Comparative Assessment of Tear Function Tests, Tear Osmolarity, and Conjunctival Impression Cytology between Patients with Pterygium and Healthy Eyes

Inflammation due to ocular surface homeostasis imbalance caused by pterygia: tear lymphotoxin-alpha study and a literature review

OBJECTIVE

To estimate the pterygium ocular surface state, and compare with healthy eyes and dry eyes. To investigate the inflammation due to pterygia growth by tear Lymphotoxin-alpha (LT α) test.

DESIGN

Prospective, single-center study.

PARTICIPANTS

400 patients, divided into 100 pterygium group, 100 mild dry eye group, 100 moderate dry eye group, and 100 age-and sex-matched normal controls.

METHODS

The non-invasive break-up time (NIBUT), tear meniscus height (TMH) test, corneal fluorescein staining (CFS), meibomian gland loss score (MGs), and lipid layer thickness (LLT) were evaluated in all patients. Pterygium status and ocular status in the pterygium group were collected. The tear LT α test was conducted in the pterygium patients group.

RESULT

Pterygium can affect the ocular surface, leading to decreased tear film stability. The TMH, NIBUT, CFS, MGs, and lipid layer thickness can provide insights into this phenomenon. The presence of pterygium can change the structure and condition of the ocular surface. Tear LT α testing shows an abnormal decrease in LT α levels in pterygium patients. This indicates an immune-inflammation microenvironment that causes tissue repair deficiency.

CONCLUSION

The dry eye triggered by the growth of pterygium may originate from the tear film instability due to pterygia. As an inflammatory index, LT α in the development of pterygium and the aggravation of dry eye patients can indicate that the ocular surface is in different inflammatory states. Future tear testing in LT α may be a potential indicator to assess the inflammatory status of the dry eye.

Subjective Dry Eye Symptoms and Objective Ocular Surface Signs in a Civil Air Crew Population: A Cross-Sectional Study

Background Aviation professionals are often exposed to conditions such as low cabin air pressure, reduced humidity, and prolonged artificial lighting, which may predispose them to dry eye disease (DED). We therefore designed a cross-sectional study with three primary objectives. Our first aim was to determine the prevalence of subjective dry eye symptoms among civil flight personnel. To achieve this, we administered the Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire. Second, we performed ocular examinations to assess objective DED indicators, such as the Schirmer's-1 (SCH-1) test and tear film break-up time (TBUT). We then correlated the results of these objective tests with the subjective symptoms reported by the participants. Last, we aimed to identify the independent risk factors for positive SCH-1 and TBUT results among aircrew personnel who did not report subjective dry eye symptoms. Methods The study sample consisted of 189 aircrew personnel (94 men and 95 women; mean age: 35.8 ± 10.4 years). They completed the SPEED questionnaire, a tool for assessing ocular surface symptoms. Participants' symptoms were classified as normal (SPEED scores 0-6), moderate (SPEED scores 7-15), or severe (SPEED scores 16-28). The objective assessment included the SCH-1 test for tear production and the TBUT test for tear film quality. Results A significant majority of participants (n = 165; 87.3%) did not report any subjective symptoms of DED. However, 12.2% (n = 23) and 0.5% (n = 1) of the study subjects experienced moderate and severe symptoms, respectively. The SCH-1 test and TBUT test were positive in 25.4% (n = 48) and 24.9% (n = 47) of the participants, respectively. Interestingly, among the aircrew personnel who did not report any subjective dry eye symptoms (SPEED scores 0-6), 18.8% (n = 31) and 17.6% (n = 29) showed abnormal results on the SCH-1 test and TBUT, respectively. Age was identified as the only independent predictor of a positive TBUT (odds ratio = 1.05, 95% confidence interval (CI) = 1.01-1.08, p = 0.01), with a borderline significant association with a positive SCH-1 test (odds ratio = 1.03, 95% CI = 0.99-1.07, p = 0.06). Conclusions The disparity between subjective symptoms and objective tests emphasizes the significance of incorporating objective measures for screening and diagnosing DED in civil flight personnel. If independently confirmed by future research, our findings could potentially lead to the routine implementation of surveillance protocols that incorporate objective DED indicators. Moreover, as age emerged as an independent predictor of positive results on objective tests, it is crucial to consider age-specific screening strategies.

The Effect of Autografts from the Inferior and Superior Bulbar Conjunctiva on the Ocular Surface in Primary Pterygium Surgery: A Cytology Study

Objectives

This study aimed to evaluate the effect of using an inferior or superior conjunctival autograft in primary pterygium surgery on the postoperative ocular surface.

Materials and Methods

Forty eyes of 40 patients who underwent pterygium surgery with autograft were included in the study. Cytological cell counts were performed on samples taken from the bulbar conjunctiva by impression cytology before and 1 year after the operation. Schirmer 1 test score, lissamine green conjunctival staining score, tear film break-up time (TBUT), and fluorescein corneal staining scores were evaluated. The pain levels of the patients were evaluated with visual analog scale at postoperative 1 day and 1 week.

