Prevalence and risk factors of pterygium: a systematic review and meta-analysis

Integrative analysis of ex vivo studies and microarray reveals the novel inhibitor effects of trehalose on the pathogenesis of pterygium

Pterygium is a frequent eye surface condition that is characterized by a high rate of proliferation, fibrovascular development, cellular migration, corneal infiltration, and angiogenesis. We investigated that ex vivo primary pterygium and conjunctival cell cultures were generated to analyze the effect of trehalose on cellular proliferation. After trehalose treatment, we performed microarray analysis to evaluate changes in the mRNA profile. We analyzed gene ontology (GO) and KEGG pathways to identify hub genes that changed expression levels after treatment and were associated with pterygium development. We selected three genes to verify their expression levels using qRT-PCR. The study also evaluated the impact of trehalose treatment on cell migration through a wound-healing assay. Our results suggested that pterygium cell proliferation was inhibited in a dose-dependent manner by trehalose. 2354 DEG were identified in pterygium and conjunctiva cells treated with trehalose compared to untreated groups. Functional enrichment analysis showed that differentially expressed mRNAs are involved in proliferation, vasculature development, and cell migration. We identified ten hub genes including upregulated (RANBP3L, SLC5A3, RERG, ANKRD1, DHCR7, RAB27B, GPRC5B, MSMO1, ASPN, DRAM1) and downregulated (TNC, PTGS2, GREM2, NPTX1, NR4A1, HMOX1, CXCL12, IL6, MYH2, TXNIP). Microarray analysis and functional investigations suggest that trehalose affects the pathogenesis of pterygium by modifying the expression of genes involved in crucial pathways related to cell function.

A Phase IIa Multicenter, Randomized, Vehicle-Controlled, Dose Escalating Study to Evaluate the Safety, Efficacy, and Pharmacokinetics of CBT-001 Ophthalmic Solution in Patients With Primary or Recurrent Pterygium

Purpose

To evaluate the safety and efficacy of CBT-001, a multitarget tyrosine kinase inhibitor eyedrop, for pterygia.

Design

Phase II clinical trial. Stage 1 was a single center, open-labeled, vehicle-controlled study. Stage 2 was a multicenter, randomized, double-masked, vehicle-controlled trial.

Participants

Patients with primary or recurrent pterygia.

Main Outcome Measures

The primary efficacy end point was lesion vascularity based on masked grading of photographs by an independent reading center. Other end points included dimensions of pterygia and safety.

Methods

In stage 1, 24 eyes of 24 patients received 1 drop of CBT-001 in a dose escalation fashion (0.02%, 0.05%, and 0.2%) to determine the maximally tolerated dose based on adverse events (AEs) and blood drug levels. In stage 2, subjects were randomly assigned to receive the maximally tolerated dose of CBT-001 or vehicle dosed 3 times a day for 4 weeks with a 20-week follow-up.

Results

In stage 1, the plasma maximum concentration values for all doses of CBT-001 were at or below the limit of detection (0.01 ng/ml). The most commonly reported AEs were mild foreign body sensation and irritation. CBT-001 0.2% was evaluated in stage 2. Baseline demographic characteristics were similar between patients receiving CBT-001 (n = 25) and vehicle (n = 23). After 4 weeks of dosing, the mean change from baseline in pterygium vascularity scores was -0.8 ± 0.7 (mean ± standard deviation) in subjects receiving CBT-001 0.2% and 0.0 ± 0.5 in subjects receiving vehicle (P < 0.001; 95% confidence interval: -1.12, -0.40). Pterygium vascularity scores remained significantly decreased, after the 4-week dosing period, at weeks 8 and 16, but not at week 24. The mean changes from baseline in the length of the pterygia were also significantly lower in subjects receiving CBT-001 compared with vehicle at weeks 2, 4, and 8 (P ≤ 0.014). The most commonly reported AEs were ocular, mild in severity, resolved after therapy, and did not result in discontinuation.

Conclusions

CBT-001 0.2% decreased pterygia vascularity and lesion length after 4 weeks of dosing with a prolonged effect after dosing. The drug was well tolerated with minimal detected systemic drug levels.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Unravelling the molecular tapestry of pterygium: insights into genes for diagnostic and therapeutic innovations

Pterygium, an ocular surface disorder, manifests as a wing-shaped extension from the corneoscleral limbus onto the cornea, impacting vision and causing inflammation. With a global prevalence of 12%, varying by region, the condition is linked to UV exposure, age, gender, and socioeconomic factors. This review focuses on key genes associated with pterygium, shedding light on potential therapeutic targets. Matrix metalloproteinases (MMPs), especially MMP2 and MMP9, contribute to ECM remodelling and angiogenesis in pterygium. Vascular endothelial growth factor (VEGF) plays a crucial role in angiogenesis and is elevated in pterygium tissues. B-cell lymphoma-2, S100 proteins, DNA repair genes (hOGG1, XRCC1), CYP monooxygenases, p53, and p16 are implicated in pterygium development. A protein-protein interaction network analysis highlighted 28 edges between the aforementioned proteins, except for VEGF, indicating a high level of interaction. Gene ontology, microRNA and pathway analyses revealed the involvement of processes such as base excision repair, IL-17 and p53 signalling, ECM disassembly, oxidative stress, hypoxia, metallopeptidase activity and others that are essential for pterygium development. In addition, miR-29, miR-125, miR-126, miR-143, miR-200, miR-429, and miR-451a microRNAs were predicted, which were shown to have a role in pterygium development and disease severity. Identification of these molecular mechanisms provides insights for potential diagnostic and therapeutic strategies for pterygium.

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.

Assessing the safety of new germicidal far-UVC technologies

The COVID-19 pandemic underscored the crucial importance of enhanced indoor air quality control measures to mitigate the spread of respiratory pathogens. Far-UVC is a type of germicidal ultraviolet technology, with wavelengths between 200 and 235 nm, that has emerged as a highly promising approach for indoor air disinfection. Due to its enhanced safety compared to conventional 254 nm upper-room germicidal systems, far-UVC allows for whole-room direct exposure of occupied spaces, potentially offering greater efficacy, since the total room air is constantly treated. While current evidence supports using far-UVC systems within existing guidelines, understanding the upper safety limit is critical to maximizing its effectiveness, particularly for the acute phase of a pandemic or epidemic when greater protection may be needed. This review article summarizes the substantial present knowledge on far-UVC safety regarding skin and eye exposure and highlights research priorities to discern the maximum exposure levels that avoid adverse effects. We advocate for comprehensive safety studies that explore potential mechanisms of harm, generate action spectra for crucial biological effects and conduct high-dose, long-term exposure trials. Such rigorous scientific investigation will be key to determining safe and effective levels for far-UVC deployment in indoor environments, contributing significantly to future pandemic preparedness and response.

The effect of different pterygium surgery techniques on the ocular surface parameters in different durations: a systematic review and meta-analysis

PURPOSE

To evaluate the effects of different pterygium surgery techniques on ocular surface (OS) in different follow-up periods.

METHODS

PubMed, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wan Fang, and China Biology Medicine disc were searched for studies reporting pre- and post-operative OS parameters in pterygium.

RESULTS

A total of 33 articles were finally included. Three OS parameters showed relatively consistent changing trends after surgery including ocular surface disease index (OSDI), tear film break-up time (BUT), and score of corneal fluorescein staining (SCFS). They worsened significantly at 1w post-operation and then gradually improved: OSDI and BUT showed obvious improvement in 1 m post-operation (SMD =  - 0.58, 95%CI = [- 1.04, - 0.13]; SMD = 0.42, 95%CI = [0.06, 0.78]); SCFS was restored to preoperative levels in 3 m after surgery (SMD =  - 0.54, 95%CI = [- 1.16, 0.07]). Another parameter, Schirmer test without anesthesia (SIT), presented transient increase at 1w post-operation (SMD = 0.87, 95%CI = [0.27, 1.47]) and presented a relatively stable improvement after 1 m post-operation (SMD = 0.52, 95%CI = [0.16, 0.89]). All parameters in amniotic membrane graft (AMT) showed better improvement in early stage and they showed non-inferior improvements in the long term compared with conjunctival autograft (CAG). Limbal-conjunctival autograft (LCAG) made excellent improvement to OS in the long term while pterygium excision (PE) showed the worst OS. The type of pterygium (primary and secondary), diabetes mellitus (DM) status, and fixation method had certain effects on the results.

