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EYE ADVICE: Professional Papers


(iv) Hard Contact Lenses

Correction of spherical or WRT astigmatic errors with spherical or back-surface toric hard contact lenses, often gives rise to some ATR refractive astigmatism, known as residual astigmatism. The reason for this is that most corneas have a WRT toricity which is partly or fully compensated mainly by tonic PMA. In normal eyes with no refractive astigmatism the amount of residual astigmatism is about 0.50 -1.0 D. When a hard contact lens is placed on the cornea, this corneal toricity may be neutralised and residual astigmatism is then manifest. It is important to realise that as the residual astigmatism is caused by muscular tone, a significant amount of this will reduce over time and need not always lead the practitioner into prescribing bitorics. Williams (1959) observed complete disappearance of astigmatism in a random sample of sixty hard lens patients.






Paper 1 - Meridional (Astigmatic) Accommodation  Abstract

Physiology of Meridional Accommodation (A) Ciliary Muscle Action and Innervations
(B) Corneal Changes due to Ciliary Muscle Action
(C) Theory of Initiation of Meridional Accommodation

Clinical Implications of Meridional Accommodation


(A) Astigmatic Changes Related to WTR Corneal Toricity (i) Latent Astigmatism
(ii) Primary Accommodative Astigmatism (PAA)       (B) Reflex or 2°PMA and Induced ATR Astigmatic Changes
(C) Eye Preference and Meridional Accommodation (i) 1° PMA and Eye Preference
(ii) 2° PMA and Eye Preference (D) Proactive Prescribing for Presbyopia (i) Phakic Presbyopes
(ii) Pseudophakes and ATR Corneal Changes (E) Refractive Techniques and MA (i) Balancing Meridional Accommodation
(ii) Binocular Test of Cylinder Power (F) Further Clinical Subject Areas and Meridional Accommodation (i) Preventing Induced Oblique Astigmatism in Children
(ii) Low Vision
(iii) Keratoconus
(iv) Hard Contact Lenses
(v) PRK and PARK (Photorefractive Astigmatic Keratectomy)



Paper 2 - Common Chronic (Infective) Conjunctivitis and Nasal Rinsing

Paper 3 - Primary Open-Angle Glaucoma

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