Marshall M. Parks

Long-term Visual Results and Complications in Children with Aphakia: A Function of Cataract Type

PURPOSE Previous studies of outcome in children with aphakia have approached the data by grouping patients according to features such as age at surgery, type of procedure, or some other common attribute. The purpose of this study is to identify factors predictive for visual outcome and complications in pediatric patients with cataracts. METHOD One hundred seventy-four eyes in 118 patients underwent lensectomy and anterior vitrectomy for congenital or juvenile cataracts. All received early optical correction, occlusion therapy when necessary, and follow-up for at least 6 months. Visual outcome and complications were analyzed statistically to determine predictive factors. Features analyzed included cataract type, laterality, age at onset, follow-up, and corneal size. RESULTS Statistical analysis showed that the most important predictor of long-term visual outcome and complications is cataract type. Visual outcome differed significantly by cataract type, with best results in the lamellar and posterior lentiglobus groups. Unilateral cases had a mean acuity lower than bilateral cases. Other factors, such as age at surgery and corneal size, were less predictive but closely linked to cataract type. Complications, such as aphakic glaucoma, also were more closely linked to the type of cataract than to other variables. CONCLUSION The results indicate that an important determinant of long-term outcome and complications in aphakic children is cataract type. Other features were found to be closely correlated to cataract type and were not independently significant.

Incidence of Chronic Glaucoma, Retinal Detachment and Secondary Membrane Surg ery in Pediatric Aphakic Patients

The eyes of 392 consecutive childhood cataract aspiration procedures were analysed for frequency of the development of chronic glaucoma and retinal detachment and the performance of secondary membrane surgery. Three different modifications of the aspiration procedure were employed: the standard needle and syringe procedure leaving the posterior capsule intact (304 eyes), rotoextraction with small opening of the posterior capsule (34 eyes) and Ocutome aspiration with wide excision of the posterior capsule (54 eyes). The mean postoperative follow-up was 5.5 years. Chronic glaucoma was found in 6.1% of the eyes. Coexisting ocular anomalies and retained lens cortex increased the risk for this complication. Retinal detachment was found in 1.5% of the cases. Coexisting ocular anomalies and uncontrolled vitreous disturbance increased the possibility of retinal detachment. Secondary membrane procedures were performed in 62% of the eyes in which the aspiration procedure left the posterior capsule intact, in nearly 12% of those in which the posterior capsule was minimally opened and in none of those which had the posterior capsule widely excised. The secondary membrane surgery itself appeared to increase the risk for both glaucoma and retinal detachment. The aspiration procedure with the lowest incidence for all three complications was the Ocutome aspiration with wide excision of the posterior capsule.

Visual Results in Aphakic Children

Sixty-five patients less than 10 years of age had cataract surgery on 99 eyes. The visual prognosis depended on the cataract type and whether the treatment was undertaken during the critical period for development of the fixation reflex. All patients received the same surgical technique, aggressive optical correction, and occlusion therapy, if needed. Partial cataracts were the most frequent and the two largest groups were lamellar and axial. The visual outcome was excellent for the lamellar cataracts, whereas axial cataracts were the most amblyogenic. Obtaining a good visual result demanded an understanding of the complexities of amblyopia.

Posterior Lens Capsulectomy during Primary Cataract Surgery in Children

Concern continues about the best and safest method to surgically manage cataracts in children. Posterior capsulectomy and anterior vitrectomy with a vitreous suction cutter eliminates the need for secondary surgery. It is the best method to avoid development of amblyopia resulting from gradual posterior lens capsule opacification. However, cystoid macular edema is reported to occur more frequently with this approach as opposed to leaving the posterior lens capsule intact. Amblyopia, however, at this time may be a greater risk to final visual acuity than cystoid macular edema.

