Role of artificial tears in reducing the recurrence of pterygium after surgery: a prospective randomized controlled trial

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

Purpose

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

Design

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

Participants

Patients with primary or recurrent pterygia.

Main Outcome Measures

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

Methods

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

Results

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

Conclusions

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

Financial Disclosures

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

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Influence of Pterygium on Meibomian Glands and Dry Eye Parameters

SIGNIFICANCE

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Key Genes of Immunity Associated with Pterygium and Primary Sjögren's Syndrome

Pterygium and primary Sjögren's Syndrome (pSS) share many similarities in clinical symptoms and ocular pathophysiological changes, but their etiology is unclear. To identify the potential genes and pathways related to immunity, two published datasets, GSE2513 containing pterygium information and GSE176510 containing pSS information, were selected from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) of pterygium or pSS patients compared with healthy control conjunctiva, and the common DEGs between them were analyzed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were conducted for common DEGs. The protein-protein interaction (PPI) network was constructed using the STRING database to find the hub genes, which were verified in clinical samples. There were 14 co-upregulated DEGs. The GO and KEGG analyses showed that these common DEGs were enriched in pathways correlated with virus infection, antigen processing and presentation, nuclear factor-kappa B (NF-κB) and Th17 cell differentiation. The hub genes (IL1R1, ICAM1, IRAK1, S100A9, and S100A8) were selected by PPI construction. In the era of the COVID-19 epidemic, the relationship between virus infection, vaccination, and the incidence of pSS and pterygium growth deserves more attention.

Surgical Techniques and Adjuvants for the Management of Pterygium

OBJECTIVE

To provide an updated review of surgical techniques and adjuvants for the management of pterygium.

METHODS

A literature search was conducted in PubMed for studies published since January 2011. "Pterygium surgery" and the MeSH term "Pterygium/surgery" was used. The results were filtered for randomized controlled trials in English, yielding 60 citations.

RESULTS

One study compared topical anesthetic agents. One study compared methods of corneal polishing of the corneoscleral bed after pterygium excision. Numerous studies evaluated the use of conjunctival autograft versus amniotic membrane, superior versus inferior conjunctival autograft, and conjunctival versus limbal-conjunctival autograft. Many studies evaluated graft fixation methods. Several studies evaluated the adjuvant use of mitomycin C, 5-fluorouracil, and bevacizumab. A few studies evaluated the adjuvant use of steroids. Eleven studies evaluated various methods of postoperative management.

CONCLUSIONS

Current evidence supports pterygium excision with conjunctival autograft fixation using fibrin glue, followed by patching until the first postoperative visit. Surgical adjuvants and postoperative use of artificial tears and topical cyclosporine 0.05% may further reduce recurrence. Postoperative use of topical steroids is highly variable because there is no consensus regarding the optimal dose, frequency, and duration of treatment.

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.

[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.

Therapeutic effects of auricular point acupressure on the recovery of patients after pterygium surgery: A pilot study

BACKGROUND

and purpose: Postoperative pain in the pterygium of the eye seriously affects patient recovery. This study was conducted to assess the efficacy of auricular point acupressure treatment on post-operative recovery in patients after pterygium surgery.

MATERIALS AND METHODS

This was a pilot, randomized controlled study. A total of 60 patients (60 eyes) were randomly assigned to two groups. After pterygium surgery, the auricular group was treated using ear acupressure (acupressure points with Cowherb seeds) and the control group was treated using sham auricular therapy (acupressure points without Cowherb seeds). Both groups were treated for one week. Outcome measures included pain score, corneal epithelial score, best-corrected visual acuity, and recurrence rate.

RESULTS

Fifty-three patients completed the study. The mean pain scores and corneal epithelial scores were significantly reduced over time in the auricular group compared with those in the control group (p < 0.05). The time-group interaction for both pain scores and corneal epithelial scores was significant between the two groups (p < 0.05). Simple main effect analysis showed the mean pain scores in the auricular group were significantly lower at each time point (the first 2-h, the first day, the third day and the first week, p < 0.05) than the control group. Mean corneal epithelial scores of the auricular group were significantly lower on the first day and third day respectively than the control group (p < 0.05). There was no significant difference in the best-corrected visual acuity or recurrence rate between the two groups (p > 0.05).

