Non-Descemet stripping automated endothelial keratoplasty for post radial keratotomy corneal edema.

An elderly male with monocular status presented with complaints of gradual loss of vision in his left eye. Slit-lamp evaluation revealed postradial keratotomy (RK) corneal decompensation. He underwent non-Descemet stripping automated endothelial keratoplasty (nDSAEK) in his left eye. Postoperatively, his visual acuity improved from counting finger at 1 m to 20/200, J5. Graft adherence was good. A preexisting epiretinal membrane with macular edema was noted, but our patient refused any further surgical intervention for the same. In conclusion, nDSAEK may be considered as an effective treatment modality for the management of post-RK corneal decompensation.

Radial keratotomy (RK) is a corneal flattening surgery that involves making radial incisions on the peripheral cornea.[1] We report a case of corneal decompensation following RK which was managed by non-Descemet stripping automated endothelial keratoplasty (nDSAEK).

Case Report

An 80-year-old male presented with complaints of gradual decrease in vision in his left eye for 3 months. He had undergone bilateral RK for myopia more than 40 years earlier and bilateral sequential cataract surgery 15 years prior. He complained of complete loss of vision in the right eye following retinal detachment 7 years ago. He had also undergone scleral buckling with SF6 gas injection for rhegmatogenous retinal detachment in his left eye 5 years prior. He had no systemic illness. On examination, his best-corrected visual acuity (BCVA) was no perception of light in his right eye and finger counting at 1 m, J16 in the left eye. Slit-lamp examination revealed the presence of 8 RK incisions in the left cornea, subepithelial scarring with diffuse corneal edema, and pseudophakia. No guttate changes were noted [Fig. 1a]. Intraocular pressure was 13 mmHg. Indirect ophthalmoscopy revealed a hazy view of the fundus. Anterior segment optical coherence tomography (AS-OCT) revealed full-thickness RK incisions inferiorly [Fig. 1b]. OCT of the posterior segment revealed epiretinal membrane with macular edema.

Figure 1

(a) (Left) Slit-lamp photograph of the left eye under diffuse illumination showing diffuse corneal edema, superficial corneal scarring, and eight radial keratotomy incisions. Posterior chamber intraocular lens is also noted. Remaining anterior chamber details are hazily seen. (b) (Right) Anterior segment optical coherence tomography of the left eye cornea showing two partial thickness radial keratotomy incisions superiorly and two full-thickness radial keratotomy incisions inferiorly

He underwent n-DSAEK under local anesthesia in the left eye. A 5.5 mm scleral tunnel was created 0.5 mm posterior to the superior limbus. Center of the cornea was marked and two side-port incisions were created at the limbus at 10 o’clock 2 o’clock meridians using a 23G microvitreoretinal blade, taking care not to apply any pressure on the cornea. Anterior chamber was filled with balanced salt solution through the side port using a 25G cannula. A lens glide was introduced into the anterior chamber and placed over the iris. An 8 mm donor disc was fashioned from a precut donor corneal tissue (Ramayamma International Eye Bank, Hyderabad, India). The donor disc was placed on the lens glide, endothelial side down, and over a bed of sodium hyaluronate and introduced into the anterior chamber with a bent 26G needle using the “push-in” technique. Complete air fill was maintained for 10 min, and the scleral incision was secured with a single interrupted 10-0 nylon suture. Air was partly replaced with a balanced salt solution through the side port using a 25G cannula. The side ports were hydrated. Supine positioning was maintained for 1 h.

On the first postoperative day, BCVA was hand motions close to face. Donor disc was attached well. He was started on topical prednisolone acetate 1% eye drop every hourly and gatifloxacin (0.3%) eye drop, every 6 hourly along with lubricants. His BCVA improved to 20/200, J5 at 6-week follow-up. Donor disc was attached well. Topical steroids were continued in tapering doses along with lubricants.

At the final follow-up, 8 months after the surgery, BCVA was maintained at 20/200, J5. Graft was well apposed and clear [Fig. 2a]. AS-OCT revealed an intact Descemet membrane of the host cornea with a well-apposed donor disc [Fig. 2b]. Repeat OCT (3D OCT-1, Maestro, Topcon, Japan) of the posterior segment revealed epiretinal membrane with significant macular edema, but patient refused any further surgical intervention for the same. A trial of semi-scleral contact lens (Jupiter Scleral, Visionary Optics, Front Royal, VA, USA) was done, but his BCVA did not improve. He was asked to continue with his glasses.

Figure 2

(a) (left) Slit-lamp photograph of the left eye under diffuse illumination showing clear cornea, well apposed and clear donor disc, superficial corneal scarring, and intact radial keratotomy incisions. (b) (right) Anterior segment optical coherence tomography of the left cornea showing an intact Descemet membrane of the host cornea with a well-apposed donor corneal tissue

Discussion

Endothelial cell loss ranging from 3.3% to 14%[123] following surgical trauma to the endothelium[1] has been reported in the early postoperative period following RK. The average time for the development of bullous keratopathy after original surgery has been reported to be 26.9 ± 8.8 years and indicates that these corneas are prone to develop late corneal decompensation.[4]

Intraoperative dehiscence of RK wound during penetrating keratoplasty (PK)[5] as well as in clear corneal incision phacoemulsification[6] has been reported. We preferred EK over PK in our patient because of his monocular status, and we wanted to avoid the potential globe-threatening complications associated with PK.

Although DSAEK is currently the most commonly performed EK procedure, n-DSAEK has been recommended in pathologies with a clear Descemet membrane without any guttate changes as guttae reflect light causing optical disturbances to the patient. Moshirfar et al. have described a case of successful DSAEK for corneal decompensation following RK.[1] Nakatani and Murakami[7] have reported four eyes with prior RK and bullous keratopathy who underwent successful DSAEK. However, three out of these four eyes developed graft dislocation and had to be re-bubbled. Graft dislocation rate was higher in these eyes (60%) as compared to DSAEK done by them for other indications (12%). They attributed this to an irregular posterior corneal surface and the inability to maintain adequate intraocular pressure in a fragile cornea. We preferred to perform n-DSAEK in our patient to minimize intraoperative manipulations and avoid complications of wound dehiscence and perforation as preoperative AS-OCT demonstrated the presence of full-thickness incisions on the cornea. We feel microperforation, leading to escape of air from the anterior chamber and inadequate tamponade of donor disc may lead to increased graft dislocation. We did not encounter complications such as wound dehiscence, perforation, and graft dislocation in our patient. This was achieved due to meticulous surgical planning based on preoperative clinical and OCT findings coupled with minimum surgical manipulations.

Conclusion

In conclusion, n-DSAEK may be considered as useful option for the management of corneal decompensation following RK.

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.