Bandage Contact Lens

A different (therapeutic) role of contact lens. Useful in corneal epithelium breach.

1. Bandage contact lens Presented by Loknath Goswami B. Optom 3 rd year 2015 - 2019 Ridley college of optometry

2. Introduction Bandage contact lenses are widely used in refractive surgery The main purpose of this practice is to reduce inflammatory cell infiltration into the corneal stroma therefore decreasing the threat of corneal scarring Also , bandage lenses assist in the regeneration of basement membrane and restoration of tight epithelial stromal adhesion The bandage lens protects the loosely adherent and regenerating epithelium from the relentless action of the eyelids In addition, the lens provides comfort without affecting the patient’s vision 

3. Aim The therapeutic lenses principle aim is to bandage the eye as a therapy which Provides relief from pain Serves mechanical protection by separating the epithelial surface from the external agents such as lid surfaces, thus protecting the epithelium Seal corneal perforations by acting as a splint for the underlying weaker tissues and supports the area while healing takes place Corrects the surface irregularities in irregular corneas and improves visual acuity

4. Ideal contact lens

5. Conditions of eye which are suitable for therapeutic lenses Eyelids abnormalities – Entropion Trichiasis Ectropion Lagophthalmos

6. Conditions of eye which are suitable for therapeutic lenses Ocular surface disorders – chemical injuries, dry eye, Stevens-Johnson syndrome

7. Conditions of eye which are suitable for therapeutic lenses Corneal surface disorder R ecurrent erosion syndrome Keratitis T raumatic epithelium abnormalities F ilamentary keratitis B ullous keratopathy

8. Lens materials for extended wear use

9. HYDROGELS—SOFT LENSES HEMA lenses used for extended period are a choice dependent on the corneal pathology. i . High water content soft lenses: Lenses with water content 80% and Plano power are available as bandage lens. They are suitable for epithelial defect patients. These lenses act as bandage which necessitate minimal epithelial disturbance and help in relieving pain

10. HYDROGELS—SOFT LENSES ii. Mid water content lenses: Lenses with 45 to 60% water content may be the choice for small perforations or leaking wounds. They act as a splint. iii . Low water content lenses: Low water (below 45%) thin lenses as bandage lenses Used in disorders of lids such as trichiasis causing trauma to cornea.

11. SILICONE HYDROGELS Silicon hydrogels are new generation lenses. They cause significantly lower level of hypoxia related effects compared to the leading EW hydrogel lenses. They also have lower level of bacterial binding with them.

12. COLLAGEN SHIELDS Their main function is drug delivery. Shields soaked in the drug. Antibiotics are applied to the eye in case like bacterial ulcers, post PK, etc. where the drug is released in high concentration.

13. High Dk RGP Rigid lenses are frequently used for a combination of optical and therapeutic indications. All corneal abnormalities leading to irregular astigmatism or high amounts of astigmatism will benefit visually only with rigid lenses. Conditions like post keratitis cornea, post PK, traumatic cornea or keratoconus , the cornea is already compromised so lenses with maximum Dk should be fitted to these patients to prevent further insult to the cornea

14. SCLERAL LENSES Scleral lenses have a host of therapeutic roles Their advantages include the following: There need be no corneal contact whatsoever . Any eye shape can be fitted. Complete protection of the cornea and bulbar conjunctiva is provided. Sealed fits are possible, using gas-permeable materials, which simplifes the ftting process and minimizes ‘settling back’. Using gas-permeable materials, overnight wear is possible.

15. SELECTION OF THE LENS 1 . Oxygen Transmissibility High water content, thin mid water content lenses, silicone hydrogels or high Dk RGP lenses give the best transmissibility. Lenses which have to be worn for extended periods should be selected from either of these materials. Select high water contact lens in eye conditions where the lens has to act as a splint. RGP lenses are for irregular compromised corneas to achieve better vision .

16. SELECTION OF THE LENS 2. Diameter Soft bandage lenses are usually larger in diameter usually 14.0 to 15.0 mm. Larger diameter lenses (15mm to 20mm) may be required where the specific function is to protect the limbus or prevent wound leakage at suture or incision sites Larger diameter lenses require flatter back optic zone radii to achieve the desired fit . 3 . Power Bandage lenses are usually plano in power.

