Changes in tear film function in patients after pterygium excision surgery done under topical anaesthesia with and without conjunctival autograft.

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To assess the function of the tear film in patients with unilateral pterygium and unaffected other eye.

This is a two-arm, open-labelled, non-randomized interventional study. It will take place over 2 years (August 2022 – August 2024). Study was conducted in Out-Patient Department of Ophthalmology, Acharya Vinobha Bhave Rural Hospital Sawangi (Meghe), Wardha, Maharashtra, after receiving approval from the Institutional Ethics Committee of Datta Meghe Institute of Higher Education and Research.

All the patients who will be coming the O.P.D from August 2022 to August 2024 with unilateral pterygium of all age groups will be included in the study with routine admissions and with proper information about benefits of surgery andafter considering inclusion and exclusion criteria and taking informed consent for surgery and follow-up.

Sample size calculation

Sample size formula for difference between two mean n = 2α + 2β 2 σ1 2 + σ2 21 k Δ 2

Where Zα is the level of significance at 5%, i.e., 95% confidence interval = 1.96

Z β is the power of test = 80% = 0.84

Σ1 = S.D. of TBUT in diseased eye Pre-test = 3.4

Σ2 = S.D. of TUBT in diseased eye Post-test = 2.7

Δ = difference between two means. = 12.8 – 9.9 = 2.9

K = 1

n = 1.96 + .84 2 3.42 + 2.72 / 1 2.92 = 17.57 = 20 patients needed in each group

Angli Manhan et al’s ¹⁶ study is used for reference in our study.

Software used: R-software version 4.3.2

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Patients who presented with a unilateral primary pterygium were observed.

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Patients having a systemic disease that leads to dry eye example: Sjogren’s syndrome.

After the enrolment of the subject in study, participants in the study will be split into two arms. Arm A (patients undergoing pterygium excision surgery combined with conjunctival autograft) and Arm B (patients with pterygium excision undergone without conjunctival autograft), randomly assigned for a 1:1 allocation with the intention for treatment. Subjects will be invited and screened as part of the study's inclusion process. For subject allocation, a randomization procedure using a computer-generated list will be used. Patients will undergo surgery. Participants will be assessed on day 1, 4 weeks, and 8 weeks postoperatively to assess primary and secondary parameters.

Firstly, a thorough history of the symptoms will be taken, including their onset, duration, and any exacerbating factors. Secondly, a routine physical examination which will include blood investigations for complete blood count (CBC), random blood sugar, Electrocardiography (E.C.G) and Chest X-Ray will be performed on the patients. Thirdly, a comprehensive ocular examination will be performed on each patient, which includes the following procedures: a) Examination of the anterior segment of the eye involving the cornea, iris, pupil, lens, and eyelids. B) Evaluation of near vision and distant vision. The following examinations will be carried out in both eyes:

Schirmer’s test: (a)

Schirmer’s test- 1 (Without anaesthesia): This test helps in evaluation of aqueous deficiency in patients with dry eye by measuring reflex tear secretion after stimulation of conjunctiva. The reflex tear secretion is measured with the help of Whatman filter paper 41. It is placed at junction of middle and lateral one third of lower lid. The amount of wettability is measured in millimetre. If the reading is less than 10 mm, then aqueous tear deficiency is likely present.

In the dim light room, the patient will undergo examination under a slit lamp, followed by Schirmer's test and Tear Film Break Up Time evaluation which is described below. At the intersection of the lateral 1/3 and medial 2/3, the lower palpebral conjunctiva was gently covered by a Schirmer strip that was folded at the notch. Ask the patient to sustain an open eyelid and regular blink pattern. Five minutes later, the strip was removed and measured in mm for the amount of wettability. After five minutes, if the wetness length was less than 10 mm, the Schirmer's-1 test—which does not involve anesthesia—was considered positive. Schirmer's tear test filter strips, also known as Whatmann no. 41 filter paper strips, which are 35 x 5 mm and folded 5 mm from one end, were the commercially available material utilized.

Following anesthesia, Schirmer's test (Basal secretion) was conducted similarly to the SCH-1 procedure but followed topical proparacaine 0.5%.

Tear film break up time (TBUT):

The cornea was first stained with fluorescein for this test, and then ophthalmic evaluation was under a red-free blue filter-lit slit lamp (Appasawamy LED Slit lamp AIA-11). The time between the first dry spots on the tear film and the lid blink is recorded. The average of the three recordings determined the TBUT. An average TBUT of less than 10 seconds indicated a positive result. Contact with the cornea was avoided to prevent excessive reflex tear production.

Operative procedure:

Every patient was recommended to instil topical antibiotic eye drops four times a day before surgery. All patients granted their consent after being informed about the surgery. Every patient underwent laboratory testing, such as haemoglobin (Hb), blood sugar, and coagulation profile.

