Figure 3-21 Floppy eyelid syndrome with papillary response on superior tarsus. (Courtesy of Vincent P. deLuise, MD.)
Superior Limbic Keratoconjunctivitis
PATHOGENESIS The pathogenesis of superior limbic keratoconjunctivitis (SLK) has not been established, but it is thought to result from mechanical trauma transmitted from the upper eyelid to the superior bulbar and tarsal conjunctiva. An association with autoimmune thyroid disease has been observed.
CLINICAL PRESENTATION SLK is a chronic, recurrent condition of ocular irritation and redness. The condition typically develops in women 20–70 years of age and may recur over a period of 1–10 years. The condition usually resolves spontaneously. It is often bilateral; however, 1 eye may be more severely affected than the other. SLK can be associated with ATD or blepharospasm. Ocular findings may include the following:
a fine papillary reaction on the superior tarsal conjunctiva
injection and thickening of the superior bulbar conjunctiva (Fig 3-22A) hypertrophy of the superior limbus
fine punctate fluorescein and rose bengal staining of the superior bulbar conjunctiva above the limbus and the superior cornea just below the limbus (Fig 3-22B)
superior corneal filamentary keratopathy
Figure 3-22 A, Superior limbic keratoconjunctivitis. B, Rose bengal dye staining pattern in superior limbic
keratoconjunctivitis. (Courtesy of Vincent P. deLuise, MD.)
LABORATORY EVALUATION Hyperproliferation, acanthosis, loss of goblet cells, and keratinization are seen in histologic sections of the superior bulbar conjunctiva. The condition can often be diagnosed by clinical signs. However, scrapings or impression cytology of the superior bulbar conjunctiva showing characteristic features of nuclear pyknosis with “snake nuclei,” increased epithelial cytoplasm–nucleus ratio, loss of goblet cells, or keratinization may be helpful in diagnosing mild or confusing cases. Patients with SLK should undergo thyroid function tests, including tests for free thyroxine (T4), thyroid-stimulating hormone (TSH), and thyroid antibody levels.
MANAGEMENT A variety of therapies have been reported to provide temporary or permanent relief of
symptoms. Treatments include topical anti-inflammatory agents, large-diameter bandage contact lenses, superior punctal occlusion, thermocauterization of the superior bulbar conjunctiva, resection of the bulbar conjunctiva superior to the limbus, topical cyclosporine, autologous serum eyedrops, amniotic membrane transplant, and conjunctival fixation sutures.
Sahin A, Bozkurt B, Irkec M. Topical cyclosporine A in the treatment of superior limbic keratoconjunctivitis: a long-term followup. Cornea. 2008;27(2):193–195.
Theodore FH, Ferry AP. Superior limbic keratoconjunctivitis. Clinical and pathological correlations. Arch Ophthalmol. 1970;84(4):481–484.
Udell IJ, Kenyon KR, Sawa M, Dohlman CH. Treatment of superior limbic keratoconjunctivitis by thermocauterization of the superior bulbar conjunctiva. Ophthalmology. 1986;93(2):162–166.
Yamada M, Hatou S, Mochizuki H. Conjunctival fixation sutures for refractory superior limbic keratoconjunctivitis. Br J Ophthalmol. 2009;93(12):1570–1571.
Recurrent Corneal Erosion
PATHOGENESIS Recurrent erosions typically occur either in eyes that have suffered a sudden, sharp, abrading injury (eg, fingernail, paper cut, tree branch) or in patients with preexisting epithelial basement membrane dystrophy. The superficial injury produces an epithelial abrasion that heals rapidly, frequently leaving no clinical evidence of damage. After an interval ranging from days to years, symptoms suddenly recur without any obvious precipitating event. Symptoms subside spontaneously in most cases, only to recur periodically. In contrast to shearing injuries, small, superficial lacerating injuries involving the cornea rarely result in recurrent erosions. Poor adhesion of the epithelium is thought to be caused by underlying abnormalities in the epithelial basement membrane and its associated filament network. The precise nature of these abnormalities has yet to be fully determined.
Gelatinase activity (MMP-2 and MMP-9) is upregulated in the epithelium of patients with recurrent corneal erosions. Chronic activation of MMPs may either result from or cause poor epithelial adherence, which leads to the symptoms of recurrent corneal erosion. Some patients with recurrent corneal erosions have been noted to have MGD, and increased levels of MMPs have been observed in the tear film of patients with MGD.
