Effect of pterygium morphology on pterygium recurrence in a controlled trial comparing conjunctival autografting with bare sclera excision

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.

Expression of CD44, PCNA and E-cadherin in pterygium tissues

PURPOSE

Pterygium is a common ocular surface disease defined by fibrovascular conjunctival growth extending onto the cornea. However, its pathogenesis remains unclear. This study aimed to determine the role of CD44, proliferating cell nuclear antigen (PCNA), and E-cadherin in pterygium formation and recurrence.

METHODS

Sixty patients with pterygium participated in the study, and we collected conjunctival samples from 30 patients to form a control group. CD44, PCNA, and E-cadherin expressions in surgically excised pterygium were compared with tissue samples from the control group.

RESULTS

We observed that the percentages of CD44 and PCNA were statistically higher in the primary pterygium group and recurrent pterygium group than in the control group (P < 0.001 and P < 0.001, respectively). Conversely, E-cadherin values were statistically higher in the control group than in the primary and recurrent pterygium groups (P = 0.013 and P < 0.001, respectively).

CONCLUSION

Cell proliferation and cell adhesion factors may play important roles in the pathogenesis of pterygium.

Timing optimization for primary pterygium excision with conjunctival-limbal autograft to restore the corneal optical properties

PURPOSE

To propose the optimal value of baseline corneal astigmatism and pterygial morphological profiles for primary pterygium surgery to restore the corneal optical properties.

METHODS

We analysed 93 eyes from 84 subjects with nasal-only primary pterygium who underwent pterygium excision with conjunctival-limbal autograft and were assessed perioperatively using anterior segment swept-source optical coherence tomography (AS SS-OCT). We collected data on anterior corneal astigmatism (ACA) and root mean square (RMS) values for anterior corneal lower- (LoA) and higher-order aberrations (HoA) as corneal optical properties using AS SS-OCT. Using preoperative ACA and four pterygial morphological profiles (horizontal invasion length [HIL], height, thickness and the ratio of residual corneal thickness [RCT] to central corneal thickness [CCT]) measured in AS SS-OCT, we plotted receiver operating characteristic (ROC) curves. These curves aimed to determine cut-off values predicting a perioperative decrease exceeding 50% in ACA, RMS LoA and RMS HoA, as well as postoperative residual ACA higher than 1.25D.

RESULTS

Preoperative ACA > 1.42D (AUC = 0.934) and >3.60D (AUC = 0.946) proved most effective in identifying subjects with perioperative decrease exceeding in ACA and RMS LoA, respectively. HIL > 3.34 mm (AUC = 0.941) was most effective in distinguishing subjects with perioperative reduction exceeding 50% in RMS HoA. Preoperative ACA > 5.78D (AUC = 0.776) and HIL > 5.03 mm (AUC = 0.700) significantly distinguished subjects with postoperative residual ACA higher than 1.25D.

CONCLUSION

Optimizing the restoration of corneal astigmatism and aberrations after pterygium surgery may be facilitated by determining the optimal surgical timing based on preoperative ACA and HIL values.

Subconjunctival dexamethasone-assisted conjunctival autograft harvesting versus normal saline during pterygium surgery - A randomized clinical trial

PURPOSE

To evaluate the effect of subconjunctival dexamethasone compared to normal saline on conjunctival autograft harvesting in patients undergoing pterygium surgery.

METHODS

Fifty-two eyes of 52 patients who underwent pterygium excision combined with autologous conjunctival graft (CAG) using releasable suture were included in this prospective interventional study. The patients were randomized into two groups of 26 patients each. Group A consisted of patients in whom CAG was harvested using subconjunctival 0.5 ml of 0.4% dexamethasone sodium phosphate and in group B patients, normal saline was used. The patients were assessed for postoperative pain, foreign body sensation, and watering as the subjective signs of inflammation and conjunctival inflammation and lid edema as the objective signs of inflammation at 12 and 24 h postsurgery.

RESULTS

The mean age of group A and B patients was 47.69 + 13.09 and 46.00 + 10.76 years, respectively. The male:female ratio was 1.6:1 in group A and 1.1:1 in group B. The mean surgical time in group A was 243.96 ± 52.13 s and in group B was 258.08 ± 43.99 s. Postoperative pain, foreign body sensation, and watering were significantly lower in group A patients than in group B patients at both 12 and 24 h postoperatively (group A: 4.65 ± 1.33, 4.88 ± 1.73, and 3.85 ± 1.43, respectively, at 12 h; 1.89 ± 1.03, 1.69 ± 1.09, and 1.69 ± 0.97, respectively, at 24 h and group B: 6.42 ± 0.95, 6.65 ± 0.98, and 6.27 ± 1.40, respectively, at 12 h; 3.27 ± 1.43, 3.12 ± 1.25, 2.58 ± 1.14, respectively, at 24 h) ( P < 0.001). Conjunctival inflammation was significantly lower in group A at 12 h ( P < 0.05) and 24 h ( P < 0.05) after surgery compared to group B. Lid edema failed to show any significant ( P = 0.17) difference with respect to severity in both the groups at 12 and 24 h ( P = 0.699).

CONCLUSION

Subconjunctival dexamethasone decreased patient discomfort following pterygium surgery. The dexamethasone group had reduced conjunctival inflammatory signs without any notable complications.

DBPF-net: dual-branch structural feature extraction reinforcement network for ocular surface disease image classification

Pterygium and subconjunctival hemorrhage are two common types of ocular surface diseases that can cause distress and anxiety in patients. In this study, 2855 ocular surface images were collected in four categories: normal ocular surface, subconjunctival hemorrhage, pterygium to be observed, and pterygium requiring surgery. We propose a diagnostic classification model for ocular surface diseases, dual-branch network reinforced by PFM block (DBPF-Net), which adopts the conformer model with two-branch architectural properties as the backbone of a four-way classification model for ocular surface diseases. In addition, we propose a block composed of a patch merging layer and a FReLU layer (PFM block) for extracting spatial structure features to further strengthen the feature extraction capability of the model. In practice, only the ocular surface images need to be input into the model to discriminate automatically between the disease categories. We also trained the VGG16, ResNet50, EfficientNetB7, and Conformer models, and evaluated and analyzed the results of all models on the test set. The main evaluation indicators were sensitivity, specificity, F1-score, area under the receiver operating characteristics curve (AUC), kappa coefficient, and accuracy. The accuracy and kappa coefficient of the proposed diagnostic model in several experiments were averaged at 0.9789 and 0.9681, respectively. The sensitivity, specificity, F1-score, and AUC were, respectively, 0.9723, 0.9836, 0.9688, and 0.9869 for diagnosing pterygium to be observed, and, respectively, 0.9210, 0.9905, 0.9292, and 0.9776 for diagnosing pterygium requiring surgery. The proposed method has high clinical reference value for recognizing these four types of ocular surface images.

