Bandage contact lenses help manage corneal disorders
Bandage contact lenses serve several purposes in the management of corneal disorders. Perhaps most commonly, they are used in the place of a pressure patch for pain relief, but there are numerous other applications for corneal protection and drug delivery. Although one must carefully weigh the relative risk of applying a contact lens to an eye that is already mechanically or physiologically compromised, safer and more feasible therapeutic applications of contact lenses have been made possible by advancements in contact lens materials.
The physiologic advantages of high-Dk lenses have been well documented, and the off-label therapeutic use of such lenses has been common. In May 2003, Focus Night & Day (CIBA Vision, Duluth, Ga.) received Food and Drug Administration approval for “therapeutic use.” A recent publication by Montero and colleagues supports the use of this fluorosilicone hydrogel contact lens as a bandage (J. Montero, J Sparholt, R Mely, B Long. Retrospective case series of therapeutic applications of lotrafilcon A silicone hydrogel soft contact lenses. Eye and Contact Lens. 2003;29(2):72-75).
The article reports on 41 cases in which a Night & Day lens was used for a range of therapeutic applications. The cases included erosion, bullous keratopathy, corneal edema, corneal dystrophy and post-surgery treatment. Bandage use of the Night & Day lens was fully successful in 71% of cases and either fully or partially successful in 93% of cases. In cases in which the therapeutic goal was pain relief, an 86% success rate was achieved. In addition to the ability to take the place of a pressure patch in many cases, the feasibility of using contact lenses including silicone hydrogels for drug delivery also continues to show promise.
Abrasions, corneal erosion, dystrophies
Probably the most common reason for choosing bandage contact lens therapy is to manage corneal surface disruption secondary to either trauma or dystrophic disease. In contrast to using the conventional pressure patch, a bandage contact lens allows concurrent application of medications, allows the physician to observe the eye without removing the bandage, allows the patient to have usable vision in the affected eye and offers significantly better cosmesis along with the ability to wear spectacles or sunglasses as needed.
When treating abrasions, the contact lens acts a barrier to further epithelial disruption and corneal nerve stimulation by the shearing force of the upper lid during the blink. Additionally, there is evidence that a lens can prolong contact time of topical ocular medications.
In the event of recurrent erosion, a bandage contact lens can be applied to the eye and worn on a 30-day continuous-wear basis for at least 2 months. It is important to leave the lens in place for many weeks after the erosion resolves to allow epithelial migration and attachment without the interference of the shearing forces of the upper lid. If the lens needs to be replaced, it can be carefully floated off with saline solution in-office and replaced.
Concurrent therapy of hypertonic saline drops may be used in addition to preservative-free ocular lubricants. Ocular ointments are avoided due to their propensity for surface deposition and visual acuity degradation.
Ectatic conditions such as keratoconus, pellucid marginal degeneration and Terrien’s marginal degeneration are typically managed with gas-permeable contact lenses. However, as the conditions progress, epithelial compromise can occur secondary to the inability to provide a stable GP contact lens fit. In these cases, a soft contact lens will have therapeutic benefit in providing a more stable base on which to place the gas-permeable contact lens and at the same time protect the corneal surface.
Bandage contact lenses can provide pressure-patching type relief for patients with Thygeson’s superficial punctate keratitis and those with superior limbic keratoconjunctivitis. Less common, but serious instances of persistent corneal ulcers or Mooren’s ulcer that do not respond to conventional medical treatment may require the use of a contact lens to provide pain relief and once again act as a splint to promote epithelial healing.
Finally, bandage contact lenses have been shown to improve the healing time of primary herpes simplex ulcers. The use of soft contact lenses in conjunction with antiviral agents, once again, provides pain relief, improves vision during treatment and, if applied early, can speed the healing process.
Laceration, perforation and burns
Bandage lenses are indicated in cases of corneal lacerations that are small with well-appositioned edges that do not cause wound gape. A contact lens can be used in conjunction with wound-closing therapies such as suturing or cyanoacrylate glue to protect the eye from mechanical trauma and promote pain relief.
Complete corneal perforation or descemetocele secondary to trauma, exposure or infection require the splinting action of a bandage contact lens to reinforce Descemet’s membrane until surgical intervention. After acid, alkali, ultraviolet and thermal burns, a bandage lens can help protect the cornea, provide pain relief and promote re-epithelialization and prevention of symblepharon formation.
Both photorefractive keratectomy and laser epithelial keratomileusis induce a large epithelial defect and require the continuous wear of a bandage contact lens for 3 to 4 days post-surgery or until complete re-epithelialization occurs. Once again, the lenses provide pressure-patching pain relief as well as corneal protection while allowing examination of the healing surface and allowing the patient usable vision during the process.
