Risk Factors for Recurrence After Pterygium Surgery: An Image Analysis Study

Pterygium recurrence following preoperative topical Mitomycin C and 5-Fluorouracil eyedrops

INTRODUCTION

Various adjuvant therapies have been used to prevent recurrence after pterygium excision. However, no single agent has been proven to be a gold standard for completely preventing recurrence with no associated complications.

PURPOSE

This study aims to compare the recurrence rate following preoperative topical mitomycin C (MMC) and 5-fluorouracil (5-FU) eye drops in pterygium excision surgery.

METHODS

In this interventional longitudinal comparative study, 90 patients with primary pterygium attending the Ophthalmology Clinic were enrolled and randomized into three equal groups of 30 each. Groups A, B, and C received preoperative 0.02% MMC eye drops, 1% 5-FU eyedrops, and placebo treatment respectively for one week before surgery followed by pterygium excision with conjunctival autograft and histopathological analysis. Patients were followed for 6months to identify recurrence.

RESULTS

At the end of the 6months, the recurrence rate in the preoperative MMC group (6.7%) was less than the 5-FU (13.3%) and placebo (20%) groups. The histopathological findings were consistent with pterygium tissues. There were high grades of inflammation, degeneration, and vascularization in both the MMC and 5-FU groups in the specimens which recurred within a period of 6months. Five patients had a novel finding of smooth muscle choristoma tissue with bundles of smooth muscle cells and fat cells clustered among the conjunctival tissue.

CONCLUSION

Based on our study results, we demonstrate that preoperative topical MMC and 5-FU eyedrops have efficacy in reducing recurrence in pterygium surgeries. The eyedrop route of administration has been proven to be an effective and easier alternative, enabling us to monitor for adverse effects of adjuvant drugs. Histopathological evaluation provides indices to predict features of future recurrence in pterygium specimens. This is the first study in which the efficacy of preoperative MMC and 5-FU is studied in eyedrop formulation along with histopathological correlation with recurrence.

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.

HIF1α and HIF2α immunoreactivity in epithelial tissue of primary and recurrent pterygium by immunohistochemical analysis

PURPOSE

Hypoxia-inducible factors (HIFs) are considered to play a significant role in the pathogenesis of pterygium. The aim of this study was to investigate the relative expression or immunoreactivity of HIF1α and HIF2α in the epithelium of primary pterygium, recurrences and healthy conjunctiva.

METHODS

Immunohistochemical staining was performed with antibodies against HIF1α and HIF2α, respectively, on 55/84 primary pterygium specimens, 6/28 recurrences and 20/20 control tissues (healthy conjunctiva).

RESULTS

Immunohistochemical staining revealed lower epithelial immunoreactivity of HIF1α and HIF2α in both primary pterygium (11% and 38%) and recurrences (18% and 21%) when compared to healthy conjunctival tissue (46% and 66%). Differences between immunoreactivity of HIF1α and of HIF2α in primary pterygium and controls were each highly significant (p < .001). Within the group of primary pterygium, epithelial immunoreactivity of HIF2α (38%) was significantly higher than that of HIF1α (11%). In recurrent pterygium and healthy conjunctiva, immunoreactivity levels of HIF2α were higher than those of HIF1α as well; however, differences between both isoforms were not significant.

CONCLUSION

Our study shows evidence that the higher expressed epithelial HIF2α, rather than HIF1α, and the balance between both HIF isoforms might be relevant factors associated with pathogenesis of primary pterygium. Modulation of HIF2α levels and activity may thus offer a new therapeutic approach to the treatment of advancing pterygium where the initial stage with its HIF1-peak has already passed.

