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When practitioners are faced with the challenge of fitting the unilateral pediatric aphake with a contact lens they have previously had to base their fitting strategy on the contact lens parameters available from the manufacturer. The introduction of custom made silicone hydrogel lenses has resulted in clinicians being able to fit the patient with the most appropriate CL parameters.
Table 1: CIBA Vision Silicone Hydrogel Lenses
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Product Details |
O2OPTIX™ |
NIGHT & DAY® |
O2OPTIX Custom™ |
Material |
lotrafilcon B |
lotrafilcon A |
sifilcon A |
Water Content |
33% |
24% |
32% |
Dk & Dk/t @
-3.00D |
110 & 138 |
140 & 175 |
82 & 117 |
Surface Treatment |
permanent plasma
surface treatment |
permanent plasma
surface treatment |
permanent plasma
surface treatment |
Modulus |
1.0 MPa |
1.2 MPa |
1.1 MPa |
Handling Tint |
Light blue |
None |
Light green |
Wearing Schedule |
DW and EW up to 6N |
DW and CW up to 30N |
DW |
Replacement Schedule |
2 Weekly |
Monthly |
Quarterly |
Packaging |
6 pack |
6 pack |
1 & 4 pack |
Design |
Bi-Aspheric |
Bi-Aspheric |
Bi-Aspheric |
Diameters |
14.2 |
13.8 |
13.2 / 14.0 / 14.8 |
Base Curves |
8.6 |
8.4, 8.6 |
7.4 – 9.2 |
Sphere Powers |
+6.00 D to -10.00D |
+6.00 D to -10.00D |
+20.00 D to -20.00D |
Center Thickness |
0.08 @ -3.00D |
0.08 @ -3.00D |
0.07 @ -3.00D |
Manufacturing Process |
Mold Cast |
Mold Cast |
Lathe Cut |
Table 2: O2 OPTIX Custom™ Parameters
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Diameter |
Base Curves |
13.2 |
7.4, 7.7, 8.0, 8.3 |
14.0 |
7.8, 8.1, 8.4, 8.7, 9.0 |
14.8 |
8.0, 8.3, 8.6, 8.9, 9.2 |
A 7 year old unilateral aphake had been unsuccessfully fit with RGP lenses. He was refit with B&L Silsoft lenses. At the age of 5 the optimal lens parameters required for fit and acuity were outside of the available range. He needed the dimensions of an adult aphakic lens with the prescription of pediatric aphakic lens. Compromising the fit resulted in poor comfort and compromising the prescription resulted in poor acuity. An O2 Optix custom- made silicone hydrogel lens was fit in April 2007. The lens ordered was 8.7:14.00 +21.00D. On collection the patient reported superior comfort to other lenses he had worn. Visual acuity was equivalent to the best corrected spectacle acuity (previously not achieved with a contact lens). The lens appeared to mask 1.00D of corneal astigmatism.
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Fig 2: Deposited silicone elastomer lens
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Fig 3a: Master NB in
spectacles due to contact
lens intolerance |
Fig 3b: Master NB wearing
O2 Optix Custom contact
lens
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Fig 4: Fit of O2 Optix Custom lens on NB, showing excellent centration. Lenticulation due to high BVP is clearly seen
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This case illustrates how a custom made SiHy lens can be used for aphakic patients who fall outside of the parameters of conventional aphakic lens designs.
Case Report |
Age 6 months
- Master NB (Fig 1) was diagnosed with unilateral congenital cataract (OD).
- Surgery followed within one month.
- Post operatively fitted with a silicone elastomer contact lens (B&L Silsoft).
Age 12 months
- Due to heavy deposition, NB was refit with an RGP lens.
- Intensive patching regime of 2/3 waking hours.
- RGP wear was unsuccessful, with frequent lens loss and poor comfort.
Age 4 years
- NB refit once again with the B&L Silsoft lens.
- The Silsoft lens proved unsuccessful again due to:
- heavy deposits (Fig 2)
- poor comfort
- poor visual acuity compared to spectacles
- limited parameter range
- Reverted to mainly spectacles (Fig 3a)
Age 7 years
- April 2007 refit with CIBA Vision O2OPTIX Custom™ silicone hydrogel lens
- Collection - May 2007
- Acuity 6/15 - equivalent to spectacle acuity
- 1.00 D corneal astigmatism masked by the lens
- Fit - well centered, moving well
- Comfort - good
- Progress check - June 2007
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- Acuity 6/15
- Comfort – excellent (Fig 3b)
- Fit – excellent centration and movement (Fig 4)
- Wearing daily for 12-13 hours
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- Moore BD: Pediatric aphakic contact lens wear: rates of successful wear. J Pediatr Ophthalmol Strabismus 1993; 30;4: 253-8.
- Ma JJ, Morad Y, Mau E, Brent HP, Barclay R, Levin AV: Contact lenses for the treatment of pediatric cataracts. Ophthalmology 2003; 110;2: 299-305.
- Polse KA, Sarver MD, Harris MG: Corneal effects of high plus hydrogel lenses. Am J Optom Physiol Opt 1978; 55;4: 234-7.
- Polse KA, Holden BA, Sweeney D: Corneal edema accompanying aphakic extended lens wear. Arch Ophthalmol 1983; 101;7: 1038-41.
- Rae ST, Huff JW: Studies on initiation of silicone elastomer lens adhesion in vitro: binding before the indentation ring. CLAO J 1991; 17;3: 181 - 186.
- Huth S, Wagner H: Identification and removal of deposits on polydimethylsiloxane silicone elastomer lenses. Int Contact Lens Clin 1981; 8;7/8: 19-26.
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