These lenses also have roles immediately following penetrating keratoplasty. Tarsal plate protection is often necessary in procedures that result in interrupted sutures with non-buried knots. The contact lens smoothes the ocular surface, providing better ocular comfort and preventing mechanically induced papillary conjunctivitis.
Lens options and fitting
Given the benefits of silicone hydrogel contact lenses, which include the virtual elimination of complications related to hypoxia in the normal eye, it would make sense to try this modality as the initial lens of choice for therapeutic applications. It can be expected that the increased oxygen permeability will more effectively promote healing by reducing the risk of hypoxia-related interference. This is of prime importance when the contact lens must be worn on a continuous-wear basis for several months.
The silicone hydrogels are also low-water-content materials for which evaporation and dehydration appear to be significantly less of a problem than with conventional hydrogels. Silicone hydrogel lenses also have surface properties that reduce protein binding.
When the treatment goal is corneal protection from mechanical trauma, the practitioner should avoid an excessively loose-fitting lens. In most instances, the 8.4-mm base curve of the Focus Night & Day will be first choice, although extremely tight-fitting lenses are never indicated, as toxic debris entrapment beneath the lens is potentially problematic. In instances where an appropriate fit cannot be obtained or when the silicone hydrogel fails due to other issues such as discomfort, it is prudent to consider other lenses approved for therapeutic use.
These lenses include the high-water-content Permalens Therapeutic Bandage (CooperVision, Fairport, N.Y.) or the low-water-content Plano T (Bausch & Lomb, Rochester, N.Y.). Although not FDA-approved for therapeutic use, success with disposable lenses has been reported in the literature as a viable alternative bandage lens option. It is expected that the high-Dk Acuvue Advance (Vistakon, Jacksonville, Fla.) may offer advantages due to its combination of high permeability and low modulus; however, this is as yet untested.
Soft contact lenses can serve as a reservoir when soaked in topically applied medications and have the ability to uptake and release the medication. The goal of bandage lens therapy in such cases is to provide an initial release of the drug into the eye and then a slower, long-term release throughout the duration of lens wear.
Any time medical therapy is indicated and a bandage contact lens is used, the customary dosage and instillation therapy should not be altered. The amount of uptake and release of drugs from contact lenses soaked in the medications has been reported in the literature, and inconsistencies exist with respect to material interactions, lens water content and ionic character.
The most recent study, published by Karlgard and colleagues, describes the uptake and release of ciprofloxacin from hydrogel contact lenses representing all four FDA groups and two silicone hydrogel lenses (CC Karlgard, LW Jones, C Moresoli. Ciprofloxacin interaction with silicone-based and conventional hydrogel contact lenses. Eye and Contact Lens. 2003;29(2):83-89). In all lenses, maximum uptake occurred within 5 to 30 minutes of soak time, and no differences existed between lenses with respect to amount. Differences did exist with respect to release of the ciprofloxacin, and the two silicone hydrogels released significantly less medication than the other groups.
Even so, the authors concluded that, for all lenses, the drug release was well above the MIC90 for commonly found pathogens and that the improved physiologic characteristics of high-Dk lenses should still be considered a better alternative for bandage and therapeutic lenses than low-Dk contact lenses.
Bandage contact lens complications are typically either mechanical in nature from the close apposition between the contact lens and the ocular surface or an inflammatory response from entrapped debris underneath the lens. Because the lenses are used on an already-compromised ocular surface, judicious follow-up is imperative. The first visit after the initial bandage lens is dispensed should be within 24 hours and then again in 3 to 7 days. Weekly follow-ups thereafter for the first month are also suggested.
The goal of a therapeutic lens is to improve healing and to provide pain relief. Therefore, lens wear should be discontinued if symptoms or signs worsen or if no improvement is seen over a reasonable amount of time depending on the condition.
For More Information:
Jennifer L. Smythe, OD, FAAO, is an associate professor of optometry and coordinator of the Cornea and Contact Lens residency at Pacific University College of Optometry. She can be reached at Pacific University College of Optometry, 2043 College Way, Forest Grove, OR 97116; (503) 352-2770; fax: (503) 352-2929; e-mail: firstname.lastname@example.org. Smythe has no direct financial interest in the products mentioned in this article, nor is she a paid consultant for any companies mentioned.
Peter Bergenske, OD, FAAO, is chief of contact lens services at Pacific University College of Optometry; (503) 352-2278; fax: (503) 352-2929; e-mail: email@example.com.