CONCLUSION

Auricular point acupressure accelerates corneal epithelium reconstruction and suppresses postoperative pain, making it an ideal adjunct treatment for postoperative pterygium recovery.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR2000032490 on http://www.chictr.org.cn/.

Recurrent pterygium: A review

Purpose:

To summarize the recent evidence regarding different aspects of pterygium recurrence.

Methods:

Human-based studies from PubMed, Scopus, and Google Scholar were identified using the following keywords: conjunctival disease, pterygium, recurrent pterygium, pterygium recurrence, pterygium management/surgery, conjunctival autograft (CAU), amniotic membrane graft/transplant, and adjuvant therapy (January 2009 to February 2021). We reviewed risk factors associated with the recurrence of pterygium, timing of recurrence, medical treatments to prevent from recurrence, and nonsurgical and surgical alternatives for management of recurrence.

Results:

Dry eye disease, black race, and young age are considered definite risk factors for recurrence. However, fleshy appearance of the pterygium and preoperative size remain controversial. Surgical techniques such as excessive suturing, insufficient conjunctival graft size, thick conjunctival graft with remained Tenon tissue, and postoperative graft retraction are considered possible risk factors for recurrence. Using fibrin glue instead of sutures can further reduce recurrence rates. Although recurrence could occur even after many years, most recurrences happen in the first 3–6 months after surgery. Multiple kinds of adjuvant medications are used before, during, or after the operation including mitomycin C (MMC), 5-fluorouracil (5-FU), corticosteroids, and anti-vascular endothelial growth factors (anti-VEGFs). Multiple weekly subconjunctival 5-FU injections are shown to be safe and effective in halting the progression of recurrent pterygium. Although topical bevacizumab is found to inhibit the growth of impending recurrent pterygium, the effect is mostly temporary. CAU is superior to amniotic membrane transplantation in the treatment for recurrent pterygia.

Conclusions:

There is yet to be a panacea in treating recurrent pterygium. Currently, there is not a globally accepted recommendation for treating recurrent pterygium with anti-VEGFs or 5-FU as a nonsurgical treatment. We strongly recommend using MMC as an adjunct to surgery in recurrent cases, with consideration of its specific complications. CAU is the most effective surgical treatment for recurrent pterygium, and other new surgical therapies need further investigation.

Healing of autologous conjunctival grafts in pterygium surgery

PURPOSE

To temporally study the healing of conjunctival autografts in consecutive patients following pterygium surgery.

METHODS

A case-cohort observational study. Thirty-two eyes of 28 patients who underwent pterygium surgery were included. All eyes had pterygium excision with conjunctival autografts. Twenty-seven eyes of 24 patients underwent excision of primary pterygium while five eyes of four patients had surgery for recurrent pterygium. All grafts were attached using fibrin glue. Mitomycin-C 0.04% was used intraoperatively in 25 eyes. All eyes were followed up at 1, 2, 4, 8, 12 weeks and 6 months postoperatively. Photographs were taken at each visit to monitor graft vessels, re-perfusion and healing. Main outcome measures were graft loss; re-perfusion of grafts and appearance and resolution of oedema, transudation and haemorrhage; approximation of graft edges to host bed and changes at donor site.

RESULTS

No graft tissue was lost. In all eyes, healing of autografts started with graft swelling due to oedema and transudation followed by re-perfusion injury, which manifested as swelling, variable vessels calibre, patchy or diffuse haemorrhage occurring within first week and resolving by fourth postoperative week. Graft vessels anastomose with vessels in surrounding conjunctiva and underlying episclera to re-establish blood circulation. Retraction of graft edges from surrounding conjunctiva was uncommon with rapid epithelialization of exposed (epi)sclera.

CONCLUSION

Conjunctival autografts in pterygium surgery follow a consistent healing pattern dominated by re-perfusion injury in early postoperative days. This produces dramatic changes in the autograft for which patients should be counselled before surgery. Conjunctival autografts are not at risk of falling off, losing epithelial cover or undergoing necrosis.