Integration of Artificial Intelligence into the Approach for Diagnosis and Monitoring of Dry Eye Disease

Dry eye disease (DED) is one of the most common diseases worldwide that can lead to a significant impairment of quality of life. The diagnosis and treatment of the disease are often challenging because of the lack of correlation between the signs and symptoms, limited reliability of diagnostic tests, and absence of established consensus on the diagnostic criteria. The advancement of machine learning, particularly deep learning technology, has enabled the application of artificial intelligence (AI) in various anterior segment disorders, including DED. Currently, many studies have reported promising results of AI-based algorithms for the accurate diagnosis of DED and precise and reliable assessment of data obtained by imaging devices for DED. Thus, the integration of AI into clinical approaches for DED can enhance diagnostic and therapeutic performance. In this review, in addition to a brief summary of the application of AI in anterior segment diseases, we will provide an overview of studies regarding the application of AI in DED and discuss the recent advances in the integration of AI into the clinical approach for DED.

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.

The Diagnostic Value of Neutrophil to Lymphocyte Ratio as an Effective Biomarker for Eye Disorders: A Meta-Analysis

The neutrophil to lymphocyte ratio (NLR) reflects a dynamic relationship between the innate (neutrophils) and adaptive (lymphocytes) cellular immune response. This systematic review and meta-analysis was conducted to critically evaluate the literature regarding the use of the NLR as a reliable means to detect several ocular disorders. Our study was registered with the PROSPERO (ID: CRD42022314850). Three databases, including PubMed, Embase, Scopus, and the Web of Science, were searched on September 9, 2022, with no restrictions on the article's language. Finally, 32 articles were recognized as eligible for our meta-analysis. We found that patients with eye diseases had significantly elevated levels of NLR in comparison to healthy controls (SMD =0.53, 95% CI =0.35-0.71, P < 0.001). In subgroup analysis, patients with keratoconus (SMD =0.69; 95% CI =0.33-1.05, P < 0.001), glaucoma (SMD =0.56, 95% CI =0.25-0.87, P < 0.001), pterygium (SMD =0.14; 95% CI =0.01-0.26, P < 0.001), and idiopathic epiretinal membrane (SMD =0.14; 95% CI =0.01-0.26, P < 0.001) had higher levels of NLR compared to healthy controls. However, NLR levels of patients with dry eye disease were similar to healthy controls (SMD =0.32, 95% CI = -0.49-1.13, P = 0.435). It can be said that NLR is a valuable marker of systemic inflammation, which is significantly increased in many eye disorders, suggesting that inflammation plays a key role in the pathophysiology of these diseases.

Automated histopathological evaluation of pterygium using artificial intelligence

PURPOSE

This study aimed to evaluate the efficacy of a new automated method for the evaluation of histopathological images of pterygium using artificial intelligence.

METHODS

An in-house software for automated grading of histopathological images was developed. Histopathological images of pterygium (400 images from 40 patients) were analysed using our newly developed software. Manual grading (I-IV), labelled based on an established scoring system, served as the ground truth for training the four-grade classification models. Region of interest segmentation was performed before the classification of grades, which was achieved by the combination of expectation-maximisation and k -nearest neighbours. Fifty-five radiomic features extracted from each image were analysed with feature selection methods to examine the significant features. Five classifiers were evaluated for their ability to predict quantitative grading.

RESULTS

Among the classifier models applied for automated grading in this study, the bagging tree showed the best performance, with a 75.9% true positive rate (TPR) and 75.8% positive predictive value (PPV) in internal validation. In external validation, the method also demonstrated reproducibility, with an 81.3% TPR and 82.0% PPV for the average of four classification grades.

CONCLUSIONS

Our newly developed automated method for quantitative grading of histopathological images of pterygium may be a reliable method for quantitative analysis of histopathological evaluation of pterygium.

Comparison of pterygium recurrence with and without using postsurgical topical cyclosporin a 0.05%: A randomized clinical trial

Purpose:

To evaluate the efficacy of 3-month administration of topical cyclosporin A (CsA) 0.05% on postoperative recurrence after pterygium surgery.

Methods:

In this randomized clinical trial, 78 patients undergoing pterygium surgery (using the rotational conjunctival flap technique with mitomycin C [MMC]) were enrolled and randomly allocated into the control (n = 39) and case (CsA) (n = 39) groups in a single-blind method. The patients were examined on postoperative days 1, 3, and 7 and months 1, 3, and 6, and their best-corrected visual acuity, intraocular pressure, clinical inflammation, postoperative complications, and recurrence were compared.