Comparison of mini-simple limbal epithelial transplantation and conjunctival-limbal autograft for the treatment of primary pterygium: a randomised controlled trial

PURPOSE

The purpose of this double-masked, parallel randomised controlled trial was to compare the recurrence rate and other outcomes between conjunctival-limbal autograft (CLAu) and mini-simple limbal epithelial transplantation (mini-SLET) after excision of pterygium.

METHODS

Eligibility criteria for participants was the presence of a primary nasal pterygium extending equally to or greater than two millimetres on the cornea on its horizontal axis from the nasal limbus. The participants were allocated into two groups (CLAu and mini-SLET) using simple randomisation with a table of random numbers. Participants and the outcome assessor were masked to the intervention. The study protocol is listed and available on https://clinicaltrials.gov (Identifier: NCT03363282).

RESULTS

A total of 61 eyes were enrolled in the study, 33 underwent CLAu (group 1) and 28 mini-SLET (group 2), all eyes were analysed in each group. At 2, 3, 6 and 12 months the CLAu group exhibited a recurrence of 0%, 6.1%, 8.1% and 8.1%, while the mini-SLET exhibited a recurrence of 0%, 17.9%, 50% and 53.5% (p<0.05). There were no intraoperative or postoperative complications in either of the two groups.

CONCLUSION

The findings of this study suggest that mini-SLET has a higher recurrence rate and provides no advantage over CLAu in the treatment of primary pterygium.

Comparison of Keratometric Change Following Various Conjunctival Autografting Techniques in Pterygium Surgery

Aim To compare the postoperative keratometric changes and duration of surgery for different techniques of conjunctival autografting in pterygium surgery. Methods Patients with primary pterygium attending the outpatient department and having appropriate indications for surgery were enrolled. Preoperative ophthalmic examination included visual acuity assessment, refraction, keratometry, slit lamp, and fundus evaluation. Pterygium excision surgery with conjunctival autografting was performed on all patients using one of the four different techniques, namely, sutures, fibrin glue, and the autologous blood and bridge techniques. Duration of surgery was recorded for all patients. Postoperatively, all patients were followed up on Day 1, Day 7, and Months 1, 3, and 6. Duration of surgery, keratometric changes, and recurrence rates were analyzed in all four groups. Results Sixty-eight eyes of 66 patients completed the study protocol. There was a significant reduction in astigmatism after the autologous blood graft technique (P value 0.0055) and the glue technique (P value < 0.0001). The success rate of the autologous and glue technique was 90%. The glue technique was found to be more time efficient (mean duration 20.40 minutes) than other techniques. Conclusion After pterygium excision, conjunctival auto grafting using either autologous blood or glue plays a significant role in reducing pterygium-induced astigmatism and recurrence rates with the added advantage of a shorter operative time.

Modified Limbal-Conjunctival Autograft Surgical Technique: Long-Term Results of Recurrence and Complications

PURPOSE

The aim of this study was to report the recurrence and complication rates of a modified limbal-conjunctival autograft surgical technique for pterygium excision.

METHODS

This was a retrospective, single-surgeon, single-operating environment, consecutive case series of 176 eyes in 163 patients with a biopsy-proven diagnosis of pterygium. All patients underwent excision using a 23-gauge needle to "behead" the pterygium head, followed by a limbal-conjunctival autograft including ∼50% of the palisades of Vogt. Outcomes measured included recurrence, defined as any conjunctival fibrovascular growth, and complication rates. Correlations between preoperative patient characteristics, pterygium morphology, and intraoperative factors (width of corneal extension, conjunctival defect, and graft) with postoperative recurrence were examined using logistic regression models.

RESULTS

The median age was 59.5 years and 122 eyes (69.3%) had primary pterygium (type I: 17%, II: 37.5%, and III: 45.5%). Kaplan-Meier analysis demonstrated the median pterygium-free follow-up period to be 723 days (range 46-7230 days). Recurrence was observed in 3 eyes of 2 patients (1.7%). No postoperative graft-related complications were observed. Postoperative symptomatology was transient. Age demonstrated a negative correlation with recurrence (odds ratio 0.888, 95% CI, 0.789-0.998, P = 0.046). However, no other correlations with preoperative or intraoperative factors, including whether pterygium was primary or recurrent, were identified (all P > 0.05).

CONCLUSIONS

This modified limbal-conjunctival autograft technique represents an effective alternative that offers a very low recurrence rate and avoids extensive dissection or antimetabolites, with minimal complications and transient postoperative symptomatology, over a long-term follow-up period. This technique is relatively simple and successful for both primary and recurrent pterygia. Future comparative studies with other surgical techniques may determine which are superior.

Snatching: A modified cosmetic technique in pterygium surgery without using scalpel

AIM

To evaluate the cosmetic surgical outcomes of primary corneal pterygia excision using the avulsion (snatching) technique.

METHODS

A prospective, interventional study included twenty-five eyes of 25 patients with primary pterygium underwent excision were followed up for at least 6 months. In all patients, snatching (modified avulsion) technique was utilised to avulse the pterygium head off the corneal surface and remove any residual fibres by Colibri without need for keratectomy with a scalpel.

RESULTS

The study involved 25 eyes of 25 patients with an average age of 42.5±56.5 years. The mean follow-up was 6 months. One-week post-op, 8 patients (32%) reported they can tell which is the operated eye but looked untouched while 17 (68%) patients reported that the operated eye looked red but is accepted. Twenty patients (80%) reported some discomfort while the remaining 5 patients (20%) reported no discomfort. Cornea examination showed a clear cornea in 18 eyes (72%), 6 eyes (24%) had mild keratitis, and 1 eye (4%) had clouding at the surgical site. Over an average of six months post-op follow-up period, all the patients (100%) reported they cannot tell which eye had the surgery and none (0%) of them reported discomfort. Examination of the cornea was clear in 24 (96%) eyes, but 1 (4%) eye had mild keratitis.

CONCLUSION

Snatching (modified avulsion) technique was found to be effective, safe, and presents decent aesthetic appearance for the management of primary corneal pterygia when safety points are firmly followed.

Effect of pterygium on corneal astigmatism, irregularity and higher-order aberrations: a comparative study with normal fellow eyes

Pterygium is an abnormal growth of fibrous conjunctival tissue that invades the cornea, resulting in corneal distortion, astigmatism, and increased higher-order aberrations (HOAs). However, few studies have compared eyes with pterygium to normal fellow eyes when interpreting HOAs and there is no study that revealed the effect of the thickness or grading of the pterygium on the change of HOAs. Therefore, we evaluated the effects of nasal pterygium by comparing the normal fellow eye of 59 patients. The pterygium significantly increased with-the-rule corneal astigmatism and corneal irregularity. Trefoils, horizontal coma, and quatrefoils were significantly induced by the pterygium. The grading of the pterygium was not correlated with its characteristics except for the thickness. In multiple linear regression analysis, pterygium-induced corneal astigmatic/irregularity values and horizontal trefoil/quatrefoil were associated with the area of the pterygium. The length of the pterygium was an independent inducer of oblique trefoil/quatrefoil, while horizontal coma was independently associated with both its length and width. The thickness was not correlated with any optical parameters. Together, the results demonstrate that nasal pterygium significantly induces corneal astigmatism, irregularity and some HOAs. These pterygium-associated changes in optical parameters could be predicted by the length, width and area of the pterygium.

