As contact lens fitters, too often we find ourselves fixated over obtaining the very best visual results for our patients. These days we can specify a dizzying array of toric powers and axes into our soft daily lenses. We can incorporate spherical aberration correction and multifocal optics into our scleral lenses. Heck we can even customise an orthokeratology lens to match a child’s pupil size. It is all very empowering. Still, there is an important application for contact lenses where the power and vision through the lens is largely irrelevant: bandage contact lenses.
Bandage contact lenses (BCL) refers to the application of contact lenses, typically soft silicone hydrogel extended-wear lenses, for therapeutic reasons such as facilitating corneal healing or protecting a fragile corneal surface. The key concept of a bandage contact lens is the relentless shearing forces of our blinking lids is nullified during wear, often offering immediate relief to patients (and practitioner!) as soon as they are inserted.
The concept of a protective eye bandage originated several millennia ago when a smart chap called Celsus reportedly applied a honey-soaked linen to the site of a pterygium removal to prevent symblepharon development. Last century the technique of pressure-patching had traditionally been used when an eye needed protection to heal. Interestingly, a study several decades ago showed patients with traumatic corneal abrasions healed significantly faster, had less pain and had fewer reports of blurred vision when they were not wearing a pressure patch. Corneal abrasions due to removal of foreign bodies showed similar results¹.
Contact lenses were first used as an alternative to pressure patching following the development of hydroxyethyl methacrylate (HEMA) soft contact lenses in the 1970s. Bandage contact lenses were superior to patching for a number of reasons: vision could be maintained during wear, topical medications could continue to be instilled, and the cosmesis was far better. Let’s be honest, not too many people enjoy stepping out into the world with half a roll of gauze taped to their face! Today’s modern bandage contact lenses provide the same benefits as their predecessors - but with enhanced convenience, improved healing and better corneal health due to the high Dk materials we now use - an important consideration if extended wear is required.
The choice of lens design depends on a few factors but, typically, a lens with a low modulus is preferred as these will drape onto the underlying tissue better and theoretically provide less mechanical interaction. My preferred lenses are those with a modulus below 0.8 MPa such as Biofinity (Coopervision) for a monthly lens and the fortnightly CAir (Coopervision) or Acuvue Oasys (J&J) if a shorter duration of wear is expected. For comparison, the Air Optix (Alcon) and Purevision (Bausch + Lomb) lenses are made of stiffer materials with a modulus above 1.0 MPa. I have spoken with several clinics using these high modulus lenses as BCLs and they report few issues. If a custom bandage lens is required the SiHg Definitive 74 material has a reasonable Dk of 60 Fatt units and a nice low modulus of 0.4 MPa.