Results:

The mean age of patients was 53.22 ± 9.99 years; most (57.7%) of them were men. The two groups were not different in terms of demographics, pterygium size, or pterygium grade. The clinical inflammation at the first and third postoperative months was not different between the groups (P = 0.108 and 0.780, respectively). No serious complications were detected; complication rates were not different between the groups (P = 0.99). The recurrence rate was 5.1% in the case group and 7.7%% in the control group (P = 0.99).

Conclusion:

The present study showed no priority for 3-month administration of CsA 0.05% drops on postoperative outcomes, including prevention of pterygium recurrence, complications, and inflammation after the rotational conjunctival autograft technique with MMC.

Comparison of Pterygium Recurrence Rates Between Attending Physicians and Supervised Trainee Residents

PURPOSE

To compare the recurrence rates after pterygium surgery performed by supervised trainee residents and attending physicians.

METHODS

This retrospective study included pterygium surgeries performed by trainee residents and attending physicians in an academic institution in South Texas in the years 2008 to 2019. All residents performed surgeries under direct supervision of an attending physician. Only primary pterygium cases with a minimum postoperative follow-up of 6 months were included. Patients' demographics, primary surgeon, use of conjunctival autograft (CAU) or amniotic membrane graft (AMG), recurrence of pterygium, follow-up length, and complications were recorded.

RESULTS

This study included 240 eyes of 229 patients with a mean age of 55.6 ± 12.3 years (range, 28-91 years). Of these eyes, 100 surgeries were performed by attending physicians (including 87 with CAU and 13 with AMG) and 140 surgeries by trainee residents (including 119 with CAU and 21 with AMG). There were no significant differences between the 2 groups of patients regarding age, sex, and surgical technique (CAU vs. AMG). Patients were followed up for an average of 19.8 ± 15.2 months. No statistically significant differences were found in comparing the rate of pterygium recurrence between attending physicians and residents when using CAU (6.8% vs. 10.0%, respectively; P = 0.42) and AMG (69.2% vs. 47.6%, respectively; P = 0.22). Moreover, there were no significant differences in other postoperative complications between the groups.

CONCLUSIONS

Pterygium recurrence rates were similar between attending physicians and supervised trainee residents. Thus, acceptable outcomes can be expected when pterygium surgery is performed by a supervised ophthalmology resident.

Association between HPV detection in swab samples and tissue specimens and ophthalmic pterygium recurrence

PURPOSE

To investigate the presence of HPV on the ocular surface after surgical excision of HPV infected pterygia and the possible correlation of HPV with pterygium postoperative recurrence.

MATERIALS AND METHODS

Both exfoliative pterygium swab samples and respective tissue specimens were received and analyzed with real-time PCR for the detection of HPV-infected pterygia. In addition, swab samples from patients that had HPV-infected pterygia with no recurrence after 1 year of follow-up, as well as swab samples from patients with healthy conjunctiva, were analyzed.

RESULTS

Forty eyes with pterygium of 40 patients and 40 eyes with normal conjunctiva were included in the study. HPV virus was detected in the tissue specimens of 11 patients (27.5%) and in the swabs of 9 patients (22.5%). The HPV subtypes detected were 33, 39, 45, 56, 59, 66, and 68. The swab test had sensitivity of 81.82% and 100% specificity. In 15 (43%) patients, a bare sclera technique was used for pterygium removal and eleven of these patients showed recurrence of the disease. Surgical excision with use of autologous conjunctival graft was performed in twenty patients and five of them had recurrence. Patients with recurrent disease were 12.41 times more likely to have an HPV-infected pterygium (p = 0.031). Furthermore, from the 11 HPV positive patients, six had no recurrence, 1 year after surgery. In five of them, a swab sample was taken from the site of the surgical excision 1 year after surgery and real-time PCR was negative for HPV presence.

CONCLUSION

Persistence of HPV infection seems to be correlated with postoperative pterygium recurrence. Further investigation with the use of the minimally invasive proposed swab technique may contribute in the understanding of pterygium pathogenesis and in the development of a more efficient treatment planning.

