Scleral Lenses

 

Notwithstanding the other contact lenses, these bigger lenses do not lay on the cornea but rather on the scleral part of the conjonctiva. Using a more common language, it lays on the white portion of the eye sourrounding the cornea, without any direct contact with cornea itself, which is bathed in a liquid reservoir (usually a physiological saline solution). The cornea is then protected from most of the constant aggressions it may undergo. Such a reservoir enables a constant lubrication of the cornea, which is essential to improve may ocular surface diseases and notably neurotrophic keratitis, some severe forms of dry eyes and other pathologies affecting the lachrymal system such as the Steven-johnson and Lyell syndromes. These lenses promote corneal healing and maintain a level of hydration superior to any other type of lachrymal substitute. This type of lens can also reduce ocular pain, photophobia, friction and other aggressions caused by the eyelids. They may  correct severe cases of irregular astigmatism often associated with this type of pathology as well. 

Although it is a relatively new type of therapeutic approach, scleral lenses were invented before the usual corneal contact lenses. However, it's the first time they've been used in ocular surface diseases with a therapeutic rather that just a visual purpose. Before this new indication, scleral had been used to correct visual impairments that could not be corrected using glasses or some other type of rigid contact lens (such as in keratoconus, cornea plana, a severe irregular or cicatricial astigmatism). Over the last few years, and in some specialised centres of the world (in 4 countries to our current knowledge: US, UK, France, Netherlands), these lenses have demonstrated to be very useful in severe ocular surface diseases, such as neurotrophic keratitis, Stevens-Johnson and Lyell syndromes or even in ocular rosacea for which most other therapies are rare or inefficient. They been used as a last ressource or as a way to avoid corneal graft procedures unlikely to succed or to avoid imminent perforation of the cornea.

Nevertheless, one should not consider that they are to be used in all cases and destined to treat all types of dry eyes. They require a very strict follow-up and impose several constraints. Therefore, they are destined to motivated patients (but if your case is serious, you'll have motivation to spare!). Adaptation, placing and removal may be quite complex for most people. The lenses alone cost (more or less €1.200 the pair in France)  and are reimbursed in France as if they were usual lenses for some specific cases (39,48 euros per lens). The total cost is however, much higher due to the adaptation process and the decontamination and cleaning products needed. Nevertheless, follow-up consultations fees are totally of partially covered by the French state. Thus, one should consider they're destined to severe cases of ocular surface disease, unless there is a very specific additional visual indication (ex: keratoconus, cicatricial astigmatism, etc). Tolerance and benefit of the lens is examined empirically and may change according to each individual case, pathology, etc.

On this scan one can see, that the cornea bathes in a very thin reservoir of sterile saline physiological solution.

This therapeutic approach remains unknown to most ophthalmolgists in France and probably worlwide.

Interesting websites on this subject: Boston scleral lenses http://www.sclerals.com/b_home.html

A selection  of articles on the subject: Modern scleral lenses part I: clinical features.Visser ES, Visser R, van Lier HJ, Otten HM, Visser Contact Lens Practice, Nijmegen-Utrecht, The Netherlands.Eye Contact Lens. 2007 Jan;33(1):13-20 Scleral lens an important tool in many 'last resort' scenarios. Patients with severe ocular surface disease and other corneal disorders may benefit from lens Cheryl Guttman,  Ophthalmology Times, Sep 1, 2005 Fluid-Ventilated, Gas-Permeable Scleral Contact Lens Is an Effective Option for Managing Severe Ocular Surface Disease and Many Corneal Disorders That Would Otherwise Require Penetrating Keratoplasty, Rosenthal, Perry M.D; Croteau, Amy O.D,  Eye & Contact Lens: Science & Clinical Practice. 31(3):130-134, May 2005. Scleral Contact Lenses: The Expanding Role. Pullum, Kenneth W; Whiting, Mark A ; Buckley, Roger J, Cornea. 24(3):269-277, Avril 2005. Vers une réhabilitation des verres scléraux?, Journal Français d'Ophtalmologie, J.-M. Laroche, F. Baëchelé, M. Drouin, M. Ortega, T. Hoang-Xuan, Volume 27 No 8 de octobre 2004.  The Boston Scleral Lens in the management of severe ocular surface disease, Rosenthal P, Cotter J, Ophthalmol Clin North Am, 16(1):89-93 Mars 2003. Scleral contact lens overnight wear in the management of ocular surface disorders, M.J. Tappin, K.W. Pullum & R.J. Buckley, Eye (2001), 15, 162-172. Treatment of persistent epithelial defect with extended wear of fluid-ventilated gas-permeable scleral contact lens, par Perry Rosenthal, Janis Cotter & Jules Baum, American Journal of Ophtalmology, Vol 130 n°1, Juillet 2000. Gas-permeable scleral contact lens therapy for ocular surface disease, par Tatiana Romero-Rangel, Panagiota Stavrou, Janis Cotter, Perry Rosenthal, Stefanos Baltzatzis & C. Stephen Foster, American Journal of Ophtalmology 130:25-32, 2000. A study of 530 referred for RGP scleral contact lens assessment, Kenneth Pullum & Roger Buckley,  in Cornea  et 16 (6):612-622, 1997; ibidem, Optometrist Today, 20 août 1999. Current indications for scleral contact lenses, Foss AJ, Trodd TC, Dart JK, Moorfields Eye Hospital, London, CLAO, 20(2):115-8 J. Avril 1994. Treatment of ocular surface disorders and dry eyes with high gas-permeable scleral lenses, Kok JH & Visser, R., Department of Ophthalmology, University of Amsterdam, The Netherlands, in Cornea 11(6):518-22, Novembre 1992.

The reimbursement of sclerals

This issue is adressed in a more thorough manner in the French section of the website. Keratos has been involving in scleral lenses related advocacy since late 2005 in France. We are currently seeing the first results of those actions: in March 2007, for the first time we were able to present our plea in front of a panel of experts of the High Health Authority, along with our partners Amalyste & Keratocône. This institution is charge of reimbursement policies in France, has emitted in late April a favorable opinion on the reimbursement of one type of scleral lenses in France. If you read French then here's the relevant "avis de la CEPP". This is the first step towards the aknowlegement that this is currently the only therapeutic option for end resort therapy for severe ocular surface damage, pain and sight rehabilitation when a corneal graft is not suitable or viable. Let's not forget that this reimbursement is also in the interest of the State since it may replace in some cases much more expensive procedures (including corneal grafts and other surgical procedures) or severe disability entitlements. We hope many other countries will follow this recognition. So far, the principle of reimbruserment has been agreed upon but the precise amount and modalities have yet to be decided.

 

     

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