CONCLUSIONS

OS of pterygium is deteriorated at 1w post-operation then gradually improved to preoperative levels after 1 m post-operation. Among various surgery techniques, LCAG had the best improvement to OS which especially displayed in the long-term outcomes.

Study of biomarkers p53, Ki-67, Bcl-2, and VEGF in pterygium

PURPOSE

To study the biomarkers present in primary pterygium samples of patients of Indian ethnicity and compare it with the samples obtained from the unaffected conjunctiva of the same eye.

METHODS

A prospective case-control study of 17 eyes in patients above 10 years of age with primary pterygium who underwent pterygium excision using limbal conjunctival autograft technique. The pterygium samples (cases) and conjunctival samples (controls) were sent for immunohistochemical (IHC) staining for the following biomarkers: p53, Bcl-2, Ki-67, and vascular endothelial growth factor (VEGF).

RESULT

The immunohistochemistry of the samples and the controls revealed p53 positivity in 47.05% of pterygium samples and 29.4% of controls ( P < 0.587). Nine cases each in pterygium and control samples were positive for Ki-67 expression. Differences in the staining pattern between the two groups were not statistically significant ( P < 1.000). Bcl-2 positivity was seen in 10 pterygium samples (58.8%) and 12 controls (70.5%), with no statistical difference between the two groups ( P < 0.455). VEGF expression was seen in both epithelial and endothelial cells of the samples and controls, with no statistical difference between the two groups, with P = 1.000 for the epithelial staining and P = 0.637 for endothelial staining.

CONCLUSION

The expression of biomarkers was comparable in both groups. We conclude that pterygium, against common belief, might not be a localized disease process but a global ocular phenomenon where the apparently healthy tissue also has some ongoing disease process at a molecular level.

Modified sutureless and glue-free method versus conventional sutures for conjunctival autograft fixation in primary pterygium surgery: a systematic review and meta-analysis

BACKGROUND

Pterygium is a common ocular surface disorder that requires surgical intervention for treatment. Conjunctival autografts are preferred over simple excision due to lower recurrence rates. This systematic review and meta-analysis compared the modified sutureless glue-free (MSGF) method with conventional sutures (CS) for conjunctival autograft fixation in primary pterygium surgery.

METHODS

A comprehensive search was conducted in MEDLINE, Embase, CENTRAL, Google Scholar and ClinicalTrials.gov for randomised controlled trials (RCTs) comparing MSGF and CS conjunctival autografts. Outcome measures included operation time, recurrence and postoperative complications. Standardised mean difference (SMD) and risk ratio (RR) were used for continuous and dichotomous outcomes, respectively.

RESULTS

11 RCTs involving 833 participants were included. The analysis revealed that MSGF had a significantly shorter operation time compared with CS (SMD -3.704, 95% CI -5.122 to -2.287, p<0.001). CS was associated with a higher risk of foreign body sensation (RR 0.22, 95% CI 0.06 to 0.74, p=0.01). MSGF was associated with a higher risk of graft dehiscence (RR 9.01, 95% CI 2.74 to 29.68, p=0.000) and graft retraction (RR 2.37, 95% CI 1.17 to 4.77, p=0.02). No significant differences were found in recurrence, graft haemorrhage, granuloma, Dellen and conjunctival oedema.

CONCLUSION

Using the MSGF technique in conjunctival autograft fixation for pterygium surgery reduces operation time by relying solely on the patient's blood for fixation. However, it increases the risk of graft dehiscence and retraction. However, CS is linked to a higher likelihood of experiencing foreign body sensations. Understanding the learning curve and surgeon familiarity with novel techniques is crucial for optimising patient care and surgical outcomes, while individualised decision-making is necessary considering the advantages and disadvantages of each approach. Further research is warranted to minimise complications and optimise surgical outcomes.

Single-cell RNA sequencing reveals the complex cellular niche of pterygium

PURPOSE

Pterygium is a vision-threatening conjunctival fibrovascular degenerated disease with a high global prevalence up to 12 %, while no absolute pharmacotherapy has been applied in clinics. In virtue of single-cell RNA sequencing (scRNA-seq) technique, our study investigated underlying pathogeneses and potential therapeutic targets of pterygium from the cellular transcriptional level.

METHODS

A total of 45605 cells from pterygium of patients and conjunctiva of normal controls (NC) were conducted with scRNA-seq, and then analyzed via integrated analysis, pathway enrichment, pseudotime trajectory, and cell-cell communications. Besides, immunofluorescence and western blot were performed in vivo and in vitro to verify our findings.

RESULTS

In brief, 9 major cellular types were defined, according to canonical markers. Subsequently, we further determined the subgroups of each major cell lineages. Several newly identified cell sub-clusters could promote pterygium, including immuno-fibroblasts, epithelial mesenchymal transition (EMT)-epithelial cells, and activated vascular endothelial cells (activated-vEndo). Besides, we also probed the enrichment of immune cells in pterygium. Particularly, macrophages, recruited by ACKR1+activated-vEndo, might play an important role in the development of pterygium by promoting angiogenesis, immune suppression, and inflammation.

CONCLUSION

An intricate cellular niche was revealed in pterygium via scRNA-seq analysis and the interactions between macrophages and ACKR1+ activated-vEndo might be the key part in the development of pterygia.

Low Rate of Postoperative Pterygium Recurrence in Patients under Treatment with Low-Dose Oral Doxycycline for Chronic Blepharitis: A First Report

PURPOSE

Low doses of systemic doxycycline (LD-SD) inhibit angiogenesis and the expression of matrix metalloproteases, which are determinants of pterygium progression. This study aimed to compare the recurrence rate and visual outcome of pterygium excision in patients undergoing chronic treatment with LD-SD for chronic refractory blepharitis and LD-SD-naive patients.

METHODS

A retrospective analysis of patients that underwent surgical excision and conjunctival graft apposition was conducted. Patients were divided in a TETRA group (under LD-SD treatment at the moment of surgery) and a control group. The main outcome was the rate of recurrence at 1 year postoperatively. Secondary outcomes were the comparisons of surface regularity, visual quality, and dry-eye symptoms at 6-week, 6-month, and 1-year follow-up in the two groups.

RESULTS

The TETRA group showed a significantly lower rate of 1-year recurrence both in primary (p = 0.034) and recurrent (p < 0.001) pterygia. The best corrected visual acuity (BCVA), astigmatic error, corneal total root mean square (RMS), and ocular surface disease index (OSDI) significantly reduced during the follow-up in both groups. The surface asymmetry index and high-order aberrations (HOAs) significantly reduced only in the TETRA group. The final BCVA was significantly higher, while the OSDI score and total RMS and HOAs were significantly lower in the TETRA group compared to the control.

CONCLUSIONS

Patients under treatment with LD-SD showed a lower rate of recurrence at 1-year follow-up compared to controls. These patients also experienced higher BCVA and surface regularity and less dry-eye symptoms.

Potential applications of artificial intelligence in image analysis in cornea diseases: a review

Artificial intelligence (AI) is an emerging field which could make an intelligent healthcare model a reality and has been garnering traction in the field of medicine, with promising results. There have been recent developments in machine learning and/or deep learning algorithms for applications in ophthalmology-primarily for diabetic retinopathy, and age-related macular degeneration. However, AI research in the field of cornea diseases is relatively new. Algorithms have been described to assist clinicians in diagnosis or detection of cornea conditions such as keratoconus, infectious keratitis and dry eye disease. AI may also be used for segmentation and analysis of cornea imaging or tomography as an adjunctive tool. Despite the potential advantages that these new technologies offer, there are challenges that need to be addressed before they can be integrated into clinical practice. In this review, we aim to summarize current literature and provide an update regarding recent advances in AI technologies pertaining to corneal diseases, and its potential future application, in particular pertaining to image analysis.

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.

Evaluation of lymphotoxin-alpha in pterygium and diagnostic value in active and inactive pterygium states

To explore the correlation between tear LT-a, pterygium status, and dry eye indicators. We established a diagnostic model to evaluate active pterygium. A retrospective study was conducted between June 2021 and June 2023 on 172 patients, comprising 108 men and 64 women. The study analyzed LT-a and various ocular parameters in all participants. The data was collected using Excel software and analyzed using SPSS 25.0 statistical software and Medcalc. We made a nomogram diagnostic model to different diagnosed the state of pterygium. This study found that pterygium has progressive eye surface damage during the active state. There was no significant difference in dry eye indicators between the two groups. However, the concentration of LT-a in the active group was significantly lower than that in the inactive group (P < 0.001). We observed that increased pterygium grade corresponded to a worse ocular surface condition. In addition, LT-a was significantly positively correlated with disease duration, but negatively correlated with age, pterygium size, active pterygium state, and LLT value. The optimal intercept value for evaluating active pterygium in Lt-a was ≤ 0.49 dg/ml. We screened three variables for evaluating active pterygium through Single and Multiple regression analysis: LT-a grading, pterygium size, and congestion score. Finally, we made a reliable diagnostic nomogram model. Pterygium development triggers immune inflammation. Our model based on LT-a identifies active pterygium for personalized treatment options and new research directions.

