Dr Adrian Bruce
BSc(Optom) PhD PGCertOcTher
Australian College of Optometry
Akpek et al1 published in the journal of the American Academy of Ophthalmology a study that highlighted the frequency of vision-threatening ocular manifestations as well as concomitant, potentially sinister systemic disorders associated with Sjögren’s syndrome (SS). The study’s main conclusions encourage clinicians to more carefully scrutinise dry eyes.
In the study, new and returning patients were investigated within a four-and-a-half year period at the Johns Hopkins Medical institutions in Baltimore, Maryland. All patients were co-assessed by a rheumatologist and ophthalmologist, and underwent extensive systemic and ocular examinations in order to reach a diagnosis of SS.
Systemic examinations included serologic testing, minor salivary gland biopsy, salivary gland scintigraphy, parotid gland ultrasonography, and magnetic resonance imaging or computed tomography scanning of the major salivary glands. Ocular investigations were performed and included a symptoms questionnaire (Ocular Surface Disease Index), full ophthalmic evaluations (visual acuities, slitlamp and dilated fundus examinations) as well as systematic dry eye testing.
Dry eye was assessed in a sequential manner as follows:
1. Schirmer testing without topical anaesthesia
2. One drop of proparacaine with fluorescein into the lower conjunctival fornix
3. Assessment of tear film break-up time
4. Corneal staining scoring with the Oxford scoring system (scale of 0 to 5) after two minutes of instillation of fluorescein eye-drops
5. Conjunctival staining scoring with lissamine green and a single drop of preservative-free saline, also using the Oxford scoring system.
A diagnosis of SS was based on the American-European Consensus Group 2002 (Table 1). A minimum of four of six criteria or three of four objective criteria had to be met to make a conclusive diagnosis. These six criteria outlined subjective and objective ocular dryness, subjective and objective evidence of salivary gland involvement, presence of Sjögren-specific antibodies either A/Ro or B/La or both, and positive minor salivary gland biopsy.
Table 1. Criteria for diagnosis of Sjögren’s syndrome: based on American-European Consensus Group 2002
Only primary SS patients were included in the study, which meant that participants had to demonstrate a positive Sjögren-specific antibody A or B serologic result, or the presence of positive minor salivary gland biopsy. Secondary SS, which was defined as individuals who were diagnosed with another autoimmune connective tissue disease, for example, rheumatoid arthritis, systemic lupus erythematosus or scleroderma, were excluded.
Of the primary SS cohort, a large majority (91 per cent) were women in their 50s (mean age = 51 ± 14 years) who experienced persistent dry eye symptoms spanning an average of 10.4 years. The study also found that extra-glandular ocular manifestations were present in 25 per cent of their patients (Table 2).
Table 2. Prevalence of ocular morbidity in Sjögren’s syndrome
Among these, 13 per cent (22 patients) had vision-threatening complications including conditions such as corneal haze/scarring/infiltration/perforation, cicatrising conjunctivitis, uveitis, episcleritis/scleritis, optic neuropathy and retinal vasculitis. The study reports close to half (55 per cent) of these individuals with more serious ocular manifestations did not have an established diagnosis of SS.
This study also investigated extra-glandular systemic manifestations of SS. Concomitant systemic involvement in those diagnosed with SS include: visceral (interstitial lung or kidney disease, autoimmune hepatitis, or pancreatitis) or non-visceral (vasculitic skin lesions, arthritis and peripheral neuropathies) diseases, with lymphoma being one of the more devastating complications.
Forty-two per cent (68 patients) of the patient cohort were classified as having an extra-glandular systemic manifestation of primary SS, five of whom had lymphoma (Table 3).
Table 3. Prevalence of extraglandular systemic manifestations of primary Sjögren’s syndrome
However, among the 22 patients who demonstrated vision-threatening manifestations of SS, 64 per cent (14 patients) reportedly had a concomitant extra-glandular systemic manifestation of SS (p = 0.025). This implied that the prevalence of SS-associated systemic manifestations, such as peripheral neuropathy, vasculitis and interstitial nephritis, were about four times higher in those diagnosed also with more serious ocular complications.
Perhaps more concerning is that the study highlights several other reports in agreement that SS is identified as an independent risk factor for non-Hodgkin’s lymphoma. Primary SS is found to be the most strongly associated risk factor for malignancy in non-Hodgkin’s lymphoma with a reported incidence rate of 18.8 per 100,000 patient-years.
Given these findings from this study, it may seem then that a delayed diagnosis of SS is unreasonable. At present, it is thought to be delayed by up to 10 years. However, SS is a challenging diagnosis that requires comprehensive and methodical objective and subjective assessments as well as multidisciplinary efforts between rheumatology and ophthalmology. In addition, this particular study cohort was derived from a large established tertiary care referral centre. When put into perspective, the numbers recorded in this study seem slightly exaggerated.
This article helps to expand the primary care practitioner’s knowledge of potentially ominous manifestations of Sjögren’s syndrome and is meaningful enough to tingle one’s sixth sense with the unusual dry eye patient. It serves as a good message to not carelessly dismiss the patient with persistent dry eye.
Concomitant systemic disorders associated with Sjögren’s syndrome
1. Akpek EK, Mathews P, Hahn S, et al. Ocular and systemic morbidity in a longitudinal cohort of Sjögren’s syndrome. Ophthalmology 2015; 122: 1: 56-61.