Curative effect assessment of bandage contact lens in neurogenic keratitis

Abstract

AIM

To observe the curative effect of bandage contact lens in neurogenic keratitis.

METHODS

Twenty cases of neurogenic keratitis were studied at the Department of Ophthalmology, the first Affiliated Hospital of China Medical University, between October 2012 and June 2013. These included 13 males and 7 females, aged from 35 to 88y. Patients were voluntarily divided into an experimental group (lens wearing group, n=10) and control group (drug therapy, n=10). In experimental group patients wore silicone hydrogel bandage soft contact lens. Both groups used the following eyedrops: 0.5% levofloxacin TID; 0.5% Sodium carboxymethyl cellulose QID; fibroblast growth factor BID; ganciclovir BID [cases complicated with herpes simplex virus (HSV)]; compound tropicamide BID (cases concurrent hypopyon). The healing time of corneal ulcer and complication rates were observed in the two groups.

RESULTS

The healing time of corneal ulcer in the experimental group was 10.80±4.44d versus 46.70±13.88d in the control group (P<0.05). No complications occurred in the experimental group, except for the lens falling off twice in one case, the patient recovered eight days after rewearing the lens. While in the control group, all cases vascularized, 2 cases were complicated with descemetocele that recovered with amniotic membrane transplantation and 1 case was complicated with corneal perforation that recovered by autologous conjunctival flap covering.

CONCLUSION

Bandage contact lens is a safe and effective method of treating neurogenic keratitis and significantly shortened the healing time of corneal ulcer.

INTRODUCTION

Neurogenic keratitis is a form of corneal epithelial degenerative disease secondary to corneal hypesthesia or loss caused by a variety of reasons^[1], such as herpes simplex viral infection, facial trigeminal nerve palsy caused by tumor and surgery, diabetes, lack of vitamin A, long-term local drops with glaucoma medication^[2]–^[6], and corneal degeneration^[7]. It is characterized by corneal anesthesia, and reduced neurotransmitters/trophic factors for corneal epithelium, resulting in drying of the ocular surface, epithelial growth rate decline, which in turn, affects epithelial healing, and even stromal dissolution and perforation. The typical clinical signs of neurogenic keratitis are the widespread lack of corneal epithelium and ulcer in palpebral fissure part, the epithelium of the ulcer edge is smooth slightly uplifted, with no obvious stroma infiltration around the ulcer, and sustained corneal ulcer. Descemet's membrane folds and hypopyon, and even corneal ulcer perforation and eyeball loss may occur in severe cases.

The previous treatments for neurogenic keratitis include: drug treatment (artificial tears, nerve growth factor, collagen enzyme inhibition and antibiotics) and surgical treatment (tarsorrhaphy, amniotic membrane transplantation and conjunctival flap covering surgery)^[1],^[8],^[9]. Drug treatment is the most commonly used but is associated with a long recovery time and a poor curative effect. Although surgery is relatively simple, it is associated with complications such as inconvenience of observation, higher cost or affected vision, and it carries a larger psychological and economic burden. Therefore, it is important to explore a new kind of convenient and feasible treatment for neurogenic keratitis.

In recent years, with the rapid development of material science, specifically many aspects of the contact lens, such as the material, and the characteristics, have led to great improvements. The bandage contact lens is a new type of lens made from silicone hydrogel. It has the advantage of high oxygen permeability and anti-surface deposition. The lens has been used for protection of the ocular surface, and treatment or auxiliary treatment of corneal disease ^[10]–^[12]. The lens has the following characteristics: 1) Promotion of corneal wound healing; 2) Convenient application of eyedrops; 3) Facilitation of follow-up of corneal lesions; 4) Easy operation; and 5) Sustainable wear. Thus, we observed the curative effect of bandage contact lens on neurogenic keratitis, and explored a new treatment for neurogenic keratitis.

SUBJECTS AND METHODS

Ethics Statement

Our investigation adhered to the tenets of the Declaration of Helsinki. This investigation was approved by the Institutional Review Board of the First Affiliated Hospital of China Medical University, and following a full explanation of the study, written informed consent was obtained from all patients.