A universal eye speculum was used to open the eye. Paracaine was used as a topical anaesthetic. Pterygium was dissected 4mm from the limbus to reveal the bare sclera. Using conjunctival scissors, fibrovascular tissue was dissected from the adjacent conjunctiva. The thickened conjunctiva and the tenon capsule below the conjunctiva were removed. The spontaneous process of haemostasis was achieved without the need for cautery. The further procedure would be different in both the groups. Group 1 was left with bare sclera and group 2 was proceeded with conjunctival autograft. The defect's size was measured using a calliper. A donor conjunctival graft, primarily obtained from the bulbar conjunctiva superiorly, was applied to the bare sclera. The original direction of the juxta-limbal boundary was carefully preserved. A lens spatula applied slight pressure to the free graft for eight to ten minutes to maintain its position. The bandage was left on for a whole day.

Postoperative care:

After a day, the bandage was removed, and topical application of a combination of antibiotic (Moxifloxacin 0.5%) and steroid (Dexamethasone 0.1%) eye drops combination formulation was prescribed. The drops were instilled four times a day for the first two weeks, tapered off to two times a day during the next 1 week and finally halted.

Following surgery, patients were not advised artificial tear drops. Following surgery, all patients were monitored on day one, one month, and two months. Schirmer's test and TBUT were done two months after surgery and they were given refraction on follow up visit. On every follow up, complications will be noted, if any and will be managed accordingly. For follow up visit routine camps were organized in the same places and patients were given spectacles free of cost on follow up. The patients who did not show up for follow up were considered drop outs from the study.

Control group

Tear film evaluation will be done in the control eye with the help of Schirmer’s Test I and II and Tear Film Break Up Time.

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Evaluation of tear film function by using Schirmer’s test I and II.-

The evaluation of tear film by using a Schirmer’s strip in the control eye should be more than 10 mm.

If the reading is less than 10mm, then Schirmer's test is considered positive.

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Evaluation of improvement in visual acuity after pterygium excision.

All the results for the outcome variables will be presented in tables and will be described over descriptive statistics. No blinding will be done in the study. Outcome variables (tear film evaluation by Schirmer’s test and Tear Film Break Up Time, visual acuity) will be firstly tested for normality for the quantitative measurement of mean and standard deviation (SD). Positional average (Median) statistics will be used to find out for skewed distributions and calculating the interquartile range (IQR). All the binary and catergorical variables will be described over the frequency and percentages for qualitative assessment. Results will be calculated using R-software free version 4.3.2 for all statistical analysis.

The inferential statistics for testing the significant difference over the outcome variables will be evaluated at 5% level of significance (p ≤ 0.05)

Outcome Variable:- Baseline to endline visit assessment for pre operative procedure in comparison for two groups (pterygium excision done with conjunctival autograft and excision done without conjunctival autograft) over the measurement score for mean of primary variable (tear film evaluation by Schirmer’s test and Tear Film Break Up Time, visual acuity) will be evaluated for finding significance in mean using Anova or Kruskal wallis test for more than 2 assessment period. Post-hoc (Tuckey’s or Dunccan) test will be used to find the significance difference between two group for pair-wise comparison. Outcome variables will be tested for intra difference in measurement at pre & post visits using paired t-test for finding the significance in mean. While for inter group difference unpaired t- test for comparison of two group. Generalised models for repeated measures will be tested for different visit periods (within the group) & for comparison of two groups (between the group) to find fixed & random effects.

For non-normal distribution Mathematical algorithms will be used for conversion of the data to normal distribution. If Data over primary variable still follows the non normal distribution then we will use alternate non parametric test (Chi square, Mann Whitney, Wilcoxon test, Kruskal wallis, Friedmann test). If data for the outcome variable for testing normality results with non normal distribution for the quantitative assessment, it will be converted for normal distribution following mathematical algorithm, besides if data persists with non normal distribution we will use alternate non parametric test (Chi square, Mann Whitney, Wilcoxon test, Kruskal wallis, Friedmann test).

Following Categorial distribution will be graded for scoring system (Binary):

Schirmer’s test value of less than 10mm is considered positive.

TBUT of less than 10 seconds is considered positive.

Assessment of visual acuity will be done through Snellen’s Chart.

Chi square analysis will be performed for categorial evaluation between two groups pterygium excision done with conjunctival autograft and excision done without conjunctival autograft for statistical evidence of finding significance on Schirmer’s test less than 10mm considered as positive against normal& TBUT of less than 10 seconds considered as positive against normal at 5% l.o.s.(P = < 0.05).

t-test unpaired or alternative non parametric test will be used for finding significance at 5% l.o.s. (P = < 0.05) between groups pterygium excision done with conjunctival autograft and excision done without conjunctival autograft

This study will help in assessment in the changes in tear film in the patients with pterygium and the change in tear film occurring after the excision of pterygium with and without conjunctival autograft. This study will also help to evaluate the better surgical method.

To publish the study outcome in an esteemed journal and present findings at a National Conference on completion of study.

Patients are yet to be recruited.

Ethical committee approval from the DMIHER was issued DMIMS (DU)/IEC/2022/201on 28 August 2022. There was no involvement of animals Considering all the ethical values, informed consent was taken from all the subjects involved. The aim of the research will be explained to each participant. The lead investigator will obtain both written and verbal informed consent from each participant before the intervention. The Helsinki Declaration of 1975, mentioned in 2008, shall be followed for all procedures in this investigation.

The study documentation will be treated as confidential information and safely archived with only the principal investigator having access. Incase of any adverse effect, reporting will be done to the investigator and the subject will be treated accordingly and will be considered as drop out from the study.