Results

Corneal and conjunctival staining, TBUT, and Schirmer test results demonstrated significant improvement in all patient groups after surgery, but there was no difference between groups (p>0.05). In both preoperative and postoperative impression cytology, the number of goblet cells in the inferior bulbar conjunctiva was higher than in the superior bulbar conjunctiva (p<0.001), while there was no such difference in epithelial cell or mucin staining. There were no significant cytological changes postoperatively in either group (p>0.05).

Conclusion

Pterygium surgery with autografting improved tear function tests regardless of graft location. Goblet cell count was higher in the inferior bulbar conjunctiva than in the superior bulbar conjunctiva in both postoperative and preoperative impression cytology. However, there was no significant difference in postoperative epithelial and goblet cell counts or mucin staining between the groups before and after surgery. We think that using the inferior bulbar conjunctiva is an appropriate choice in cases where the superior conjunctiva cannot be used as a graft or when future glaucoma surgery is possible.

Comparison of postoperative recovery of primary pterygium excision combined with either limbal stem cell transplantation or amniotic membrane transplantation: a randomized controlled trial-based meta-analysis

OBJECTIVE

To compare the postoperative recovery of primary pterygium excision combined with either limbal stem cell transplantation (LSCT) or amniotic membrane transplantation (AMT).

METHODS

All relevant studies on the primary pterygium excision combined with either LSCT or AMT conducted before August 2022 were extracted from PubMed, EMBASE, Web of Science, and Cochrane Library databases. The main outcomes compared were tear film stability at 1, 3, and 6 months after surgery, postoperative corneal epithelial healing time, recurrence rate, and complications.

RESULTS

Sixteen randomized controlled trials (RCTs) with 1390 eye cases were included in this meta-analysis. We found that patients of the AMT group improved significantly in the results of the tear break-up time (BUT) and Schirmer I test at 1 month after surgery (BUT: MD=-0.37, 95% CI: -0.62, -0.12, P<0.05; Schirmer I test: MD=-0.32, 95% CI: -0.57, -0.07, P<0.05) compared with those of the LSCT group, suggesting that the early stage of tear film stability after primary pterygium excision combined with AMT was superior to the LSCT combination. However, according to the Schirmer I test result, the patients in the LSCT group showed increased tear production compared to the AMT group at 3 and 6 months after surgery (3 months: MD=0.36, 95% CI: 0.08, 0.64, P<0.05; 6 months: MD=0.33, 95% CI: 0.07, 0.60, P<0.05), suggesting that the LSCT combination was superior to the AMT combination in long-term postoperative tear film stability. As for postoperative corneal epithelial healing time, the LSCT group exhibited shorter time than the AMT group (MD=-1.17, 95% CI: -2.15, -0.19, P<0.05). Furthermore, the recurrence rate was lower in the LSCT group than in the AMT group (RR=0.42, 95% CI: 0.30, 0.59, P<0.05). Lastly, there was no statistical difference in BUT and complication rate at 3 and 6 months after surgery between the LSCT and AMT groups.

CONCLUSIONS

Our analysis suggests that primary pterygium excision combined with LSCT may be a better choice compared to the combination with AMT in postoperative recovery.

Systematic Review: Effects of Pterygium and Pingueculum on the Ocular Surface and Efficacy of Surgical Excision

PURPOSE

This systematic review examines the specific effects of pingueculum and pterygium on the ocular surface and evaluates the efficacy of surgical excision in reversing those effects.

METHODS

A systematic review was performed according to the Preferred Reporting Items for the Systematic Review and Meta-Analyses statement and included 59 articles studying the effects of pterygium and pingueculum on the ocular surface as measured by tear break-up time (TBUT), Schirmer testing, tear osmolarity, Ocular Surface Disease Index (OSDI), and the effects of surgical removal on these ocular surface parameters.

RESULTS

In most studies, eyes with pterygium or pingueculum when compared with control eyes had a statistically significantly lower TBUT (average 3.72 s), lower Schirmer I without anesthesia (average 3.01 mm), lower Schirmer II (average 4.10 mm), higher tear osmolarity (average 12.33 mOsm/L), and higher OSDI (average 6.82 points). Moreover, excision of pterygium and pingueculum led to a statistically significantly higher TBUT (average 3.15 s higher at 1 mo postexcision), lower tear osmolarity (average 3.10 mOsm/L lower at 3 mo postexcision), and lower OSDI score (average 2.86 points lower 1 mo postexcision) in most of the studies. The effect of excision on Schirmer test scores was equivocal because most studies did not reach significance.

CONCLUSIONS

Our data confirm the relationship between pterygium and pingueculum and abnormal tear function and symptoms of dry eye disease. Furthermore, the data suggest that tear film parameters might improve after surgical removal of pterygium or pingueculum. Future studies would be helpful in exploring the potential role of pterygium and pingueculum excision in the management of dry eye disease.