Subjects

Twenty cases of neurogenic keratitis at Department of Ophthalmology at the China Medical University Affiliated Hospital, were studied between October 2012 and June 2013. These included 13 males and 7 females aged from 35 to 88y.

Diagnosis of Neurogenic Keratitis

The twenty patients were diagnosed with neurogenic keratitis using the following criteria:

1) Medical history: Herpes zoster virus or herpes simplex virus (HSV) infection, intracranial or maxillofacial surgery, head trauma, diabetes, long-term local with anti-glaucoma eyedrops;

2) Corneal sensation: hypesthesia or loss (tested by Cochet-Bonnet aesthesiometer);

3) Corneal scraping or confocal laser scanning microscopy: infection of bacteria, fungi and amoebic pathogen were eliminated.

Condition of Corneal Ulcers

Ulcers in the twenty patients were 3 to 7 mm in diameter, and did not exceed the elastic layer in depth.

Materials

Bandage contact lens: PureVision of BAUSCH&LOMB Incorporated. The lens parameters were: water content: 36%, oxygen transmission rate (DK/t): 110; material: balafilcon A, surface treatment: Performa, diameter: 14.00 mm; center thickness: 0.09 mm; the base of arc: 8.60 mm; diopter: 0 D, service life: 24 h/d, 1-21d.

Compound tropicamide and 0.5% levofloxacin (Santan company, Japan), 0.5% Sodium carboxymethyl cellulose (AiErJian Ireland pharmaceutical companies), bovine restructuring fibroblast growth factor (bFGF) (YiSheng biological pharmaceutical co., Ltd., China), ganciclovir (KeYi Pharmaceutical co., Ltd., China).

Group

All cases were evaluated for wearing the bandage lens, the size and depth of corneal ulcer in each of these cases were eligible for wearing lens treatment. To determine the risk of wearing contact lens or drug treatment to the patients and their families, patients were voluntary assigned to the experimental group (wearing lens group) and the control group (drug therapy).

Medication

Both groups used the following eyedrops: 0.5% levofloxacin TID; 0.5% Sodium carboxymethyl cellulose QID; bFGF BID; ganciclovir BID (cases complicated with virus infection); compound tropicamide BID (cases concurrent hypopyon).

Curative Effect Assessment

To consider corneal ulcer healing once fluorescein staining was negative. To observe the healing time of corneal ulcer and complication rates in the two groups.

Follow-up

All twenty cases received medicine or contact lens therapy according to their different groups. All the cases were followed up for 7 to 15mo.

Statistical Methods

To compare the healing time of corneal ulcer in the two groups by t-test method.

RESULTS

There were ten cases in each group, and the ages in the experimental group and control groups were 62.60±14.90y and 56.80±15.88y, respectively. In the experimental group, neurogenic keratitis was caused by HSV infection in 4 cases, and by intracranial or maxillofacial surgery in 5 cases, while by facial herpes zoster virus infection occurred 1 case. In the control group, neurogenic keratitis was caused by HSV infection in 4 cases, and by intracranial or maxillofacial surgery in 5 cases, and by diabetes in 1 case.

The healing time of corneal ulcer was 10.80±4.44d in the experimental group (Figures 1, 2) compared with 46.70±13.88d in the control group (Figures 3, 4; P<0.05).

Figure 1. Case 1, male, 56y, 2mo post maxillofacial tumor surgery, neurogenic keratitis in right eye.

A: Pre-treatment anterior segment photograph showing a ulcer of 7×4 mm in diameter, without stroma infiltration; B: Ten days after wearing the bandage contact lens, the ulcer healed, and the cornea was transparent, without neovascularization.

Figure 2. Case 2, male, 66y, herpes simplex viral keratitis (HSK) 3mo, neurogenic keratitis in left eye.

A: Pre-treatment anterior segment photograph showing a ulcer of 4×7 mm in diameter, slight stromal opacity in the ulcer, neovascular around the limbus, and hypopyon was about 1 mm; B: Seventeen days after wearing the bandage contact lens, the ulcer healed, the cornea became transparent, and neovascular faded and shrunk.