[Transplantation of the Bowman's layer in combined treatment of recurrent pterygium]

Pterygium is among the most frequent indications for extraocular ophthalmic surgery. The main method of pterygium treatment - its excision - is often combined with transplantation, non-transplantation, medication and other methods. However, the frequency of pterygium recurrence can exceed 35%, and the cosmetic and refraction outcomes satisfy neither the patient, nor the surgeon.

PURPOSE

The study analyses the technical capability and feasibility for transplantation of the Bowman's layer in the treatment of recurrent pterygium.

MATERIAL AND METHODS

The transplantation of the Bowmen's layer was performed according to the developed technique on 7 eyes with recurrent pterygium (7 patients aged 34 to 63 years). The combined surgery technique consisted of pterygium resection, laser ablation, autoconjunctival plasty, exposure to a cytostatic drug, non-suture transplantation of the Bowman's layer. Maximum length of the follow-up was 36 months. Analysis involved data from refractometry, visometry (without correction and with spectacle correction), and optical coherence tomography of the retina.

RESULTS

There were no complications in any of the studied cases. The cornea and the transplant retained transparency throughout the entire follow-up duration. 36 months after surgery mean spectacle-corrected visual acuity amounted to 0.86±0.2, topographic astigmatism - 1.48±1.4 diopters. Recurrence of pterygium was not observed. All patients were satisfied with the cosmetic outcomes of the treatment.

CONCLUSION

Non-suture transplantation of the Bowmen's layer recovers normal anatomy, physiology and transparency of the cornea after repeat surgical intervention for pterygium. No pterygium recurrences were observed throughout the entire follow-up after treatment with the proposed combined technique.

Topical cyclosporine A and interferon alpha-2b as adjuvants to surgery to decrease pterygium recurrence

BACKGROUND

Pterygium is very common in India and is usually removed by limbal conjunctival autograft transplantation (LCAT), which, despite being the first-line therapy, is still associated with recurrences of up to 18%.

OBJECTIVES

To compare the safety and efficacy of topical cyclosporine A (CsA) and interferon (IFN) alpha-2b in the prevention of postoperative recurrence of pterygium.

METHODS

A total of 40 patients with primary pterygium were randomized into two equal groups, Group C and Group I. Both the groups underwent LCAT, with Group C kept on topical cyclosporine 0.05% (CsA) 4 times daily and Group I on topical IFN alpha 2b 0.2 million IU 4 times daily postoperatively for 3 months. Pre- and posttreatment best-corrected visual acuity (BCVA), recurrence, and complications were assessed at day 1, week 1, 1 month, and 3 months.

RESULTS

The mean preoperative BCVA of 0.51 ± 0.18 and 0.51 ± 0.23 improved to 0.13 ± 0.13 and 0.13 ± 0.13 in Group C and Group I, respectively, after 3 months of treatment (P < 0.0001). Recurrence was seen in 2 cases in Group C and in 1 case in Group I at 3 months. No significant complications occurred in either of the groups.

CONCLUSION

Topical CsA and IFN Alpha-2b are newer efficacious adjuvants with LCAT for prevention of postoperative pterygium recurrence.

Pharmacological treatment strategies of pterygium: Drugs, biologics, and novel natural products

Pterygium is a fibrovascular tissue growth invading the cornea. Adjunctive treatment post-surgery includes conventional immunosuppressants as well as antiviral drugs. The use of large- and small-molecule antivascular endothelial growth factor (VEGF) agents remains an integral part of pterygium treatment as well as other neovascular conditions of the eye. Naturally occurring polyphenolic compounds have favorable characteristics for treating neovascular and inflammatory eye conditions, including good efficacy, stability, cost-effectiveness, and the versatility of their chemical synthesis. In this review, we discuss pharmacological treatments of pterygium. Natural products, such curcumin, ellagic acid, and chalcones, are reviewed, with emphasis on their potential as future pterygium treatments.

Changes in TRPV1 Expression as Well as Substance P and Vasoactive Intestinal Peptide Levels Are Associated with Recurrence of Pterygium

Pterygium, a disease of the ocular surface, is characterized by the proliferation and invasion of fibrovascular tissue. Chronic inflammation contributes to pterygium occurrence. Sensory neuropeptides of TRPV1-positive nerve fibers are involved in inflammation and corneal wound healing. The possible association between TRPV1 in nerve fibers and neuropeptides such as Substance P (SP) and Vasoactive Intestinal Peptide (VIP) in the recurrence of pterygium has not been examined before. The pterygia from 64 patients were used to determine changes in SP and VIP levels using 10 min acetic-acid extraction that yielded mainly neuronal peptides. There was a sufficient amount of pterygium tissues from the 35 patients for further immunohistochemical analysis of TRPV1 and S100, which is a glial marker to visualize nerve fibers. SP and VIP levels increased markedly in cases with primary and secondary recurrences, and there was a close correlation between SP and VIP levels. TRPV1 expression increased in the epithelium, while stromal expression decreased in recurrences. Nerve fibers were demonstrated mainly in the stroma, and serial sections confirmed the localization of TRPV1 with the nerve fibers. These results together with previous findings demonstrated that the increased epithelial expression of TRPV1 in recurrent pterygia might be involved in the pathogenesis, and the inhibition of epithelial TRPV1 activity may prevent recurrence.

Sandwich (Amnion/Conjunctival-Limbal Autograft/Amnion) Transplantation for Recurrent Pterygium with Restrictive Strabismus

(1) Background: This study aimed to evaluate the clinical outcome of Sandwich (Amnion/Conjunctival-Limbal Autograft/Amnion) transplantation for recurrent pterygium with restrictive strabismus. (2) Methods: This retrospective study included 11 eyes in 11 patients diagnosed with recurrent pterygium with restrictive strabismus who received sandwich transplantation. The outcomes were measured by pterygium recurrence, best-corrected visual acuity, esotropia (prism diopters), and treatment complications. (3) Results: Eleven patients (six males, five females) had a mean age of 60.5 (range 36-80) years. The previously received pterygium excision surgery number was 1.8 ± 1.02 (range 1-4). The mean follow-up period was 19.9 ± 8.41 (range 12-36) months. All patients had a restriction of abduction in the previously operated eye, causing esotropia in the primary position. Pre-operative esotropia was 17.2 (range 10-30) prims diopter (PD). Five eyes (45.5%) had symblepharon before surgery. All patients were orthotropic until the last follow-up. Symblepharon was released in all eyes. Free ocular motility was present in all eyes. No donor site scar formation, scleral melt, or corneal ulcer was noted. (4) Conclusions: Sandwich transplantation for recurrent pterygium with restrictive strabismus is safe and effective.

