Tests in dry eye

EVALUATION OF DRY EYE
COMMON TESTS TO ASSESS SEVERITY OF DRY EYE IN EYE OPD

1. Evaluation of Dry Eye Common tests to assess Dry Eye severity Dr. Krati Shrivastava , JR Dept. of Ophthalmology, AIIMS, Jodhpur Dr. Monika Samota , SR Dept. of Ophthalmology, AIIMS, Jodhpur Dr . Arvind Kumar Morya MS(Gold Medalist ) MNAMS Associate Professor Cataract, Glaucoma, Refractive , Squint Paediatric Ophthalmology and Medical Retina Services Associate Editor UKJOS, Assistant Editor IJO Editorial Board Member IJOVS, IJCC, EC-Ophthalmology, DOS Times, Journal of HOS Reviewer Elsevier, AIMDR and IJO Department of Ophthalmology All India Institute of Medical Sciences, Jodhpur

2. Introduction Dry Eye Workshop (DEWS) II in 2017 defined , “Dry eye as a multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and accompanied by ocular symptoms, in which tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neurosensory abnormalities play etiological roles” It also include aqueous deficiency dry eye and evaporative dry eye Patients were explained about the nature of the dry eye disease, its risk factors and the effects it will have on vision

3. The procedure and nature of the tests were explained to subjects in their own language to their full satisfaction. They were given opportunity to ask questions regarding the procedure and nature of the study They were given option to opt out of the study The subjects who opted in to participate in the study were asked to fill the consent form

4. Tests performed to assess the Dry Eye disease- 1-OSDI Questionnaire 2-Schirmer Test-Type 1,2 & 3 3-Tear film break up time test 4-Tear film height 5-Modified van Bijisterveld Score 6-Hyperosmolarity in Dry Eye 7-Impression Cytology 8-Inflammatory markers

5. OSDI Questionnaire OSDI questionnaire, developed by Allergan, this questionnaire is widely used to assess several aspects of ocular surface disease. Although it is a very subjective test. The responses range from 0 to 4 with 0 indicating none of the time and 4 indicating always; the OSDI score range from 0 to 100 . (6) The criteria used for the grading will be: 0-12, normal 13-22, mild 23-32, moderate 33-100, severe.

6. OSDI Questionnaire Ocular Surface Disease Index (OSDI )- Circle the number in the box that best represents each answer. Then fill in boxes A,B,C,D and E according to the instructions beside each.

7. Have you experienced any of the following during the last week :   All of the time Most of the time Half of the time Some of the time None of the time 1 .Eyes that are sensitive to light? 4 3 2 1 2. Eyes that feel gritty? 4 3 2 1 3. Painful or sore eyes? 4 3 2 1 4. Blurred vision? 4 3 2 1 5. Poor vision? 4 3 2 1 Subtotal score for answers from 1-5: ( )

8. Have problems with your eyes limited you in performing any of the following during the last week :   All of the time Most of the time Half of the time Some of the time None of the time   6. Reading? 4 3 2 1 N/A 7. Driving at night? 4 3 2 1 N/A 8. Working with a computer or bank machine? 4 3 2 1 N/A 9. Watching TV? 4 3 2 1 N/A Subtotal score for answers from 6-9:( )

9. Have your eyes felt uncomfortable in any of the following situations during the last week:   All of the time Most of the time Half of the time Some of the time None of the time   10. Windy conditions? 4 3 2 1 N/A 11. Places or areas with low humidity (Very dry)? 4 3 2 1   N/A 12. Areas that are air conditioned? 4 3 2 1 N/A Subtotal score for answers from 10-12:( )

10. Add subtotal A, B, C to obtain D- (D=Sum of scores for all questions answered) Total number of questions answered (Do not include questions answered OSDI= Sum of scores for all the questions Asked X25 Total number of questions Answered

11. Schirmer’s Test-I Purpose - Done to test basal and reflex tear secretion Schirmer’s strip prepared from Whatman filter paper no. 41 measuring 40×5 mm, marked 0 to 35 mm was used in study. Test was performed by placing strip on lower fornix at the junction of outer 1/3 and inner 2/3 Eyes should not be manipulated before starting the procedure.(dyes or local anesthetics) No contraindications

12. Strip placed at the junction of medial 2/3 rd and lateral 1/3 rd of lower eyelid

13. Depending on the wetting of the strip after 5min ,the results of Schirmer’s test were graded as: >10 mm, normal (grade 0); 5-10 mm, mild (grade 1); 3-4 mm, moderate (grade 2); 0-2 mm, severe (grade 3).

