Please select the eligibility criteria that correspond to the clinical trial below.
Title: Assessment of Bifocal and Prismatic Bifocal Spectacles for Myopia Control in Children
Brief Summary: 1. To determine if the effect of near-addition lenses (bifocals) is more prominent for children with high myopia progression.
2. To study how different subject characteristics such as age, gender, baseline degree of myopia, baseline near phoria and baseline lag of accommodation affect the efficacy of bifocal lens wear in myopic children.
3. To investigate the effect of incorporating near base-in prisms along with the near-addition lenses (prismatic bifocals) on myopia progression in myopic children.


Options:
A: Inclusion Criteria:

* Myopia (refractive sphere): \> 5.75D
* Astigmatism: \< ½ of myopia; with-the-rule astigmatism (axes 180 +/- 30) ≤1.25D; astigmatism of other axes ≤ 0.50D
* Spherical equivalent (SE): \> 5.75D
* Anisometropia: ≤ 1.50D in both refractive sphere, refractive cylinder and SE
* Best corrected monocular visual acuity: equal to or better than 0.10 in logMAR scale in both eyes
* Willingness for randomization
* Availability for follow-up for at least 2 years

Exclusion Criteria:

* Strabismus at distance or near
* Contraindication for contact lens wear and orthokeratology (e.g. limbus to limbus corneal cylinder and dislocated corneal apex
* Systemic or ocular conditions which may affect contact lens wear (e.g. allergy and medication)
* Systemic or ocular conditions which may affect refractive development (e.g. Down syndrome, ptosis)
B: Inclusion Criteria:

1. Written Informed Consent from parent and assent from child has been obtained
2. Children aged 6 to 12 years
3. Refractive error of spherical equivalent -2.00 D or worse in each eye as measured by cycloplegic autorefraction
4. Active myopia progression of at least spherical equivalent -0.50 D over the last 12 months as determined or suggested by refractive records or change in lens power
5. Astigmatism of less than or equal to -1.50 D as measured by cycloplegic or non-cycloplegic autorefraction
6. Distance vision correctable to logMAR 0.2 or better in both eyes
7. A difference between non-cycloplegic subjective spherical refraction and cycloplegic subjective spherical refraction of not greater than -1.00 D
8. Normal intraocular pressure of not greater than 21 mmHg
9. Normal ocular health other than myopia
10. In good general health with no history of cardiac or significant respiratory diseases
11. No asthma-requiring medications in the past one year
12. No allergy to atropine, cyclopentolate, proparacaine and benzalkonium chloride
13. Willing and able to comply with scheduled visits and other study procedures

Exclusion Criteria:

1. Ocular or systemic diseases which may affect vision or refractive error
2. Any ocular condition wherein topical atropine is contraindicated
3. Defective binocular function or stereopsis
4. Amblyopia or manifest strabismus including intermittent tropia
5. Previous or current use of atropine or pirenzepine
6. Any other conditions precluding adherence to the protocol including unwillingness to refrain from contact lens wear for the duration of the study
C: Inclusion Criteria:

* Age: 8 to 13 years
* Myopia: -1.00 to -5.00 D
* Myopia progression: at least 0.50 D/yr
* Astigmatism and anisometropia: not more than 1.50 D
* Distance monocular visual acuity: 6/6 or better
* Near monocular visual acuity: 0.4 M or better
* Stereoacuity: not more than 40 sec of arc at 40 cm

Exclusion Criteria:

* Strabismus
* Ocular diseases
D: Children between the ages of 6 and 12 years with myopia in both eyes (defined as spherical equivalent between -1.25 D and -4.50 D in each eye as measured by cycloplegic autorefraction), astigmatism less than or equal to 1.50 D, and no anisometropia (defined as a difference in spherical equivalent between the two eyes greater than 1.0 D) are eligible for inclusion. Exclusion criteria include visual acuity greater than 20/25, strabismus, use of contact lenses, birth weight less than 1,250 grams, use of bifocal or progressive addition lenses, or any conditions precluding adherence to the protocol.

Answer: C