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.

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.

5-Fluorouracil in primary, impending recurrent and recurrent pterygium: Systematic review of the efficacy and safety of a surgical adjuvant and intralesional antimetabolite

Pterygium is an ultraviolet-related disease characterized by an aberrant, wing-shaped and active wound-healing process. There is nothing quite as disheartening for the surgeon or patient as the recurrence of pterygium, and various adjuvants have been studied to ameliorate this. This systematic review provides a comprehensive summary of the efficacy and safety of 5-Fluorouracil (5-FU) as an antimetabolite agent for pterygium management. An appraisal of electronic searches of six databases identified 34 clinical studies reporting recurrence outcomes of 5-FU use in primary, impending recurrent and recurrent pterygia. In vitro and in vivo studies of 5-FU showed dose- and duration-dependent cytostatic and cytotoxic effects in human cells. 5-FU is relatively inexpensive, available, and easy to administer, making it attractive for resource-limited scenarios. However, the published evidence demonstrates a recurrence rate of 11.4-60% with the bare scleral technique, 3.5-35.8% with conjunctival rotational flaps, 3.7-9.6% with conjunctival autografts for intraoperative topical 5-FU, and 14-35.8% for preoperative and intraoperative injections. This suboptimal efficacy brings the role of 5-FU as an adjuvant for pterygium surgery into question and the authors do not recommend its use. In contrast, postoperative intralesional injections of 5-FU to arrest progression in impending recurrent pterygium and true recurrent pterygia were more promising, with success rates of 87.2-100% and 75-100%, respectively. Furthermore, 5-FU as a treatment modality, without surgery, effectively arrested progression in 81.3-96% of primary and recurrent pterygia. Other treatments such as topical and intralesional corticosteroids, cyclosporine and anti-VEGF agents are discussed. Complications of 5-FU increase with higher doses and range from transient and reversible to severe and sight-threatening. For pterygium, 5-FU has a predilection for causing scleral thinning, corneal toxicity, and graft-related complications. Additional study with extended follow-up is needed to elucidate the optimal dose, frequency, duration, and long-term safety of 5-FU injections. If 5-FU is used in the management of pterygium, it should be with caution, in selected patients and with vigilant long-term monitoring.

Autologous simple conjunctival epithelial transplantation for primary pterygium

PURPOSE

To evaluate the feasibility of a new method of conjunctival transplantation to achieve recovery of the normal conjunctival epithelium over the bare sclera after pterygium excision and prevent its recurrence.

METHODS

After excision of the primary pterygium, we performed simple conjunctival epithelial transplantation (SCET) in which we glued an amniotic membrane patch pre-loaded with tiny autologous conjunctival tissue fragments over the scleral defect. Slit-lamp evaluation was performed at 2 and 7-10 days, and then at 1, 3, 6, and 12 months after surgery, together with confocal microscopy at 3, 6, and 12 months.

RESULTS

Surgical excision and SCET for nasal primary pterygium were performed in 6 eyes (6 patients). No graft detachment occurred. An inflammatory granuloma was excised without sequelae in one patient 2 months after surgery. No signs of recurrence or sight-threatening complications were recorded at 12 months, and in vivo confocal microscopy showed progressive expansion of the conjunctival cell population and formation of a clear corneal-conjunctival transition.

CONCLUSIONS

SCET takes advantage of the ability of the amniotic membrane and conjunctival cells to renew. Outcomes after SCET are comparable to conventional conjunctival flap surgery and can be achieved in less surgical time and with less donor tissue to be removed.

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.

Computer-Assisted Pterygium Screening System: A Review

Pterygium is an eye condition that causes the fibrovascular tissues to grow towards the corneal region. At the early stage, it is not a harmful condition, except for slight discomfort for the patients. However, it will start to affect the eyesight of the patient once the tissues encroach towards the corneal region, with a more serious impact if it has grown into the pupil region. Therefore, this condition needs to be identified as early as possible to halt its growth, with the use of simple eye drops and sunglasses. One of the associated risk factors for this condition is a low educational level, which explains the reason that the majority of the patients are not aware of this condition. Hence, it is important to develop an automated pterygium screening system based on simple imaging modalities such as a mobile phone camera so that it can be assessed by many people. During the early stage of automated pterygium screening system development, conventional machine learning techniques such as support vector machines and artificial neural networks are the de facto algorithms to detect the presence of pterygium tissues. However, with the arrival of the deep learning era, coupled with the availability of large training data, deep learning networks have replaced the conventional networks in screening for the pterygium condition. The deep learning networks have been successfully implemented for three major purposes, which are to classify an image regarding whether there is the presence of pterygium tissues or not, to localize the lesion tissues through object detection methodology, and to semantically segment the lesion tissues at the pixel level. This review paper summarizes the type, severity, risk factors, and existing state-of-the-art technology in automated pterygium screening systems. A few available datasets are also discussed in this paper for both classification and segmentation tasks. In conclusion, a computer-assisted pterygium screening system will benefit many people all over the world, especially in alerting them to the possibility of having this condition so that preventive actions can be advised at an early stage.

A Novel System for Measuring Pterygium's Progress Using Deep Learning

Pterygium is a common ocular surface disease. When pterygium significantly invades the cornea, it limits eye movement and impairs vision, which requires surgery to remove. It is medically recognized that when the width of the pterygium that invades the cornea is >3 mm, the patient can be treated with surgical resection. Owing to this, this study proposes a system for diagnosing and measuring the pathological progress of pterygium using deep learning methods, which aims to assist doctors in designing pterygium surgical treatment strategies. The proposed system only needs to input the anterior segment images of patients to automatically and efficiently measure the width of the pterygium that invades the cornea, and the patient's pterygium symptom status can be obtained. The system consists of three modules, including cornea segmentation module, pterygium segmentation module, and measurement module. Both segmentation modules use convolutional neural networks. In the pterygium segmentation module, to adapt the diversity of the pterygium's shape and size, an improved U-Net++ model by adding an Attention gate before each up-sampling layer is proposed. The Attention gates extract information related to the target, so that the model can pay more attention to the shape and size of the pterygium. The measurement module realizes the measurement of the width and area of the pterygium that invades the cornea and the classification of pterygium symptom status. In this study, the effectiveness of the proposed system is verified using datasets collected from the ocular surface diseases center at the Affiliated Eye Hospital of Nanjing Medical University. The results obtained show that the Dice coefficient of the cornea segmentation module and the pterygium segmentation module are 0.9620 and 0.9020, respectively. The Kappa consistency coefficient between the final measurement results of the system and the doctor's visual inspection results is 0.918, which proves that the system has practical application significance.