Genetic evidence implicating circulating lipids and lipid drug targets in pterygium

There is limited knowledge about the impact of circulating lipids and lipid-modifying drugs on pterygium development, with conflicting results reported. Our study aimed to address these questions by applying the Mendelian randomization (MR) approach. A two-step MR model was developed. In the first step, bidirectional two-sample MR was employed to establish the causal relationship between circulating lipids and pterygium risk. In the second step, drug-target MR analysis was conducted to assess the causal effect of proprotein convertase subtilisin/kexin type 9 (PCSK9) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) inhibitors on pterygium outcomes. Genetically predicted low-density lipoprotein cholesterol (LDL-c) levels were found to be significantly associated with an increased risk of pterygium (Inverse variance weighted [IVW] odds ratio [OR] = 2.227; P = 1.53 × 10-4). Similarly, higher total cholesterol (TC) levels exhibited a suggestive association with greater susceptibility to pterygium (IVW OR = 1.806; P = 1.70 × 10-3). Through drug-target MR, a positive causal association was noted between HMGCR-mediated LDL-c levels and pterygium (IVW OR = 6.999; P = 0.016), suggesting that statins may be effective in reducing pterygium risk. The present findings suggest that circulating TC and LDL-c are risk factors for pterygium. Additionally, the results indicate that HMGCR inhibitors, which lower LDL-c levels, have a potential protective effect on pterygium outcomes. Further research is warranted to elucidate the underlying mechanisms involved in pterygium pathogenesis, with a particular focus on cholesterol metabolism.

Are Periocular and Systemic Allergy Conditions Risk Factors for Pterygium?

PURPOSE

To evaluate risk factors for pterygium and prevalence of periocular and systemic diseases among patients with pterygium.

METHODS

A retrospective case-control study was conducted among members of Clalit Health Services (CHS) in Israel, from 2001 to 2022. A total of 13,944 patients diagnosed with pterygium were included. For each case, three controls were matched among all CHS patients according to year of birth, sex, and ethnicity. Mixed models were used to assess differences in demographic characteristics, ocular and systemic diseases between the groups. Generalized estimating equation (GEE) logistic regression was used to estimate the odds ratios (OR) and adjust for confounders.

RESULTS

The average age of pterygium patients was 49 ± 17 years; 51% were male. The results showed significant associations between pterygium and risk factors of vernal kerato-conjunctivitis (OR 2.52, 95% confidence interval [CI]: [1.96-3.24]), chronic allergic conjunctivitis (OR 1.98, 95% CI: [1.65-2.39]), blepharitis (OR 1.91, 95% CI: [1.78-2.04]), chalazion (OR 1.47, 95% CI: [1.30-1.67]) and unspecified systemic allergy (OR 1.21, 95% CI [1.09-1.34]), after adjusting for rural residency status. Glaucoma (OR 0.74, 95% CI [0.64-0.85]) and smoking (OR 0.70, 95% CI [0.66-0.75]) were protective factors against pterygium.

CONCLUSION

Systemic and periocular inflammatory and allergic diseases are risk factors for pterygium.

A New Approach: Determination of the Safe Surgical Margin in Pterygium Surgery

PURPOSE

In this retrospective study, we aimed to determine the safe surgical limit for excision of pterygium tissue. Therefore, we aimed to prevent excessive or incomplete normal conjunctival tissue excision during surgery in the coming years.

METHODS

Autografted pterygium surgery was performed between January 2015 and April 2016, and the excised pterygium tissue was examined histopathologically. The files of 44 patients, who had not previously undergone any ocular surgery, who did not have an inflammatory disease and who continued to be checked for at least 1 year, were retrospectively examined. The distance (P-DSEM) from the excised pterygium tissue to the surgical excision margin was measured by a pathologist. Postoperative recurrence rates were evaluated according to this value. In this way, the clean surgical margin was determined.

RESULTS

The mean age of the participants was 44.77 ± 12.70, and the mean follow-up time was 55.61 ± 16.38 months. Recurrence developed in 5 out of 44 patients (11.4%). The average recurrence duration was 51 ± 13.87 days. Distance to the average surgical margin was 3.88 ± 0.91 mm. The surgical distances of 5 patients with recurrence were 2, 2.5, 2, 3, and 3 mm, respectively. It was determined that recurrence was less as the distance (P-DSEM) from the tissue to the surgical excision margin increased (p = 0.001).

CONCLUSIONS

We found that the recurrence rate in pterygium surgery was linked to the clean surgical margin. When planning pterygium surgery, we believe that determining the amount of tissue to be excised before surgery will reduce recurrence rates.

The role of HPV in the etiopathogenesis of pterygium and the relationship with recurrence

PURPOSE

The primary aim of this study was to determine the prevalence of HPV in pterygium with polymerase chain reaction (PCR) testing and to investigate the relationship with clinicopathological factors. A secondary aim was to evaluate the relationship between HPV and the recurrence of pterygium.

METHODS

The study included 60 patients. PCR analysis was used to determine the presence of HPV. All the patients were followed up in respect of the development of recurrence. Analyses were performed of patient age, pterygium site, specimen and pterygium size, histopathological findings, HPV status, operation technique and postoperative follow-up findings. In the HPV-positive patients, the relationship between HPV subtypes and other factors was evaluated. To determine the risk factors affecting recurrence rates, multivariate Cox regression analysis was applied subsequent to univariate analysis. In the Cox regression model, HPV status, age, sex, specimen size, size and site of pterygium were included among factors that may affect recurrences rates.

RESULTS

Of the total 60 patients, the HPV-PCR test result could not be analysed in 14 because of an insufficient sample. Of the 46 patients with sufficient material for HPV-PCR analysis, the HPV-PCR result was positive in 15 (32.6%). The HPV subtype most often determined was type 16. No statistically significant relationship was determined between HPV positivity and HPV subtype and age or sex. Recurrence was determined in 10% of all the patients. Of the cases determined with recurrence, 66.7% were HPV positive. According to Kaplan-Meier analysis, the recurrence rates in HPV-positive and HPV-negative patients were 26.7% and 6.5%, respectively. A statistically significant difference was found between two groups in terms of recurrence rates (p: 0.046). According to the results of multivariate Cox regression analysis, though not statistically significant, the risk of recurrence was increased 6.18 times in HPV-positive patients with pterygium compared to HPV-negative ones.

CONCLUSION

HPV infection may have a role in the development of pterygium and recurrence, but may not be sufficient alone. HPV probably has a role in the development of pterygium by acting together with several co-factors in the multi-stage process.

Surgical Time and Postoperative Symptoms Study in Pterygium Excision and Amniotic Membrane Graft Using Celularity Triple Layer Dehydrated Amniotic Membrane

Purpose

To evaluate a novel sutureless glueless technique using a triple-layer dehydrated amniotic membrane (TLDAM) for pterygia excisions in surgical time, postoperative pain, epiphora, irritation, and FBS.

Methods

Twenty eyes with pterygia underwent excision with mitomycin C. The conjunctival defect was closed with TLDAM placed on the dried scleral bed with the edges of the amniotic membrane tucked under the edges of the conjunctival defect. Surgical times were measured from injection of lidocaine to final placement of bandage contact lens. After a bandage contact lens was placed, the eye was patched until POD1. Patients graded self-administered questionnaires to rate pain, FBS, irritation, and epiphora on a scale of 1-5 (1-none; 5-severe) at POD1 and POW1.

Results

Surgical times ranged from 6:55 to 12:00, with mean of 8:29. Compared with a previous study of sutureless glueless methodology, the difference in mean surgical time was 11.9 (p < 0.0001). Mean questionnaire scores were as follows: POD1 pain 1.8, FBS 2.3, irritation 1.0, and epiphora 2.6; POW1 pain 1.5, FBS 1.6, irritation 1.6, and epiphora 1.6. Compared to previous studies, this technique showed significantly improved pain at POD1 (p=0.0086, p<0.0001, p<0.0001, p<0.0001) and POW1 (p=0.0002, p=0.0016, p<0.0001). Significant improvement in irritation and FBS was noted at POD1 and POW1. See Table 1 for full analysis.

