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The critical period for surgical treatment of dense congenital bilateral cataracts
Eileen E Birch1, Christina Cheng, David R Stager
1Retina Foundation of the Southwest, Dallas, Texas; Department of Ophthalmology, University of Texas Southwestern Medical School, Dallas, Texas.
Insights
Early surgery for bilateral cataracts is crucial. Delaying treatment beyond 14 weeks significantly impacts visual acuity, increasing the risk of deprivation amblyopia.
Area of Science:
- Ophthalmology
- Pediatric Medicine
- Visual Neuroscience
Background:
- Dense bilateral congenital cataracts can lead to deprivation amblyopia.
- Determining the optimal timing for surgical intervention is critical for visual development.
Purpose of the Study:
- To identify the critical period for surgical treatment in infants with dense bilateral congenital cataracts.
- To investigate the relationship between age at surgery and visual acuity outcomes.
Main Methods:
- Prospective enrollment of 37 infants with bilateral congenital cataracts, with surgery by 31 weeks of age.
- Statistical modeling (linear, bilinear) to assess visual acuity outcomes at >/= 5 years based on age at surgery.
- Review of adverse outcomes including strabismus, nystagmus, and glaucoma.
Main Results:
- A bilinear model with a critical age of 14 weeks best described the data.
- Visual acuity declined by one line for every three-week delay in surgery between 0-14 weeks.
- Post-14 weeks, visual acuity was consistent (20/80) regardless of surgery timing; early surgery (<4 weeks) had higher risks of secondary membrane formation and glaucoma, while later surgery (>4 weeks) increased strabismus and nystagmus prevalence.
Conclusions:
- No latent period was found for treating dense bilateral congenital cataracts.
- Early surgical intervention is recommended to minimize deprivation amblyopia.
Introduction:
We examined the critical period for deprivation amblyopia in a cohort of patients with dense bilateral congenital cataracts to investigate the optimum timing for surgical treatment.
Methods:
Thirty-seven infants with dense bilateral congenital cataracts that were extracted by 31 weeks of age were enrolled prospectively. Visual acuity outcome was assessed at >/=5 years of age. We statistically evaluated which of 4 models provided the best fit to the data: (1) no change in visual acuity outcome with delay in surgery, (2) linear decline of outcome with delay, (3) a bilinear model in which a critical age exists after which outcome depends on delay, and (4) a bilinear model in which a critical age exists before which outcome depends on delay. In addition, we reviewed medical records for associated adverse outcomes, including strabismus, nystagmus, secondary membrane formation, and glaucoma.
Results:
A bilinear model with a critical age of 14 weeks fit the data better than a linear model (chi(2) = 14.7; p < 0.0006). During weeks 0-14, mean visual acuity decreased by 1 line with each 3 weeks' delay in surgery. From 14 to 31 weeks, visual acuity was independent the subject's age at surgery, averaging 20/80. Surgery after 4 weeks was associated with a greater prevalence of strabismus and nystagmus than surgery before 4 weeks, whereas surgery during the first 4 weeks was associated with a greater prevalence of secondary membrane formation and glaucoma.
Conclusions:
We did not find a latent period for the treatment of children with dense bilateral congenital cataracts. Deprivation amblyopia may be minimized with early surgery for bilateral cataracts.
