Eyeworld

EW CORNEA 34 November 2017 by Rich Daly EyeWorld Contributing Writer Scleral lenses can revolutionize the treatment of irregularly shaped corneas, surgeons say fluid, which not only improves vision but treats the surface disease, Dr. Jeng said. Treatment algorithm Sanjay Patel, MD, FRCOphth, pro- fessor and chair of ophthalmology, Mayo Clinic, Rochester, Minnesota, typically exhausts all types of con- tact lens options—moving from cor- neal lenses to scleral lenses—before considering DALK or PK for ectasia. "Of course, if opacity from scar- ring is the main problem, then PK/ DALK may be necessary because no contact lens option will give ideal vision," Dr. Patel said. In distorted cornea cases, scleral lenses should be tried ahead of surgery, said Deborah Jacobs, MD, medical director, BostonSight, Need- ham, Massachusetts, and associate professor of ophthalmology, Harvard Medical School, Boston. "It is hard to tell, even with an axial opacity, how much visual deficit is related to the opacity and how much is related to the irregular astigmatism," Dr. Jacobs said. "A rig- id gas permeable [RGP] corneal lens or scleral lens refraction should be undertaken before considering sur- gery for poor vision in any patient with keratoconus or other causes of corneal distortion." If the RGP lens is unstable, scleral lens refraction should be undertaken. Since a high proportion of PKP procedures for ectasia require RGP lens correction for good vision after PKP, and since DALK does not lower risk of postop astigmatism, eyes with good vision in RGP corne- al lenses or scleral lenses should go that route rather than the surgical route for predictability of outcome and lower overall risk, according to Dr. Jacobs. "Likewise, in recurrent ectasia after PKP for keratoconus, I would recommend scleral lenses prior to repeat keratoplasty, especially if the graft itself remains clear and com- pact, which it typically does," Dr. Jacobs said. "We have patients doing well in scleral lenses 25–35 years after PKP." In ocular surface disease and dry eye cases, scleral lenses are "a pretty big commitment for the patient as far as initial expense, daily logistics, and ongoing expense is concerned," Dr. Jacobs said. Typically, Dr. Jacobs recom- mends lubricants, punctal occlusion, and suppression of any inflamma- tion prior to moving to scleral lens. Understanding the role of scleral lenses in ocular surface disease W hile fitting contact lenses and patient contact lens care is typically managed by optome- trists, it is important for ophthalmologists to understand that there is a role for thera- peutic scleral contact lenses, especially in ocular surface disease and ectatic corneal conditions. Some patients may fear undergoing corneal transplantation or may have co- morbidities leading to a poor prognosis (for example, limbal stem cell deficiency, neu- rotrophic corneas, corneal exposure, and lid malposition issues). Corneal transplantation, while very successful, especially with the advent of deep anterior lamellar kerato- plasty (DALK), which preserves the patient's native healthy endothelial layer, has reduced the risk of rejection. However, there are still intraoperative risks and postoperative risks of infection, wound dehiscence, rejection, elevated intraocular pressure from steroid response, and high degrees of refractive error to consider. Scleral lenses may be tried in advance of corneal surgery, and even when there appears to be some corneal scarring, one can be pleasantly surprised at the degree of visual improvement achieved once the irregular astigmatism is neutralized with a scleral lens. Those with the most severe ocular surface disease (Stevens-Johnson syndrome, graft-versus-host disease, neurotrophic corneas, Sjögren's syndrome, exposure keratitis, and neuropathic pain) may have symptoms refractive to all med- ical dry eye therapies. Therapeutic scleral lenses allow the cornea to be continuously bathed in fluid and can provide some of these patients with relief. Deborah Jacobs, MD, Bennie Jeng, MD, and Sanjay Patel, MD, discuss the various types of scleral lenses, indications for use, and pearls for patient selection in this month's "Cornea editor's corner of the world." Clara Chan, MD, Cornea editor Scleral lens in a patient with an epithelial defect from severe dry eye secondary to ocular graft-versus-host disease. The defect healed within 1 week of use of the scleral lens. Source: Bennie Jeng, MD continued on page 36 S cleral lenses are providing benefits in the treatment of irregularly shaped corneas and severe ocular surface disease, according to surgeons. Scleral lenses can benefit pa- tients with two general categories of corneal disease: any condition characterized by a distorted cornea (e.g., keratoconus, pellucid mar- ginal degeneration, keratoglobus, post-LASIK ectasia, post-PKP/DALK, post-RK, and post-trauma), and most forms of ocular surface disease from various etiologies such as graft-ver- sus-host disease or Stevens-Johnson syndrome. In cases of an irregularly shaped cornea, scleral lenses basically vault over it and effectively give it a new shape. "It's revolutionized the way that we can manage these patients medically," said Bennie Jeng, MD, professor and chair, Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore. In advanced dry eye cases that don't respond to tear supplements, scleral lenses allow for placing fluid with a contact lens on the eye and continuously bathing the eye in Cornea editor's corner of the world

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