Impact of pterygium on the ocular surface and meibomian glands

Risk Factors for Recurrence in the Treatment of Recurrent Pterygium

PURPOSE

The aim of this study was to identify the postoperative recurrence rate of recurrent pterygium and to evaluate risk factors for the recurrence.

METHODS

This study was a retrospective interventional nonrandomized consecutive case series. In this single-center study, 119 eyes of patients with recurrent pterygium who underwent surgery with a follow-up period of >12 months after the surgery were analyzed. The clinical characteristics of pterygium were classified according to the length of corneal involvement and Tan grade. The main outcome was the recurrence rate. The secondary outcome was the risk factors for recurrence.

RESULTS

The mean follow-up period was 42 ± 28.6 months. Recurrence was observed in 15 patients (12.6%). The average postoperative recurrence period was 7.7 ± 6.7 months. Twelve patients experienced a recurrence within 12 months. Eyes with recurrence had a significantly greater length of corneal involvement (2.47 ± 0.72 mm) and number of previous surgery (1.9 ± 1.3) than those without (1.97 ± 0.74 mm, and 1.3 ± 0.7, both P = 0.04). Multivariate analysis showed that recurrence was significantly associated with the length of corneal involvement (odds ratio [OR] 2.38, 95% confidence interval [CI], 1.02-5.57, P = 0.05) and the number of previous surgeries (OR: 1.91, 95% CI, 1.03-3.58, P = 0.04) but not with sex (OR: 3.71, 95% CI, 0.90-15.2, P = 0.07), age (OR: 0.99, 95% CI, 0.94-1.04, P = 0.59), and use of mitomycin C (OR: 0.31, 95% CI, 0.07-1.21, P = 0.09).

CONCLUSIONS

The postoperative recurrence rate of recurrent pterygium was 12.6%. The preoperative length of corneal involvement and number of previous pterygium surgeries were significantly correlated with recurrence. Male sex and nonuse of mitomycin C tended to correlate with recurrence.

Accurate detection and grading of pterygium through smartphone by a fusion training model

BACKGROUND/AIMS

To improve the accuracy of pterygium screening and detection through smartphones, we established a fusion training model by blending a large number of slit-lamp image data with a small proportion of smartphone data.

METHOD

Two datasets were used, a slit-lamp image dataset containing 20 987 images and a smartphone-based image dataset containing 1094 images. The RFRC (Faster RCNN based on ResNet101) model for the detection model. The SRU-Net (U-Net based on SE-ResNeXt50) for the segmentation models. The open-cv algorithm measured the width, length and area of pterygium in the cornea.

RESULTS

The detection model (trained by slit-lamp images) obtained the mean accuracy of 95.24%. The fusion segmentation model (trained by smartphone and slit-lamp images) achieved a microaverage F1 score of 0.8981, sensitivity of 0.8709, specificity of 0.9668 and area under the curve (AUC) of 0.9295. Compared with the same group of patients' smartphone and slit-lamp images, the fusion model performance in smartphone-based images (F1 score of 0.9313, sensitivity of 0.9360, specificity of 0.9613, AUC of 0.9426, accuracy of 92.38%) is close to the model (trained by slit-lamp images) in slit-lamp images (F1 score of 0.9448, sensitivity of 0.9165, specificity of 0.9689, AUC of 0.9569 and accuracy of 94.29%).

CONCLUSION

Our fusion model method got high pterygium detection and grading accuracy in insufficient smartphone data, and its performance is comparable to experienced ophthalmologists and works well in different smartphone brands.

The unique properties of tear film breakup process in patients with nasal unilateral pterygium

SIGNIFICANCE

This study found that the unique properties of tear film breakup process in eyes with pterygium, combined with ocular surface parameters, further revealed specific dynamic mechanism. It suggested that the thickness of pterygium was especially valuable in deciding the necessity of surgical management.

PURPOSE

This study aimed to explore the dynamic mechanism of tear film instability in eyes with pterygium.

METHODS

A paired-eye controlled cross-sectional study was conducted. Seventy-eight patients with nasal pterygium were enrolled. Fluorescein tear film breakup was observed. Several key parameters related to tear film quality were defined and analyzed, including total breakup area (mathematically derived from pixel size using MATLAB), breakup velocity, fluorescein breakup time, breakup location and pattern, tear meniscus height, score of fluorescein corneal staining, and meiboscore.

RESULTS

With comparable tear meniscus height, score of fluorescein corneal staining, and meiboscore between paired eyes (p > 0.05), eyes with pterygium had shorter breakup time, larger breakup area, and faster breakup velocity (p < 0.05). In eyes with pterygium, a positive correlation between meiboscore and pterygium parameters including length, thickness, and size was observed (p > 0.001). As the thickness increased, difference of breakup time and area between paired eyes increased (p = 0.02 and 0.046). Eyes with pterygium had more fixed inferonasal breakup location and often presented as dimple break (60%), whereas random break was the most common in contralateral normal eyes (62%). A unique breakup pattern named pterygium-induced local dimple break was found. It displayed as an irregular but vertical line-like shape appearing after lipid layer spreading, which was adjacent to the lower margin of pterygium and presented with unique properties including inferonasal breakup location, local breakup area, shorten breakup time, and faster breakup velocity.

