Medical Care
Patients with pterygium can be observed unless the lesions exhibit growth toward the center of the cornea or the patient exhibits symptoms of significant redness, discomfort, or alterations in visual function. Pterygia can be removed for cosmetic reasons, as well as for functional abnormalities of vision or discomfort. [24]
Surgical Care
Surgery for excision of a pterygium is usually performed in an outpatient setting under local or topical anesthesia with sedation, if necessary.
A prospective, randomized, interventional study by Kheirkhah et al assessed 56 patients who underwent pterygium excision with MMC application and an amniotic graft. [25] Of those 56 patients, 28 received MMC on the perilimbal bare sclera from 1-5 minutes, whereas 28 other patients received MMC under the conjunctiva. Endothelial cell studies revealed loss of 3.4% of cells in the bare sclera group compared with 4.8% in the subconjunctival group at 6 months. No complications were observed in either group; however, the study was small.
A prospective, nonrandomized study by Bahar et al examined the risk of endothelial cell loss in 43 subjects following pterygium surgery with MMC and conjunctival autograft. [26] The study included a control group who had a primary pterygium excision without MMC. Although the number of patients in each group was small, the patients who received MMC experienced a 4% reduction in endothelial cells at 3 months, compared with no loss in the control group. This suggests that MMC can affect the endothelial cell counts in patients undergoing pterygium excision.
Despite the relatively small sample sizes, both studies reported statistically significant decreases in corneal endothelial cell counts (P values ≤0.05) as long as 3 months after surgery. The authors note that placement of MMC at the limbus can be a risk factor for scleral melts. Thus, the authors advise placement of MMC only in the area of the fibrovascular conjunctival tissue.
Hirst initiated a prospective nonrandomized study of an evolution of previous pterygium surgical techniques involving extensive excision of overlying conjunctiva and underlying Tenon fascia in the vicinity of the pterygium, combined with a large, limbal-sparing autograft harvested from the superior conjunctival surface. [27] Hirst subsequently published his longer-term results after more than 1000 surgeries, including 806 primary pterygia and 194 recurrent pterygia. The author had a follow-up of longer than 1 year in 99% of those patients, with a mean follow-up of 616 days. The author reported only one recurrence among those 1000 patients, significantly lower than has been previously reported for both primary and secondary pterygium surgeries. [28]
This technique did not require the use of antimetabolites and it spared limbal stem cells at the site of conjunctival autograft harvesting. In addition to a reduction in expected recurrences, Hirst also reported a lower rate of postoperative complications with fewer than expected postoperative granulomas and fewer than expected conjunctival inclusion cysts.
In a prospective chronological study of 60 eyes in 53 patients, Yin, et al found a statistically significant reduction in recurrence with the use of interferon (IFN) alpha-2b eye drops, 4 times per day for 3 months postsurgery. After 12 months, the recurrence rate in control eyes was 33.3%, compared with a recurrence rate of 7.4% in the treatment group. The difference between the two groups was statistically significant (P = 0.048). The recurrence rates at the end of 18 months were the same. Adjunctive interferon alpha-2b eye drops in the postoperative period may be a useful addition to present therapy. The study is limited by the 18-month follow-up period. [29]
Postoperatively, the eye is generally patched overnight, and it is treated subsequently with topical antibiotics and anti-inflammatory drops and/or ointments.
Prevention
Theoretically, minimizing exposure to ultraviolet radiation should reduce the risk of development of pterygium in susceptible individuals. Patients are advised to use a hat or a cap with a brim, in addition to ultraviolet-blocking coatings on the lenses of glasses/sunglasses to be used in areas of sun exposure. This precaution is even more important for those patients living in tropical or subtropical areas or for those patients who are engaged in outdoor activities with a high risk of ultraviolet exposure (eg, fishing, skiing, gardening, outdoor construction work).
Further Outpatient Care
Postoperatively, after pterygium excision, the topical steroids are slowly tapered. Patients on topical steroids need to be observed to reduce the risk of related problems, such as elevated intraocular pressure and cataracts. [30]
