Prickly pear spine keratoconjunctivitis.

OBJECTIVES: To study the ocular and extra-ocular features, clinical presentation, and treatment of prickly pear glochids.
MATERIALS AND METHODS: This retrospective study included 23 eyes of 21 patients with ocular prickly pear spines who were seen between August and October 2011 in the outpatient ophthalmic clinic at Prince Rashid Bin Al Hassan military hospital in Jordan. Medical records of patients including age, gender, history of exposure to prickly pear plants, and ocular examination were reviewed. All glochids were localized and removed with forceps under topical anesthesia with the patient at the slit lamp. Patients were followed up after one week.
RESULTS: The mean age of patients was 37.1 years with a male to female ratio of 1.6: 1. Involvement of the right eye was seen in 61.9% patients, left eye in 28.6% patients, and bilateral involvement in 9.5% patients. Glochids were most commonly found in the upper subtarsal conjunctival space (47.6%) followed by inferior palpebral conjunctiva in 23.8% eyes. The most common complaint was eye irritation in 95.2% patients. Pain was a complaint in 57.1% patients. Superior corneal epithelial erosions or ulcer were found in 33.3% patients, inferior corneal epithelial erosions in 19.1% patients, and diffuse epithelial erosions in 9.5% patients. Glochids were found in other parts of the body in 38.1% patients.
CONCLUSION: Although prickly pear glochid ocular surface injury is not uncommon in the region during summer, it should be considered in patient with eye pain during that period. Farmers who are in close contact with prickly pears should use protective eyeglasses and gloves.

INTRODUCTION

Opuntia, which was named for the Ancient Greek city of Opus, is a genus in the cactus family, Cactaceae. There are more than 200 species that belong to opuntia, and prickly pears are one of them.1

Prickly pears are found all over the Mediterranean area, and in Jordan, they are grown by the side of farms for food, decoration, and as natural barriers to protect from animals.

Prickly pears, which are known also as Sabr in Jordan that means patience because they can withstand harsh weathers, Sabra in Israel,2 teen shouky in Egypt, Hindi which means Indian figs in Libya, and tuna in Spanish,3 have large flat pads and thorny fruits that ripen through late July to September.

The fruit of the prickly pear cactus, which is called Chumbo, is sold in summer by street vendors in Jordan, and is considered a nice refreshing fruit that is rich with vitamin C.

Chumbo has small, hair-like semi-translucent yellow prickles; about 2 mm in length, called glochids that easily detach from the plant and penetrate skin, so it has to be peeled carefully to remove the small spines on the outer skin before consumption. If the outer layer is not properly removed, glochids can be ingested, causing discomfort of the throat, lips, and tongue, as the small spines are easily lodged in these sites including the skin.

In scanning electron microscopy, the distal tip of the glochid was found to be spear-shaped and to end in a fine point. Parallel fibrous bundles extended proximally from this point and spiral in a clock-wise direction. The individual bundles are fairly short. Each terminates in a sharp point directed towards the base of the glochid, but detached and angulated outwards to form a barb. Successive bundles and barbs in spiral rows extended back to surround the conical base of the glochid.4

In Jordan, the fruits are harvested with a special tool connected to a long stick, and the glochids are removed by rolling the fruit in sand and brushed then soaked in water before peeling the skin. If the farmer stands against the direction of the wind while harvesting, cleaning, or peeling the skin of the fruits, the glochids might be blown into the eyes. Unless it is removed from the eye, it may cause ocular morbidity like conjunctivitis and keratitis.5

The latex (milky sap) of other Cactaceae species such as Euphorbia tirucalli (pencil cactus), which is usually used as a house plant for landscaping, is very irritant and toxic to the eye and skin. If the latex comes in contact with eye, a severe chemical burn might occur that may lead to reversible or permanent ocular surface damage.67

This study was conducted retrospectively at Prince Rashid Bin Al Hassan military hospital in Irbid northern Jordan to study the ocular and extra ocular features, clinical presentation, and treatment of prickly pear spines on a cohort of patients who had eye complaints secondary to prickly pear spines.

MATERIALS AND METHODS

This retrospective study included 23 eyes of 21 Jordanian patients with ocular prickly pear spines who were seen over 3 months period between August and October 2011 in the outpatient ophthalmic clinic at Prince Rashid Bin Al Hassan military hospital in Irbid, north Jordan. Medical records of patients including age, gender, history of exposure to prickly pear plants, clinical examination (visual acuity, eyelids, slit lamp bio-microscopy examination of the palpebra, fornices, bulbar conjunctiva, cornea, anterior chamber, iris, lens, fundus evaluation, and applanation tonometry) were reviewed and analyzed.

The clinical diagnosis of ocular prickly pear spines was based on patients’ history and slit lamp biomicroscopy with double eyelid eversion [Figure 1]. All prickly pear spines were localized and removed with forceps under topical anesthesia using Minims® Lidocaine and Fluorescein (Bausch and Lomb, Rochester, NY, USA) under the slit lamp. After removal of the spines, all patients received topical antibiotic eye ointment and steroid eye drops. Patients were seen in the second day to search for more spines and then followed up after one week.

Figure 1

Everted upper eyelid showing a glochid penetrating the tarsal conjunctiva

Any patient with conjunctival foreign body other than prickly pear spines, patients with no history of exposure to prickly pear spines or non-Jordanian patients were excluded from the study.

An approval from the ethical committee of the Royal medical services of Jordan was obtained before starting the study.