CONCLUSIONS

Eyes with pterygium showed a unique tear film breakup process and novel breakup pattern named pterygium-induced local dimple break . Dynamic mechanism played a significant role in tear film instability of eyes with pterygium rather than aqueous deficiency and increased evaporation.

TFOS Lifestyle Report: Impact of environmental conditions on the ocular surface

Environmental risk factors that have an impact on the ocular surface were reviewed and associations with age and sex, race/ethnicity, geographical area, seasonality, prevalence and possible interactions between risk factors are reviewed. Environmental factors can be (a) climate-related: temperature, humidity, wind speed, altitude, dew point, ultraviolet light, and allergen or (b) outdoor and indoor pollution: gases, particulate matter, and other sources of airborne pollutants. Temperature affects ocular surface homeostasis directly and indirectly, precipitating ocular surface diseases and/or symptoms, including trachoma. Humidity is negatively associated with dry eye disease. There is little data on wind speed and dewpoint. High altitude and ultraviolet light exposure are associated with pterygium, ocular surface degenerations and neoplastic disease. Pollution is associated with dry eye disease and conjunctivitis. Primary Sjögren syndrome is associated with exposure to chemical solvents. Living within a potential zone of active volcanic eruption is associated with eye irritation. Indoor pollution, "sick" building or house can also be associated with eye irritation. Most ocular surface conditions are multifactorial, and several environmental factors may contribute to specific diseases. A systematic review was conducted to answer the following research question: "What are the associations between outdoor environment pollution and signs or symptoms of dry eye disease in humans?" Dry eye disease is associated with air pollution (from NO2) and soil pollution (from chromium), but not from air pollution from CO or PM10. Future research should adequately account for confounders, follow up over time, and report results separately for ocular surface findings, including signs and symptoms.

The Influence of Pterygium on Meibomian Glands and Dry Eye Parameters

SIGNIFICANCE

Mechanical factors are also associated with meibomian gland dysregulation in patients with pterygium. Dry eye parameters were assessed, and the results support the association between pterygium and dry eye disease.

PURPOSE

This study aimed to investigate how meibomian gland dysfunction and dry eye parameters relate to the existence of pterygium.

METHODS

Patients with pterygium and healthy volunteers of similar age and demographic characteristics were included. Schirmer 1 test, Ocular Surface Disease Index score, fluorescein tear film breakup time, and ocular surface staining scores (Oxford score) were recorded. Meiboscores were estimated based on meibomian gland loss rate on infrared meibography (SL-D701; Topcon, IJssel, the Netherlands). The symmetry of meibomian gland loss with respect to eyelid midline was assessed.

RESULTS

Fifty-four eyes with pterygium (group 1) and 50 eyes of healthy volunteers (group 2) were included. The mean ages were 54.0 ± 12.3 and 52.3 ± 8.0 years, respectively. Schirmer 1 test results and tear film breakup time were lower in group 1 ( P = .007, P < .001). Oxford and Ocular Surface Disease Index scores were significantly higher in group 1 ( P = .009, P < .001). The mean meiboscores were significantly higher in group 1 ( P < .001). There was meibomian gland depletion in 90.7% (49 of 54) of group 1 and 32% (16 of 50) of group 2 ( P < .001). Meibomian gland loss region was distributed asymmetrically in 75.5% (37 of 49) of the eyes in group 1, but not in any of the eyes in group 2. The asymmetry was located on the side where the pterygium was detected in 94.5% (35 of 37) of these eyes.

CONCLUSIONS

Meibomian glands are influenced morphologically and functionally in eyes with pterygium. The overlap of the pterygium location and meibomian gland abnormality suggests a direct mechanical relationship. In managing pterygium patients, the possibility of meibomian gland dysfunction and associated evaporative dry eye should be considered.

Impact of pterygium on central corneal thickness measured by optical coherence tomography in older adults

PURPOSE

To measure the central corneal thickness (CCT) using anterior segment optical coherence tomography (AS-OCT) in older adults with and without pterygium from the Brazilian Amazon Region Eye Survey (BARES).

METHODS

BARES is a population-based epidemiological cross-sectional study conducted in Parintins city. Participants were residents ≥45 years of age identified through a door-to-door interview. Eligible participants were invited for a comprehensive eye exam. Pterygium occurrence and severity were assessed by ophthalmologists through slit-lamp examination considering its location (nasal or/and temporal) and severity (lesion with extension <3 mm, ≥3 mm not reaching the pupillary margin or ≥3 mm reaching the pupillary margin). CCTs were obtained and measurements from the more severely affected eye were included. Images were analyzed offline by masked observers.

