Severe sterile inflammatory keratitis associated with recurrent epithelial erosion after small incision lenticule extraction: A case report

Jie Hou; Yulin Lei; Qi Li; Zhixing Ma; Guangfu Dang

doi:10.4103/ijo.IJO_842_22

CASE REPORT

Year : 2023 | Volume : 3 | Issue : 1 | Page : 22-25

Severe sterile inflammatory keratitis associated with recurrent epithelial erosion after small incision lenticule extraction: A case report

Jie Hou¹, Yulin Lei¹, Qi Li¹, Zhixing Ma¹, Guangfu Dang²
¹ Jinan Mingshui Eye Hospital, Jinan, China
² The First Affiliated Hospital of Shandong First Medical University and Shandong Provincial Qianfoshan Hospital, Jinan, China

Date of Submission	01-Apr-2022
Date of Acceptance	22-Aug-2022
Date of Web Publication	20-Jan-2023

Correspondence Address:
Guangfu Dang
The First Affiliated Hospital of Shandong First Medical University and Shandong Provincial Qianfoshan Hospital, Number 16766, Jingshi Road, Lixia District, Jinan
China

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijo.IJO_842_22

Abstract

A 32-year-old man had undergone small incision lenticule extraction (SMILE) that was complicated by intraoperative epithelial detachment in the right eye. Corneal epithelial erosion reoccurred at two and four months after surgery. At the third time of epithelial erosion, slit-lamp examination revealed dense white infiltrates throughout the corneal cap-stromal interface. The patient was initially managed with high-dose topical antibiotics. After the negative culture and Gram staining results from the interface washout, diffuse lamellar keratitis was confirmed and topical steroids were administered. The inflammation resolved, and corneal transparency was achieved after treatment. Timely diagnosis and appropriate treatment are highly critical for prognosis.

Keywords: Diffuse lamellar keratitis, recurrent epithelial erosion, small incision lenticule extraction

How to cite this article:
Hou J, Lei Y, Li Q, Ma Z, Dang G. Severe sterile inflammatory keratitis associated with recurrent epithelial erosion after small incision lenticule extraction: A case report. Indian J Ophthalmol Case Rep 2023;3:22-5

How to cite this URL:
Hou J, Lei Y, Li Q, Ma Z, Dang G. Severe sterile inflammatory keratitis associated with recurrent epithelial erosion after small incision lenticule extraction: A case report. Indian J Ophthalmol Case Rep [serial online] 2023 [cited 2023 Feb 1];3:22-5. Available from: https://www.ijoreports.in/text.asp?2023/3/1/22/368225

Small incision lenticule extraction (SMILE) has emerged as an effective and safe procedure for the correction of myopia for over 10 years. However, this technique has its own challenges and various intraoperative and postoperative complications. Previous studies have shown that the incidence of diffuse lamellar keratitis (DLK) in patients undergoing SMILE ranges from 0.45 to 2.17%.^[1],[2],[3]

Reinstein et al.^[2] reported the incidence of DLK after SMILE in a large population and demonstrated that unlike the classic appearance observed after LASIK, one-third of SMILE-related cases could present with a few distinguishing features. Here, we describe a unique case of acute and severe interface sterile inflammatory keratitis that was triggered by recurrent epithelial erosion four months after SMILE.

Case Report

A 32-year-old man underwent SMILE on March 14, 2021, at our hospital. Preoperatively, refraction errors were −8.25/−1.50 × 175 and −8.00/−1.25 × 15 in the right and left eyes, respectively, and the corrected distance visual acuity (CDVA) was 20/20 in both the eyes. The central corneal thickness was 649 μm in the right eye and 633 μm in the left eye. No other abnormalities were observed during the ocular examinations. Informed consent was obtained from the patient and approval for the study was obtained well. The VisuMax femtosecond laser system (Carl Zeiss Meditec AG, Jena, Germany) was used for SMILE. The surgery in the left eye was uneventful, but a large corneal epithelial detachment was observed in the inferior temporal area of the right eye after dissecting the intrastromal corneal tissue. The lenticule was removed and the cap was smoothed carefully. A bandage contact lens was placed on the right eye and 0.1% fluorometholone (FML) and levofloxacin eye drops were administered four times daily after the surgery. At one week follow-up, the corneal epithelium had healed, and the use of the bandage contact lens was discontinued. The uncorrected distance visual acuity (UDVA) was 20/60 and the CDVA was 20/40 with a manifest refraction of +0.25/−1.50 × 110°. At this time, 0.1% FML drops were prescribed four times daily and tapered every seven days. One month later, UDVA returned to 20/40 and the 0.1% FML drops were discontinued.

Two months later, the patient presented with a one-day history of photophobia, redness, and foreign-body sensation in the right eye. The UDVA was 20/60. A 4 × 3 mm epithelial erosion was found in the same location where the intraoperative epithelial detachment was present [Figure 1]a. No interface inflammation was noted, and a bandage contact lens was applied to the right eye. The patient was instructed to use a combination of 0.1% FML and 20% autologous serum eye drops four times daily. After eight days, the epithelial defect had healed and UDVA had increased to 20/30 [Figure 1]b. Bandage contact lens use was then discontinued and 0.02% FML drops were prescribed four times daily and tapered every seven days.