14. Schirmer’s Test-II Done under topical anesthesia Purpose-To evaluate the basal secretions If the wetting <10mm then irritate the nasal mucosa with cotton bud and note the wetting after 2 min Less than 15mm-failure to reflex secretion

15. Schirmer’s test II is performed after installing topical anaesthetic drops to evaluate basal secretions

16. Schirmer’s Test-III Done without any anesthetic agent Done after nasal irritation-nasal mucosal stimulation reveals the maximum secretory capacity of the lacrimal glands

17. Tear Film Break UP time Test Tear film break up time test is defined as the time interval between the last blink and tear disruption. This test was done to check the test tear film stability and meibomian gland disorder. Grading was done after installing the topical anesthesia in the eye and then applying fluorescein solution onto the inferior palpebral conjunctiva after gentle depression of the lower eyelid.

18. The tear film was examined under slit lamp with cobalt blue light. The interval between the last blink and the appearance of first hypofluorescent spot or streak was recorded as the TBUT.

19. TBUT less than 10 s is abnormal TBUT graded as: >10 s, normal (grade 0); 6.1-10 s, fair (grade 1); 3.1-6 s, moderate (grade 2); <3 s, poor (grade 3).

20. Tear Film Height Tear meniscus is a continuous , full and slightly concave meniscus formed by the tears between the eyelids and inferior bulbar conjunctiva. A height of 0.5mm of tear strip is considered normal Test performed by applying fluorescein solution in the inferior palpebral conjunctiva after gentle depression of the lower eyelid Subject asked to blink and then height of tear meniscus measured by under slit lamp after making a vertical slit and measuring the height of the tear meniscus

21. Tear film height

22. Modified van Bijisterveld Score This scoring system was used for grading of conjunctival rose Bengal staining The density of rose Bengal staining was recorded as a scale of 0-3 for each of 6 areas of the conjunctiva, and then summed for each eye

23. Rose Bengal strip

24. Hyperosmolarity in Dry Eye Reduced aqueous tear flow and/or increased evaporation of the aqueous tear phase leads to tear hyperosmolarity, a key step in the vicious circle of DED pathology. The TearlabTM Osmolarity System is a new user-friendly tool that needs tiny volumes for analysis and determines hyperosmolarity semiautomatically

25. The Tearlab Osmolarity System requires less than 50 nl of tear fluid for analysis. After calibration of the instrument, tears are collected directly from the eye, eliminating the need for a standard glass capillary tube. Embedded nanofluidic channels move the tear sample to the measuring electrodes. Sampling time is reduced to less than 1 s.

26. At the core of the Tearlab is a disposable lab-on-a-chip system that functions as both a tear collection device and a measurement system A desktop instrument converts the electrical signals generated from the lab card into a quantitative measurement and displays it to the user. The cutoff value provided by the company is 316 mosm /l. The entire workflow, from sample to result, requires less than 2 min

27. Impression Cytology Conjunctival impression smear was taken by using 1x1 cm strip of cellulose acetate filter paper Strip was applied to upper temporal bulbar conjunctiva of each eye and kept pressed firmly for five seconds. Each strip was transferred on to glass slides and fixed immediately using 1:1 mixture of absolute alcohol. One of the smears was subjected to Papanicolau stain and the other to Periodic Acid Schiff stain.

28. The stained smears were graded into Goblet cells density of: >75/HPF, 50-75/HPF, 15-50/HPF, <15/HPF; mild, moderate and severe squamous metaplasia and presence or absence of inflammatory cells.

29. Inflammation and Dry eye Markers studied/known to be associated with OSD T cell infiltrates Upregulation of CD3, CD4 and CD8 IL-1 = most studied MMP’s IL-6 and TNF-alpha CD80/86 Upregulation of ICAM, various chemokines and CCR7 on resident APC’s

30. Acute and Chronic phase markers Acute phase IL-1, TNF-alpha IL-6, chemokines ICAM, CCR7 Chronic Autoreactive T cells leads to chronic inflammation IFN-gamma IL-17, MMP/9

31. MMP-9 In dry eye, desiccating stress and hyperosmolarity are known to increase levels of MMP-9 significantly in corneal epithelial cells and tears Interaction between these cytokines and MMPs creates a cycle of escalating inflammation on the ocular surface in dry eye. Matrix metalloproteinase 9 promotes corneal extracellular matrix degradation and epithelial cell loss

32. MMP-9 in the tear film was evaluated using the InflammaDry in both eyes. InflammaDry uses direct sampling microfiltration technology. Matrix metalloproteinase 9, if present in the tear sample, is captured between MMP-9especific monoclonal and polyclonal antibodies at a concentration of more than 40 ng/ml. T

33. No drops were placed in the patient’s eye within 2 hours of conducting the test. The eyelid was lowered to expose the palpebral conjunctiva. The sampling wisp was dabbed 8 to 10 times in multiple locations until the sampling wisp was saturated. The test was assembled by placing the wisp of the sample collector into the sample transfer window of the test cassette body.

34. The absorbent tip was immersed into the buffer vial for 20 seconds and laid flat on a horizontal surface for 10 minutes. The test was read thereafter under brightly lit conditions and reread after 10 minutes for negative results as recommended by the manufacturer. Only test results showing a positive control line were evaluated. Test results were rated positive when a second even faintd line appeared in the result zone

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