A comparative study of conjunctival autograft and minimally invasive pterygium surgery in primary pterygia

Epidemiologic characteristics and the change of surgical methods of pterygium and pseudopterygium from 2013 to 2019 in China: A retrospective analysis

Introduction

Pterygium is a common multifactorial external eye disease, which causes various ocular symptoms and negatively affects appearance. The aim of this study was to analyze the epidemiological characteristics and the change of surgical methods of pterygium and pseudopterygium in China from 2013 to 2019.

Materials and methods

This study was a hospital-based nationwide retrospective study to estimate the epidemiologic characteristics and the change of surgical methods of pterygium and pseudopteygium in China from 2013 to 2019. The data was extracted from the Hospital Quality Monitoring System (HQMS) database. The diagnosis was based on the tenth revision of the International Classification of Diseases (ICD-10) code.

Results

Our study included 1,007,800 pterygium and 2,681 pseudopteygium inpatients. From 2013 to 2019, the proportion of pterygium and pseudopterygium patients who underwent surgery, among all ophthalmology inpatients, increased from 3.3% in 2013 to 7.84% in 2019. The male-female ratio of surgically treated pterygium and pseudopterygium is 1:1.8 and 1.6:1 respectively. Among all age groups, the hospitalized pterygium patients who received surgery were mainly 60-69 years old, accounting for 36.53%. The pseudopterygium patients who received surgery were mostly 50-59 years old, accounting for 24.02%. Among the 31 provinces of mainland China, Yunnan Province has the highest proportion of pterygium patients treated surgically (6.40%), while Shanghai has the highest proportion of pseudopterygium patients treated surgically (12.98%). The most common occupation of participants in the study was farmer, accounting for 47.62% and 28.53%, respectively. During the study period, the application of autologous stem cell transplantation increased year by year, and became the first choice for pterygium and pseudopterygium surgery.

Discussion

This study was the first to describe the epidemiological characteristics and surgical methods of hospitalized pterygium and pseudopterygium patients in China. This study provides important information for better diagnosis, treatment and prevention of pterygium and pseudopterygium.

Optimal size of pterygium excision for limbal conjunctival autograft using fibrin glue in primary pterygia

BACKGROUND

In our study we describe a method that optimizes size of excision and autografting for primary pterygia along with the use of intraoperative MMC and fibrin glue. Our objective is to propose a simple, optimizedpterygium surgical technique with excellent aesthetic outcomes and low rates of recurrence and otheradverse events.

METHODS

Retrospective chart review of 78 consecutive patients with stage III primary pterygia who underwent an optimal excision technique by three experienced surgeons. The technique consisted of removal of the pterygium head, excision of the pterygium body and Tenon's layer limited in proportion to the length of the head, application of intraoperative mitomycin C to the defect, harvest of superior bulbar limbal conjunctival graft, adherence of graft with fibrin glue. Outcomes included operative time, follow up period, pterygium recurrence, occurrences of incorrectly sized grafts, and other complications.

RESULTS

All patients were followed up for more than a year. Of the 78 patients, there were 2 cases of pterygium recurrence (2.6%). There was one case of wound dehiscence secondary to small-sized donor conjunctivaand one case of over-sized donor conjunctiva, neither of which required surgical correction. There were no toxic complications associated with the use of mitomycin C.

CONCLUSION

Correlating the excision of the pterygium body and underlying Tenon's layer to the length of the pterygium head, along with the use intraoperative mitomycin C, limbal conjunctival autografting, and fibrin adhesionresulted in excellent outcomes with a low rate of recurrence for primary pterygia.