Outcomes of Ipsilateral Simple Limbal Epithelial Transplantation, Tenonectomy, Mitomycin and Amniotic Membrane Transplantation for Treatment of Recurrent Pterygium

PURPOSE

To report on the outcomes of recurrent pterygium treated by ipsilateral simple limbal epithelial transplantation (SLET), mitomycin, tenonectomy, and amniotic membrane transplantation.

METHODS

A retrospective, interventional study was conducted including all patients with recurrent pterygium who underwent SLET surgery under a single surgeon using ipsilateral donor tissue with a minimum 6-month follow-up at Toronto Western Hospital, Canada. Outcome measures included the following: recurrence rates, best spectacle-corrected visual acuity, and postoperative complications.

RESULTS

Ten eyes of 10 patients, aged 60.7 ± 18.5 years (range 23-79) with a mean follow-up time of 15.2 ± 10.0 months of which 50% (n = 5) were men, were included. Eight eyes (80%) had a history of 2 or less pterygium operations. Two patients had 3 and 5 previous pterygium operations, respectively. Concurrent limbal stem cell disease was noted in 6 eyes (60%). Average number of pterygium recurrences per eye was 1.9 ± 1.3 (range 1-5). Mean pre-op best-corrected visual acuity was 0.5 LogMAR (Snellen equivalent 20/60, range 20/20 to counting fingers). Best-corrected visual acuity remained the same or improved in 6 eyes (60%). Recurrence was noted in 1 eye (10%) with a history of 5 previous pterygium excisions and remained stable at the last follow-up. No patients required a second operation.

CONCLUSIONS

Ipsilateral SLET with mitomycin, tenonectomy, and amniotic membrane transplantation is a novel technique to address recurrent pterygium. Concurrent limbal stem cell diseases are often present. Initial results demonstrate low recurrence. Visual improvement is modest. Stabilization of the ocular surface to improve vision is possible.

Characteristics and recurrence of pterygium in Saudi Arabia: a single center study with a long follow-up

Background

This study described the clinical features of patients with pterygium and analyzed the recurrence rate of conjunctival autografting alone, conjunctival autografting combined with intraoperative mitomycin C, and amniotic membrane grafting.

Methods

A retrospective cohort study of primary pterygium was conducted between January 2017 and February 2020. Factors associated with pterygium severity and recurrence were analyzed by univariate analysis and logistic regression models.

Results

The study included 292 patients with an average age of 53.3 ± 14.1 years, while the number of operated cases was 94. Pterygia involving the cornea were observed in 55 % of the cases. The overall rate of recurrence for the three procedures was 17 %. The average time of recurrence was 14.2 ± 11.9 months, with 37 % of the recurrences occurring after the first year. The only factor associated with a significant risk of recurrence was dry eye disease in both univariate (p = 0.021) and multivariate analysis (p = 0.026). The recurrence rates following conjunctival autografting with and without mitomycin C were 15.6 and 15.8 %, respectively. The recurrence rate following the amniotic membrane graft was  twofold (OR= 2.02)  (27 %) that following the conjunctival autograft (15.8 %).

Conclusions

The only factor associated with the recurrence of pterygium was dry eye disease. More than one-third of recurrences developed after the first year, which stresses the importance of a long follow-up. The recurrence rate in our study following conjunctival graft was slightly higher compared to the literature mainly due to differences in study areas, populations, and follow-up periods.

Effect of Topical Brimonidine 0.15% on Conjunctival Injection after Strabismus Surgery in Children

Purpose

To investigate the effects of topical brimonidine 0.15% instillation on conjunctival injection after strabismus surgery in children.

Methods

We retrospectively analyzed 63 Korean children who underwent strabismus surgery for intermittent exotropia. Patients received topical brimonidine 0.15% after surgery for up to 4 weeks. Conjunctival injection was objectively assessed using a software that automatically scored the region of interest from the image of the bulbar conjunctiva. Conjunctival injection scores were compared with those of the control group who were not prescribed topical brimonidine.