Conclusion

The sutureless glueless technique using TLDAM is a safe and effective technique compared to current standard methods. There appears to be a significant benefit regarding surgical time and postoperative pain, irritation, epiphora, and FBS compared to previous studies.

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 corneal densitometry evaluated using the Oculus Pentacam system

Purpose

To assess the effect of pterygium on corneal densitometry (CD) values.

Methods

One hundred and nine patients (155 eyes) with primary pterygium were divided into a severe pterygium group (79 eyes) and a mild-to-moderate pterygium group (76 eyes) according to pterygium severity. Among them, 63 patients had monocular pterygium; and 25 patients (38 eyes) underwent pterygium excision combined with conjunctival autograft follow-up. A Pentacam anterior segment analyzer was used to obtain the CD values and corneal morphological parameters, including central corneal thickness (CCT), flat-axis keratometry (K1), steep-axis keratometry (K2), corneal astigmatism, irregular astigmatism, and spherical aberration. CD was subdivided into four concentric radial regions based on corneal diameter and three layers according to depth.

Results

CD values at 0-12 mm of the anterior 120 μm layer, 0-10 mm of the center layer and full thickness, and 2-6 mm of the posterior 60 μm layer were significantly higher in eyes affected by pterygium than in the contralateral unaffected eyes (all P < 0.05). CD values were significantly higher in the severe pterygium group than in the mild to moderate pterygium group (all P < 0.05). Corneal astigmatism, irregular astigmatism, K1, K2, CCT, and spherical aberration correlated with CD values in eyes with pterygium (all P < 0.05). CD values at 6-10, 0-12 mm in the anterior 120 μm layer and full thickness, 10-12 and 0-12 mm in the center layer were significantly decreased 1 month after pterygium surgery compared with those before surgery (all P < 0.05).

Conclusion

Patients with pterygium had increased CD values, particularly in the anterior and central layers. CD values were correlated with pterygium severity grading and corneal parameters. Pterygium surgery partially reduced the CD values.

Use of Cryopreserved Amniotic Membrane During Pterygium Excision: Health Economic Analysis

Purpose

To determine the health economic opportunity cost or gain associated with performing pterygium excision surgery using the TissueTuck technique with cryopreserved amniotic membrane (AM) instead of conjunctival autograft (CAU).

Methods

We performed a literature review to determine the average surgical duration of pterygium surgery using CAU with fibrin glue or sutures to calculate the average time saved with the TissueTuck technique. Such time savings was then used to determine the opportunity revenue gain per national average Medicare reimbursement if adjusted to the average surgical duration of cataract surgery.

Results

The time savings achieved using the TissueTuck technique over CAU with fibrin glue is 8.9 min per procedure, which can be applied to additional MSICS or phacoemulsification procedures to generate an opportunity revenue gain of $1167 or $762 per 2022 National Average Medicare reimbursement, respectively. After subtracting the current list cost of AmnioGraft (ie, $645), the opportunity gain is $522 or $117 if the time saving is applied to the above procedures, respectively. Alternatively, the time savings achieved by using the TissueTuck technique over CAU with sutures is 23.4 min per procedure, which can be applied to additional MSICS or phacoemulsification procedures to generate an opportunity revenue gain of $3068 and $2004 per TissueTuck procedure or $2423 or $1359 when accounting for the list cost of AmnioGraft, respectively.

Conclusion

The TissueTuck surgical technique using cryopreserved AM for pterygium takes less time, has lower recurrence rates, and provides an opportunity gain compared to pterygium excision with CAU.

TFOS lifestyle: Impact of societal challenges on the ocular surface

Societal factors associated with ocular surface diseases were mapped using a framework to characterize the relationship between the individual, their health and environment. The impact of the COVID-19 pandemic and mitigating factors on ocular surface diseases were considered in a systematic review. Age and sex effects were generally well-characterized for inflammatory, infectious, autoimmune and trauma-related conditions. Sex and gender, through biological, socio-economic, and cultural factors impact the prevalence and severity of disease, access to, and use of, care. Genetic factors, race, smoking and co-morbidities are generally well characterized, with interdependencies with geographical, employment and socioeconomic factors. Living and working conditions include employment, education, water and sanitation, poverty and socioeconomic class. Employment type and hobbies are associated with eye trauma and burns. Regional, global socio-economic, cultural and environmental conditions, include remoteness, geography, seasonality, availability of and access to services. Violence associated with war, acid attacks and domestic violence are associated with traumatic injuries. The impacts of conflict, pandemic and climate are exacerbated by decreased food security, access to health services and workers. Digital technology can impact diseases through physical and mental health effects and access to health information and services. The COVID-19 pandemic and related mitigating strategies are mostly associated with an increased risk of developing new or worsening existing ocular surface diseases. Societal factors impact the type and severity of ocular surface diseases, although there is considerable interdependence between factors. The overlay of the digital environment, natural disasters, conflict and the pandemic have modified access to services in some regions.

Conjunctival and Limbal Conjunctival Autograft vs. Amniotic Membrane Graft in Primary Pterygium Surgery: A 30-Year Comprehensive Review

INTRODUCTION

The purpose of this study is to compare the "real-life" effectiveness of amniotic membrane graft (AMG) and conjunctival (CAT) or limbal conjunctival (LCA) autograft in the management of primary pterygium.

METHODS

Human-based studies on primary pterygium surgery that were published between 1993 and 2022 with at least 3 months of follow-up were identified, and only those that were retrospective were included. The global recurrence rate of pterygium was assessed for each surgical technique separately. Specific recurrence rates taking into consideration the fixation technique (glue versus sutures) were also measured.

RESULTS

35 real-life retrospective subgroups comprising a total of 3747 eyes were included in the final review. The mean global recurrence rates for CAT, LCA and AMG were 7.61%, 5.50% and 9.0%, respectively. Recurrences were less common for patients who received fibrin glue (5.92%, 2.56% and 3.60%) than for those who received sutures (8.99%, 6.03% and 23.0%) for the three groups, respectively. Surgical techniques combining CAT or LCA with AMG yielded an even lower global recurrence rate (1.83%).

CONCLUSION

AMG seems like a reasonable option that could be considered in primary pterygium surgery, especially when glued to the underlying sclera. Combining AMG with other treatment modalities such as CAT or LCA seems to offer an interesting alternative in terms of recurrence.

The effects of exposure to solar radiation on human health

This assessment by the Environmental Effects Assessment Panel (EEAP) of the Montreal Protocol under the United Nations Environment Programme (UNEP) evaluates the effects of ultraviolet (UV) radiation on human health within the context of the Montreal Protocol and its Amendments. We assess work published since our last comprehensive assessment in 2018. Over the last four years gains have been made in knowledge of the links between sun exposure and health outcomes, mechanisms, and estimates of disease burden, including economic impacts. Of particular note, there is new information about the way in which exposure to UV radiation modulates the immune system, causing both harms and benefits for health. The burden of skin cancer remains high, with many lives lost to melanoma and many more people treated for keratinocyte cancer, but it has been estimated that the Montreal Protocol will prevent 11 million cases of melanoma and 432 million cases of keratinocyte cancer that would otherwise have occurred in the United States in people born between 1890 and 2100. While the incidence of skin cancer continues to rise, rates have stabilised in younger populations in some countries. Mortality has also plateaued, partly due to the use of systemic therapies for advanced disease. However, these therapies are very expensive, contributing to the extremely high economic burden of skin cancer, and emphasising the importance and comparative cost-effectiveness of prevention. Photodermatoses, inflammatory skin conditions induced by exposure to UV radiation, can have a marked detrimental impact on the quality of life of sufferers. More information is emerging about their potential link with commonly used drugs, particularly anti-hypertensives. The eyes are also harmed by over-exposure to UV radiation. The incidence of cataract and pterygium is continuing to rise, and there is now evidence of a link between intraocular melanoma and sun exposure. It has been estimated that the Montreal Protocol will prevent 63 million cases of cataract that would otherwise have occurred in the United States in people born between 1890 and 2100. Despite the clearly established harms, exposure to UV radiation also has benefits for human health. While the best recognised benefit is production of vitamin D, beneficial effects mediated by factors other than vitamin D are emerging. For both sun exposure and vitamin D, there is increasingly convincing evidence of a positive role in diseases related to immune function, including both autoimmune diseases and infection. With its influence on the intensity of UV radiation and global warming, the Montreal Protocol has, and will have, both direct and indirect effects on human health, potentially changing the balance of the risks and benefits of spending time outdoors.

