Clinical Indications

The most frequent indication for Scleral lenses is Keratoconus, but they have applications for post corneal transplant, high myopia, aphakia and high astigmatism. They retain a fluid reservoir behind the lens while they are in the eye, so may assist in the management of dry eye conditions.

Before the introduction of rigid gas permeable materials, Scleral lenses were only considered for the most advanced eye conditions, but now they can be available for lower grades of keratoconus where there are problems with Corneal lens tolerance or to give an alternative to corneal lens wear.

Irregular or abnormal corneal topography

 

  • High astigmatism

  • Keratoconus or other primary corneal ectasia

  • Corneal transplant

  • Traumatized eye

  • Post-refractive surgery

 

Keratoconus

Downwardly displaced and protrusive ectasia. A scleral lens is seen in situ with a glancing apical contact.

 

 

 

 

 

 

Corneal transplant

25.00DC post-op astigmatism with a ridge in the inferior sector. A non-ventilated RGP scleral lens gave a VA of 6/9 with all day wear.

 

 

 

 

 

 

High refractive errors

 

  • High powers leading to centration difficulties with high-power corneal lenses.

  • Intolerance to corneal or hydrogel lens wear in myopia or hypermetropia

  • Significant non-pathological corneal astigmatism 

 

 

Iris encapsulation

 

  • Intractable diplopia.

  • Cosmetic shells.

  • Unsightly blind eyes.

  • Aniridia. Microphthalmos

 

 

Therapeutic or protective applications

 

  • Corneal hydration in serious dry eye conditions such as

  • Stevens Johnson syndrome and cicatricising pemphigoid

  • Potential for corneal healing

  • Prevention of tear film evaporation with poor lid closure or lid absence

  • Corneal protection against trichiasis or lid margin keratinisation

  • Preventing mucus filaments adhering to the cornea

  • Ptosis

 

The main role of scleral lenses is to augment the options when contact lenses are clinically necessary for satisfactory vision or as a therapeutic appliance. However, there is also a role across the whole range of contact lens usage.

 

 

Recreational or occupational applications

 

  • Intermittent use where short-term adaptation may be

  • easier than with corneal lenses

  • Contact sports

  • Water sports

  • Work in dusty environments 

 

 

Potential Disadvantages of Scleral Lenses

 

  • Even if skilfully fitted, the full corneal coverage considerably reduces oxygen available to the cornea for PMMA sclerals

  • They are labour intensive to produce compared to most other lens types

  • Their physical size can intimidate some patients

  • Some patients are conscious of the feeling of bulk

  • The scleral zone substance may cause a pseudo-proptosis appearance during wear

  • Fenestrations in scleral lenses admit air bubbles to the pre-corneal reservoir causing visual disturbances and localised dehydration

  • Fenestrations also cause settling back on the globe with consequent tightness of the fit, especially at the limbus