A comparison of the rate of refractive growth in pediatric aphakic and pseudophakic eyes

OBJECTIVE To compare the rate of refractive growth in pseudophakic childrens eyes to that of aphakic eyes. DESIGN Multicenter, retrospective observational case series. PARTICIPANTS 83 patients with pseudophakic eyes (100 eyes) and 74 patients with aphakic eyes (106 eyes), with an age of surgery between 3 months and 10 years and a minimum follow-up time of 3 years or more, depending on the age at surgery. METHODS A logarithmic model was used to analyze the rate of refractive growth for each eye. MAIN OUTCOME MEASURES Age at surgery, intraocular lens power, intraocular lens A-constant, initial postoperative refraction, final refraction, and final age. RESULTS Overall, pseudophakic eyes showed a lesser rate of refractive growth than aphakic eyes (-4.6 diopter vs. -5.7 diopter, P = 0.03). This trend was also present but less significant when the eyes were grouped into those less than 6 months of age at surgery (-3.3 diopter vs. -4.6 diopter, P = 0.09) and older patients (-5.0 diopter vs. -6.1 diopter, P = 0.07). However, the mean quantity of myopic shift was greater in pseudophakic eyes than in aphakic eyes (-5.26 diopter vs. -4.54 diopter), despite shorter follow-up times in the pseudophakic eyes. This is due to the optical effects of a constant intraocular lens power in a growing eye. CONCLUSIONS Pediatric pseudophakic eyes have a slightly lesser rate of refractive growth than aphakic eyes. The new rate values should be used for predicting future refractions in these eyes.

An Analysis of Treatment of Congenital Glaucoma by Goniotomy

We used goniotomy as the initial surgical procedure in 34 patients (50 eyes) with congenital glaucoma. An overall success rate of 88% was achieved with one or more goniotomies. The age at disease onset, level of intraocular pressure, and corneal diameter did not significantly influence the surgical outcome. The refractive error proved to be a valuable indicator of operative success or disease progression. A satisfactory visual outcome was associated with treatment by goniotomy.

Autosomal Dominant Congenital Cataract: Interocular Phenotypic Variability

PURPOSE While intrafamilial morphologic heterogeneity of autosomal dominant congenital cataracts has been well established, interocular variation in individual patients of described pedigrees is small. The authors describe a seven-generation family with 48 of 138 individuals known to be affected with autosomal dominant congenital cataracts of the pulverulent type. Affected patients exhibit a seemingly random expression of either unilateral or bilateral lens opacities. METHODS Ophthalmic and medical histories were obtained, complete ophthalmologic examinations were performed, blood samples were drawn, and transformed lymphoblastoid lines were established on 53 patients. Eighty-five members of the family were unable to be examined. RESULTS Twenty-eight of the 53 individuals examined had congenital cataracts. Of these patients, 19 eyes (8 right eyes and 11 left eyes) were unilateral and 9 were bilateral. The clinically unaffected eye in patients with unilateral cataracts showed no evidence of lenticular opacity under detailed slit-lamp examination. Severity of the cataracts included a subtle unilateral zonular cataract with 20/20 visual acuity, bilateral inner fetal nuclear pulverulent opacities with 20/16 visual acuity in both eyes, and dense unilateral and bilateral nuclear cataracts requiring early surgical removal. Incorporating the historic data on patients who were not examined, we found 48 affected members (28 unilateral, 17 bilateral, 3 obligate carriers who were not examined). CONCLUSIONS Hereditary cataracts typically are symmetric in affected individuals. The authors describe a large pedigree with the apparently random expression of an autosomal dominant gene as either unilateral or bilateral cataract. To their knowledge, this is the first such family described in the literature. Currently, work is under way to determine if the causative gene is linked to previously defined cataract loci on chromosomes 1, 2, or 16.

Timely surgery in intermittent and constant exotropia for superior sensory outcome.