17. SELECTION OF THE LENS 4. Disposable Lenses or FRP Lenses Disposable lenses or FRP lenses are selected as bandage lenses. Therapeutic lenses should be preferably discarded after every use. They are nowadays rarely cleaned and reinserted. Deposits formation is very likely and heavy in such eye conditions.

18. Use after Refractive Surgery Surface Ablation Immediately after surface ablation procedures such as LASEK or PRK, bandage contact lenses are routinely applied to patients’ eyes to encourage re-epithelialization and healing, and to reduce discomfort and pain

19. LASIK Bandage contact lenses can be applied after, to reduce discomfort and prevent epithelial in-growth However , some believe this actually increases the risk for striae , or may not have any beneficial effects Some patients are at risk of developing an epithelial slide, especially those with a history of anterior basement membrane dystrophy. If an epithelial slide occurs during the operation, a bandage contact lens may be applied to the eye to improve healing and protect the eye until the epithelium has regrown 

20. Striae and epithelial in-growth

21. Striae Striae , or flap folds, are a complication of LASIK in up to 3.5% of cases. The folds can disturb visual acuity, though often they resolve on their own. Causes of striae include flap dessication , flap misalignment and flap tenting. Striae can be classified as macrostriae or microstriae T he treatment for both groups can involve the use of bandage contact lenses .

22. Macrostriae These are caused by flap dislocation and often involve the entire thickness of the flap. If the macrostriae are not detected early, the flap must be refloated and stretched again. Different methods have been proposed for this procedure, but many involve the use of bandage contact lenses after completion to help the epithelium re-grow correctly.

23. Microstriae These are smaller flap folds that are caused by problems in flap settling. These striae more often resolve on their own with the help of artificial tears and bandage contact lenses. However , if the striae persist, stretching or refloating of the flap may be necessary, and a bandage contact lens is used.

24. Epithelial In-growth Epithelial in-growth is an infrequent complication of LASIK, that is caused either by implantation of epithelial cells during surgery or from epithelial cells growing underneath the flap. Removal of the in-growth involves lifting the flap, irrigating the interface and subsequently placing a bandage contact lens. This prevents epithelium from re-entering the flap interface

25. Overcorrection In cases of consecutive hyperopia, also known as overcorrection, bandage contact lenses may be used in conjunction with non-steroidal anti-inflammatory drugs (NSAIDs) to reduce the need for a second surgery. The contact lens helps increase the NSAIDs penetration into the cornea to stimulate stromal re-growth. The tight fit of the contact lens also creates a contour that helps correctly shape the growth.

26. Complications In some cases, bandage contact lenses can lead to infectious keratitis . Other complications can include dry eye, corneal hypoxia and corneal edema Patients should be aware of proper lens hygiene .

27. B andage contact lens after photorefractive keratotomy Although there are many conventional therapeutic soft lenses on the market, disposable contact lenses have become very popular bandage lenses. The advantages of disposable lenses include less expense, less risk of corneal infection, and less risk of toxic complications with concurrent use of topical medications. They are also easy to replace if a contact lens is accidently dislodged or lost.

28. Bandage contact lens after photorefractive keratotomy Standard hydrophillic disposable lenses (e.g. Acuvue TM, Vistakon ) approved for extended wear have shown good clinical efficacy, but silicone hydrogel disposable lenses ( PureVision TM, B&L; or focus Night & Day TM, CIBAVision ) also offer the advantage of decreasing the risk of hypoxic complications with continuous wear

29. Bandage contact lens after photorefractive keratotomy Although the risk of infectious keratitis with the use of therapeutic contact lenses after PRK is low, bacterial contamination has been found on the bandage contact lenses after removal. Microorganisms found on the lenses typically represent the bacteria found in the normal ocular flora, indicating the need for careful monitoring and follow-up. Topical antibiotics combined with no handling of the lenses by the patient reduce the risk of bacterial infection

30. F itting a therapeutic hydrophilic lens after photorefractive keratotomy At the conclusion of the PRK procedure, the surgeon generally places a disposable contact lens on the eye. The contact lens should be chosen based on the preoperative measurements. The patient should be examined at the slit lamp approximately 30 minutes later to determine the contact lens-cornea relationship There may be both patient discomfort as well as interference with reepithelialization . Check to be sure the contact lens is not inverted before changing base curves.