RESULTS

A total of 671 subjects, 533 (79.4%) with pterygium in at least one eye and 138 (20.6%) without pterygium in either eye, were examined. The mean CCT evaluated by multiple linear regression and adjusted for demographic variables and pterygium severity was 521 ± 34 μm (median = 521; range = 304-665). Decreased CCT was significantly associated with age and pterygium severity. Individuals aged 65-74 years had CCT 7 μm thinner than those aged 45-54 years (p = 0.044), individuals aged 75 years and older had CCT 15 μm thinner than those aged 45-54 years (p = 0.001), and eyes with severe pterygium had CCT 33 μm thinner than eyes without pterygium (p < 0.001).

CONCLUSIONS

The CCT analysis in this population-based sample shows that a thinner cornea is associated with pterygium severity and older age.

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.

Acupoint Massage plus Recombinant Bovine Basic Fibroblast Growth Factor Ophthalmic Gel and Limbal Stem Cell Transplantation on Visual Quality, Corneal Refraction, and Aesthetic Outcome in Patients with Pterygium

Objective

To investigate the clinical study of acupoint massage combined with recombinant bovine basic fibroblast growth factor (rbFGF) ophthalmic gel combined with limbal stem cell transplantation on visual quality, corneal refraction, and aesthetic outcome in patients with pterygium.

Methods

Sixty patients with pterygium treated in People's Hospital of Lujiang County from March 2018 to May 2021 were randomized into the control group and the research group by the random number table method, with 30 cases in each group. The control group received rbFGF plus limbal stem cell transplantation. The research group was treated with acupoint massage additionally.

Results

The total clinical effective rate in the study group was higher than that in the control group (P < 0.05); after treatment, the modulation transfer function (MTF) cutoff and Strehl ratio (SR) levels in the study group were significantly higher than those in the control group, and the tear film-related objective scatter index (TF-OSI) was significantly lower than that in the control group (P < 0.05); corneal horizontal curvature and corneal vertical curvature in the study group after treatment were significantly higher than those in the control group, and corneal astigmatism degree (CAD) levels were significantly lower than those in the control group (P < 0.05); the levels of the break-up time (BUT) and Schirmer test (SIT) in the study group were significantly higher after treatment, compared with the control group (P < 0.05); and the incidence of adverse manifestations in the study group was significantly lower than that in the control group (P < 0.05).

Conclusion

Acupoint massage combined with rbFGF ophthalmic gel combined with limbal stem cell transplantation is effective in clinical treatment of pterygium.

Efficacy of bevacizumab in the treatment of pterygium: An updated meta-analysis of randomized controlled trials

Recurrence is the most common problem following pterygium surgery. Whether bevacizumab can prevent pterygium recurrence is controversial. To address this point, we carried out a meta-analysis of randomized controlled trials evaluating the efficacy and safety of bevacizumab in the treatment of pterygium. We searched the PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Literature, China National Knowledge Infrastructure, and Wan fang databases up to September 20, 2020 for relevant articles. We used the Cochrane assessment tool to evaluate the methodologic quality of the included studies, and calculated the relative risk (RR) and 95% confidence interval (CI) of the reported recurrence and complication rates. A total of 17 studies including 1124 patients with 1144 eyes were included in the meta-analysis. The combined results showed that bevacizumab significantly reduced the recurrence rate of pterygium after surgery (RR = 0.652, 95% CI: 0.504-0.845, Z = 3.24, P = 0.001) and was not significantly associated with the occurrence of postoperative complications compared to control treatments (RR = 0.832, 95% CI: 0.604-1.145, Z = 1.13, P = 0.259). A subgroup analysis showed that the rate of pterygium recurrence was significantly lower with bevacizumab than in the control group at a dose of 2.5 mg (RR = 0.47, 95% CI: 0.24-0.91) administered by subconjunctival injection (RR = 0.54, 95% CI: 0.39-0.75) after a follow-up time of ≤ 6 months (RR = 0.63, 95% CI: 0.45-0.88). Thus, bevacizumab can reduce the risk of pterygium recurrence after surgery, and does not differ from placebo or other drug treatments in terms of the risk of complications.

[Pterygium: pathogenesis, diagnosis and treatment]

The pterygium is a frequent ultraviolet (UV) light-induced focal fibrovascular proliferation of the conjunctival tissue onto the cornea. Surgical excision should be performed in the case of reduced visual acuity, progressive astigmatism, impending invasion of the optical axis and ocular surface complaints. The main factors in preventing recurrence include optimal surgical treatment by an excision combined with a free conjunctival autograft, consistent postoperative treatment with preservative-free artificial tears and topical steroids as well as long-term UV protection.

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.