PURPOSE To determine whether time of strabismus surgery for patients with acquired intermittent exotropia and constant exotropia influences postoperative sensory outcome. METHODS In a retrospective, cross-sectional study, 76 patients with acquired intermittent or constant exotropia and motor realignment were evaluated for postoperative sensory status. Age at surgery, duration of exotropia, and presence of intermittent or constant exotropia were correlated with postoperative sensory status. The 23 male and 53 female patients had an average age of 9.3 years at the time of surgery and a mean follow-up of 5.9 years. RESULTS Patients had a significantly greater chance of having postoperative stereoacuity better than 60 seconds of arc (bifixation) if they were surgically aligned before 7 years of age (P <.01) or before 5 years of strabismus duration (P <.05), or with intermittent as compared with constant exotropia (P <.001). Patients with postoperative bifixation had earlier surgical intervention (P <.025) and shorter duration of exotropia (P <.025) than those with postoperative monofixation. CONCLUSIONS Patients with intermittent or constant exotropia may achieve superior sensory outcome with motor realignment before age 7, before 5 years of strabismus duration, or while the deviation is intermittent.

Theoretic Refractive Changes after Lens Implantation in Childhood

OBJECTIVE Children with aphakia tend to have decreasing hyperopia as they grow older. No large study of the long-term refractive changes in children with pseudophakia has been published, although myopic shifts of greater than 10 diopters (D) have been reported. The authors used the refractions of children with aphakia and long follow-up to calculate the theoretic long-term refractive effects of pseudophakia. DESIGN The study design was a chart review of eyes that underwent cataract surgery before age 10 with documented refractions for more than 7 years. PARTICIPANTS Ninety-three eyes were studied. INTERVENTION The initial aphakic refractions of the study eyes were used to calculate the intraocular lens (IOL) powers that would have been required to give emmetropia at cataract removal. The aphakic refractions at last follow-up were used to calculate the final pseudophakic refractions, and these were compared with the predictions of a logarithmic model of myopic shift. RESULTS The mean follow-up time was 11 years. The median calculated pseudophakic refraction at last follow-up was -6.6 D with a range of -36.3 to +2.9 D. Children who underwent surgery in the first 2 years of life had a substantially greater myopic shift than older children (P < 0.001) and a larger variance in this myopic shift (P < 0.001). The logarithmic model accurately predicted the final refraction within 3 D in 24% of eyes undergoing surgery before 2 years of age and in 77% of eyes undergoing surgery after this age. CONCLUSIONS Pseudophakia in children is predicted to result in a large quantity of myopic shift, particularly in very young children. An IOL power chosen to leave a child initially hyperopic should lessen both the quantity of myopic shift and the extreme myopia that can result with growth. The surgeon who implants IOLs in young children must be prepared for a wide variation in long-term myopic shift.

Myopic Shift After Cataract Removal in Childhood

BACKGROUND Children who have had cataract removal tend to have decreasing hyperopia (myopic shift) as they grow older. We wondered if the rate of myopic shift could be determined by age at surgery, cataract type, glaucoma, or other factors. METHODS We studied 156 aphakic eyes of children who had cataract surgery before age 10 and documented refractions for more than 3 years. Refraction was corrected with contact lenses and spectacles; glaucoma was managed with medicine and surgery. Stepwise multiple regression was used to analyze differences in the rate of myopic shift between subgroups. RESULTS The average refraction tended to follow a logarithmic decline with age (P < 0.01, R2 = 0.97). The average rate of myopic shift (the slope of spectacle plane refraction vs log of age, where age is in years and log is base 10) was -5.5, with a standard deviation of 3.8. Age at surgery had a small but statistically significant effect on the rate (P < 0.01, R2 = 0.04). No other studied factor reached statistical significance. However, among the 86 eyes with cataract removal after age 6 months, age at surgery was not as significant (P = 0.21), and unilateral cataract eyes tended to have a greater rate than bilateral cataract eyes (-7.7 vs -5.7; P = 0.05, R2 = 0.05). CONCLUSIONS Aphakic refraction tends to follow a logarithmic decline with age. The rate of myopic shift is determined partly by age at surgery and whether the cataract was unilateral or bilateral, although the effects are small. A wide variation in the rate of myopic shift exists. The following factors made little difference in the rate: cataract type, glaucoma, sex, side, and best corrected visual acuity.