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.

Cryopreserved Amniotic Membrane Using the TissueTuck Technique: A Sutureless Approach for Pterygium Surgery

PURPOSE

The purpose of this study was to evaluate the clinical outcomes of the TissueTuck technique in the management of pterygium.

METHODS

This was a single-center, retrospective review of patients with primary or recurrent pterygium that underwent surgical excision followed by application of cryopreserved amniotic membrane (AM) using the TissueTuck technique. All patients underwent surgery between January 2012 and May 2019. Patient profile, surgical time, complications, and rates of pterygium recurrence were analyzed.

RESULTS

A total of 582 eyes of 453 patients (328 female patients; 65.1 ± 13.9 years) were included for analysis and initially presented with primary (92%) pterygium. The average duration of pterygium excision surgery was 14.7 ± 5.2 minutes (median: 14, range: 4-39 minutes) with mitomycin C administration in 257 (45%) eyes. At the last follow-up of 30.2 ± 22.2 months (median: 24.5, range: 3-94 months), BCVA significantly improved from logMAR 0.23 at baseline to logMAR 0.19 ( P < 0.0001). Recurrence rate was 2.3% but only 0.7% (2/274) in those cases with primary, single-headed pterygium without mitomycin C treatment. Other postoperative complications in that cohort included granuloma (7.9%), scarring (3.8%), and diplopia in extreme lateral gaze (2.5%). The AM remained secured to the ocular surface throughout the postoperative period.

CONCLUSIONS

The TissueTuck surgical technique with cryopreserved AM can be performed in minimal time and result in a low recurrence and complication rate after pterygium surgery.

Prevalence and associated factors for pterygium in a Chinese rural population with type 2 diabetes in a cross-sectional study: Jiangsu Diabetic Eye Disease Study (JDEDS)

PURPOSE

To investigate the pterygium prevalence and evaluate risk factors of pterygium in rural type 2 diabetic (D2M) patients aged 50 years and above in Funing Country, Jiangsu Province, China.

METHODS

A cross-sectional ophthalmic survey was conducted in type 2 diabetes mellitus (D2M) patients aged ≥ 50 years in Funing County, Jiangsu Province, China, which was named Jiangsu Diabetic Eye Disease Study (JDEDS). All participants underwent a comprehensive questionnaire and ocular examination. Pterygium was diagnosed by slit lamp examination. The risk factors associated with pterygium were evaluated with logistic regression models.

RESULTS

The prevalence of pterygium was 22.37% (n = 427) and 95% confidence interval (CI) (20.50-24.24%) in D2M patients aged 50 years and above in JDEDS. The prevalence of pterygium was 18.32% (95% CI 15.33-21.32%) in men and 24.43% (95% CI 22.06-26.80%) in women. Women had a higher prevalence than men (p = 0.001). Multivariate analysis showed, for male participants with D2M, pterygium was independently associated with increasing age [70-79 years: OR and 95% CI 2.49(1.20-5.18), p = 0.014; ≥ 80 years: 4.84(2.04-11.47), p < 0.001], while cigarette smoking was the protective factors, especially in current smoker [OR and 95% CI 0.79(0.67-0.92); p = 0.003]. For female participants with D2M, age [60-69 years OR and 95% CI 1.68(1.07-2.62), p = 0.023; 70-79 years: 2.62(1.69-4.06), p < 0.001; ≥ 80 years:3.24(1.70-5.90), p < 0.001], hypertension [OR and 95% CI 1.40(1.05-1.87), p = 0.024], BMI 24-27.9 [OR and 95% CI 1.20(1.00-1.44), p = 0.047], higher HbA1c [(5.6-7.9) % OR and 95% CI 1.42(1.10-1.82), p = 0.006; (8.0-9.9) %: 1.32(1.10-1.58), p = 0.003] were risk factors.

CONCLUSIONS

D2M patients aged over 50 years has a high prevalence of pterygium in JDEDS. The pterygium prevalence is higher in female D2M participants. Diabetes and related factors may be risk factors of pterygium in female D2M patients. Further studies are needed to explore the gender difference in the pathogenesis of pterygium in D2M subjects.

[Correction of refractive disorders after surgical treatment of recurrent pterygium (case study)]

Lamellar keratoplasty is the most effective and safe method of surgical treatment of recurrent pterygium, providing restoration of the corneal frame and optical properties and a high anti-relapse effect due to the barrier properties of the lamellar graft. However, potential postoperative changes in the regularity of the anterior and posterior surfaces of the cornea (especially in case of advanced stage of fibrovascular tissue growth) do not always allow achieving high functional results of treatment. The article presents a clinical case that demonstrates the effectiveness and safety of excimer laser correction of refractive disorders after surgical treatment of pterygium.

Advances in artificial intelligence applications for ocular surface diseases diagnosis

In recent years, with the rapid development of computer technology, continual optimization of various learning algorithms and architectures, and establishment of numerous large databases, artificial intelligence (AI) has been unprecedentedly developed and applied in the field of ophthalmology. In the past, ophthalmological AI research mainly focused on posterior segment diseases, such as diabetic retinopathy, retinopathy of prematurity, age-related macular degeneration, retinal vein occlusion, and glaucoma optic neuropathy. Meanwhile, an increasing number of studies have employed AI to diagnose ocular surface diseases. In this review, we summarize the research progress of AI in the diagnosis of several ocular surface diseases, namely keratitis, keratoconus, dry eye, and pterygium. We discuss the limitations and challenges of AI in the diagnosis of ocular surface diseases, as well as prospects for the future.

Deep learning algorithms for automatic detection of pterygium using anterior segment photographs from slit-lamp and hand-held cameras

BACKGROUND/AIMS

To evaluate the performances of deep learning (DL) algorithms for detection of presence and extent pterygium, based on colour anterior segment photographs (ASPs) taken from slit-lamp and hand-held cameras.

METHODS

Referable pterygium was defined as having extension towards the cornea from the limbus of >2.50 mm or base width at the limbus of >5.00 mm. 2503 images from the Singapore Epidemiology of Eye Diseases (SEED) study were used as the development set. Algorithms were validated on an internal set from the SEED cohort (629 images (55.3% pterygium, 8.4% referable pterygium)), and tested on two external clinic-based sets (set 1 with 2610 images (2.8% pterygium, 0.7% referable pterygium, from slit-lamp ASP); and set 2 with 3701 images, 2.5% pterygium, 0.9% referable pterygium, from hand-held ASP).

RESULTS

The algorithm's area under the receiver operating characteristic curve (AUROC) for detection of any pterygium was 99.5%(sensitivity=98.6%; specificity=99.0%) in internal test set, 99.1% (sensitivity=95.9%, specificity=98.5%) in external test set 1 and 99.7% (sensitivity=100.0%; specificity=88.3%) in external test set 2. For referable pterygium, the algorithm's AUROC was 98.5% (sensitivity=94.0%; specificity=95.3%) in internal test set, 99.7% (sensitivity=87.2%; specificity=99.4%) in external set 1 and 99.0% (sensitivity=94.3%; specificity=98.0%) in external set 2.

CONCLUSION

DL algorithms based on ASPs can detect presence of and referable-level pterygium with optimal sensitivity and specificity. These algorithms, particularly if used with a handheld camera, may potentially be used as a simple screening tool for detection of referable pterygium. Further validation in community setting is warranted.

SYNOPSIS/PRECIS

DL algorithms based on ASPs can detect presence of and referable-level pterygium optimally, and may be used as a simple screening tool for the detection of referable pterygium in community screenings.

Preoperative Intralesional Bevacizumab Injection in Primary Pterygium in Tunisian Patients: A Randomized Controlled Prospective Study

Purpose

To assess the efficacy and safety of a single preoperative intralesional bevacizumab injection as an adjuvant treatment before primary pterygium surgery.

Methods

We conducted a randomized controlled interventional study from January 2019 to December 2020. The study included a total of 60 patients (60 eyes) with primary pterygium. We defined two groups of 30 patients each. Group A received an intralesional injection of bevacizumab (Avastin), 1 month before surgery (lesion excision and conjunctival autograft). Group B (control) had only the surgical treatment. Patients were followed up 7 days (D7), 1 month (M1), 3 months (M3), and 6 months (M6) postoperatively. Pre-, per-, and postoperatively, photographs of the lesions were taken, as well as a histopathological examination. The main outcome measures were the change in functional discomfort following intralesional bevacizumab injection and pterygium recurrence. Recurrence was defined as fibrovascular tissue growth invading the cornea. Therapeutic success was defined as the absence of pterygium recurrence in M6.

