Argon Laser Photoablation for Treating Benign Pigmented Conjunctival Nevi

Abstract

Purpose:

To evaluate the outcomes of argon laser photoablation of benign conjunctival pigmented nevi with different clinical presentations.

Patients and Methods:

This interventional case series was conducted between July 2014 and January 2015. Patients presenting with benign conjunctival nevi were included. Data were collected on the clinical features at presentation, argon laser photoablation, and follow-up at 8 and 24 weeks. Postoperative photography allowed recording of the success of each case and the overall success rate. Complete removal of conjunctival pigments was considered an absolute success. Partial pigmentation requiring repeat laser treatment was considered a qualified success.

Results:

There were 14 eyes (four right eyes and ten left eyes) with benign pigmented conjunctival nevi. There were three males and eight females in the study sample. The median age was 36 (25% percentile: 26 years). Three patients had bilateral lesions. The nevi were located temporally in nine eyes, nasally in three eyes, and on the inferior bulbar conjunctiva in two eyes. The mean horizontal and vertical diameters of nevi were 5 ± 2 mm and 4 ± 2.7 mm, respectively. The mean follow-up period was 5 months. Following laser treatment, no eyes had subconjunctival hemorrhage, infection, scarring, neovascularization, recurrence, or corneal damage. The absolute success rate of laser ablation was 79%. Three eyes with elevated nevi had one to three sessions of laser ablation resulting in a qualified success rate of 100%.

Conclusions:

Argon laser ablation was a safe and effective treatment for the treatment of selective benign pigmented conjunctival nevi in Arab patients.

INTRODUCTION

Conjunctival nevus is a common benign ocular tumor that can manifest with a spectrum of clinical features.¹ It can be located on the bulbar conjunctive, the caruncle, plica, fornix, tarsal region, or cornea. Conjunctival nevi can be brown, tan, or amelanotic. Cases are documented with or without feeder or intrinsic vessels and they can be cystic or noncystic.²

Treatment of benign conjunctival nevi is surgical and is indicated to prevent transformation into malignant melanoma or for esthetics. Treatment options include surgical excision and argon laser photoablation.³,⁴,⁵ Manual surgical excision of a nevus often requires hospitalization and close monitoring during the postoperative recovery period. Hence, manual surgical excision is costly and could lead to scarring and neovascularization, especially if the nevus is large.³

Argon laser photoablation is an alternative treatment for conjunctival nevi. Some have claimed it is safe, fast, and more economical.³,⁴,⁵ Advantages of the argon laser ablation include the lack of sutures, less pain, no scarring, and a uneventful recovery period. Promising outcomes have been reported for superficial conjunctival nevi in Asian patients.³,⁵ To the best of our knowledge, outcomes of argon laser of conjunctival nevi in Arab patients are not published.

In our study, we evaluate argon laser photoablation for the treatment of benign conjunctival pigmented nevi with different clinical presentations.

PATIENTS AND METHODS

The Institutional Ethics and Research board of Specialised Medical Center approved this study. Written informed consent of the participants was obtained. Patients who consented to participate and met the inclusion criteria were enrolled in this study. The study was performed between July 2014 and January 2015.

Study participants were selected from patients presenting to the outpatient clinic with clinically benign pigmented conjunctival nevi who requested removal of the lesions for cosmetic reasons. Argon laser photoablation was performed for cases with the following inclusion criteria: Benign pigmented nevi located at the bulbar conjunctiva that were freely mobile overlying or underlying the sclera and were stable without any change in size or color in the last 6 months and without corneal involvement.

Each patient underwent a comprehensive ophthalmic examination. Anterior segment eye examination was performed with slit-lamp bio-microscopy (Haag-Streit AG, Koeniz Switzerland). The posterior segment and peripheral retina were assessed using slit-lamp and +78 D Volk lens (Volk, Kyoto, Japan).

