*2.5.7 Sjögren's international collaborative clinical alliance ocular surface staining (SICA OSS)*

Ocular surface staining with various dyes is used to characterize the disease, assess its severity, and monitor the clinical response to therapy. Fluorescein stains macroulcerative and punctate epithelial defects (positive staining) and appears orange under cobalt blue light. Classification of ocular surface staining after instillation of vital dyes is a critical diagnostic component of dry eye. These changes in the ocular surface are now documented with various staining scales such as Oxford, Nei-Clek, and SICA OSS [66]. The evaluation of the ocular surface and the qualification of the three scales are carried out with the methodology described in **Table 3**.

To evaluate the SICCA OSS, it gives the same numerical weight to the corneal and conjunctival changes, the staining must be done in two steps. Fluorescein staining is first performed and the cornea is examined with the slit lamp using the cobalt blue filter. Corneal epithelial staining is a dynamic and time-sensitive process; therefore, to ensure that the test is reproducible, the fluorescein evaluation should begin 4–8 min after instillation of the dye. Punctate epithelial erosions (PEE) that stain with fluorescein are counted and scored as follows. If there is no PEE, the score is 0. If 1–5 PEE are seen, the corneal score is 1 (**Figure 1a**). From 6 to 30 PEE they are scored as 2; and >30 PEE are scored as 3. An additional point is added if: (1) PEE occurred in the central 4 mm diameter part of the cornea (**Figure 1b**); (2) one or more filaments are seen anywhere on the cornea; or (3) one or more confluence patches. The spots, including the linear spots, are found anywhere on the cornea (**Figure 1c**). The fluorescein score for the cornea (the PEE grade plus any extra points for modifiers) is noted in the center square of the SICCA eye staining score form (**Figure 2**). The maximum possible score for each cornea is 6 [67].

The second step is the evaluation of the conjunctiva with lysamine green, it is observed in the slit lamp using a 10× magnification but with reduced illumination and using a neutral density filter. It is important to examine and grade the eyes immediately after applying the lysamine green tint because the intensity and spread of the tint in the eye rapidly diminish after the first 2 min. In addition, the patient must blink several times to prevent the dye from accumulating in the conjunctival folds, which can mimic conjunctival staining. If the dye is not properly instilled, a second drop can be administered and the test is performed immediately afterward.


## *Tomado de [66].*

### **Table 3.**

*Evaluation of the ocular surface (Oxford, Nei-cleck and Sica OSS).*

### **Figure 6.**

*Sjogren international collaboration clinical Alliance (sicca) ocular staining score form.*

The evaluation of this second staining in SICCA OSS, grade 0 (**Figure 3a**) is defined as 0–9 points of lysamine green staining of the interpalpebral bulbar conjunctival (nasal and temporal bulbar conjunctiva classified separately); grade 1 (**Figure 3b**) is defined by the presence of 10–32 points; grade 2 (**Figure 3c**) from 33 to 100; and grade 3 (**Figure 3d**) >100 points. Due to the difficulty of counting individual points in a moving eye in the slit lamp, any area of confluent staining ≥4 mm<sup>2</sup> is considered >100 points. The nasal and temporal areas of the conjunctiva are classified separately with a maximum score of 3 for each area or a maximum total score of 6 for each eye (nasal plus temporal). The total SICCA OSS value for each eye is the sum of the fluorescein score for the cornea and the lysamine green scores for the nasal and temporal bulbar conjunctiva. Therefore, the maximum possible score for each eye is 12. The eyes are classified separately and the scores are recorded on the SICCA OSS Eye Staining Scoring Form at each patient visit. Pinguecula stain, pterygium, and Schirmer's strip artifacts should not be included in the evaluation [67].

A value greater than 0 is considered abnormal and can be a sign of KCS. But scores of 1 or 2 can also represent a late staining artifact, if in the corneal fluorescein interpretation the staining pattern is delayed more than 8 min. Since this could lead to a high level of misclassification, an abnormal OSS is defined as a score of 3 or more (**Figure 6**) [67].

In one study, the relationship between serological markers and dry eye severity was investigated in subjects with primary Sjögren's syndrome (SS). The serum markers anti-Ro/SSA, anti-La/SSB, rheumatoid factor (RF) and antinuclear antibody (ANA), ocular surface disease index (OSDI), Schirmer test I values, time to rupture of the tear film, and SICCA ocular staining score (OSS) were determined. Finding what serum RF and ANA levels are associated with conjunctival staining scores and total OSS based on SICCA OSS in primary SS [68].

## *2.5.8 The tear meniscus height (TMH)*

The meniscus, or lacrimal lake, is the amount of tears that rest at the junction of the bulbar conjunctiva and the margin of the lower eyelid. Measurements of