Transcriptomics and network analysis highlight potential pathways in the pathogenesis of pterygium

Pterygium is a common ocular surface condition frequently associated with irritative symptoms. The precise identity of its critical triggers as well as the hierarchical relationship between all the elements involved in the pathogenesis of this disease are not yet elucidated. Meta-analysis of gene expression studies represents a novel strategy capable of identifying key pathogenic mediators and therapeutic targets in complex diseases. Samples from nine patients were collected during surgery after photo documentation and clinical characterization of pterygia. Gene expression experiments were performed using Human Clariom D Assay gene chip. Differential gene expression analysis between active and atrophic pterygia was performed using limma package after adjusting variables by age. In addition, a meta-analysis was performed including recent gene expression studies available at the Gene Expression Omnibus public repository. Two databases including samples from adults with pterygium and controls fulfilled our inclusion criteria. Meta-analysis was performed using the Rank Production algorithm of the RankProd package. Gene set analysis was performed using ClueGO and the transcription factor regulatory network prediction was performed using appropriate bioinformatics tools. Finally, miRNA-mRNA regulatory network was reconstructed using up-regulated genes identified in the gene set analysis from the meta-analysis and their interacting miRNAs from the Brazilian cohort expression data. The meta-analysis identified 154 up-regulated and 58 down-regulated genes. A gene set analysis with the top up-regulated genes evidenced an overrepresentation of pathways associated with remodeling of extracellular matrix. Other pathways represented in the network included formation of cornified envelopes and unsaturated fatty acid metabolic processes. The miRNA-mRNA target prediction network, also reconstructed based on the set of up-regulated genes presented in the gene ontology and biological pathways network, showed that 17 target genes were negatively correlated with their interacting miRNAs from the Brazilian cohort expression data. Once again, the main identified cluster involved extracellular matrix remodeling mechanisms, while the second cluster involved formation of cornified envelope, establishment of skin barrier and unsaturated fatty acid metabolic process. Differential expression comparing active pterygium with atrophic pterygium using data generated from the Brazilian cohort identified differentially expressed genes between the two forms of presentation of this condition. Our results reveal differentially expressed genes not only in pterygium, but also in active pterygium when compared to the atrophic ones. New insights in relation to pterygium's pathophysiology are suggested.

Conjunctival Autograft versus Combined Amniotic Membrane and Mini-Simple Limbal Epithelial Transplant for Primary Pterygium Excision

Purpose

To compare outcomes of conjunctival autograft (CAG) and combined amniotic membrane with mini-simple limbal epithelial transplant (mini-SLET) after primary pterygium excision.

Methods

All consenting adults with primary pterygium were included in this study. After pterygium excision, patients were randomized to receive either CAG or mini-SLET and both grafts were held in place with fibrin glue. The patients were followed-up at days 1, 3, 7, 14, and 30 and subsequently at the third, sixth, and ninth months. The recurrence rate was considered as the primary outcome measure whereas the operating time, postoperative symptoms, and surgical complications were considered the secondary outcome measures.

Results

The study comprised of 264 eyes of 264 patients, of which 233 (88%) completed the nine months of follow-up. Of these, 118 (51%) received CAG and 115 (49%) received mini-SLET. The groups were comparable at baseline. Recurrence of pterygium was seen in two (1.6%) eyes in the CAG group and three (2.6%) eyes in the mini-SLET group (P = 0.68). Operative time for mini-SLET (20.33 ± 1.28 min) was significantly higher than that for CAG (12.01 ± 1.26 min) (P < 0.001). Graft displacement was observed in one case in group II (P = 0.999). The Lim Bon Siong (foreign body sensation, lacrimation, pain, and irritation) score in the CAG group was statistically significant for all four symptoms at days 1 and 3; however, at day 7, foreign body sensation, pain, and irritation scores were significantly higher for the CAG group.

Conclusion

In this study, the overall recurrence rate was very low and comparable between mini-SLET and the established technique of CAG after performing the primary pterygium excision. Despite a longer surgical time, mini-SLET appears to be a viable option for the management of primary 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.

The Role of the Stromal Extracellular Matrix in the Development of Pterygium Pathology: An Update

Pterygium is a benign fibrovascular lesion of the bulbar conjunctiva with frequent involvement of the corneal limbus. Its pathogenesis has been mainly attributed to sun exposure to ultraviolet-B radiation. Obtained evidence has shown that it is a complex and multifactorial process which involves multiple mechanisms such as oxidative stress, dysregulation of cell cycle checkpoints, induction of inflammatory mediators and growth factors, angiogenic stimulation, extracellular matrix (ECM) disorders, and, most likely, viruses and hereditary changes. In this review, we aim to collect all authors’ experiences and our own, with respect to the study of fibroelastic ECM of pterygium. Collagen and elastin are intrinsic indicators of physiological and pathological states. Here, we focus on an in-depth analysis of collagen (types I and III), as well as the main constituents of elastic fibers (tropoelastin (TE), fibrillins (FBNs), and fibulins (FBLNs)) and the enzymes (lysyl oxidases (LOXs)) that carry out their assembly or crosslinking. All the studies established that changes in the fibroelastic ECM occur in pterygium, based on the following facts: An increase in the synthesis and deposition of an immature form of collagen type III, which showed the process of tissue remodeling. An increase in protein levels in most of the constituents necessary for the development of elastic fibers, except FBLN4, whose biological roles are critical in the binding of the enzyme LOX, as well as FBN1 for the development of stable elastin. There was gene overexpression of TE, FBN1, FBLN5, and LOXL1, while the expression of LOX and FBLN2 and -4 remained stable. In conclusion, collagen and elastin, as well as several constituents involved in elastic fiber assembly are overexpressed in human pterygium, thus, supporting the hypothesis that there is dysregulation in the synthesis and crosslinking of the fibroelastic component, constituting an important pathogenetic mechanism for the development of the disease.

Membrane of Plasma Rich in Growth Factors in Primary Pterygium Surgery Compared to Amniotic Membrane Transplantation and Conjunctival Autograft

This prospective and comparative study aimed to compare the use of a conjunctival autograft (CAG), plasma rich in growth factors fibrin membrane (mPRGF) or amniotic membrane transplantation (AMT) in primary pterygium surgery. Patients were assigned for surgery with CAG (group A), mPRGF (group B), or AMT (group C). Pterygium recurrence, Best Corrected Visual Acuity (BCVA), graft size (measured with anterior segment optical coherence tomography (AS-OCT)), and ocular surface symptoms (visual analogue scale (VAS) and ocular surface disease index (OSDI)) were evaluated. Thirteen eyes in group A, 26 in group B, and 10 in group C were evaluated. No changes in BCVA (p > 0.05) were found. Recurrence cases for groups A, B, and C were none, two, and two, respectively, and three cases of pyogenic granulomas in group A. The horizontal/vertical graft size was lower in group B vs group A (p < 0.05) from months 1 to 12. The improvement in VAS frequency for groups A, B, and C was: 35.5%, 86.2%, and 39.1%, respectively. The OSDI scale reduction for groups A, B, and C was: 12.7%, 39.0%, and 84.1%. The use of the three surgical techniques as a graft for primary pterygium surgery was safe and effective, showing similar results. The mPRGF graft represents an autologous novel approach for pterygium surgery.

