Surgical Treatment of Corneal Ectasia with Motowa's Trephine and Selective Suturing Technique.

A 40-year-old male presented with bilateral ectasia, contact lens intolerance, and astigmatism >10 D in both eyes. The patient had end-stage pellucid marginal degeneration that warranted surgical treatment. We present a unique surgical technique to stabilize the cornea, minimize astigmatism, improve vision and corneal status, and avoid penetrating keratoplasty.

Introduction

Keratoconus and pellucid marginal degeneration (PMD) are noninflammatory progressive ectatic corneal disorders, characterized by thinning of the corneal stroma that often leads to irregular astigmatism and a subsequent decrease in visual acuity.[1] Keratoconus is the leading indication for corneal transplantation surgery worldwide.[1]

PMD is a bilateral ectasia characterized by a peripheral band of thinning that incorporates the inferior quadrant of the cornea, with a central 1–2 mm zone of normal cornea.[2] The topographic pattern often resembles a “lobster-claw.”

As corneal ectasia progresses, the management changes from optical aids such as spectacles and contact lenses (CLs) to surgical intervention. A variety of surgical techniques have been described for corneal ectasia, including intracorneal ring segments (ICRSs), full-thickness crescentic wedge resection in PMD,[3] and lamellar keratoplasty, and penetrating keratoplasty (PKP).[4567]

Two common surgical treatments for corneal ectasia are lamellar keratoplasty and PKP. PKP involves the replacement of diseased cornea with a full-thickness donor cornea.[1] The disadvantages of PKP include graft rejection and long-term use of topical and systemic steroids.[1] Lamellar keratoplasty mitigates many of the complications of PKP. However, lamellar keratoplasty is a technically challenging procedure. Some cases of graft rejection have been reported, and long-term use of topical and systemic steroids to mitigate graft rejection is required after lamellar keratoplasty.[1]

In this case report, we describe the presentation and surgical management of a patient with PMD. The patient underwent a novel surgical technique to manage high astigmatism and irregularity secondary to PMD, avoiding the need for keratoplasty.

Case Report

A 40-year-old male with a document of the history of PMD presented with complaints of decreased vision and extreme discomfort with CL. The patient had undergone bilateral wedge resection, 7 years before presentation. The presenting uncorrected visual acuity (UCVA) was 20/300 in the right eye and 7/200 in the left eye. His best-corrected visual acuity (BCVA) was 20/25 OU with the following refractions: OD, Plano − 11.00 × 90° and OS, +0.25 − 12.00 × 85°. Corneal topographies were consistent with the patterns characteristic of PMD in both eyes [Figure 1]. The patient was offered a novel surgical technique (Motowa's Trephine with Selective Suturing Technique) that would allow him to retain his cornea rather than undergo corneal transplantation. This surgical technique is a partial thickness corneal trephination with adjusted compression sutures. The risk and benefits of PKP, lamellar keratoplasty, and Motowa's Trephine with Selective Suturing Technique were explained to the patient. The patient consented to the undergo Motowa's Trephine with Selective Suturing Technique.

Figure 1

(a) Image of the right eye showing a clear cornea with 360° scar from the trephine and some remaining sutures, (b) postoperative image of the left eye

Surgical technique

The right eye underwent surgery first in April 2012. The eye was prepared in a sterile fashion, and two drops of topical anesthetic were instilled. A surgical drape was placed on the eye, and a lid speculum was placed to maximize globe exposure. The geometric center of the cornea was marked with a Sinskey Hook and a marking pen. A Hessburg-Barron vacuum trephine (Barron Precision Instruments, Grand Blanc, MI, USA) was used, and the cornea was partially trephined at 8 mm diameter to 90% of the actual corneal thickness. The vacuum trephine was then released. The cornea was sutured in a manner similar to PKP using 16-interrupted 10–0 nylon sutures. Sutures were selectively adjusted and tightened unequally to address preexisting astigmatism. For example, the superior half of sutures was intentionally adjusted very tightly and the inferior half was normal tightness to equalize and distribute the cylinder power over the entire corneal surface. At the conclusion of surgery, the Maloney surgical keratometer (Katena Products Inc., Denville, NJ, USA) was used to measure residual astigmatism and some sutures were modified accordingly. Erythromycin ointment was applied and the eye was patched. Postoperatively, the patient was prescribed Maxitrol (Alcon Inc., Fort Worth, TX, USA) eye drops for 2 weeks and topical lubricants as required. The left eye underwent the same procedure 9 months after right eye surgery.

