April 2011: C-15873 Paediatric Optometry Part 1

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The correct answer is D. Spherical lenses (not toric) are appropriate for the prescription shown and children adapt well to daily disposable lenses which have the advantage of not needing daily cleaning. 4 Rigid gas permeable lenses are an option, but some children are discouraged by discomfort during the early stages of adaptation. Continuous wear with silicone hydrogel lenses is another option, but this modality is fitted less often to children because of the higher risk of microbial keratitis. 3. When fitting contact lenses for the patient in Image A, which of the following statements is TRUE? a. They will accommodate more with spectacles compared to contact lenses b. They will accommodate less with spectacles compared to contact lenses c. A correction for back vertex distance is required for the left eye but not the right eye d. Over-refraction will not be necessary after correction for back vertex distance The correct answer is A. The ocular accommodation that is required through contact lenses is different from that through spectacles. Spectacles induce less accommodation in myopes and more accommodation in hyperopes than that exerted by an emmetrope, or the ametrope when wearing contact lenses. A correction for back vertex distance is most important in the more hypermetropic eye. But even if such a correction is made the patient should still be over-refracted to check the optimal power for contact lenses. IMAGE B: SPH CYL AXIS Prism VA BVD R +5.50 -0.25 180 ---- 6/6 12mm L +5.00 ---- ---- ---- 6/6 12mm 4. What is the CORRECT description for the binocular vision anomaly shown in Image B? a. Superior oblique palsy b. Fully accommodative esotropia c. Divergence weakness esotropia d. Convergence weakness exotropia The correct answer is B. The photographs show a right esotropia without spectacles, which is straightened by refractive correction. This is a fully accommodative esotropia. 5 5. What is the CORRECT description for the refractive condition shown in Image B? a. Anisometropic hypermetropia b. Symmetrical hypermetropia c. Pseudo over-accommodation
d. All the above The correct answer is B. The prescription shows hypermetropia that is similar in each eye. This is therefore symmetrical hypermetropia. 6. What is the MOST appropriate management option for the patient in Image B? a. Use of spectacles only for near concentrated work b. Full time wear of spectacles or contact lenses c. Strabismus surgery d. All the above The correct answer is B. For accommodative esotropia, which is eliminated when the hypermetropia is corrected, the only management is refractive correction. With this degree of hypermetropia the patient is likely to need spectacles for distance vision as well as near, which will help to prevent strabismus at distance. Strabismus surgery would be the wrong option. This is because even if surgery could straighten the visual axes in childhood, then later when the hypermetropia needed correction because accommodation reduces with age, refractive correction could cause a secondary exotropia. IMAGE C: Reproduced with kind permission from Professor David Thomson (Thomson Software Solutions’ Test Chart 2000 Pro) I II III IV 7. A four-year-old patient attends for their first eye examination. Which of the charts shown in Image C is the LEAST appropriate to use? a. PANEL I b. PANEL II c. PANEL III d. PANEL IV The correct answer is D. an isolated optotype is the least appropriate target to use. One of the main purposes of testing visual acuity in children is to detect strabismic amblyopia, which is most likely to be detected if crowded rather than single optotypes are used. 5 Generally, it is better to use letters that have been matched for legibility rather than pictures, but crowding is such an important factor that it is probably preferable to use crowded pictures in preference to isolated letters.
Page 1: Detailed Answers IMAGE A: SPH CYL A
Page 5: d. Prompt referral to ophthalmology

April 2011: C-15873 Paediatric Optometry Part 1

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