Results

The mean scores of conjunctival injection after rectus muscle recession and resection were significantly lower in the brimonidine group than the controls at 4 weeks after surgery (P = 0.008  and  0.046, respectively). There was no significant difference in intraocular pressure between the two groups. No adverse effects, such as dry mouth, fatigue/drowsiness, headache, sedation, hypotension, or bradycardia, were reported.

Conclusions

Administration of topical brimonidine 0.15% after strabismus surgery is efficacious and safe in reducing postoperative conjunctival injection.

Evaluation of Neutrophil-Lymphocyte Ratios, Mean Platelet Volumes, and Platelet-Lymphocyte Ratios in Pterygium

Objectives:

To assess the neutrophil-to-lymphocyte ratio (NLR), mean platelet volumes (MPV), platelet–lymphocyte ratios (PLR) and other complete blood count parameters (CBC) as indicators of inflammation in patients with pterygium.

Methods:

This study was carried out retrospectively in 111 consecutive pterygium patients and 106 control subjects. Laboratory and clinical parameters were obtained from the patient data management system. NLR and PLR were calculated by dividing neutrophil and platelet count by lymphocyte count.

Results:

A significant difference was found in NLR and lymphocyte values between the pterygium and control groups (p<0.05). However, there was no significant difference found in MPV, PLR and other parameters between groups (p>0.05).

Conclusion:

NLR may have an association with pterygium, which should be investigated at larger subgroups in further studies.

Optical Coherence Tomography Angiography for Evaluation of Reperfusion After Pterygium Surgery

PURPOSE

To describe the use of optical coherence tomography angiography (OCTA) to quantitatively monitor the conjunctival graft revascularization after pterygium excision and conjunctival autograft (CAG) transplantation.

DESIGN

Prospective, interventional case series.

METHODS

Ten patients undergoing pterygium excision and femtosecond laser-assisted CAG transplantation were included. OCTA was performed at 1 week, 1 and 3 months postoperatively at the CAG transplantation site and harvested area. The vessel density at three different depths: conjunctival epithelium or CAG epithelium, conjunctival stroma or CAG stroma, and episclera, was evaluated and quantified. The revascularization rate was assessed and correlated with the postoperative CAG thickness.

RESULTS

No intraoperative and postoperative complications occurred. Reperfusion of the CAGs was observed at 1 week, and early reperfusion within the first month accounted for more than half of graft revascularization. The vessel regrowth density was 9.6±2.6 % and 11.1±2.8 % between 1 week and 1 month, and was 9.8±1.8 % and 11.9±1.9 % between 1 and 3 months, at the CAG and underlying episcleral levels, respectively. All the CAGs were well-perfused at 3 months. The vessel regrowth density was significantly and strongly correlated with the changes of CAG thickness in a negative relationship (γ = -0.94, P = 0.019). At the harvested site, the vascular network of episclera was not affected, and the conjunctival vascularization was restored at 1 month.

CONCLUSIONS

OCTA is a promising tool to evaluate the vascularization or revascularization of conjunctiva, conjunctival graft and episclera, in a quantitative and serial manner, helping in diseases diagnosis and treatment monitoring. The graft revascularization rate was predictive of postoperative graft deswelling.

Efficacy of a new automated method for quantification of corneal neovascularisation

BACKGROUND/AIMS

To evaluate the efficacy of a new automated method for quantification of corneal neovascularisation (NV).

METHODS

An in-house software for automated measurement of corneal NV was developed. Anterior segment photographs (ASPs) of 81 consecutive patients with corneal NV were analysed using our newly developed software. Manual measurements were performed by three independent examiners using ImageJ software V.1.48 (National Institute of Health, Bethesda, Maryland, USA). Interobserver reliability of the automated and manual methods, and correlations between the results of both methods were evaluated.

RESULTS

The automated method showed a strong interexaminer reliability (intraclass correlation coefficient (ICC)=0.994), which was slightly better than the manual method (ICC=0.958). A significant correlation was found between the results of both methods (p<0.001 for all three examiners). The time spent for analysis of each ASP was significantly reduced in the automated method compared with the manual method (p<0.001 for all three examiners).

