereditary subluxated lens in children. Ophthalmology1996;103:681–686.
  2. Salehpour O, Lavy T, Leonard J, Taylor D. The surgical management of nontraumatic ectopic lenses. J Pediatr Ophthalmol Strabismus1996;33:8–13.
  3. Plager DA, Parks MM, Helveston EM, Ellis FD. Surgical treatment of subluxated lenses in children. Ophthalmology1992; 99:1018–1023.
  4. Hakin KN, Jacobs M, Rosen P, Taylor D, Cooling RJ. Management of the subluxed crystalline lens. Ophthalmology1992;99:542–545.
  5. Behki R, Nöel LP, Clarke WN. Limbal lensectomy in the management of ectopia lentis in children. Arch Ophthalmol1990;108:809–811.
  6. Reese PD, Weingeist TA. Pars plana management of ectopia lentis in children. Arch Ophthalmol1987;105:1202–1204.
  7. Syrdalen P. Pars plana technique for removal of congenital subluxated lenses in young patients. Acta Ophthalmol (Copenh)1987;65:585–588.
  8. Speedwell L, Russell-Eggitt I. Improvement in visual acuity in children with ectopia lentis. J Pediatr Ophthalmol Strabismus1995;32:94–97.
  9. Romano PE. Earlier “surgical management of nontraumatic ectopic lenses.”J Pediatr Ophthalmol Strabismus1996;33:273.
  10. Romano PE. Early lensectomy for ectopia lentis: a continuing controversy. J Pediatr Ophthalmol Strabismus1995;32:398–399.

Patient Data

Patient No.Age at Presentation (y)Age at Surgery (y)EyeEtiologyDirection of SubluxationVA at PresentationPreoperative VAPreoperative RefractionPostoperative VAPostoperative RefractionTime to Reach Best VA (mo)Postoperative Follow-Up (y)Correction*
12.83.0LMSuperotemporal5/605/60NA6/6+14.0/+1.0 × 18083.3CL
3.6RSuperotemporal6/246/24NA6/9+15/+1.0 × 4012.7CL
20.53.2LMSuperotemporalCSM1/60−4.0/−0.5 × 906/12+11.75/+0.75 × 110155.7Glasses
3.0RSuperiorCSM1/60−1.25/−2.0 × 206/24+9.25/+1.75 × 11555.8Glasses
33.06.6LMSuperotemporal6/186/24−4.0/−4.0 × 1806/6+13.0/+1.0 × 90611.4CL
6.5RSuperonasal6/126/24−3.0/−4.0 × 1806/6+15.0/+1.0 × 90611.5CL
43.06.5LMTemporal6/96/18NA6/6+14.0124.3CL
50.63.3LMSuperiorCSM< 6/60-6/9+14.5/+1.0 × 9052.9CL
3.1RSuperiorCSM< 6/60-6/9+15.073.1CL
67.38.0LISuperior6/366/36NA6/6+10.063.0Glasses
9.3RSuperior6/126/18−0.75/−1.25 × 1806/9+10.571.7Glasses
70.82.8LFSuperiorCSM< 6/60+2.0/+0.5 × 906/9+17.0189.6CL
2.7RSuperiorCSM< 6/60+2.56/9+17.0/+1.5 × 90179.7CL
86.06.0LFSuperior6/246/24NA6/9+13.0211.0CL
6.1RSuperior6/366/36NA6/9+13.5/+1.0 × 70110.9CL
91.51.8LFSuperiorCSM< 6/60NA6/6 BEO+14.050.7Glasses
1.7RSuperiorCSM< 6/60NA6/6 BEO+14.060.8Glasses
109.013.3RHSuperonasal6/366/60−6.5/−1.0 × 56/12+11.0/+1.5 × 130913.3CL
115.55.5LMSuperior6/246/24−6.75/−2.25 × 906/6+16.0/+1.25 × 11594.5CL
5.6RSuperior6/246/24−6.5/−1.0 × 56/6+15.5/+1.5 × 9084.6CL
120.80.9LMSuperior6/386/38Plano/−1.5 × 1806/30+17.5/+1.0 × 80141.6Glasses
1.0RSuperior6/606/60Plano/−1.75 × 1806/60+16.5/+2.0 × 100141.5Glasses
139.09.5LHSuperior6/186/18−16/−2.5 × 1806/9+12.5/+0.5 × 8031.6Glasses
9.7RInferior6/186/18−16/−2.5 × 1806/9+12.5/+1.0 × 11081.4Glasses

Studies Published Regarding Limbal or Pars Plana Lensectomy

StudyNo. of EyesNo. of PatientsMean Age at Surgery (y)Mean Follow-Up (y)% of Patients With Increased VA Postoperatively% of Patients With Decreased VA PostoperativelyRate of Complications (%)
Limbal lensectomy
  Salehpour et al., 199625030339248
  Plager et al., 1992329155.83.510000
  Hakin et al., 1992426145.92.6100023
  Behki et al., 199051596.2410000
Pars plana lensectomy
  Halpert and BenEzra, 199615437> 54.59003
  Hakin et al., 1992418102.92.89406
  Syrdalen, 198771611182.487.500
  Reese and Weingeist, 19876128NA5.19100
  Current241355.59200
Distribution of age at the time of surgery.

Figure.

Distribution of age at the time of surgery.

10.3928/01913913-20040901-03

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