Results

The mean age of the 60 patients was 54.17 ± 10.53. After bevacizumab injection, the preoperative functional discomfort score decreased significantly (P = 0.048). There was a significant improvement in grade and color intensity (P = 0.001). We noted no local nor systemic complications after intralesional injection of bevacizumab. After pterygium excision, the success rate was statistically higher in Group A (P = 0.047). There was no significant difference in either final best-corrected spectral visual acuity or astigmatism between the two groups. We noted a statistically significant association between recurrence and color intensity (P = 0.046), vascular density (P = 0.049), and the degree of elastic tissue degeneration (P = 0.040).

Conclusion

A single preoperative subconjunctival injection of bevacizumab 1 month before surgery decreases the vascularity of newly formed blood vessels and hence may reduce the recurrence rate.

Amniotic membrane transplantation and conjunctival autograft combined with mitomycin C for the management of primary pterygium: A systematic review and meta-analysis

Background

Pterygium is a common ocular surface disease. Recurrence is the greatest concern in the treatment of pterygium. Thus, a standardized and effective treatment modality with minimal risk for complications is needed for the management of pterygium. The aim of this systematic review and meta-analysis was to evaluate different tissue grafting options, including conjunctival autograft (CAG) with mitomycin C (MMC), CAG alone, and amniotic membrane transplantation (AMT), for the management of primary pterygium.

Methods

We searched the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases for relevant studies. We included randomized controlled trials (RCTs) in which CAG + MMC and AMT were compared with surgical excision with CAG alone for the treatment of primary pterygium. The rates of recurrence and adverse events reported in the studies were also evaluated. Risk ratio (RR) was used to represent dichotomous outcomes. The data were pooled using the inverse variance weighting method. The quality of the evidence derived from the analysis was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Risk of bias was assessed using the revised Cochrane risk-of-bias tool for randomized trials.

Results

Twelve RCTs (n = 1144) were deemed eligible and included for analysis. Five RCTs had a low risk of bias, five had some concerns, and two had a high risk of bias. Subgroup analysis showed a statistically significant reduction in the rate of pterygium recurrence after CAG + MMC (RR = 0.12; 95% confidence interval [CI], 0.02–0.63). This outcome was rated as high-quality evidence according to the GRADE criteria. There were insignificant differences between the rates of recurrence after AMT and CAG (RR = 1.51; 95% CI, 0.63–3.65). However, this result was rated as low-quality evidence. Regarding adverse events, patients treated using AMT showed significantly lower rates of adverse events than those treated using CAG (RR = 0.46; 95% CI, 0.22–0.95). However, this finding was rated as low-quality evidence as well. CAG + MMC showed a safety profile comparable to that of surgical excision with CAG alone (RR = 1.81; 95% CI, 0.40–8.31). This result was also rated as low-quality evidence.

Conclusion

A single intraoperative topical application of 0.02% MMC during excision of pterygium followed by CAG has significantly shown to decrease the rate of pterygium recurrence to 1.4% with no severe complications.

The effect of pterygium surgery on intraocular lens power and ocular biometric parameters

AIMS

To evaluate the effect of pterygium surgery on intraocular lens (IOL) power and ocular biometric parameters and to evaluate the factors affecting these parameters.

METHODS

Twenty-eight eyes of 25 patients diagnosed with pterygium were evaluated. Axial length (AL), mean keratometry (Sim K), K1, K2, anterior chamber depth (ACD), corneal astigmatism, and ocular biometry parameters were obtained with a dual Scheimpflug analyzer. Pterygium sizes (horizontal, vertical) were measured manually, and pterygium height was analyzed with anterior segment optic coherence tomography. IOL power was calculated according to SRK/T, SRK II, Hoffer Q, Haigis, and Holladay formulas. Limbal conjunctival autograft was performed in all patients after excisional pterygium surgery. Preoperative and postoperative 1st month measurements were analyzed and compared.

RESULTS

The mean age of the patients was 51.5 ± 13.8 years. Mean horizontal pterygium length, vertical width, height, and percentage extension of the pterygium were 2.4 ± 0.9, 4.7 ± 1.0 mm, 297 ± 93µm, and 20.2 ± 7.2%, respectively. There was a significant increase in Sim K, K1, and K2 values postoperatively. Postoperative IOL power was significantly lower than preoperative values in all formulas. The change in IOL power after surgery was -0.3 ± 0.6D in the SRKT, -0.3 ± 0.5D in SRK II, -0.4 ± 0.7D in Hoffer Q, -0.5±0.7D in Haigis, and -0.3 ± 0.7D in Holladay 2 formulas. The change in IOL power has a moderate positive linear correlation with the horizontal and vertical sizes of the pterygium and a high positive linear correlation with the percentage extension of the pterygium.

CONCLUSIONS

Pterygium surgery causes a significant decrease in calculated IOL power obtained with all formulas. It becomes more pronounced with the increase in the size of the pterygium.

Fibroblast Growth Factor-2 (FGF-2) Expression in Pterygia Using Cell Spot Arrays

Fibroblast growth factor (FGF) is a main regulator of cell differentiation, cell migration and angiogenesis in normal and abnormal conjunctiva epithelia, but specific mechanisms of its aberrant expression are yet to be investigated. In the present study, we investigated FGF-2 protein expression within several pterygia. Using a liquid-based cytology assay, we obtained cell specimens from pterygia and healthy tissues directly from patients. A combination of immunocytochemistry followed by digital image analysis showed significant overexpression of FGF-2 in all the examined pterygia. In 30/60 (50%) cases there were high levels of staining intensity, whereas in the remaining 30/60 (50%) cases there were moderate levels of expression. FGF-2 levels of the control group were significantly lower in comparison with the pterygia group. There was no significant correlation between FGF-2 levels and either sex or location of the pterygium. FGF-2 levels had a significant correlation with morphological characteristics of the pterygia. More specifically, FGF-2 levels were significantly higher in the pterygia with a fleshy morphology. Interestingly, recurrent lesions demonstrated high expression levels. An overexpression of FGF-2 has been observed frequently in pterygia, where it may play a crucial role in determining the lesion’s progression. FGF-2 upregulation correlates with the morphology of pterygia and its tendency to recur. Cell spot analysis based on liquid-based cytology is a simple, yet effective, method for detecting a broad spectrum of protein markers and could be useful in analyzing potential pterygia patient samples.

Evaluating the Efficacy and Safety of Different Pterygium Surgeries: A Review of the Literature

The search for the "gold standard" in the surgical treatment of pterygium has been ongoing for over two decades. Despite the development of various surgical techniques, recurrence rates range from 6.7% to 88% depending on the method used. This review discusses the latest and most commonly used methods for the surgical removal of pterygium, primarily focusing on efficacy and safety. Moreover, this review includes articles that either evaluated or compared surgical methods and clinical trials for primary and recurrent pterygium. Limited data are available on combined methods as well as on the efficacy of adjuvant treatment. The use of adjuvant intraoperative mitomycin C (MMC) and conjunctival autografting (CAU) are the two most highly recommended options, as they have the lowest rates of postoperative recurrence.

Morphometric Measurement of Pterygium with Anterior Segment Optical Coherence Tomography and Relationship with Astigmatism

Purpose: We used anterior segment optical coherence tomography (AS-OCT) to measure the pterygial subepithelial invasion length and thickness before and after surgery, and to evaluate the corneal epithelium and the extent of astigmatism.Methods: This was a retrospective study. Ten eyes that underwent pterygial excision surgery were analyzed. We used corneal topographic data to assess astigmatism before surgery and employed AS-OCT to measure corneal epithelial thickness and the length of subepithelial invasion. We measured the relative pterygial length, width, and area on anterior segment photographs. Corneal topographic assessment and AS-OCT were repeated 1 month after surgery. Multiple regression and Pearson correlation analyses were used to analyze the relationships between normalization of astigmatism and the size and thickness of the excised pterygium.Results: The mean With-the-Rule proportion of preoperative astigmatism was 2.9 ± 2.3 D and the mean corneal epithelial thickness 269.60 ± 84.17 µm. The mean thickness of the excised pterygia was 210.73 ± 80.36 µm. Pterygial thickness was significantly associated with the extent of preoperative With-the-Rule astigmatism and the normalized With-the-Rule astigmatism after pterygial excision. These correlations were stronger than those of the relative pterygial length, width, and area. The mean subepithelial invasion length was 595.00 ± 310.32 µm.Conclusions: An increase in pterygial epithelial thickness influenced the extent of With-the-Rule astigmatism to a much greater extent than did the relative pterygial length, width, and area. AS-OCT measurement of the subepithelial invasion length identifies the required excisional area prior to surgery.