31. Fitting a therapeutic hydrophilic lens after photorefractive keratotomy If the contact lenses does not have movement, the causes may be: A steep base curve, which may produce corneal edema. In this case, try a flatter curve. Edema of the conjunctiva produced by the use of a device such as a suction ring. In this case, the contact lens should not be disturbed.

32. Fitting a therapeutic hydrophilic lens after photorefractive keratotomy If there is foreign material, rolled epithelial edges, and/or significant debris under the contact lens, it should be exchanged. On the other hand, if the quantity of debris is very small, one should avoid disturbing the lens. Its removal, aside from producing discomfort, may actually increase the size of the epithelial defect.

33. Advice to the patient Avoid removing the lens at home specially if the patient have no experience with contact lenses. Removal will typically be done at an office visit, once the epithelium is intact. Manipulation of the contact lenses by the patient can increase the risk of infection Avoid environmental pollutants and activities that significantly reduce the blink rate, which may cause dehydration of the contact lens. A dry contact lens produces discomfort, facilitates deposit formation, diminishes oxygenation of the cornea and increases the risk of infection.

34. Advice to the patient Avoid cosmetic around the eyes until the contact lens has been removed Use lubricants, preferably non-preserved, between administration other topical medications in order to lubricate and clean the contact lens Discard the contact lens if it comes out of the eye

35. Removing the lens The following steps are recommended Wet the contact lens and wait 2-5 mins before removing it Use a drop of anaesthetic if necessary to reduce trauma Ask the patient to look up Pull the contact lens inferiorly and remove it with fingers or with a fine, non toothed forceps at the slit lamp

36. FITTING GUIDELINES KERATOMETRY It is usually not possible to determine the corneal curvature in such eye conditions. The mires are heavily distorted. Corneal topography or Keratoscopy can give some useful information in selecting curvatures. In case of traumatic corneas, the good eye K reading can form a base line to start with, on the assumption that the corneal curvature may have been same before trauma in the eye to be fitted with contact lens.

37. FITTING GUIDELINES ANTERIOR SEGMENT ASSESSMENT Anterior segment assessment is important. Staining if possible should be done with rose Bengal dye and recorded and graded. Also the eye should not be in acute infective state during fitting. Tear film stability should also be measured. TYPE OF LENS Select the type of lens according to the eye condition

38. For Soft Lenses Allow the lens to settle on the eye may be for 15 to 20 minutes - Optimal fit—reasonably well centered - Complete coverage of the cornea . Movement slightly restricted at the same time does not allow the debris to accumulate behind.About 0.3 to 0.5 mm with each blink. Observe the eye condition after 4 hours, then 24 hours of wear. Ensure there is no complication developing because of the lens and the wound has started healing.

39. For Soft Lenses In most cases the bandage lens is worn for short periods of extended wear, regular follow-ups are important. It is the practitioner who inserts and removes these lenses whenever needed. However, the patient should also be explained the emergency removal technique and contact lens care and maintenance. He should have a container with the soaking solution at hand with him.

40. For RGP Measure the good eyes keratometry in case of uniocular disorders as base line. The fitting is done on hit and trial basis. There should not be excessive bearing or clearing areas. The tears should exchange properly and debris should also not collect behind the lens Achieve a stable centered lens.

41. References Mark J. Mannis , contact lenses in Ophthalmic Practice, 1 st edition, page no. 148 – 187 Monica Chaudhry , Contact Lens Primer, 1 st edition, page no. 162 – 173 Therapeutic Contact lens, Manoj Aryal , B . Optometry, Institute Of Medicine, Maharajgunj Medical campus http://eyewiki.aao.org/Bandage_Contact_Lenses_After_Refractive_Surgery

42. Thank you