Progressive keratoconus, retinal detachment, and intracorneal silicone oil with obsessive-compulsive eye rubbing.

An 18-year-old boy with an obsessive-compulsive disorder of eye rubbing presented with forme fruste keratoconus (KC) and posterior subcapsular cataracts. After evaluation, he underwent phacoemulsification in his left eye with intraocular lens implantation. The aggressive eye rubbing, however, aggravated the rapid progression to established KC, and further acute corneal hydrops within 3 months. Within the next 3 months, the eye rubbing precipitated rhegmatogenous retinal detachments (RDs) in both eyes. Furthermore, after undergoing a combined cataract and RD surgery with belt buckling and silicone oil endotamponade in his right eye, the repeated eye rubbing caused extrusion of the implanted silicone oil into the subconjunctival space and within the corneal stroma. This is the first report to our knowledge describing this unique complication associated with eye rubbing. It also highlights the need for increased vigilance and care that needs to be directed toward patients predisposed to such complications.

Introduction

The association between eye rubbing and keratoconus (KC) has been reported since the beginning of the 20th century in a number of descriptive studies. Allergy-associated eye rubbing can cause progression to hydrops. Retinal detachment (RD) has also been reported to be associated with eye rubbing in atopic dermatitis.

We report a case of rapidly progressive KC and RD with post-RD surgery, intracorneal lamellar silicone oil in a patient with an obsessive–compulsive disorder of eye rubbing.

Case Report

An 18-year-old male of Indian origin with an obsessive-compulsive disorder of eye rubbing under psychiatric treatment was referred to our institute for suspected KC. His best-corrected visual acuity (BCVA) was 20/40 in both eyes (BE). Anterior segment examination showed posterior subcapsular cataracts in BE. A detailed evaluation entailing keratometry, pachymetry, and Orbscan evaluation showed no signs of KC in his left eye (LE) and forme fruste KC in his right eye (RE) [Figure 1]. Keratometry showed RE – 41.2 × 46.9 at 94° and LE – 44.2 × 39.8 at 180°. Fundus examination revealed no significant abnormalities. He underwent phacoemulsification with posterior chamber intraocular Lens implantation in his LE. The BCVA in LE 1 month postoperatively was 20/20. However, 2 months later, the BCVA reduced to 20/80 in RE and 20/600 in LE. A detailed evaluation including indirect ophthalmoscopy, electroretinography, and visual evoked potential revealed no significant abnormalities. Corneal examination revealed multiple superficial corneal abrasions in his RE and a paracentral cone in his LE. Keratometric findings were RE – 40.5 × 51.0 at 96° and LE – >52.0 × 52.0 at 180°. Collagen Collamer Cross-linking Riboflavin (C3R) in BE was advised, but before it was done, within a week he returned with sudden painful diminution of vision in his LE. A central dense corneal stromal edema with underlying linear oblique Descemet's tears suggestive of acute hydrops was seen. Orbscan RE showed the rapid progression of KC [Figure 2]. He was treated with corneal compression sutures with C3F8 gas injection in anterior chamber in LE and C3R with a protective shield contact lens in his RE [Figure 3]. The patient defaulted from routine reviews and next presented 3 months later with a complaint of a sudden, painless loss of vision in his RE. His BCVA was hand movements close to face in BE. His eyeballs showed hypotony and anterior segment showed corneal edema with a paracentral cone in both the eyes. Fundus examination showed a GRT in RE through a hazy media. An ultrasonography (USG) B-scan revealed RE 360°choroidal detachment with inferior RD and a partial posterior vitreous detachment (PVD); and LE showed shallow peripheral RD superiorly with a complete PVD [Figure 4]. RE cataract surgery, vitrectomy with belt buckling, and silicone oil endotamponade were undertaken. The retina was attached postoperatively. He defaulted from reviews and on his next visit, BCVA in BE had dropped to perception of light. RE showed subconjunctival and corneal intrastromal silicone oil bubbles, whereas LE showed a leucoma grade central corneal scarring with superficial and deep vascularization [Figure 5]. A temporary keratoprosthesis was planned for the LE.