Evaluation of optical quality in pterygium patients with a new modified sutureless and glue-free method

BACKGROUND

Modified sutureless and glue-free method is an effective and novel surgical approach for pterygium. We aim to evaluate optical quality in pterygium treated with the new method and investigate the clinical application of the Optical Quality Analysis System (OQAS) and Anterior segment optical coherence tomography (AS-OCT) to evaluate the pterygium surgery.

METHODS

A total of 52 eyes of 52 patients with pterygium were randomly divided into 2 groups. After surgical excision, the bare sclera was placed with a tight fit limbal conjunctival autograft fixed via the modified sutureless and glue-free method in group 1 (26 eyes) and conventional sutures in group 2 (26 eyes). Objective scattering index (OSI), modulation transfer function (MTF) and Strehl ratio (SR) were measured using OQAS in both groups during the perioperative period. Pterygium diameter was measured on AS-OCT. Ocular surface disease index (OSDI) questionnaire also was used.

RESULTS

The group 1 had significantly lower mean OSI, higher mean MTF, and higher mean SR at 1 month and 3 months after surgery (p < 0.05). The group 1 had significantly lower mean OSDI at 1 month (p < 0.05), while was similar to group 2 at 3 months (p > 0.05). Pterygium diameter positively correlated with OSI (r = 0.528, p < 0.001), while it negatively correlated with MTF (r = - 0.501, p < 0.001) and SR (r = - 0.174, p = 0.217) before operation.

CONCLUSIONS

The modified sutureless and glue-free method might be more advantageous in improving the optical quality during early postoperative recovery times and pterygium diameter affected optical quality. OQAS can be reliably used to evaluate postoperative outcomes.

Postsurgery Classification of Best-Corrected Visual Acuity Changes Based on Pterygium Characteristics Using the Machine Learning Technique

Introduction

Early detection of visual symptoms in pterygium patients is crucial as the progression of the disease can cause visual disruption and contribute to visual impairment. Best-corrected visual acuity (BCVA) and corneal astigmatism influence the degree of visual impairment due to direct invasion of fibrovascular tissue into the cornea. However, there were different characteristics of pterygium used to evaluate the severity of visual impairment, including fleshiness, size, length, and redness. The innovation of machine learning technology in visual science may contribute to developing a highly accurate predictive analytics model of BCVA outcomes in postsurgery pterygium patients.

Aim

To produce an accurate model of BCVA changes of postpterygium surgery according to its morphological characteristics by using the machine learning technique. Methodology. A retrospective of the secondary dataset of 93 samples of pterygium patients with different pterygium attributes was used and imported into four different machine learning algorithms in RapidMiner software to predict the improvement of BCVA after pterygium surgery.

Results

The performance of four machine learning techniques were evaluated, and it showed the support vector machine (SVM) model had the highest average accuracy (94.44% ± 5.86%), specificity (100%), and sensitivity (92.14% ± 8.33%).

Conclusion

Machine learning algorithms can produce a highly accurate postsurgery classification model of BCVA changes using pterygium characteristics.

Dynamic thiol disulphide homeostasis in patients with surfer's eye: a case-control study

PURPOSE

The role of oxidative stress in the pathogenesis of pterygium is still unclear. However, abnormal thiol disulfide homeostasis levels are involved in the pathogenesis of various systemic or ocular diseases. We aim to analyze dynamic thiol disulphide homeostasis in patients suffering from conjunctival pterygium using a contemporary technique.

METHODS

Thirty-eight subjects suffering from pterygium and 35 age-gender matched healthy volunteers were recruited for the study. For each case, total thiol, disulfide and native thiol levels in blood were obtained. Additionally, the ratio of disulfide over total thiol, native thiol over total thiol and disulfide over native thiol were computed.

RESULTS

The level of median native thiol was lower in pterygium group (318.2 µmol/L vs. 333.4 µmol/L) and median disulfide was slightly higher in pterygium group (24.3 µmol/L vs. 22.8 µmol/L) compared to control group. Both disulfide over total thiol and disulfide over native thiol ratios were higher in pterygium group, ratio of native thiol over total thiol was found to be higher in control group. Nevertheless, none of those differences were statistically significant at 95% confidence level. Notably, correlation test pointed to a negative correlation both between pterygium grade and native thiol and between total thiol and pterygium grade in pterygium group (P = 0.03 and 0.02, respectively).

CONCLUSION

A negative correlation hinting that slightly weakened dynamic thiol disulphide homeostasis in subjects with pterygium, a local ocular disease. Further studies with larger sample sizes may shed light on this potential relationship and justify systemic antioxidant therapies in these cases.

Lyophilized amniotic membrane graft for primary pterygium surgery: preliminary results

The aim of this study was to investigate the tolerability, safety and efficacy of new lyophilized amniotic membrane (LAM) presentation for ocular use. A prospective case-series cohort of four patients with primary nasal pterygium which undergone excision and LAM implantation was evaluated for complications and clinical outcomes. Surgical manipulation of LAM was also assessed. LAM was stiff and easy to manipulate as well as no tearing occurred during surgery or suturing. Ocular comfort was checked and similar among those patients with LAM glued or sutured. After 12 months, there were no issues about tolerability or adverse events. Lower cosmetic outcomes (recurrence) were stated in 3 patients. Our study showed that LAM could be an effective alternative to cryopreserved amniotic membrane for graft after pterygium excision surgery. Its main advantage, storage at room temperature, can make it of immediate availability. Further studies comparing clinical outcomes of pterygium surgery with cryopreserved amniotic membrane versus LAM would confirm the benefits of the last.

Conjunctival Autofluorescence and Cytological Changes in Pterygium

PURPOSE

The purpose of this study was to evaluate the presence and pattern of autofluorescence and its related cytological changes in pterygium.

METHODS

Eighty-six patients with unilateral pterygium and 76 controls were recruited. We graded pterygium, looked for autofluorescence, performed cytology of the nasal conjunctiva, repeated evaluation after 6 months, compared findings with controls, and assessed the progression of pterygium from photographs with the help of ImageJ software.