Weather-Related Human Outdoor Behavior with Respect to Solar Ultraviolet Radiation Exposure in a Changing Climate

Climate-related changes in human sun exposure behavior can be an important influence on future ultraviolet radiation (UVR) related disease risks. In particular, active leisure mobility and leisure activities are more dependent on weather conditions than routine activities. However, the direction and extent of the effects vary. For temperate and cold climates, the available studies provide indications that a possible increase in UVR exposure would primarily result from a reduction in clothing and only secondarily from changes in the time spent outdoors. Existing studies suggest a nonlinear, bell-shaped relationship with threshold value effects for the relationship between outdoor time and thermal conditions. If the local climate is already very warm and there are only minor seasonal differences, there is no statistically significant evidence of changes in behavior. If there is significant warm discomfort, there is a tendency to avoid being outdoors or in the sun. It is not justified to simply transfer and generalize results and conclusions to different climates and seasons and between different leisure activities and forms of active mobility. The geographical context must be considered also in terms of cultures and habits, adaptations, traffic and land use (urban, rural). In addition, changes in behavior can develop differently depending on individual characteristics of people such as heat affinity, leisure type, age and gender. Differentiated analyses are required that take into account and balance opposing effects.

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.

Decreased Macular Retinal Thickness in Patients With Pterygium

Purpose

To explore alterations in macular retinal thickness (RT) and analyze correlation between macular RT and pterygium area, length in pterygium patients.

Methods

Totally 13 patients with pterygium (left eye) and 13 healthy controls (left eye) were recruited. OCTA was applied to scan each eye to generate three-dimensional images. Based on the Early Treatment Diabetic Retinopathy Study (ETDRS) method, each image was divided into nine subregions for the ETDRS: central (C); inner superior (IS); outer superior (OS); inner nasal (IN); outer nasal (ON); inner inferior (II); outer inferior (OI); inner temporal (IT); and outer temporal (OT). The macular RT in each subregion was measured. Furthermore, the correlation between RT and the area, length of pterygium was analyzed.

Results

The visual acuity of pterygium patient was different from that of the control (P < 0.05). Besides, decreased intraretinal thickness of the IN and ON, increased intraretinal thickness of OT, decreased extraretinal thickness of OT, IN, ON, OS, and decreased retinal full layer thickness of medial superior, OS, IN, ON, and II subregions in pterygium group were observed. There was a negative correlation between RT of the IN and ON subregions and the length of pterygium (r = -0.5803 and r = -0.6013, P = 0.0376 and P = 0.0297). The RT of IN subregion was negatively correlated with pterygium area (r = -0.5844, P = 0.0359). According to the receiver operating characteristic analysis, in the ON subregion, the areas under the curve of the inner retinal thickness, outer retinal thickness and the whole retinal thickness were 1.0 (95% CI: 1.0), 0.882 (95% CI: 0.715 and 0.963), and 1.0 (95% CI: 1.0). The smallest area under the curve of retinal thickness in OT subregion was 0.018 (95% CI: 0-0.059).

Conclusion

RT of pterygium patients was significantly decreased, and the main alterations occurred in the temporal side suggesting there might exist retinal structural alterations in pterygium.

Host Defense Peptides at the Ocular Surface: Roles in Health and Major Diseases, and Therapeutic Potentials

Sight is arguably the most important sense in human. Being constantly exposed to the environmental stress, irritants and pathogens, the ocular surface – a specialized functional and anatomical unit composed of tear film, conjunctival and corneal epithelium, lacrimal glands, meibomian glands, and nasolacrimal drainage apparatus – serves as a crucial front-line defense of the eye. Host defense peptides (HDPs), also known as antimicrobial peptides, are evolutionarily conserved molecular components of innate immunity that are found in all classes of life. Since the first discovery of lysozyme in 1922, a wide range of HDPs have been identified at the ocular surface. In addition to their antimicrobial activity, HDPs are increasingly recognized for their wide array of biological functions, including anti-biofilm, immunomodulation, wound healing, and anti-cancer properties. In this review, we provide an updated review on: (1) spectrum and expression of HDPs at the ocular surface; (2) participation of HDPs in ocular surface diseases/conditions such as infectious keratitis, conjunctivitis, dry eye disease, keratoconus, allergic eye disease, rosacea keratitis, and post-ocular surgery; (3) HDPs that are currently in the development pipeline for treatment of ocular diseases and infections; and (4) future potential of HDP-based clinical pharmacotherapy for ocular diseases.

High HDL-C and high LDL-C are risk factors of pterygium in a population-based cross-sectional study in Southern China: the Dongguan Eye Study

OBJECTIVES

To investigate the relationship between serum lipids and pterygium in a large-scale rural population aged 40 years or older from Southern China.

STUDY DESIGN

The Dongguan Eye Study was a cross-sectional population-based study from September 2011 to February 2012.

SETTING

The area was set in the rural area of Dongguan, Southern China.

PARTICIPANTS

Adult rural population aged 40 or older.

METHODS

Participants underwent physical, haematological and ophthalmic examinations.

PRIMARY AND SECONDARY OUTCOME MEASURES

The frequency and risk factors of pterygium.

RESULTS

A total of 11 357 participants were eligible for inclusion and 8952 (78.8%) participants were enrolled for the systemic and ophthalmic examinations. The prevalence of pterygium was 17.3% after adjusting the sex and age distribution, 22.0% in participants with hypercholesterolaemia (total cholesterol ≥6.22 mmol/L (240 mg/dL)) and 21.8% in those with low-density lipoprotein-cholesterol (LDL-C) ≥4.14 mmol/L (160 mg/dL), respectively. After adjusting for multiple confounding factors, higher level of high-density lipoprotein-cholesterol (HDL-C) (OR: 1.23, 95% CI: 1.06 to 1.41) and LDL-C (OR: 1.13, 95% CI: 1.06 to 1.20) were positively associated with the risk of pterygium. The ORs for HDL-C or LDL-C with pterygium were significantly greater in participants aged 40-49 years than those aged 50 years or above (P for interaction <0.001). Furthermore, increased HDL-C showed greater association with pterygium in normal body mass index (BMI) group compared with overweight group (P for interaction=0.002).

CONCLUSION

Increased HDL-C and LDL-C are risk factors of pterygium, especially in people <50 years or those with normal BMI level. Strict control of HDL-C and LDL-C may be a new prevention method in reducing the risk of pterygium.

Repeated use of fibrin sealants kept at room temperature in conjunctival autografting: An animal study

Purpose:

In this study, our aim was to investigate if fibrin adhesives used in conjunctival wound surgery with autologous conjunctival grafts could be used repeatedly at different times after surgical opening.

Methods:

40 New Zealand rabbits were used in the study. These animals were divided into four groups, each consisting of 10 rabbits, and hence 20 eyes. In the first group (control group), Tisseel fibrin sealant was used on the day the eye was first opened surgically; in the second group, it was used on the seventh day; on the third group, it was used on the 14^th day; and in the fourth group, it was used 28 days after surgical opening. The graft from the inferior bulbar conjunctiva was attached using Tisseel fibrin glue to the superior scleral bed at the location where the superior bulbar conjunctiva was excised in the same eye.

Results:

No microbial growth was detected in the cultures of the samples tested. There were two partial graft loss in group 2 and there was one partial graft loss in each group of the other groups, and further total graft loss was present in one rabbit in group 3. None of the rabbits had any complications like granuloma, Corneal dellen or infection.

Conclusion:

Based on these results, fibrin sealants can be used repeatedly by storing them at room temperature. Repeated use of fibrin adhesives will reduce the cost of ophthalmologic surgeries and non-ophthalmologic surgeries.