CONCLUSIONS

Our newly developed automated method for quantification of corneal NV was more reproducible and time-saving compared with the manual method. Our method can be useful for diagnosis and monitoring diseases causing corneal NV.

Corneo-pterygium total area measurements utilising image analysis method

PURPOSE

To describe an objective method to accurately quantify corneo-pterygium total area (CPTA) by utilising image analysis method and to evaluate its association with corneal astigmatism (CA).

METHODS

120 primary pterygium participants were selected from patients who visited an ophthalmology clinic. We adopted image analysis software in calculating the size of invading pterygium to the cornea. The marking of the calculated area was done manually, and the total area size was measured in pixel. The computed area is defined as the area from the apex of pterygium to the limbal-corneal border. Then, from the pixel, it was transformed into a percentage (%), which represents the CPTA relative to the entire corneal surface area. Intra- and inter-observer reliability testing were performed by repeating the tracing process twice with a different sequence of images at least one (1) month apart. Intraclass correlation (ICC) and scatter plot were used to describe the reliability of measurement.

RESULTS

The overall mean (N=120) of CPTA was 45.26±13.51% (CI: 42.38-48.36). Reliability for region of interest (ROI) demarcation of CPTA were excellent with intra and inter-agreement of 0.995 (95% CI, 0.994-0.998; P<0.001) and 0.994 (95% CI, 0.992-0.997; P<0.001) respectively. The new method was positively associated with corneal astigmatism (P<0.01). This method was able to predict 37% of the variance in CA compared to 21% using standard method.

CONCLUSIONS

Image analysis method is useful, reliable and practical in the clinical setting to objectively quantify actual pterygium size, shapes and its effects on the anterior corneal curvature.

Cauterisation versus fibrin glue for conjunctival autografting in primary pterygium surgery (CAGE CUP): study protocol of a randomised controlled trial

INTRODUCTION

Pterygium is a non-cancerous growth of the conjunctival tissue over the cornea that may lead to visual impairment in advanced stages, restriction of ocular motility, chronic inflammation and cosmetic concerns. Surgical removal is the treatment of choice, but recurrence of pterygium is a frequent problem. It has been previously shown that fibrin glue may result in less recurrence and may take less time than sutures for fixing the conjunctival graft in place during pterygium surgery. However, fibrin glue is a biological material and it carries the risk of transmitting infectious agents from pooled and single-donor blood donors and anaphylaxis in susceptible individuals. Cauterisation is another surgical option, and it would be advantageous to know whether cauterisation may be superior surgical option compared with fibrin glue. This protocol describes the rationale and design of the randomised controlled trial (RCT) in which we will compare cauterisation versus fibrin glue for conjunctival autografting in primary pterygium surgery.

METHODS AND ANALYSES

This will be a parallel group RCT comparing cauterisation versus fibrin glue for conjunctival autografting in primary pterygium surgery. Computer-generated randomisation will be used, and allocation concealment will be conducted using sequentially numbered opaque sealed envelopes. Surgeons will not be blinded to the procedures, but participants, other investigators and outcome assessors will be blinded. Adult participants with primary pterygium operated in a tertiary hospital in Split, Croatia, will be included. Primary outcome will be recurrence of pterygium, defined as any regrowth of tissue from the area of excision across the limbus onto the cornea after 180 days.

ETHICS AND DISSEMINATION

The trial was approved by the ethics review board of the University Hospital Split (500-03/17-01/68). Results will be disseminated at conferences and through peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03321201; Pre-results.

Conjunctival Autograft Combined With Either Preoperative Mitomycin C Injection or Intraoperative Local Mitomycin C Over the Medial Rectus Muscle Tendon in Primary Pterygium Surgery

PURPOSE

To evaluate and compare the recurrence rate and complications of conjunctival autograft (CAG) combined with preoperative mitomycin C (MMC) injection versus CAG with intraoperative local MMC over the medial rectus muscle tendon in primary pterygium.