RESULTS

Autofluorescence was present in 51% of cases with pterygium. Autofluorescence at the leading edge (65.9%) was the predominant pattern seen. In total, 83.3% of grade 3 pterygia, 64.7% of grade 2 pterygia, and 28.9% of grade 1 pterygia (P value <0.0005) had autofluorescence. Impression cytology showed conjunctival epithelial cells in 60% of cases, significant squamous metaplasia in grade 3 pterygia (45%) compared with grade 2 pterygia (11.8%), and normal conjunctival epithelial cells in grade 1 pterygia (P value < 0.0005).

CONCLUSIONS

The presence and pattern of conjunctival autofluorescence and cytological changes, especially squamous metaplasia, are linked to the severity or grade of pterygium.

Pterygium surgery by double-sliding flaps procedure: Comparison between primary and recurrent pterygia

Purpose

This study aimed to evaluate the surgical outcomes of pterygial excision for primary and recurrent pterygia by a single method of pterygia excision combined with two conjunctival flaps.

Methods

This retrospective study divided 193 cases of pterygium into the primary (140 cases) and recurrent (53 cases) pterygium groups. Following double-sliding conjunctival transposition flap operation and surgical excision of the pterygium, the success and recurrence rates of pterygial surgery were assessed based on visual acuity and corneal and total astigmatism during follow-up at least 6 months.

Results

Both primary and recurrent pterygium groups showed significant improvements in visual acuity and astigmatism (corneal and total) between before and after this procedure. Total astigmatism and success rate of primary pterygium were significantly better than those for recurrent pterygium. Two cases (1.4%) of primary pterygium and four cases (7.5%) of recurrent pterygium developed recurrence, corresponding to a rate of 3.1% (6/193 cases). The success rates significantly make a difference between primary and recurrent groups but did not differ significantly between the first recurrent and over twice recurrent pterygium. However, visual acuity, cornea, and total astigmatism improved significantly after surgery in first recurrent group but not in over twice recurrent group.

Conclusion

The double-sliding conjunctival flaps surgery appeared to be a useful method, with a better success rate and lower pterygial recurrence in pterygium surgery. Especially, when pterygium is larger or recurrent type, this technique can be easily covered the bare sclera, as compared to any transposition conjunctival flap operation.

Evaluation of Primary Pterygia on Basis of the Loss of Vertical Length of Plica Semilunaris

Purpose

To propose a new grading system for primary pterygia based on the morphological loss of vertical length of plica semilunaris (LPS).

Methods

We included 50 eyes from 41 patients with primary pterygium. LPS was defined and quantified as the ratio of the length of loss of the normal vertical morphology at plica semilunaris to the vertical corneal diameter using anterior-segment photographs. Grades of tear metalloproteinase 9 (MMP-9) expression by point-of-care immunoassay, which is a well-known biomarker for inflammation, was correlated with the extent of LPS (%) of pterygia. Then, LPS was paralleled with the pre-established grading systems on the basis of tissue translucency (i.e., T grade) and vascularity (i.e., V grade) of the pterygium body.

Results

MMP-9 grades was 2.39 ± 1.12 in the group with LPS ≥50% and was 1.56 ± 1.12 in the group with LPS <50% (P = 0.016). In a linear regression, the extent of LPS was positively correlated with MMP-9 grades (r = 0.315, P = 0.026). MMP-9 expression did not differ between T grades or V grades. The extents of LPS were well correlated positively with both T grades (r = 0.495 and P < 0.001) and V grades (r = 0.344 and P = 0.015).

Conclusions

We devised a new grading system using LPS on the basis of morphological loss of the normal vertical plica semilunaris in primary pterygia. The extent of LPS correlated well with T grades and V grades and also reflected the expression of MMP-9 in tears.

Translational Relevance

The new clinical LPS grading system reflects severity and MMP-9 expression in tears in primary pterygia.

Quantifying the Size of the Pterygium Head by Evaluating the Fibrous Area or the Vascularized Area

PURPOSE

Pterygium is characterized by the development of wing-shaped fibrovascular tissue from the bulbar conjunctiva across the limbus onto the cornea. The purpose of this study was to quantify the discrepancy of the pterygium size between the fibrous area and the vascularized area.

METHODS

Color photographs of 146 eyes with pterygia obtained with a single-lens reflex camera system were analyzed by 2 independent graders for width (vertical dimension), length (horizontal dimension), and surface area of the pterygium head using 2 methods: the fibrous method, which measures any fibrovascular tissue crossing the corneal limbus, and the vascular method, which measures only tissue with discernible active blood flow, without any avascular tissue or opacity. Statistics of intraclass correlation coefficients for intergrader and intragrader reproducibility were calculated, and the paired t test between methods was used.

RESULTS

Both intergrader and intragrader intraclass correlation coefficients for both methods were above 0.85. The vascular measurement was significantly larger in width (vertical dimension, fibrous 3.97 ± 1.02 mm vs. vascular 4.49 ± 1.33 mm, P = 0.01), whereas the fibrous measurement was significantly larger in length (horizontal dimension, fibrous 2.41 ± 1.16 mm vs. vascular 2.23 ± 1.05 mm, P = 0.04). No significant difference was found in the surface area (fibrous 7.27 ± 4.65 mm vs. vascular 7.40 ± 5.13 mm, P = 0.67).

CONCLUSIONS

With both methods, reproducibility of the size of the pterygium head was high. Significant differences were shown between the two methods in quantification of the width and length but not in the surface area. Such methods can be used to standardize the evaluation of pterygia in clinical research and clinical trials.

Morphometric evaluation and measurements of primary pterygium by anterior segment optical coherence tomography and its relation with astigmatism

Purpose:

To evaluate the relationship between measurements and various morphometric parameters of primary pterygium on anterior segment optical coherence tomography(AS-OCT) and refractive and keratometric astigmatism.

Methods:

In this cross-sectional study, patients with primary pterygium were included. The AS-OCT parameters of pterygium consisting of epithelial thickness near apex(µm), apical or head thickness(µm), its thickness at limbus(µm), horizontal length of pterygium(mm), central corneal thickness (µm) and maximum pterygium thickness(mm) were evaluated.

Results:

Sixty three patients comprising of 63 eyes with a primary pterygium were studied. The mean keratometric and refractive astigmatism were 1.69 ± 3.15 Diopter(D) and0.5 ± 1.4D, respectively. There was a significant association between pterygium grade and stocker’s line with keratometric astigmatism (p = 0.02, 0.00) respectively. Vertical and horizontal length on slit lamp and horizontal length on AS-OCT showed significant association with keratometric astigmatism (p = 0.05, 0.00,0.00), respectively. Limbal thickness on AS-OCT showed significant positive correlation with refractive astigmatism (r = 0.29, p = 0.02).

Conclusion:

The pterygium grade influences the keratometric astigmatism. Increased limbal thickness of pterygium on AS-OCT leads to more refractive astigmatism.