Mitomycin C in pterygium treatment

Pterygium is a benign lesion usually growing from the nasal side of the conjunctiva onto the cornea. Most cases of pterygium does not cause problem or requires specific treatment. The exact cause of pterygium is not clear yet, but some factors are pointed as causes, being the most important the long-term ultraviolet ray exposure. Pterygium surgery is usually considered when there are symptoms that do not respond to conservative treatment. Recurrence is the main complication of the surgery, and much has been done to avoid it. Mitomycin C (MMC) has been used as a fibroblast proliferation inhibitor during the surgery to reduce the chance of recurrence of the pterygium. This review describes the use of MMC as an adjunctive, the optimal dosage, the duration of administration of MMC and possible complications, when used during, after and before the surgery. Most studies suggest that increased exposure (dose or duration) of MMC is associated with a lower recurrence, but with higher risks of complications.

Recurrence rate with use of intraoperative Mitomycin C versus Conjunctival Autograft following pterygium excision

Objectives: To determine the recurrence rate following Conjunctival Autograft versus Mitomycin C for pterygium excision.

Methods: Fifty Patients in this Randomized Clinical Trial who underwent pterygium excision from July 2013 to October 2013 at Department of Ophthalmology, Ziauddin University Hospital, Keamari, Karachi were included. All patients underwent detailed ophthalmic examination before surgery. Few drops of lidocaine were instilled, subconjunctival xylocaine 2% was injected. The pterygium was then excised from bulabar conjunctiva and peeled off from the corneal surface. Mitomycin C was applied to bare sclera in group A and Conjunctival autograft taken from superior bulbar conjunctiva of same eye was sutured to the bare sclera in group B. Data for pterygium recurrence was collected and analyzed using SPSS version 17.

Results: Among the 50 patients operated 64% (n=32) were male and 36% (n=18) female. Their age ranged from 28 -58 years with mean age 44.8yrs. Right eye was affected in 54% (n= 27) patients and left in 46% (n= 23). In group “A” (intraoperative MMC) conjunctival granuloma was noted in 1(4%), pterygium recurrence 4(16%) and ocular irritation was experienced by 5 (20%) patients. In group “B” (CAG) graft retraction was seen in 2(8%), patients, 1(4%) patients experienced persistent redness over the grafted tissue and pterygium recurrence was seen in 2(8%) patient. All of them were followed at day 1, week1, week 4 and week 12.

Conclusion: Both Conjunctival Autograft and Mitomycin C are effective in reducing the recurrence of pterygium but CAG gives better cosmetic results, the only drawback with it is the duration of the procedure.

Concomitant examination of inflammation and angiogenesis in the pathogenesis of primary moderate pterygium in a well-designed case-control study

Pterygium is a common ocular lesion whose exact etiology is a point of contention. Chronic inflammation and angiogenesis are two major proposed mechanisms of the disease in the current literature. The objective of this study is to examine these two mechanisms in a very well-designed setting. In a case-control study, 24 tissue specimens from the patients with primary moderate pterygium (cases) and 15 specimens excised from the nasal bulbar region in healthy counterparts (controls) were compared in terms of the count of mast cells (inflammation), as well as the status of Cd31/vascular Endothelial Growth Factor (VEGF) expression (angiogenesis) in Tabriz Nikookari and Sina Teaching Hospitals. The case (mean age: 58.08 +/- 10.03 years, 84% males) and control (Mean age: 62.33 +/- 9.19 years, 80% males) groups were age-and sex-matched (p = 0.19, 0.75, respectively). The mean mast cell count was significantly higher in the case group (27.72 +/- 15.19 versus 12.00 +/- 7.09 cells mm(-2), p = 0.001). The study of immunoreactivity revealed that the positive expression (moderate-severe) of CD31 was significantly more frequent in the case group (88 versus 26.7%; p<0.001; Odds ratio = 20, 95% confidence interval 3.85-100). There was also higher rate of VEGF-positive (moderate-severe) cells in the group with pterygium (88 versus 20%; p<0.001; Odds ratio= 33.3, 95% confidence interval 5.00-100). This study indicates that both inflammation and angiogenesis play pivotal role, in parallel, in pathogenesis of pterygium.