Eye colour and skin pigmentation as significant factors for refractive outcome and residual accommodation in hypermetropic children: a randomized clinical trial using cyclopentolate 1% and tropicamide 1
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Helena M van Minderhout1,2, Maurits V Joosse1, Diana C Grootendorst3
1Department of Ophthalmology, Haaglanden Medical Centre, The Hague, The Netherlands.
Insights
Skin pigmentation, not iris color, impacts cycloplegic effectiveness in children. Combining cyclopentolate and tropicamide offers more accurate refractive outcomes, especially for darker-skinned individuals needing cycloplegic eye exams.
Area of Science:
- Ophthalmology
- Pediatric Ophthalmology
- Clinical Optics
Background:
- Accurate refractive error assessment is crucial for managing pediatric hyperopia.
- Cycloplegic agents are commonly used to paralyze accommodation for precise refraction.
- Individual variations in iris and skin pigmentation may influence cycloplegic drug efficacy.
Purpose of the Study:
- To compare refractive outcomes and residual accommodation in hyperopic children based on iris and skin pigmentation.
- To evaluate the efficacy of two different cycloplegic regimens: cyclopentolate 1% (C+C) versus cyclopentolate 1% with tropicamide 1% (C+T).
Main Methods:
- A randomized, double-blind study involving 251 hyperopic children.
- Participants were classified by iris and skin pigmentation (light, medium, dark).
- Refractive error (spherical equivalent) and residual accommodation were measured using Retinomax-K+3 and PlusoptiX PowerRefractor, respectively.
Main Results:
- Skin pigmentation significantly influenced refractive outcomes and residual accommodation.
- Darker skin pigmentation was associated with less hyperopia and higher residual accommodation.
- The C+T combination demonstrated more accurate refractive outcomes, particularly in darker-skinned subjects.
Conclusions:
- Skin pigmentation is a more critical factor than iris pigmentation in determining cycloplegic effectiveness.
- Clinicians should be aware of potential limitations of cycloplegic agents in darkly pigmented children.
- The combination of cyclopentolate and tropicamide offers improved refractive accuracy, considering skin pigmentation.
Purpose:
To compare the refractive outcome and residual accommodation with respect to various degrees of iris and skin pigmentation in hypermetropic children using 2 drops of cyclopentolate 1% (C + C) or 1 drop of cyclopentolate 1% and 1 drop of tropicamide 1% (C + T).
Methods:
Two hundred fifty-one hypermetropic children were classified according to iris and skin pigmentation (light, medium, dark) and received randomized and double-blind C + C or C + T. Refractive error (spherical equivalent, SEQ) was determined using the Retinomax-K + 3. In 204 subjects, residual accommodation (RA) was determined using the PlusoptiX PowerRefractor.
Results:
A linear mixed model with a light-irided and light skin-pigmented reference group receiving C + T (mean SEQ +3.10 ± 1.87D) indicated significant less hypermetropia in subjects with a dark iris having a medium- and dark-pigmented skin in C + T, -1.02 ± 0.29 (-1.59/-0.45) and -1.53 ± 0.30 (-2.10/-0.95); and in subjects having a light-, medium- and dark-pigmented skin in C + C, -0.74 ± 0.34 (-1.41/-0.06), -1.26 ± 0.30 (-1.85/-0.66) and -1.84 ± 0.30 (-2.42/-1.26). Similar findings were present for RA. Our model with a light-irided and light skin-pigmented reference group receiving C + T (mean RA +0.84 ± 0.61D) indicated significantly higher RA in dark-irided subjects with medium- and dark-pigmented skin in C + T, +1.05 ± 0.19 (+0.67/+1.43) and +1.35 ± 0.20 (+0.9/+1.74), and in C + C, +1.13 ± 0.21 (+0.71/+1.55) and +1.90 ± 0.19 (+1.51/+2.28).
Conclusions:
We found solid evidence that skin pigmentation rather than iris pigmentation is the decisive factor for effectiveness of cycloplegics. Awareness of the limitations of cycloplegic regimens in dark-irided/pigmented children is needed. Our study showed that cyclopentolate 1% combined with tropicamide 1% provides more accurate refractive outcomes both statistically and clinically integrating the factor skin pigmentation for dark-irided subjects.
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