Pterygium: an update on pathophysiology, clinical features, and management

Pterygium is a relatively common ocular surface disease. The clinical aspects and the treatment options have been studied since many years ago, but many uncertainties still exist. The core pathologic pathway and the role of heredity in the development of pterygium are still attractive fields for the researchers. The role of pterygium in corneal irregularities, in addition to the refractive properties of pterygium removal, has been increasingly recognized through numerous studies. The association between pterygium and ocular surface neoplasia is challenging the traditional beliefs regarding the safe profile of the disease. The need for a comprehensive clinical classification system has encouraged homogenization of trials and prediction of the recurrence rate of the pterygium following surgical removal. Evolving surgical methods have been associated with some complications, whose diagnosis and management are necessary for ophthalmic surgeons. According to the review, the main risk factor of pterygium progression remains to be the ultraviolet exposure. A major part of the clinical evaluation should consist of differentiating between typical and atypical pterygia, where the latter may be associated with the risk of ocular surface neoplasia. The effect of pterygium on astigmatism and the aberrations of the cornea may evoke the need for an early removal with a purpose of reducing secondary refractive error. Among the surgical methods, conjunctival or conjunctival-limbal autografting seems to be the first choice for ophthalmic surgeons because the recurrence rate following the procedure has been reported to be lower, compared with other procedures. The use of adjuvant options is supported in the literature, where intraoperative and postoperative mitomycin C has been the adjuvant treatment of choice. The efficacy and safety of anti–vascular endothelial growth factor agents and cyclosporine have been postulated; however, their exact role in the treatment of the pterygium requires further studies.

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.

The Effect of a Novel Strategy in Treating Primary Pterygium: A Prospective Randomized Clinical Study

OBJECTIVE

We sought to compare the efficacy and safety of conjunctival autograft (CAG), amniotic membrane transplantation (AMT) with postoperative interferon alfa-2b (IFN alfa-2b), and modified conjunctival autograft plus amniotic membrane transplantation (mCAG plus AMT) with postoperative IFN alfa-2b for primary pterygium.

DESIGN

Randomized controlled clinical trial.

METHODS

Eyes with nasal and primary pterygia were randomized in a 1:1:1 ratio to receive CAG, AMT with IFN alfa-2b, or mCAG plus AMT with IFN alfa-2b. Subjects were followed up for 12 months. Primary outcomes included recurrence rate and complications. Secondary outcomes included corneal epithelium status, ocular surface symptom score, and visual acuity change.

RESULTS

Eighty-five subjects (30 in the CAG group, 25 in the AMT group, and 30 in the CAG+AMT group) completed the 12-month follow-up. No complication or grade 4 recurrence was found. There was no significant difference among the 3 groups in recurrence grade, corneal epithelium status, and visual acuity change. Compared with mCAG+AMT, CAG has a negative effect (β = -0.62, P = .001), and AMT has a negative effect (β = -2.02, P < .001) on postoperative symptom scores. Compared with AMT, CAG has a positive effect (β = 1.28, P < .001) on postoperative symptom scores.

CONCLUSIONS

All 3 strategies had good safety and clinical efficacy in the study. Compared with conjunctival autograft, the 2 surgeries using no autograft or limited autograft was less traumatic and gave more flexibility for future ocular surface condition changes.

[Pterygium: pathogenesis, diagnosis and treatment]

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

Time to Keratometric Stability After Pterygium Excision and the Associated Factors: A Clinical Perspective

Purpose

To determine the percentage of eyes with corneal astigmatic power stability and mean corneal keratometric power at 6-month post-pterygium excision, and to identify the time, and the associated factors, required to achieve stability.

Methods

This prospective observational study enrolled patients undergoing pterygium excision. Patients were evaluated for baseline characteristics and keratometric data before and every month after pterygium excision for six months using IOL Master 500^® (Carl Zeiss, Meditec). Clinically stable corneal astigmatic power and keratometric power were, respectively, defined as changes in these parameters of less than 0.25 and 0.27 diopters after two consecutive visits. Time to corneal astigmatic and keratometric power stability, as well as factors associated with the stability, were analyzed.

Results

Forty percent and 73.3% of eyes, respectively, demonstrated corneal astigmatic and corneal keratometric stability at six months post-operation. Within three months of reaching initial stability, the corneal astigmatic power and the mean keratometric power showed instability in 46.7% and 27.3% of patients, respectively. No patients with keratometric stability for more than three months became unstable during the study period. The extension of pterygium exceeding 3.0 mm was associated with a delay in time to corneal astigmatic stability (HRadjusted 0.41; 95% CI 0.19-0.89; P= 0.02).

Conclusion

According to the clinical relevance, 40% and 73% of patients, respectively, presented corneal astigmatic and keratometric stability within six months post-operation. Patients with a pterygium extension of more than 3 mm required a longer time for corneal astigmatic stability. It is recommended that keratometric stability be achieved for at least three months before commencing with additional procedures.

Is Pterygium Morphology Related to Loss of Corneal Endothelial Cells? A Cross-Sectional Study

Purpose

To determine the difference in mean corneal endothelial cell density (CECD) between the healthy and diseased eyes of the patients with unilateral pterygium with different morphology patterns by using a non-contact specular microscope (SP2000: Topcon Corporation, Japan) and to find out any relationship between severity of pterygium and daily sunlight exposure with the CECD loss.

Methods

A descriptive cross-sectional prospective study was carried out at Al-Shifa Trust Eye Hospital (ASTEH), Rawalpindi, Pakistan from 21st January 2019 to 22nd January 2020. Two hundred eyes (n= 100 patients) of age range18 -68 years with unilateral pterygium were selected. Necessary demographic data and essential variables like age, smoking status, occupation, and daily direct sunlight exposure were determined. The severity of pterygium (grading) based on its morphology was determined by slit-lamp examination. CECD of each patient was carried out using a non-contact Specular Microscope. The healthy eye (without pterygium) of a patient was considered as control.

Results

The age range in this study was 18–68 years, with a mean age of 43.80 ± 24.37 years with a male to female ratio of 1.6:1 (62.00% males vs 38% females). Out of six occupations, the most common occupation was labour/construction work (n=31) followed by farming (n=27). The study reported a mean corneal endothelial cell density (CECD) of 2411.61±143.64 vs 2751.41 ± 123.674 cells/mm² in diseased and normal eyes, respectively (p-value = 0.0001). CECD was lower in grade 3 pterygium compared to less severe pterygium { grade 3 (Fleshy) =2261 cells/mm² vs grade 2 (Intermediate)= 2413 cells/mm² vs grade 1 (Atrophic)=2459 cells/mm²} although this difference between the groups was not found to be significant (p=0.065). No significant association between sunlight exposure and CECD loss was observed (p=0.065).

Conclusion

This study concluded that the mean corneal endothelial cell density in patients with unilateral pterygium using a non-contact specular microscope were 2411.61±143.64 cells/mm².