Application of a new grading scale for tear ferning in non-dry eye and dry eye subjects

• The Masmali five-point tear ferning grading scale was applied on non-dry and dry eye.
• The validation of the grading scale was tested in practice.
• Grades ≥2 can be considered as dry eye.
• The Masmali TF grading scale showed good validity in describing the TF patterns.
• TF test can be used as a clinical and research method to detect the dryness of the eye and investigate the tear film along with other additional tests.

PurposeTo apply the Masmali tear ferning (TF) grading scale on non-dry eye (NDE) and dry eye (DE) subjects to test the validity of the grading scale in practice, and to describe the grading scale range for NDE and DE.MethodForty NDE subjects (20 males, 20 females) and 40 DE subjects (23 males, 17 females) ranging in age from 19 to 53 years (mean ± SD: 25.3 ± 5.5) with no other ocular disease, no contact lens wear, and not pregnant or breastfeeding were recruited. McMonnies scores were used for subject grouping. Phenol red thread (PRT) and slit-lamp test were used. A tear sample was collected from right eye, which was then dried to produce a ferning pattern, that was observed using a digital microscope, and graded.ResultsMean McMonnies, PRT and TF grade in NDE subjects were 7.1 ± 3.8, 27.4 ± 4.3 mm and 0.78 ± 0.40, respectively. Median McMonnies, PRT and TF grade in DE subjects were 16.5 ± 3.0, 9.0 ± 2.0 mm and 2.3 ± 1.48, respectively. In NDE subjects, grades 0.0–1.8 were observed (82.5% Grade 0.0–1.00). Grades 2.0–4.0 were observed in DE subjects (72.5% Grades 2.0–3.0). For all subjects, there were large correlations between TF grade and PRT (r = −0.79), PRT and McMonnies (r = −0.60), and TF and McMonnies (r = 0.73).ConclusionsThe Masmali TF grading scale showed good validity in describing the TF patterns. Grades ≥2 can be classified as abnormal patterns. The TF test has the potential to be used in the clinic.