STUDY DESIGN

Randomized prospective study.

METHODS

This study included 108 eyes of 108 patients with primary fleshy or growing pterygium. All patients were from rural areas and less than 50 years old. Fifty-three patients were treated with injection of 0.1 mL of 0.15 mg/mL MMC into the body of pterygium followed 1 day later by pterygium excision and CAG (group I), and 55 patients were treated with pterygium excision and local application of 0.2 mg/mL MMC for 2 min over the medial rectus tendon followed by CAG (group II). The minimum follow-up period was 18 months.

RESULTS

Two patients from group I and one patient from group II did not complete the follow-up period and were excluded. There were no statistically significant differences between the two groups regarding age, sex, laterality, or follow-up period. Recurrence occurred in 2 eyes in group I (3.92%) and 1 eye in group II (1.85%); (P=0.52). All recurrences occurred in male patients of less than 30 years of age. No significant complications were encountered in both groups.

CONCLUSIONS

Both preoperative MMC injection followed 1 day later by pterygium excision with CAG, and pterygium excision and intraoperative local application of MMC on the medial rectus tendon are successful in treating primary pterygium with low recurrence rate and few complications.

Low recurrence rate of anchored conjunctival rotation flap technique in pterygium surgery

Background

To report the recurrence rate for an anchored conjunctival rotation flap technique in primary pterygium surgery.

Methods

Primary pterygium surgeries performed using anchored conjunctival rotation flap techniques (110 eyes in 110 patients) with a minimum follow-up of 12 months were reviewed. In this technique, a conjunctival flap is rotated to cover the bare sclera and suture-fixated with either 8–0 polyglactin (41 eyes) or 10–0 nylon (69 eyes). The recurrence rate was determined, and the two suture materials utilized were compared.

Results

The recurrence rate was 2.71% (3 cases in 110 eyes) when an anchored conjunctival rotation flap technique was used and patients were monitored for 26.40 ± 17.09 months. Interestingly, the recurrences were only observed in polyglactin-sutured eyes. No recurrence was detected in nylon-sutured eyes. No other complications were observed in either group.

Conclusions

The anchored conjunctival rotation flap technique for pterygium surgery has a relatively low recurrence rate. Nylon suture-fixation of the flap was found to be superior to polyglactin suture-fixation in preventing recurrence.

Electronic supplementary material

The online version of this article (10.1186/s12886-017-0587-z) contains supplementary material, which is available to authorized users.

Outdoor Air Pollution and Pterygium in Korea

We investigated relationships between outdoor air pollution and pterygium in Korean adults. This study includes 23,276 adults in population-based cross-sectional data using the Korea National Health and Nutrition Examination Survey 2008-2011. Pterygium was assessed using slit lamp biomicroscopy. Air pollution data (humidity, particulate matter with aerodynamic diameter less than 10 μm [PM₁₀], ozone [O₃], nitrogen dioxide [NO₂], and sulfur dioxide levels [SO₂]) for 2 years preceding the ocular examinations were acquired. Associations of multiple air pollutants with pterygium or pterygium recurrence after surgery were examined using multivariate logistic models, after adjusting for several covariates. Distributed lag models were additionally used for estimating cumulative effects of air pollution on pterygium. None of air pollution factors was significantly associated with pterygium or pterygium recurrence (each P > 0.05). Distributed lag models also showed that air pollution factors were not associated with pterygium or pterygium recurrence in 0-to-2 year lags (each P > 0.05). However, primary pterygium showed a weak association with PM10 after adjusting for covariates (odds ratio [OR] 1.23; [per 5 μg/m³ PM₁₀ increase]; P = 0.023). Aging, male sex, and greater sun exposure were associated with pterygium, while higher education level and myopia were negatively associated with pterygium (each P ≤ 0.001). Male sex and myopia were negatively associated with pterygium recurrence (each P < 0.05). In conclusion, exposure to higher PM10 levels was associated with primary pterygium, although this study observed no significant association between air pollution and overall pterygium or pterygium recurrence in Korean adults.