Figure 3. Case 3, female, 82y, diabetic for 23y, 2.5mo post PEA+IOl, neurogenic keratitis in left eye.

A: Pre-treatment anterior segment photograph showing a ulcer of 5×3 mm in diameter, and 3×1 mm slight stromal opacity in the ulcer; B: Sixty days after drug treatment, the ulcer healed, but the nebula and neovascular was observed around the limbus.

Figure 4. Case 4, male, 59y, 5mo post craniocerebral operation, neurogenic keratitis in left eye.

A: Pre-treatment anterior segment photograph showing a ulcer of 6×5 mm in diameter, slight stromal opacity in the ulcer; B: Fifty-seven days after drug treatment, the ulcer healed, and the keratoleukoma and neovascular were observed around the limbus.

Complications

There were no complications in the experimental group except for the lens falling off in one case twice, this patient recovered eight days after re-wearing the lens. Only 1 patient who infected HSV 3mo experienced corneal neovascularization prior to wearing the lens, but the neovascular faded and shrunk after the corneal ulcer had healed (Figure 2).

In the control group, 2 cases were complicated with descemetocele; these patients recovered with amniotic membrane transplantation. One case complicated with corneal perforation recovered with autologous conjunctival flap covering. Neovascularization occurred in all cases.

Twenty cases had no complications with bacterial, fungal or acanthamoeba infection during the treatment period.

Follow-up

There were no cases of recurrence during the follow-up period of 7 to 15mo.

DISCUSSION

In neurogenic keratitis, artificial tears and neurotrophic factor eyedrops are associated with a long time to cure of corneal lesions (many months)^[8]. This was also demonstrated in this study: the healing time in the corneal ulcer control group was 46.70±13.88d. Furthermore, if the storma dissolved faster than the process of repair in the course of the treatment, descemetoceleor or corneal perforation appeared. In the control group, descemetoceleor occurred in two cases, and corneal perforation occurred in one case. At the same time, it is well known that the vascularization is an important component of chronic inflammation, the longer recovery time observed in the control group, was associated with more neovascularization^[13].

While in the experimental group, the healing time of corneal ulcer only was 1/4 to 1/6 of the control group. More rapid recovery of neurogenic keratitis by bandage contact lens not only avoided complications during the treatment and pain in surgery for patients, but also reduced the economic burden of patients and their families. Despite the use of the same eyedrops in the two groups, the healing time of the corneal ulcer was completely different. The reason for rapid recovery of neurogenic keratitis with bandage contact lens maybe the special characteristics of the bandage contact lens, such as shelter, aquosity, flexibility, comfort and extending the duration of action of the drugs. Firstly, for the shelter characteristic, the lens could protect the surface of cornea and promote repair of the ulcer by acting as a “shield”. Secondly, for the characteristics of flexibility, comfort, aquosity and higher oxygen transmission rate, the silicone hydrogel lens could be worn continuously^[11],^[12]. Therefore, continuous wear could reduce or avoid injury and infection of cornea in the process of removing lens. Thirdly, the bandage contact lens could extend the duration of action of the drugs, so the eyedrops used in experimental group could have a greater effect on the ocular surface^[14].

At the same time, the transparent feature of the bandage contact lens makes the follow-up of corneal lesions more convenient, and avoids the difficulty of the palpebral fissures operation.

The bigger diameter (14 mm) of bandage contact lens ensures it sticks to the cornea and makes it difficult to fall off. The incorrect operation may be the real reason for lens falling off.

More important is that no cases in the experimental group were complicated with bacterial, fungal or acanthamoeba infection during the treatment period^[15]–^[17], which suggested that the bandage soft contact lens is safe^[18]–^[20]. Anti-precipitation technology of bandage contact lens and antibiotics eyedrops may be the reason for preventing infection.

In conclusion, the bandage corneal contact lens is a safe and effective way of treating neurogenic keratitis, and the healing time of corneal ulcer can be significantly shortened.