Aftercare 28 Chapter

28.3.8 Blinking

Infrequent or incomplete blinking is a particular difficulty with rigid lenses. It causes several problems:

•3 and 9 o’clock staining.

•Other corneal and conjunctival desiccation.

•Conjunctival injection.

•Oedema because of insufficient tear pump.

•General discomfort.

•Lens deposits and blurred vision.

Incomplete blinking with soft lenses also causes problems because of dehydration. This in turn can lead to inferior or lower mid-peripheral staining (smile stain) and lens deposits.

PRACTICAL ADVICE

Rigid lenses act as a strong disincentive to correct blinking, so retraining is rarely successful. Refitting with soft lenses is often a better solution.

28.4 Aftercare at yearly intervals or longer

Examination after 12 months or longer is particularly concerned with the possible long-term consequences of contact lens wear and the condition of the lenses. It includes the same stages as the first aftercare routine (see Sections 28.1.1 to 28.1.10) with the key additions of:

• Reassessment of contact lens refraction and fitting.

• Spectacle refraction.

• Ophthalmoscopy – this may be the only opportunity for fundus and ophthalmic examination.

• Assessment of contact lens condition.

28.4.1 Ocular examination

•Vascularization or neovascularization.

•Oedematous responses (microcysts, bullae, striae).

•Signs of infection or inflammatory response (see Section 29.1.1).

•Corneal thinning.

•Endothelial polymegathism.

•Chronic staining.

Conjunctiva

•Desiccation.

•Injection.

•Pingueculae.

341

Section FIVE Management

Lids

•Position, including ptosis.

•CLIPC.

•Concretions.

•Patency of meibomian glands.

Tears

•Qualitative assessment.

•Break-up time.

Over-refraction

•Comparison with previously recorded acuities.

•Change in myopia or hypermetropia.

•Change in astigmatism.

28.4.2 Other factors

Reassessing contact lens refraction and fitting

Old and deposited lenses frequently give reduced acuity. Rigid lenses may have distorted with repeated handling and conventional soft lenses become less flexible with age. Spurious refractive changes of up to 1.00 D can be found, so it is essential to reassess both refractive result and fit. Disposable trial lenses should be used routinely for soft lenses in order to obtain a reliable result.

Assessing contact lens condition

It is also important to examine the lens condition, most easily effected on the eye with the slit lamp. Digital image capture and viewing on a computer monitor are particularly useful to demonstrate to the patient surface and edge defects or signs of ageing (see Section 29.4).

Solutions

It is important to establish that the patient is using solutions correctly. Common errors are:

•Changing brands without consulting the practitioner.

•Omitting to use a daily cleaner.

•Insufficient rinsing of cleaning solution.

•Forgetting to use enzyme tablets.

•Using preserved instead of unpreserved saline.

•Thinking saline is a storage and disinfection solution.

342

Aftercare 28 Chapter

References

1.Andrasko G, Ryen K. A series of evaluations of MPS and silicone hydrogel lens combinations. Review of Cornea and Contact Lenses 2007;March:36–42.

2.Allansmith MR, Korb DR, Freiner JV, Henriquez AS, Simon MA, Finnemore VM. Giant papillary conjunctivitis in contact lens wearers. American Journal of Ophthalmology 1977;83:697–708.

3.Jupiter D, Karesh J. Ptosis associated with PMMA/rigid gas-permeable contact lens wear. CLAO Journal 1999;25(3):159–62.

4.Harvey W, Ruston D. Visual recognition in contact lens practice Part 1: initial assessment. Optician 2002;223(5849):32–5.

343