**4. Discussion**

were followed up from 12 to 14 months after injection (the mean follow-up period was 12 months). According to this study, 22.50% were farmers, 45% were housewives, and 32.50%

Within 1–3 days after the subconjunctival injection of MMC, 6 patients complained of irritation accompanied with mild conjunctiva swelling, hyperemia, and tearing (15%). These processes were controlled completely by using betamethasone 0.1% more frequently within 1 week. The pterygia were less vascular and less inflamed at the 6th-month visit after MMC injection.

We detected the reduced size of pterygium (mean size before MMC injection: 5.3mm (base) ×2.3 (apex) ×2.4(length) vs. mean size after MMC injection: 5mm (base) ×2.1mm (apex) ×1.56mm (length)) with mean 0.48 mm (base means: up to down of pterygium in limbos, apex means: end of pterygium in cornea that were evaluated by biomicroscope measurement (slit-lamp)). The size of pterygium was reduced in 83% of cases, and in all cases there were not seen progression and reduced the amount of astigmatism (mean 0.27 diopter) in 70% cases that were evaluated by topography and keratometry {p=0.00} (Table 2). We also detected no

**Sex Job Eyes Age**

**Before injection After injection P Value**

**<sup>s</sup> Others Left Right <40 years >40 years**

**hemorrhage pigmentation**

**Housewive**

**Hyperemia Tearing Long discomfort Subconjunctival**

Average of size pterygium 2.40 1.56 P=0.00 Average of refraction 1.19 0.92 P=0.00 Average of keratometry 1.67 1.33 P=0.00

 + + **- - -** + + + **- - -** + + **- -** + **-** + **- -** + + + + **-** + **- - - -**

Number 18 22 9 18 13 16 24 16 24 Percent 45% 55% 22.50% 45% 32.50% 40% 60% 40% 60% Total 40 100% 40 100% 40 100% 40 100%

significant change in visual acuity and intraocular pressure.

**Table 1.** The prevalence of study participant according to sex, job, age, and affected eye

**Male Female Farmer**

**Table 2.** Dear Authors, please add Caption

**Table 3.** Complication of MMC injection in 6 patients

had other occupations.

72 Advances in Eye Surgery

Primary pterygium is one of the most common corneal disorders in topical countries such as India and south of Iran [4, 19]. A wide range of surgical procedures for removal of pterygia have been reported over the past decade, and several techniques are now available for the ophthalmic surgeon to choose from [4].

This study evaluated efficacy and complications of subconjunctival injection of MMC in treatment of primary pterygia. In fact, the potent effect of topical MMC on the conjunctiva epithelium has been demonstrated by its ability to prevent the recurrence of conjunctival intraepithelial neoplasia [14]. We use 0.1 ml of 0.2 mg/ml of MMC. Chen et al. [12] showed that a concentration of 0.10 mg/ml MMC inhibits fibroblast replication and that concentrations of 0.3 mg/ml actually cause death of fibroblasts.

Intraoperative use of MMC significantly retards epithelial healing in a dose-related manner in rabbit corneas [15]. In our study, 6 patients complained of irritation accompanied with mild conjunctiva swelling, hyperemia, and tearing (15%). These processes were controlled com‐ pletely by using betamethasone 0.1% more frequently within one week. The pterygia were less inflamed at the 1st-month visit after MMC injection.

Recently, a new study evaluated adjunctive subconjunctival MMC (0.1 ml of 0.15 mg/ml) before pterygium excision. They reported recurrence rate of 6% with no sever complications [20, 21].

The advantage of low-dose subconjunctival MMC is that it is effective in preventing pterygium recurrence yet avoids the ocular surface toxicity associated with epithelial and bare sclera delivery of the medication. The medication is administered directly to the activated fibroblasts in the subconjunctival space, where it can work to avoid or diminish long-term epithelial healing difficulties associated with MMC. Intraoperative and postoperative MMC are two methods of adjunctive therapy that have been most commonly reported recently [22]. At the present time, we injected low dose subconjunctivally 0.1 ml of 0.2 mg/ml of MMC. Our shortterm experience with MMC consistently shows no severe complications and reduces recur‐ rence rate; these findings are similar to the study by Raiskup F et al. in 2004 [22]. Most of the complications of MMC are associated with persistent epithelial defects and ischemic sclera necrosis. Both of these complications are secondary to side effects produced by the direct action of MMC on these tissues. Because the epithelium and sclera are not target tissues for the MMC and because inadvertently treating these tissues does not contribute to the prevention of pterygia recurrence but is associated with significant side effects, the conjunctiva epithelium and sclera should be avoided. With subconjunctival application of MMC, the epithelial and sclera toxicity can be diminished; this occurred in our study. Eric D Donnenfeld et al reported that subconjunctival injection of MMC is an effective treatment before pterygium excision [23]. We chose their method but we used MMC in higher concentration (0.1 ml of 0.2 mg/ml) to reduce the size of pterygium.

In our study, the size of pterygium was reduced in 83% of cases and in all cases there were not seen progression and the amount of Astigmatism reduced (mean 0.27 diopter) in 70% cases that were evaluated by topography and keratometry (Table 1). In research by Khakshoor H et al, they found that subconjunctival injection of MMC reduced size and recurrence rate of pterygia [24]. Our study shows similar results. Also in another study, Oguz H, in Nassau University Medical Center, East Meadow, New York, USA [25], studied 36 eyes of 36 patients prospectively that received 0.1 ml of 0.15 mg/ml MMC subconjunctivally injected into the head of the pterygium 1 month before bare sclera surgical excision. He reported: the pterygia resolved in 34 (94%) of 36 eyes, with a recurrence rate of 6% over a mean follow-up of 24.4 months. No wound-healing complication developed in any patient. Their findings are similar to our study.

Therefore, low recurrence rate and safety profile with a mean follow-up of longer than 12 months without complication show the efficacy of this treatment and compare favorably with previous studies with MMC in the treatment of pterygia.

Limitation of the study: Despite the fact that we did not observe any significant short-term complications after MMC use, we are aware that only 40 patients were available for evaluation in our study.

We feel that adjunctive use of MMC for pterygium is a safe procedure, but requires a strict selection of patients, controlled use of MMC, and long-term follow-up of these patients. In particular, a very long follow-up of the avascular conjunctival area is required.