Figure 1

Orbscan showing. (a) Normal picture in the right eye. (b) Forme fruste keratoconus in the left eye

Figure 2

Orbscan picture of the right eye depicting the red flag sign of keratoconus

Figure 3

Clinical photograph depicting. (a) Right eye after undergoing C3R. (b) Leucomatous corneal scarring of left eye after compression sutures and intracameral C3F8

Figure 4

B-scan ultrasonography of (a) right eye showing 360° choroidal detachment with inferior retinal detachment and a partial posterior vitreous detachment. (b) Left eye showing shallow peripheral retinal detachment superiorly with a complete posterior vitreous detachment

Figure 5

Clinical photograph depicting. (a) subconjunctival and corneal intrastromal silicone oil in the right eye. (b) Leucomatous scarring and vascularization of left eye

Discussion

KC is a bilateral progressive corneal ectasia, classically defined as a predominantly degenerative disease. It is characterized by progressive corneal steepening and thinning, induced myopia, and both regular and irregular astigmatism.

The prevalence of KC in the general population is estimated to be approximately 1 case per 2000.[1]

Although it's exact etiology is unknown, studies suggest that an increased expression of lysosomal enzymes and decreased levels of inhibitors of proteolytic enzymes in the corneal epithelium may play a role in corneal stromal degradation.[2]

Eye rubbing has been implicated as a cause, and the cytokine interleukin-1 has been suggested as a mediator of stromal degradation.[3]

Diagnosis via computerized videokeratography using Rabinowitz criteria has a sensitivity of 98% and a specificity of 99.5%.[4]

Associations on univariate analysis have been shown between KC and eye rubbing, atopy, and family history of KC. However, in the multivariate analysis, only eye rubbing was still a significant predictor of KC.[5]

Mechanical changes in the cornea in KC include epithelial thinning, thixotropically reduced ground substance viscosity, slippage between collagen fibrils at the cone apex, and changes to keratocytes in addition to scar formation.[6]

Biochemical responses to eye rubbing include increased corneal temperature, increased concentrations of inflammatory mediators in the precorneal tears, and abnormal enzyme activity.

Histopathologic features include stromal thinning, iron deposition in the epithelial basement membrane, and breaks in Bowman's layer.

Acute corneal hydrops is characterized by tears in the Descemet's membrane, with stromal edema due to ingress of aqueous. Tight eye closure and forceful rubbing raise the intraocular pressure (IOP) to more than ten times the normal level combined with high hydrostatic tissue pressure, and thus predisposes the eye to acute hydrops.

With a conservative approach, self-resolution takes around 2–3 months. Corneal compression sutures combined with an intracameral injection of air or perfluoropropane is the most common surgical procedure done in recalcitrant cases.

An abnormal immune reaction causing inflammation occurs directly under the area of trauma induced by rubbing the eye causing retinal damage.[7] In our case, a GRT was responsible for the RD, which by definition involves 90° or more of the retinal circumference. The RD secondary to traumatic rubbing of the lids also has a high incidence of proliferative vitreoretinopathy.

The primary surgical procedure is scleral buckling in 78% of the cases and vitreous surgery in 22%, and initial and final reattachment rates being 75.3% and 92.6%, respectively.[8]

Complications of silicone oil endotamponade are increased IOP, band keratopathy, silicone oil emulsification, and also silicone oil migration into the upper lid with associated blepharoptosis.[9]

A literature review showed a previous report describing intracorneal silicone oil identified by microscopic examination of an excised corneal button.[10] To our knowledge, this is the first report identifying intracorneal migration of intraocular silicone oil. The postulated route of entry of silicone oil into the corneal intrastromal space is via the breaks in the Descemet's layer.

This case thus highlights the rapidity with which eye rubbing can worsen the prognosis in corneal ectatic condition and how increased vigilance in such cases can limit ocular morbidity.

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Conflicts of interest

There are no conflicts of interest.