Myopic shift and preoperative axial length after congenital cataract surgery in Peruvian patients - The Association for Research in Vision and Ophthalmology Meeting (ARVO) 2018 Honolulu, Hawaii - Poster presentation

1. PREOPERATIVE AXIAL LENGTH AND MYOPIC SHIFT AFTER CONGENITAL
CATARACT SURGERY WITH PRIMARY INTRAOCULAR LENS IMPLANTATION
Diego A. Valera Cornejo MD1 , Abel Flores Boza 2
1 Vista Clinic 2 National Institute of Ophthalmology of Peru
The authors declare no financial or conflicting interests. No research funding was received for this study
INTRODUCTION
PURPOSE
There was no relationship between the initial axial length and the myopic shift in
all patients.
Unilateral cataracts had a greater myopic shift over 3 years.
In bilateral cataracts, a tendency to greater myopic shift with smaller axial
lengths was found; hence, this variable should be investigated more in this
group.
METHODS
RESULTS
CONCLUSION
Table 1.- Baseline characteristics (n=76)
Table 3 .- Mean myopic shift (diopters) in children with pseudophakia and bilateral cataracts (n=63)
Figure 2 Mean myopic shift in children with pseudophakia according to time after
surgery.
Baseline characteristic are summary in table 1. The mean myopic shift at 3 years
in all patients was 3.6 D (SD: 2.3 D), in group 1 was 3.2 D (SD: 3.3) and in group 2
was 3.9 D (SD: 3.2) (p=0.359) (Table 2) . In bilateral cataracts, this shift was 2.6 D
(SD: 2.0) and 3.4 D (SD: 1.8), respectively, in each group (p=0.098) (Table 3).
The mean follow-up time in bilateral cataracts was 38.9 months (SD: 12.9
months) with a mean myopic shift of 3.0 D, and 43.6 months (SD: 19.2 months)
in unilateral cataracts with a mean myopic shift of 6.3 D (p=0.001) (Table 2). In
this type of cataract, a greater myopic shift was observed in both groups (6.7 D
[SD: 6.7] and 6.1 D [SD: 6.3], p=0.882).
In the regression analysis, no relationship between the myopic shift and the
initial axial length was found in all the patients (R2=0.03; p=0.13), but a tendency
to show a negative correlation was seen (Figure 1).
The myopic shift had a tendency to have a direct relationship with the time after
the surgery being 1.95 D (at 1–2 years), 3.46 D (at 2–3 years) and 3.84 D (at 3
years) (Figure 2).
1. Rahi JS, Dezateux C; British Congenital Cataract Interest Group. Measuring and interpreting the incidence of congenital ocular
anomalies: lessons from a national study of congenital cataract in the UK. Invest Ophthalmol Vis Sci. 2001;42(7):1444–1448.
2. Plager DA, Lynn MJ, Buckley EG, Wilson ME, Lambert SR; Infant Aphakia Treatment Study Group. Complications in the first 5
years following cataract surgery in infants with and without intraocular lens implantation in the Infant Aphakia Treatment
Study. Am J Ophthalmol. 2014;158(5):892–898
3. Flitcroft DI, Knight-Nanan D, Bowell R, Lanigan B, O’Keefe M. Intraocular lenses in children: changes in axial length, corneal
curvature, and refraction. Br J Ophthalmol. 1999;83(3):265–269.
4. Tartarella MB, Carani JCE, Scarpi MJ. The change in axial length in the pseudophakic eye compared to the unoperated fellow
eye in children with bilateral cataracts. J AAPOS. 2014;18(2):173–177
5. Hussin HM, Markham R. Changes in axial length growth after congenital cataract surgery and intraocular lens implantation in
children younger than 5 years. J Cataract Refract Surg. 2009;35(7):1223–1228.
6. Lambert SR, Lynn MJ, DuBois LG, et al. Axial elongation following cataract surgery during the first year of life in the infant
Aphakia Treatment Study. Invest Ophthalmol Vis Sci. 2012;53(12):7539–7545.
7. Crouch ER, Crouch ER, Pressman SH. Prospective analysis of pediatric pseudophakia: myopic shift and postoperative
outcomes. J AAPOS. 2002;6(5):277–282.
We performed an analytical retrospective cohort study. Patients who underwent
congenital cataract surgery with intraocular lens implantation in the pediatric
ophthalmology service at the National Institute of Ophthalmology of Perú in the period
of 2007 to 2011.
We included patients younger than 4 years of age who underwent cataract surgery with
primary IOL implantation, primary posterior capsulorhexis and anterior vitrectomy.
Patients who had cataracts of another etiology or other associated ocular pathology
were excluded.
The population was divided into 2 groups: patients with an axial length of >21.5 (group
1) and patients with an axial length of ≤21.5 mm (group 2). The mean myopic shift was
estimated to be 2.5 D (standard deviation [SD]: 2) and 3.8 D (SD: 2) in group 1 and
group 2, respectively. With this, a sample size of 76 patients was estimated, with a
power of 80%, a 95% confidence interval and a 5% error. The sample was randomly
selected (probabilistic sampling), and the sample unit was the operated eyes of
congenital cataract.
10 to 38% of blindness in children is caused by congenital cataract 1. Cataract
aspiration with primary intraocular lens (IOL) implantation and primary posterior
capsulorhexis with anterior vitrectomy has been the choice of surgical procedure since
quite some time now in patients who are less than 2 years. However, the age at which
IOL needs to be implanted is still debatable especially due to its complications 2.
How the presence of cataract, surgical removal, and insertion of an IOL
(pseudophakia) may affect the ocular growth and his subsequent refractive change is
poorly understood 3. Factors such as time of surgery, aphakia, pseudophakia, laterality,
visual deprivation and axial length have been reported to influence axial growth and
visual prognosis 4. Many studies show much variability on how axial growth behaves in
pseudophakic children after surgery 4-7.
An expected myopic shift (-2.00 a -6 .00D) 5,6, its seen due to increased axial growth
during the first 3 years of life 7. However, the factors that are related to this refractive
change have not been evaluated in detail.
We anticipate a large myopic shift (because the pseudophakic eye of a young child
stills grows), and it is recommended the selection of an intraocular lens power that
results in a large hyperopic error in the immediate postoperative period. For which the
child will need to wear spectacles, but there is no consensus on how hyperopic the IOL
must be. It would be useful to determine which factors are related to greater myopic
shift and which IOL power to choose, that could bring the child closer to emetropia in
adulthood.
Our purpose was to evaluate if there is any relationship between pre operative axial
length and myopic shift after congenital cataract extraction and primary IOL
implantation.
A the secondary endpoint was to identify other possible factors that could be
associated with greater myopic shift.
REFERENCES
Figure 1 Relationship between axial length and average myopic shift in children with
pseudophakia (n=76).
Table 2.- Relationship between axial length and others factors associated with average myopic shift
(diopters) in children with pseudophakia (n=76)
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