Clinical presentation of conjunctival nevi including color, site, size, cystic changes, feeder vessels, and intrinsic vessels were noted. All laser ablations were performed by an ophthalmologist using an argon green laser (532 nm) after application of topical anesthetic eye drops (Benoxinate hydrochloride 0.4%). The laser was directly focused on an area of the nevus, with a spot size of 100 microns without overlap, the duration of the laser pulse was 0.1 s, and laser energy delivery ranged from 100 to 300 mW. Laser application was stopped after hearing a popping sound and visual confirmation of a reaction over the pigmented lesion such as shrinkage, darkening, elevation, and bubble formation. After photoablation, the nevus was removed by gentle rubbing with a cotton-tipped swab. Postoperatively, all patients were prescribed antibiotic and steroid eye drops (dexaflox) QID for 1 week.

Follow-up visits were at day 1, 6, and 24 weeks after laser treatment. All patients underwent slit-lamp bio-microscopy and anterior segment photography to compare the status of conjunctival nevi before and 6 and 24 weeks after laser treatment.

The absence of a pigmented nevus on the bulbar conjunctiva at 24-week follow-up after the first laser treatment was considered an absolute success. If more than one session of laser was required for residual pigmented nevus, it was considered a qualified success. Presence of pigmented nevus, 24 weeks following last laser treatment was defined as failure of treatment.

RESULTS

This study included 14 eyes of 11 patients (three males and eight females). The median age was 36 (25% percentile: 26 years). The mean duration of follow-up was 20 weeks (range, 8–32 weeks).

There were nine cases of nevi located at the temporal bulbar conjunctiva, three cases of nevi at the nasal bulbar conjunctiva, and two cases of nevi at the inferior bulbar conjunctiva. The mean horizontal and vertical diameters of nevi were 5 ± 2 mm and 4 ± 2.7 mm, respectively.

Clinically, all nevi were flat and brown with no feeder or intrinsic vessels except in two eyes where one nevus was cystic, elevated, with a feeder vessel; the second nevi was partly elevated [Figures 1 and 2].

Figure 1.

Eye with flat conjunctival nevus before and 1 month after laser photoablation. Figure on the left side is before and figure on the right side is 1 month after procedure

Figure 2.

Eye with raised conjunctival nevus before and 1 month after laser photoablation. Figure on the right side is before and figure on the left side is 1 month after procedure

All nevi except two were successfully removed with one session of argon laser photoablation. The two nevi that were not removed with one laser ablation session were the elevated, cystic nevus, and the elevated portion of the other nevus. Both nevi were surgically removed and sent for pathology after failed argon laser treatment.

Argon laser application resulted in an immediate and complete disappearance of all flat conjunctival nevi after rubbing them with a sterile cotton-tipped swab directly after the procedure [Video 1].

Patients were followed for a median duration of 20 weeks (25% quartile 8 weeks; minimum, 8 weeks and maximum, 32 weeks).

All patients had conjunctival hyperemia that lasted for 2 days and then resolved. There were no cases of significant complications such as subconjunctival hemorrhage, infection, scarring, neovascularization, recurrence, or corneal damage.

DISCUSSION

This study confirmed the positive effect of laser photoablation as a mode of managing conjunctival nevi in a patient friendly procedure in Arab patients. This procedure was safe as there were no vision-threatening complications. The effect of argon laser photoablation on a flat nevus is instant, however raised nevi require more sessions of laser treatment.

In an Egyptian study, benign nevi comprised 45% of histological samples that were sent to rule out malignancy.⁶ This would be a gross underestimation as many flat nevi are accepted as birthmarks and are often not managed.⁷ Cosmetic consultations are, however, fundamental when the nevi are in an exposed region of the conjunctiva. Surgical excision of lesion was the treatment option. However, photoablation of tissue is an alternative that is now available to manage conjunctival nevi. Argon laser is used in a number of ophthalmic procedures to manage glaucoma, corneal pathology, and retinal diseases.⁸,⁹ In an advance ophthalmic unit, an argon laser is usually available and can be used for conjunctival lesions without a significant investment.

CONCLUSION

Compared to manual excision, in-office laser application requires less time, is less costly, more client friendly, and with least risk of recurrence. We found that argon laser application was highly successful, without any major complications. Further longitudinal studies or randomized controlled trials are recommended to increase the use of argon laser photoablation.

For flat nevi, the energy required to ablate is minimal and predictable compared to nevi that are thick and pigmented. More than two sessions of argon laser photoablation could achieve the goal without damaging host tissue.

Videos available on: www.meajo.org

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.