Posters

Study of non-contact infrared meibography and non-invasive tear film break up time in normal and evaporative dry eye subjects

Poster Details

First Author: H.Matalia INDIA

Co Author(s):    A. Ranganath   D. R Meda   R. Parekh        

Abstract Details

Purpose:

Meibomian gland dysfunction (MGD) has emerged as a major ocular surface disorder, with significant morbidity. The standard fluorescein tear film break up time (f-TBUT) and and Schirmer's test need to be supplemented with newer imaging techniques for better dry eye classification and management. The purpose of this study is to evaluate non-invasive infrared meibography and non-invasive tear film break up time using a novel Keratograph in normal and evaporative dry eye subjects and to compare the same with the standard dry eye tests.

Setting:

Narayana Nethralaya, a tertiary eye care center and teaching institute, Bangalore, India.

Methods:

Noncontact infrared meibography and non-invasive keratograph break up time (NIKBUT) was performed using Keratograph 5M, OCULUS in 50 eyes of 25 normal subjects and 50 eyes of 25 patients with evaporative dry eye as defined by those who presented with symptoms of dry eye and had slit lamp evidence of MGD along with a normal Schirmer's test. The severity of dry eye symptoms in the MGD group was evaluated using Ocular Surface Disease Index (OSDI) score. The OSDI score, f-TBUT, Schirmer's test with anaesthesia was obtained in the normal subjects as control. The NIKBUT scores were compared to the gold standard f-TBUT. MGD on meibography was graded on the basis of meibomian glands (MG) drop outs and was calculated as follows (per eyelid) - Grade 0 -no loss of MGs, Grade 1- lost area less than 1/3rd of the total area of MGs, Grade 2 - lost area between 1/3rd and 2/3rd of the total area of MGs, Grade 3 - lost area >2/3rd of the total MG area. The severity of MG dropouts was compared to the f-TBUT and NIKBUT and to the severity of the OSDI scores.

Results:

There was no significant difference in Schirmer's scores between both normal and MGD groups. There was statistically significant difference in the OSDI scores and f-TBUT between the normal and MGD group respectively OSDI - 0.87±1.86 and 44.96±20.52 (p=<0.0001); f-TBUT - 18.42±4.45 and 8.24±2.65 seconds (p=<0.0001) confirming the diagnosis of evaporative dry eye. NIKBUT in normal subjects and dry eye patient was 16.22±6.58 and 12.15±7.32 seconds respectively (p=0.03). In the normal group, the f-TBUT values correlated with the NIKBUT (P=0.08), but in the MGD group, the NIKBUT was higher than the f-TBUT (P=0.02). Meibography in normal subjects showed normal MGs, which had uniform caliber and length, which is defined by linear and 3 - 4 mm in length, traversing the posterior eyelid perpendicularly from the lid margin to the opposite edge of the tarsus. Majority of the patients in the MGD group had grade 2 MG drop outs (38%). The OSDI scores and f-TBUT worsened with increasing grades of MG dropouts on meibography but a similar change was not noted with NIKBUT.

Conclusions:

Non-contact infrared meibography and NIKBUT are useful tools to study evaporative dry eye. Meibography can provide valuable information about the health of meibomian glands, which correlates well with the symptoms of the patient and can also help in the management. Large areas of the MG drop out would predict the poor outcome of conventional treatment of warm compresses and lid massage also save patients from newer but expensive treatment such as Lipiflow and meibomian gland probing etc. NIKBUT has poor sensitivity and would require further studies to correlate with conventional invasive tests of evaporative dry eye such as f-TBUT and subjective symptoms. FINANCIAL INTEREST: NONE