CLINICAL PRESENTATION Recurrent corneal erosions are characterized by the sudden onset of eye pain, usually at night or upon first awakening, accompanied by redness, photophobia, and tearing. Individual episodes may vary in severity and duration. Minor episodes usually last from 30 minutes to several hours; typically the cornea has an intact epithelial surface at the time of examination. More severe episodes may last for several days and are often associated with greater pain, eyelid edema, decreased vision, and extreme photophobia. Many patients seem to suffer from ocular discomfort that is out of proportion to the degree of observable pathology. However, slit-lamp examination using retroillumination can frequently reveal subtle corneal abnormalities (eg, epithelial cysts). The corneal epithelium is loosely attached to the underlying basement membrane and Bowman layer, both at the time of a recurrent attack and between attacks, when the cornea appears to be entirely healed. During an acute attack, the epithelium in the involved area frequently appears heaped up and edematous. Although no frank epithelial defect may be present, significant pooling of fluorescein over the affected area is often visible.
The key to distinguishing between posttraumatic erosion and dystrophic erosion in a patient who has no clear-cut history of superficial trauma is careful examination of the contralateral eye following maximal pupillary dilation. Occasionally, subtle areas of loosely adherent epithelium can be identified by applying gentle pressure with a surgical sponge following instillation of topical anesthetics. The presence of basement membrane changes in the unaffected eye implicates a primary
basement membrane defect in the pathogenesis, whereas the absence of such findings suggests a posttraumatic etiology. Other clinical conditions with associated abnormalities of the epithelial basement membrane include diabetes mellitus and dystrophies of the stroma and Bowman layer (see also the discussion on corneal dystrophies in Chapter 10).
MANAGEMENT Traditional therapy for the acute phase of this condition consists of frequent lubrication with antibiotic ointments and cycloplegia, followed by use of nonpreserved lubricants or hypertonic saline solution (5% sodium chloride) during the day and ointment at bedtime for 6–12 months to promote proper epithelial attachment. Hypertonic agents provide lubrication and may transiently produce an osmotic gradient, drawing fluid from the epithelium and theoretically promoting the adherence of epithelial cells to the underlying tissue. Some patients find hypertonic medications unacceptably irritating, although many others do quite well with this therapy indefinitely. Low-dose oral doxycycline and topical corticosteroids have been shown to be very efficacious. The mode of action is thought to be localized inhibition of MMPs.
Although use of a therapeutic bandage contact lens may be helpful, proper patient education and judicious monitoring are crucial. The ideal therapeutic lens has a flat base curve and high oxygen transmissibility (Dk). New-generation soft contact lenses with surface treatments that decrease bacterial adherence may offer a better safety profile. Concomitant use of a topical broad-spectrum antibiotic 3–4 times daily may reduce the possibility of secondary infection.
Patients with recalcitrant disease should be treated through a sequence of interventions. When consistent conservative management fails to control the symptoms, more invasive surgical therapy may be indicated. In patients with posttraumatic recurrent erosions, anterior stromal micropuncture can be very effective if the area can be identified (Fig 3-23). Using a bent 25-gauge needle, the clinician makes numerous superficial puncture wounds in the involved area, producing firm adhesion between the epithelium and the underlying stroma. This procedure should be used with caution in the visual axis. Rarely is a significant scar visible for more than a few months after this procedure. The treatment may need to be repeated in patients whose condition is at first adequately controlled but who later become symptomatic, usually because the initial area of treatment was inadequate. Histologic studies have revealed that the lesions produced by this procedure create subepithelial scars. Use of diathermy to create similar lesions in experimental animals has shown that the efficacy of these procedures is related to their ability to stimulate the formation of new basement membrane complexes. Polishing with a diamond burr is another alternative in some cases.
Figure 3-23 Anterior stromal puncture. The needle is used to encourage microcicatrization among epithelium, Bowman
layer, and stroma. (Reproduced with permission from Kenyon KR, Wagoner MD. Therapy of recurrent erosion and persistent defects of the corneal epithelium. Focal Points: Clinical Modules for Ophthalmologists. San Francisco: American Academy of Ophthalmology; 1991, module 9. Illustration by Laurel Cook.)
In patients with dystrophic, degenerative, or other severe secondary basement membrane disorder–related recurrent erosions, the procedure of choice is epithelial debridement, which can easily be performed at the slit lamp. Following adequate application of topical anesthetic, loosely adherent epithelium is debrided using a surgical sponge, spatula, or surgical blade. Care must be taken not to damage the underlying Bowman layer. Light application of an ophthalmic diamond burr to Bowman layer in the affected area (outside the visual axis) may be effective in reducing recurrences in resistant cases.
Because a significant amount of discomfort can be expected for 3–4 days following this procedure, the patient will likely be more tolerant if debridement is performed at the time of a painful recurrent episode. Topical antibiotic ointment, cycloplegia, and, in some cases, bandage contact lenses are used until reepithelialization is complete. Oral analgesics are often necessary in the first 24 hours.
Excimer laser phototherapeutic keratectomy is an alternative modality for treating patients with