Pterygium Surgery Utilizing Limbal Conjunctival Autograft and Subconjunctival Amniotic Membrane Graft in High-Risk Populations

Collagen-Based Artificial Cornea for Lamellar Keratoplasty: An Early Case Report

PURPOSE

The aim of this study was to evaluate Viscoll collagen membrane (VCM) for lamellar keratoplasty.

METHODS

A 54-year-old man with grade 4 recurrent pterygium underwent lamellar keratoplasty using VCM as the graft material. Standard keratoplasty postoperative treatments, including topical antibiotic-corticosteroid and artificial tears, were administered.

RESULTS

Complete graft epithelialization was achieved after 4 days of the surgery. Follow-up at 9 months showed no pterygium recurrence as well as good integration of the VCM graft into the surrounding tissues with preserved transparency.

CONCLUSIONS

This case demonstrated that VCM possesses great potential as an alternative to the human donor cornea for lamellar keratoplasty; however, the application of VCM for lamellar keratoplasty still needs additional evaluation.

Amniotic membrane transplantation: structural and biological properties, tissue preparation, application and clinical indications

The amniotic membrane is a single epithelial layer of the placenta. It has anti-inflammatory, anti-scarring, anti-angiogenic and possibly bactericidal properties. The basement membrane of the amniotic membrane acts as a substrate to encourage healing and re-epithelialisation. It has been used in many ocular surface diseases including persistent epithelial defects (corneal or conjunctival), chemical or thermal burns, limbal stem cell deficiency, cicatrising conjunctivitis, ocular graft versus host disease, microbial keratitis, corneal perforation, bullous keratopathy, dry eye disease, corneal haze following refractive surgery and cross-linking, band keratopathy, ocular surface neoplasia, pterygium surgery, and ligneous conjunctivitis. This review provides an up-to-date overview of amniotic membrane transplantation including the structural and biological properties, preparation and application, clinical indications, and commercially available products.

The role of anterior segment optical coherence tomography in the evaluation of the pterygium

BACKGROUND

To evaluate the ability of anterior segment optical coherence tomography (AS-OCT) to visualize the anatomic features of the pterygium and its invasion of the corneal layers.

METHODS

Seventy-five eyes of 54 patients diagnosed with pterygium were included. All subjects underwent complete ophthalmologic examinations, including AS-OCT. The limbus-apex distance, vertical height at the limbus, invasion of the Bowman's and stromal layers, and other morphologic structures of the pterygium tissue were analyzed.

RESULTS

The mean age of the patients was 49.67 ± 16.49 (20-85) years. The mean apex-limbus distance was 2548.37 ± 1026.32 (933-4597) μm, and the mean vertical height at the limbus was 4843.89 ± 1374.10 (1740-7784) μm. A space was observed beneath the pterygium tissue in 44 (58.67%) eyes. The mean width and height of this space were 1756.33 ± 560.22 (1009-3095) μm and 231.70 ± 85.88 (109-465) μm, respectively. Invasion of the Bowman's layer was apparent in 74 (98.67%) eyes, and invasion of the stromal layer was detected in 33 (44%) eyes. A hyperreflective layer was observed beneath the epithelial layer at the edge of the pterygium apex in 31 (41.33%) eyes. In 24 (92.31%) of the 26 advanced pterygium cases and 20 (40.82%) of the 49 early pterygium cases, a subpterygium space was found beneath the lesion (p = 0.0001).

CONCLUSION

AS-OCT enables measurement of the actual size and thickness of pterygia, assessment of invasion of the Bowman's and stromal layers of the cornea, and evaluation of the pterygium structure. Over half of the eyes exhibited space beneath the pterygium.

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

Background

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

Methods

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

Results

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

Conclusion

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

Optimization of the Ocular Surface Through Treatment of Ocular Surface Disease Before Ophthalmic Surgery: A Narrative Review

Ocular surface disease commonly exists in individuals requiring ophthalmic surgery and may compromise the structure and function of ocular surface components. Ophthalmic surgery may further affect the ocular surface by injuring the epithelium and sensory nerves, disrupting the tear film, or causing local inflammation. Medical management of ocular surface disease prior to ophthalmic surgery aids in reducing inflammation, resolving infection, improving epithelial pathology, stabilizing the tear film, and easing patient symptoms, promoting positive long-term outcomes and minimizing the incidence of postoperative complications. This review summarizes frequently encountered ocular surface diseases and available preoperative medical management options, discusses common ophthalmic surgeries and their effects on the ocular surface, examines potential postoperative complications, and defines recommendations for postoperative ocular surface maintenance.

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.