Impact of pterygium on the ocular surface and meibomian glands

Abstract

2627 Purpose: To analyze how ocular surface parameters correlate to pterygium and investigate the 28 possible impact on tear film and meibomian glands. Methods: we investigated objective parameters 29 of the ocular surface such as conjunctival hyperemia, tear film stability and volume, meibomian gland 30 dysfunction, dry eye disease, corneal topography comparing healthy individuals and correlating with 31 the pterygium clinical presentation. Results: A total of 83 patients were included. Corneal 32 astigmatism induction was 2. 65 ± 2.52 D (0.4-11.8). The impact of pterygium on the ocular surface 33 parameters compared to matched controls was seen in: conjunctival hyperemia (control 34 1.55±0.39/pterygium 2.14±0.69; p=0.0001), tear meniscus height (control 0.24±0.05 mm/pterygium 35 0.36±0.14mm; p 0.0002), meiboscore lower eyelid (control 0.29±0.64/pterygium 1.38±0.95; p 36 0.0001) and meiboscore upper eyelid (control 0.53±0.62/pterygium 0.98±0.75; p=0.0083). We found 37 a high number of pterygium patients (88%) presented meibomian gland alterations. Interestingly, 38 meibomian gland loss was coincident to the localization of the pterygium in 54% of the upper and 39 77% lower lids. Conclusion: Pterygium greatly impacts on ocular surface by inducing direct 40 alterations in the pattern of meibomian glands besides corneal irregularities, conjunctival hyperemia 41 and lacrimal film alterations, inducing significant symptoms and potential signs of dysfunction. 3 42 Introduction 43 Pterygium is a degenerative fibrovascular disease of the ocular surface that can cause 44 symptoms of discomfort, corneal irregularities, aesthetics issues thus compromising visual acuity and 45 patients` quality of life. [1-3] The prevalence of pterygium varies worldwide. Global prevalence was 46 estimated in 10.2% to 12%, reaching higher numbers in tropical regions. Several risk factors have 47 been associated with pterygia, such as geographical latitude, residence in rural areas, old age, race, 48 sex, sun exposure, chronic irritation and inflammation. [4,5] 49 Some studies have pointed tear film and ocular surface changes related to pterygium, but 50 consistent correlations remain unknown. [6-9] Although numerous theories have been implicated in 51 pterygium pathogenesis, including ultraviolet radiation exposure, viral infection, oxidative stress, 52 genetic issues, inflammatory mediators, extracellular matrix modulators, it remains controversial as 53 well as its impact on ocular surface homeostasis and function.[10] And a better understanding of the 54 pathophysiological mechanisms associated with pterygium, the morphological alterations on the 55 ocular surface and functional impact may contribute to specific approaches and more effective 56 therapeutic proposals for this common ocular condition. 57 This study aimed to evaluate how ocular surface parameters correlate with pterygium clinical 58 presentation and its impact on ocular surface structures and homeostasis. 4 59 Materials and Methods 60 The present study had a transversal, obs...

Assessment of Tear Production among Adults with Pterygium

“…Hence, the mean tear production values were significantly higher among the control subjects. This was corroborated in several studies [14][15][16][17] where people with pterygium where found to have lower tear production values. This study showed complaints of tearing, itching, foreign body sensation and redness among the pterygium subjects.…”

“…[14] Pterygium growth and development has also been shown to be associated with tear film instability. [15] Hence the aim of this study was to investigate the level of tear production among adults with pterygium.…”

A study of meibomian gland and tear film changes in patients with pterygium in a tertiary care centre

“…Fen Y et al 22 found significantly higher OSDI score(14.2) in pterygium patients. Ning Li 23 found pterygium patients had a significantly elevated OSDI value relative to the controls (20.11 ± 4.27 and 12.00 ± 2.87, respectively; p <0.001).Huping Wu et al 21 found that the OSDI value was significantly higher in pterygium patients than that of volunteers, 20.05 and 12.00 respectively, ( P<0.001).…”

“…Mean difference of Meibomian gland expression was 92.86 in pterygium group and 48.14 in comparison group and the differences were highly significant(P<.05) ,indicating that pterygium patients suffer from meibomian gland dysfunction more than normal persons. Fen Y et al 12 Huping Wu et al 21 AnaCláudia et al 22 Ning Li et al 23 found pre and post-surgery effect on meibomian gland dysfunction, it improved after excision of pterygium.…”

Tear Film Stability After Primary Pterygium Excision Combined with Limbal Stem Cell Transplantation is Superior to Amniotic Membrane Transplantation: A Meta-Analysis

“…Tear osmolarity is a function of tear secretion and tear evaporation [26]. Studies have shown that lower tear production can lead to higher tear osmolarity levels [27]. And there is an interconnection between hyperosmolarity and tear instability [28].…”