Evaluation of the Efficacy of Different Pterygium Surgeries in Polish Caucasian Population

The aim of the study was to compare the efficacy of the two most commonly used surgical methods for pterygium removal in the Polish population, conjunctival autograft versus amniotic membrane transplantation, and to evaluate the postoperative recurrence rate. A retrospective analysis of the medical records was conducted, including 65 patients who underwent surgery for primary or recurrent pterygium at an ophthalmology clinic in Bialystok, Poland, between 2016 and 2020. Surgical success (no regrowth) was achieved in almost half of the amniotic membrane patients (44%) and in most of the conjunctival autograft patients (79%), with statistical significance. The odds of successful surgery were 79% lower for subjects with amniotic membranes than for those with conjunctival autografts (OR with 95% CI = 0.21 (0.05; 0.94); $p=0.045$ ). Our study confirms that the conjunctival autograft surgeries present more favorable success rates in Polish Caucasian population when compared to procedures involving amniotic membranes.

Application of a Deep Learning System in Pterygium Grading and Further Prediction of Recurrence with Slit Lamp Photographs

Background: The aim of this study was to evaluate the efficacy of a deep learning system in pterygium grading and recurrence prediction. Methods: This was a single center, retrospective study. Slit-lamp photographs, from patients with or without pterygium, were collected to develop an algorithm. Demographic data, including age, gender, laterality, grading, and pterygium area, recurrence, and surgical methods were recorded. Complex ocular surface diseases and pseudopterygium were excluded. Performance of the algorithm was evaluated by sensitivity, specificity, F1 score, accuracy, and area under the receiver operating characteristic curve. Confusion matrices and heatmaps were created to help explain the results. Results: A total of 237 eyes were enrolled, of which 176 eyes had pterygium and 61 were non-pterygium eyes. The training set and testing set were comprised of 189 and 48 photographs, respectively. In pterygium grading, sensitivity, specificity, F1 score, and accuracy were 80% to 91.67%, 91.67% to 100%, 81.82% to 94.34%, and 86.67% to 91.67%, respectively. In the prediction model, our results showed sensitivity, specificity, positive predictive value, and negative predictive values were 66.67%, 81.82%, 33.33%, and 94.74%, respectively. Conclusions: Deep learning systems can be useful in pterygium grading based on slit lamp photographs. When clinical parameters involved in the prediction of pterygium recurrence were included, the algorithm showed higher specificity and negative predictive value in prediction.

Atypical U3 snoRNA Suppresses the Process of Pterygium Through Modulating 18S Ribosomal RNA Synthesis

Background

The progression and recurrence of pterygium mainly occur due to the abnormal proliferation and migration of stromal pterygium fibroblasts. This research explores the aberrant expression of small nucleolar RNA U3 (U3 snoRNA) in pterygium and elucidates the molecular mechanisms of U3 snoRNA in pterygium development.

Methods

Primary human conjunctival fibroblasts (HCFs) and human pterygium fibroblasts (HPFs) were separated and cultured from fresh conjunctiva grafts and pterygium tissues. The PLKO.1 lentiviral system and CRISPR/Cas9 recombinant construct were, respectively, used to overexpress and silence U3 snoRNA in HPFs and HCFs for further specific phenotype analysis. RNA-seq and TMT-labeled quantitative protein mass spectrometry were utilized to evaluate the effect of U3 snoRNA on mRNA transcripts and protein synthesis.

Results

Reduced U3 snoRNA in pterygium promotes HCF or HPF cells’ proliferation, migration, and cell cycle but has no significant effect on apoptosis. U3 snoRNA modulates 18S rRNA synthesis through shearing precursor ribosomal RNA 47S rRNA at the 5′ external transcribed spacer (5′ ETS). Moreover, the altered U3 snoRNA causes mRNA and protein differential expression in HCF or HPF cells.

Conclusions

The atypical U3 snoRNA regulates the translation of specific proteins to exert a suppressive function in pterygium through modulating the 18S rRNA synthesis. Here, we uncover a novel insight into U3 snoRNA biology in the development of pterygium.

Vascular Endothelial Growth Factor expression patterns in non- Human Papillomavirus - related pterygia: an experimental study on cell spot arrays digital analysis

PURPOSE

The role of angiogenic factors -such as vascular endothelial growth factor (VEGF) - in development and progression of pterygia lesions remains under investigation. In the current study, we analyzed VEGF protein expression in a series of pterygia and normal conjunctiva epithelia.

METHODS

Using a liquid based cytology assay, thirty (n = 30) cell specimens were obtained by applying a smooth scraping on conjunctiva epithelia and fixed accordingly. None of them had a history of Human Papillomavirus (HPV) infection. Similarly, the same process was applied also in normal conjunctiva epithelia (n = 10; control group). We constructed five (n = 5) slides each containing eight (n = 8) cell spots. An immunocytochemistry (ICC) assay was implemented. Digital image analysis was also performed for evaluating objectively the corresponding immunostaining intensity levels.

RESULTS

All the examined pterygia cell samples over expressed the marker. High staining intensity levels were detected in 15/30 (50%), whereas the rest 15/30 (50%) demonstrated moderate expression. Overall VEGF expression was statistically significantly higher in pterygia compared to normal conjunctiva epithelia (p=.0001). Concerning the other parameters, VEGF protein expression did not associate with the gender of the patients (p = 0.518), the presence of recurrent lesion (p = 0.311), the anatomical location (p = 0.191) or with their morphology (p = 0.316). Interestingly, the recurrent lesions demonstrated the highest levels of VEGF expression.

CONCLUSIONS

VEGF over expression is a frequent event in pterygia playing a potentially central molecular role in the progression of the lesion. Cell spot array analysis -based on liquid cytology- seems to be an innovative, easy to use technique for analyzing a broad variety of molecules in multiple specimens on the same slide by applying different ICC assays.

A novel lncRNA lnc-PPRL promotes pterygium development by activating PI3K/PDK1 signaling pathway

A sight threatening, pterygium is a common proliferative and degenerative disease of the ocular surface. LncRNAs have been widely studied in the occurrence and development of various diseases, however, the study of lncRNAs in pterygium has just relatively lacking. In the present study, we performed the high-throughput RNA sequencing (HTS) technology to identify differentially expressed lncRNAs in pterygium. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were carried out to forecast the regulatory and functional role of lncRNAs in pterygium. Notably, we identified a novel lncRNA, LOC102724238, which we named pterygium positively-related lncRNA (lnc-PPRL), was up-regulated in pterygium. Lnc-PPRL showed to be preferentially accumulated in cytoplasm, and it can promote cell proliferation, migration and invasion of human pterygium epithelium cells (hPECs). Further study of underlying mechanisms demonstrated that lnc-PPRL may exert its biological effect by activating canonical PI3K/PDK1 pathway, and subsequently promoting the activation of Akt/mTOR signaling pathway and its downstream effectors. Interestingly, lnc-PPRL was also proved to influence YAP nuclear localization. Taken together, our study firstly suggested that the "big molecule" lnc-PPRL have potential as a novel therapeutic target for the prevention and treatment of pterygium.

Ocular surface squamous neoplasia in Northern Thailand: a 16-year review

Purpose

To evaluate clinical characteristics, treatments, and outcomes in patients with ocular surface squamous neoplasia (OSSN) at a tertiary center in Northern Thailand.

Methods

Patients diagnosed with either corneal-conjunctival intraepithelial neoplasia (CIN) or squamous cell carcinoma (SCC) from May 2000 to December 2015, were recruited. The patients’ demographics, symptoms, clinical characteristics, cytopathology, treatments, and outcomes were reviewed.

Results

Overall 171 eyes from 168 patients, 92 eyes were CIN and 79 eyes were SCC. Males were affected in 65.5%. The mean age was 58.8 ± 16.8 (29–99) years. In most cases (60.3%), the tumors were located at the limbus. The most common clinical characteristic was papilliform appearance (46.2%). Human immunodeficiency virus (HIV) infection was found in 37 (22.0%) patients with a mean age of 40.5 ± 7.7 years. The treatments and outcomes were evaluated in 136 eyes whose main initial treatment was wide excision with adjunctive cryotherapy (47.8%), followed by topical mitomycin C (30.9%). The mean follow-up time after treatment was 20.8 ± 2.2 (3–110) months and the recurrence occurred in 18 eyes (13.2%) during the follow-up period. The mean recurrence-free time (months) for CIN was significantly longer than that of SCC (81.3 ± 10.0 [95%CI 61.5 – 101.1] vs 33.2 ± 4.6 [95%CI 24.0 – 42.3], p = 0.030). SCC was the only significant risk factor that influences the recurrence of the tumors with the adjusted hazard ratio of 5.69 (p = 0.005).

Conclusion

OSSN in Northern Thailand usually involved a limbal area and presented as a papilliform mass. HIV infection should be suspected in young patients. CIN had better outcomes after treatments than invasive SCC.