Results

The right eye was evaluated postoperatively at 1 week, 1 month, 3 months, 6 months, and 1 year. The progression of postoperative UCVA was 20/200 at 1 week, 20/125 at 1 month, 20/20 at 3 months, 20/30 at 6 months, and 20/30 at 1 year. Serial corneal clinical photographs are presented in Figure 1. Corneal topography was performed at each postoperative visit [Figure 2]. At each postoperative visit, loose sutures were removed as required.

Figure 2

(a) Preoperative corneal topography of the right eye with advanced steepening mainly in the inferior half, (b) improvement in corneal topography postoperatively, (c) advanced steepening of the left eye preoperatively, (d) improvement in corneal service postoperatively

The refraction in the right eye at 1-year postoperatively was − 2.5 − 3.00 × 100° with 20/20 BCVA.

The left eye underwent the same procedure with satisfactory results. At 1-year follow-up, most of the sutures were removed and the UCVA OS was 20/30. Refraction at 1-year postoperatively was +2.0 −2.0 × 70° with 20/20 BCVA. Topography showed a dramatic improvement in corneal astigmatism.

At the last follow-up visit in April 2016, the uncorrected vision was 20/300 (OD) and 20/300 (OS). BCVA OD was 20/30 with a refraction of + 1.00 − 4.00 × 30 and BCVA OS was 20/30 OS with a refraction of − 1.25 − 4.50 × 85. Slit lamp examination indicated a clear cornea with scar 360° at the trephination site [Figure 3].

Figure 3

The final corneal image after removal of all sutures. There are a 360° ring-like scar and corneal stability

Discussion

This case report describes a novel surgical technique for corneal ectasia that reduces and possibly eliminates the need for corneal transplant. This is done by creating a 360° scar in the area of thinning, located paracentrally and sparing the visual axis. Full-thickness perforation in some areas will create a greater scarring response which will help strengthen the cornea.

Based on the data from the USA,[4] Australian Corneal Graft Registry, the New Zealand National Eye Bank, Saudi Arabia,[5] and Ireland, PKP has been the mainstay treatment for keratoconus for decades.[6]

The main indications for corneal transplantation are CL intolerance, high astigmatism that cannot be corrected with ICRS, and intraocular Collamer lenses and significant corneal opacities. In our case, the preoperative cylinder was −11 D which is beyond the limit for ICRS and intraocular Collamer lenses. In addition, the patient refused to wear hard CL due to extreme discomfort. Hence, the only option was either large-diameter corneal transplantation to overcome the inferior bulging or partial corneal trephination and adjusted compression suturing. The former carries a high risk of rejection due to the diameter of the graft and proximity to the limbus.[1]

Partial thickness corneal trephination and adjusted compression suturing were performed in this case with excellent postoperative results at 1-year follow-up. This new surgical technique saved the patient's cornea. In addition, this new technique circumvented the attendant risks of keratoplasty including graft rejection and failure and the possibility of steroid-induced glaucoma.

Possible selection criteria for patients with keratectasia who can benefit from this new surgical technique are (1) progressive ectasia, (2) no previous surgery, (3) clear central cornea, (4) corneal thickness >350 μ, (5) no connective tissue diseases, and (6) CL intolerance.

To the best of our knowledge, this is the first report of this technique for the surgical management in keratectasia. This technique may help restore vision for many patients and avoid the costs associated with PKP or other surgeries. Further follow-up and more cases of this technique are required to determine the long-term outcomes and more definitive selection criteria.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.