Figure 1: (a) Epithelial erosion appeared in the area of intraoperative epithelial detachment. (b) The epithelial defect had healed 8 days after treatment

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Four months after SMILE, the patient was referred to our hospital again due to the reappearance of discomfort and blurred vision in the right eye. Loose corneal epithelium reappeared at the same location as before. The UDVA was 20/40. The above-mentioned steps were performed again. However, four hours later, the patient returned due to increased irritation and blurring accompanied by a sharp stabbing pain in the right eye. The UDVA was reduced to 30 cm. Slit-lamp examination revealed dense white infiltrates throughout the corneal cap-stromal interface [Figure 2]a. The contact lens was immediately removed. Fluorescein staining revealed a large (6 × 5 mm) corneal epithelial sloughing area on the infratemporal part of the cornea [Figure 2]b. Anterior segment optical coherence tomography (ASOCT) (RTVue, Optovue, Inc) showed clear and diffuse hyper-reflective infiltration at the corneal interface [Figure 2]c. Infection was suspected initially, and high-dose topical antibiotics (moxifloxacin and 5% ceftazidime) were initiated along with tropicamide for cycloplegia. Corneal scrapings were obtained from the damaged epithelial area and the conjunctival sac for microscopy and culture.

Figure 2: (a) Slit-lamp photography showed diffuse distribution of white dense infiltrates in the right cornea. (b) Fluorescein staining showed a large corneal epithelial defect. (c) OCT showed a clear and hyper-reflection between cap and stromal bed

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At 8 am the following day, the corneal infiltrates appeared denser but the epithelial defect in the right eye was unchanged. Given the severity of the infiltrates, 5.0% vancomycin eye drops were administered hourly. An oral steroid dose of 40 mg was also administered. During the two-hour observation period using a slit-lamp microscope, we found that the distribution of corneal infiltration changed with the position of the patient [Figure 3]a. In view of these features, surgical intervention was performed. Fluctuations of the white infiltrates within the interface were observed under the microscope during surgery [Figure 3]b. The infiltrates were removed with a 1 mL syringe via a corneal incision for microscopy and culture. Following this, interface washout was performed immediately using copious volumes of balanced salt solution and 5.0% vancomycin solution. During surgery, we discovered that the infiltrates were confined to the interface and had not extended into the cap or stromal bed. A bandage contact lens was placed on the right eye after surgery.

Figure 3: (a) Dense distribution of the corneal infiltration. (b) Screenshot of surgery video showing the white liquid infiltrates in the interface (red arrow)

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On the second day after the intervention, the patient's discomfort improved and the UDVA was 20/100. Slit-lamp and OCT examinations showed that the infiltrates had faded, and the epithelial defect was healing rapidly. Cultures and Gram staining of the corneal and conjunctival sac epithelial scrapings and from the interface washout were negative. The patient was diagnosed with sterile inflammatory keratitis. Topical steroids (0.1% dexamethasone) were administered, and topical antibiotic application was reduced. Four days after treatment, the UDVA increased to 20/50. The patient's right eye showed continued improvement and contact lens use was discontinued. The ASOCT and slit-lamp findings for the right eye are shown in [Figure 4]. Dexamethasone was changed to 1.0% prednisolone acetate drops and gradually tapered over the following four weeks.

Figure 4: The slit-lamp (a) and ASOCT (b) showed the epithelial defect had healed and the infiltrates faded with a slight corneal opacity

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One month after the steroid treatment, the lamellar inflammation had resolved. A slight corneal haze could still be observed under a slit-lamp examination. All topical medications except for lubricants were stopped. Six months later, UDVA had increased to 20/20, and the manifest refraction was −1.75 × 165° (20/20). The cornea was more transparent than before. ASOCT showed a regular epithelium and a clear cap-stromal interface.

Discussion

Wang et al.^[3] investigated the incidence of corneal complications after SMILE in 3223 patients (6373 eyes) and found that DLK developed in 138 eyes (2.2%). All the cases were within grade 3 and manifested on postoperative day 01. Several other reports described cases of DLK after SMILE caused by epithelial defects; however, the symptoms were mild.^{[2],[4],[5],[6]} Stuart et al.^[7] reported a case of atypical DLK following SMILE in which the patient presented with multiple focal, white infiltrates instead of diffuse infiltration, as in our case.

The causes of secondary DLK after SMILE include corneal epithelial defects, epithelial loosening, sterile keratitis, and autoimmune keratitis, the most common of which is corneal epithelial defects.^[2] The presence of epithelial cell defects can increase the incidence of DLK from 2% to 56%.^[8],[9] In this case, the patient had recurrent epithelial erosion after SMILE, which may have been caused by anterior basement membrane dystrophy. The recurrent epithelial defect triggered an episode of severe interfacial inflammation. Epithelial injury can cause changes in corneal metabolism and oxygenation and allow more inflammatory mediators to diffuse from the tear film or alter the permeability of the limbal vascular system to inflammatory cells.^[10]

Unlike LASIK, SMILE leaves the anterior cornea intact rather than creating a corneal flap. After SMILE, inflammatory mediators might penetrate the corneal cap-stromal bed interface through the corneal surface or limbal vasculature and then accumulate in the potential cap-stromal space. Once interface fluid or infiltrates develop after SMILE, timely interface washout is necessary to prevent serious complications.

Conclusion

In conclusion, DLK may occur several months or years after SMILE with different clinical presentations. Early diagnosis and appropriate management of DLK after SMILE are crucial for a good prognosis of visual acuity.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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