RESULTS

The mean age of patients was 37.1 years with a male to female ratio of 1.6: 1 [Table 1], which shows the demographic data, location of the glochid in the eye, clinical picture, and extra ocular locations. Involvement of the right eye was seen in 13 (61.9%) patients, left eye in 6 (28.6%) patients, and bilateral involvement in 2 (9.5%) patients. The prickly pears spines were most commonly found in the upper subtarsal conjunctival space in 10 (47.6%), [Figure 2] followed by inferior palpebral conjunctiva in 5 (23.8%) eyes, [Figure 3] superior bulbar conjunctiva in 3 (14.3%) eyes, forniceal conjunctiva in 2 (9.5%) eyes, temporal and nasal bulbar conjunctiva in 2 (9.5%) eyes, and superior palpebral conjunctiva in 1 (4.8%) eye. The most common complaint was eye irritation in 20 (95.2%) patients, and this symptom was absent only in patient with forniceal conjunctival prickly pear spines. Pain was a complaint in 12 (57.1%) patients and photophobia in 9 (42.9%) patients. All patients had conjunctival congestion. Superior corneal punctate epithelial erosions or ulcer was found in 7 (33.3%) patients, [Figure 4] inferior corneal punctate epithelial erosions in 4 (19.1%) patients, and diffuse punctate epithelial erosions in 2 (9.5%) patients. Prickly pear spines were found in other parts of the body in 8 (38.1%) patients [Figure 5].

Table 1

Demographic data, location of the glochid in the eye, clinical picture, and extra-ocular locations

Figure 2

Everted upper eyelid showing a glochid penetrating the superior subtarsal space

Figure 3

A glochid penetrating the inferior palpebral conjunctiva

Figure 4

Corneal erosion and skiing marks caused by upper subtarsal glochid, demonstrated by fluorescein stain

Figure 5

A glochid penetrating the skin of the distal phalanx of the left ring finger

DISCUSSION

Patients with conjunctival foreign body are usually seen in the ophthalmic emergency unit with eye pain due to ocular surface mechanical damage.

Ocular surface damage inflicted by vegetable matter may be of variable severity from mild local conjunctival reaction to the loss of an eye.8

Glochids easily detach from the plant and penetrate skin, and if left in skin, it cause dermatitis.2 If the glochids are blown into the eyes, they may penetrate the conjunctiva and cause conjunctivitis and keratitis. Glochids rarely penetrate the cornea because of natural eye protective mechanisms like menace reflex that cause eyelid closure, Bell's phenomenon, and reflex tearing that washes them outside the eye. None of our patients had glochids in the cornea. Only one case has been reported in the literature, which involved cactus spines embedded deep in the cornea reaching the anterior chamber in a young male, which were removed with the aid of a fiberoptic illuminator.9

Ocular morbidity caused by prickly pear fruits spine usually affect male farmers who do not use protective eyeglasses while harvesting the crop or while cleaning or peeling the skin of the fruits. In this study, most of the patients were male farmers who do not comply with work precautions by using protective eyeglasses, long sleeves, and gloves. Accidental contact with skin or eyes in non-farmers is very rare and usually seen in patients on picnic in the countryside.

Most of the patients had right eye involvement, and only 2 (9.5%) patients had both eyes affected, and those patients were standing against the direction of the wind in front of the plants and not using protective eyeglasses.

The prickly pears spines were most commonly found in the upper subtarsal conjunctival space (10 (47.6%) patients), and this may be due to the spear-shape of the glochid and the presence of successive bundles and barbs in spiral rows extending back to surround the conical base of the glochid that cause the glochid to move in one direction toward a space during blinking or eye movement.4

When the glochids come in contact with the ocular surface and if it has not penetrated the conjunctiva, yet it causes foreign body sensation and irritation, and if the patient rubs the eye, it moves toward the fornices or superior subtarsal space_[Figure 2]. Hence, it is imperative to evert and sometimes to double evert the eyelid in patients with eye pain with a history of direct contact with cactus plants.

The most common complaint was irritation, and this is due to the presence of the prickly pear spine on the ocular surface that irritate the eye with blinking and eye movement, and this complaint was absent in one patient with forniceal conjunctival prickly pear spines only.

Superior subtarsal prickly pear spines caused corneal erosions or ulcers either superiorly or diffusely while inferior palpebral cases cause inferior corneal erosions [Figure 4].

Removal of the glochids from the conjunctiva after instillation of topical anesthesia resulted in immediate relieves of symptoms, and patients were given topical antibiotic eye ointments and steroid four times daily to prevent infection, enhance corneal epithelial healing, and treat conjunctival congestion. On the next visit, one week later, all patients were free of symptoms and signs and were discharged from the clinic.

Prickly pear spines were found in other parts of the body in 8 (38.1%) patients. Exposed skin of the upper limb was most commonly involved in 7 (33.3%), and none had papules or pustules [Figure 5]. The symptoms disappeared after mechanical removal of the spines with forceps.

Cactus dermatitis is a common problem among harvesters of cactus fruit. The glochids are responsible for most of the dermatitis.10

None of the patients had dermatitis, and this is because patients were seen at the same day or the next day after the onset of pain after pricking.

One patient who had inferior palpebral glochid had pain at the tip of the tongue that was enhanced with talking; he claimed that pain started when he ate a chumbo. He was sent to the dentist and oral surgeon who removed one prickly pear spine from the tip of his tongue.

CONCLUSION

Although prickly pear spine ocular surface injury is not uncommon in the Mediterranean region during summer, it should be kept in mind in any patient with eye pain during that period. As the color of the glochids is yellow and they are translucent, it is sometimes difficult to locate them at the ocular surface, especially when fluorescein stain is used. Farmers who are in close contact with prickly pears should use protective eyeglasses, long sleeves, and gloves.