Superior limbic keratoconjunctivitis: Update on pathophysiology and management

Superior limbic keratoconjunctivitis (SLK) is an under-recognized condition characterized by a final common pathologic presentation of superior conjunctival and limbal inflammation and staining. Existing literature attributes both microtrauma and local inflammation, frequently in the setting of tear film insufficiency, as the underlying mechanisms that lead to a self-perpetuating pathologic process dependent in on inflammatory cells and signaling. Effective treatments act by targeting inflammation and by mitigating mechanical stressors. This critical review discusses the latest in our understanding of the pathophysiology of SLK and how it guides our treatment strategies.

Risk factors for development of superior limbic keratoconjunctivitis in thyroid eye disease in Japanese

PURPOSE

To analyse risk factors for the development of superior limbic keratoconjunctivitis (SLK) in thyroid eye disease (TED).

METHODS

This prospective, observational study included 638 eyes/sides from 319 patients with TED. The eyes were classified into two groups, based on the presence and absence of SLK. Multivariate logistic regression analysis was performed to evaluate potential risk factors, including sex, patient age, past treatment history (steroid, orbital radiotherapy and radioiodine therapy), smoking, clinical activity score, margin reflex distance (MRD)-1 and -2, Graefe sign/lid lag, Hertel exophthalmometric results, Schirmer's test results, tear break-up time (TBUT) and tear meniscus height (TMH).

RESULTS

SLK was found in 198 eyes (31.0%) from 121 patients. Young age (OR, 0.977; P = 0.006), smoker (OR, 1.785; P = 0.009), presence of Graefe sign (OR, 2.912; P < 0.001), absence of lid lag (OR, 0.485; P = 0.031), high Hertel exophthalmometric values (OR, 1.125; P = 0.002), shorter Schirmer's test results (OR, 0.962; P < 0.001), shorter TBUT (OR, 0.815; P = 0.002) and high upper TMH (OR, 1.003; P = 0.013) were associated with the development of SLK. A high MRD-1 measurement value also tended to be associated with a risk of SLK, with an OR of 1.187 (P = 0.056).

CONCLUSION

The present study proposed several risk factors in relation to the development of SLK in TED.

Recharacterization of superior limbic keratoconjunctivitis via a subdividing grading method in 236 Chinese patients

PURPOSE

Superior limbic keratoconjunctivitis (SLK) is an uncommon and often overlooked chronic ocular surface disease. This retrospective consecutive case series study on Chinese patients aimed to characterize the features of this disease, including those undescribed in previous literature.

METHODS

Two hundred thirty-six patients diagnosed with SLK were enrolled into this consecutive case study from 2016 to 2019. The demographics, symptoms, Ocular Surface Disease Index, and ocular signs were collected and analyzed. A scoring system (SLK scale index, SSI) that integrated five major sign scores was applied to evaluate SLK severity.

RESULTS

Of the 236 SLK patients, dryness was the most common complaint (59.3%). Of 459 SLK eyes, superior limbus/conjunctival staining (SCS) was present in 98% eyes, followed by the superior tarsal conjunctival alterations (85.2%) and superior bulbar conjunctiva hyperemia (80.8%). Approximately 63% of eyes were accompanied by corneal staining. Superior bulbar conjunctivochalasis was a relatively rare sign (41.6%). Among the five major signs, only the prevalence of SCS gradually increased with its severity. In addition, fluorescein staining at the inferior limbus and adjacent conjunctiva (ICS) was found positive in 163 eyes of 84 patients (36%) who had significantly higher SSI than those without ICS (p = 0.013).

CONCLUSIONS

We found that SCS is the most common out of the 5 typical signs of SLK. ICS, a new sign, occurred in one-third of patients. SCS, a simple marker of SLK, as well as SSI, an integrated evaluation system, had the advantage of evaluating the severity and objectively characterizing SLK in clinical practice.

Superior limbic keratoconjunctivitis: a comprehensive review

Superior limbic keratoconjunctivitis (SLK) is characterized by chronic inflammation of the superior limbus and superior bulbar and tarsal conjunctivae. Patients also often have fine punctate staining of the limbus and adjacent area, superior limbic proliferation seen as thickening of the limbal epithelium and surrounding conjunctiva, and occasionally filaments at the superior limbus and upper cornea. SLK frequently presents with ocular irritation, foreign body sensation, and photophobia. SLK can be associated with other ocular and non-ocular conditions, such as thyroid disease. Although the pathogenesis of SLK is still unknown, it is thought to be related to mechanical injury, tear film instability, or an autoimmune/inflammatory etiology. Many patients with SLK can be asymptomatic or have symptoms that resolve or remit spontaneously. For symptomatic SLK, patients are managed medically with treatments such as lubricants, topical anti-inflammatory or immunomodulatory medications, punctal occlusion, and bandage contact lenses. Patients with symptoms refractory to medical management may need surgical interventions. We detail the current literature on the epidemiology, clinical manifestations, associated conditions, histopathology, pathogenesis, and treatment of SLK.