Outcomes of Descemet stripping endothelial keratoplasty combined with near total iridectomy in iridocorneal endothelial syndrome

Abstract

To report the outcomes of endothelial keratoplasty (EK) combined with near total iridectomy in the management of iridocorneal endothelial (ICE) syndrome with severely disorganised anterior segment. Three patients with ICE syndrome, who had a severely disorganised anterior segment underwent near total iridectomy, with/without cataract surgery, followed by EK at the same time. Mean age was 35 years. Prior to EK, the intraocular pressure (IOP) was in the range of 12–15 mm Hg. One patient (patient 2) had advanced disc damage prior to EK. Two eyes (patients 1 and 2) had a glaucoma drainage device, and in one, the IOP was controlled with two antiglaucoma medications. All grafts were clear, and IOP was well controlled till the last mean follow-up of 53 (range 30–72) months. The outcomes of EK with this surgical approach are favourable and should be considered in selective cases of ICE syndrome.

Background

Iridocorneal endothelial (ICE) syndrome is characterised by an abnormal proliferation of endothelial cells that lead to broad peripheral anterior synechiae (PAS), changes in the iris and the angle, thereby leading to raised intraocular pressure (IOP), glaucoma and corneal decompensation.^{1 2} In some eyes, the broad PAS can eventually lead to a severe distortion, contraction and partial to near complete obliteration of the anterior chamber.

Herein, we report the outcomes of three eyes that underwent endothelial keratoplasty (EK) combined with near total iridectomy in those patients of ICE syndrome that had severely disorganised anterior segment. The disorganised anterior segment was characterised by loss of distinct anatomical landmarks such as anterior and posterior chamber; resulting from extensive PAS that led to large areas of iridocorneal contact, with shallow or flat anterior chamber.

Case presentation

The three patients were comanaged in the glaucoma and cornea clinic. All the three eyes underwent Descemet stripping automated endothelial keratoplasty (DSAEK) via a similar surgical approach. The surgical procedure involved three main sequential steps: first, anterior chamber reconstruction; second, cataract surgery (in two of three patients); and third, EK. Initially a paracentesis was made and viscoelastic injected to create a separation plane between the iris and posterior cornea. Synechiolysis was performed with an iris repositor and the Descemet membrane was removed. The peripheral Descemet membrane had fibrous attachments on the iris surface which were peeled meticulously. Under anterior chamber maintainer, iridectomy was performed up to the peripheral attachment or root of the iris using a vitrector. Care was taken to avoid the extreme peripheral root of iris that has the major arterial arcade to prevent severe bleeding during iridectomy. A minor bleed during iridectomy was easily managed by a temporary air/viscoelastic tamponade for a small length of time. Thereafter, phacoemulsification with intraocular lens implantation was performed. DSAEK was performed using 8.0 mm precut tissue, using Sheet glide push in technique. The interface was irrigated with balanced salt solution, graft was centred and attached by air tamponade. The main incision and side port incisions were sutured with 10-0 nylon. Postoperatively, prednisolone acetate eyedrops was prescribed every 3 hours for initial 1 week followed by weekly tapering doses and then maintained on two times per day. Antiglaucoma was prescribed medications at the discretion of glaucoma clinicians as needed. The clinical details and course of the three patients after surgery are described as below.

Patient 1

A 28-year-old woman had progressive decrease in vision in the left eye for 3 years. The IOP was 16 mm Hg on three anti-glaucoma medications (AGMs). Anterior segment was severely disorganised. Ahmed glaucoma valve (AGV) implant was performed in the inferotemporal quadrant with the tube in sulcus. DSAEK was performed 3 months later. At 1 month, visual acuity improved to 20/40 and IOP was well controlled. At the last follow-up, the best corrected visual acuity was 20/25 and IOP was 20 mm Hg on timolol maleate 0.5% (figure 1A, B).

Figure 1.

(A) The slit-lamp photograph of patient 1 showing near-complete iridocorneal touch with AGV tube in the sulcus at 4 O’clock area. (B) Post operative slit-lamp photograph of the left eye of the patient at the last follow-up visit of 5 years shows clear and compact cornea and the posterior lamellar graft. AGV, Ahmed glaucoma valve.

Patient 2

A 41-year-old woman had trabeculectomy elsewhere and was using three AGMs in her left eye. The left eye was exotropic since childhood. Cornea showed oedema, central scarring and facet ~3 mm size. The anterior chamber was severely disorganised with clear lens. IOP was 13 mm Hg and cup–disc ratio was 0.9:1. AGV was implanted followed by DSAEK 6 years later. The postoperative course was uneventful. At 1 month, the IOP was normal, the visual acuity improved to 20/100 with eccentric viewing. One year later, phacoemulsification with intraocular lens was performed. At the last follow-up, the graft was compact, best corrected visual acuity was 20/80, with a faint central haze, IOP was 14 mm Hg (figure 2A, B).

Figure 2.

Slit-lamp diffuse (A) and retro illumination (B). Photographs of patient 2 at the 6-month follow-up visit. The cornea shows scarring in the centre at the site of facet.

Patient 3

A 37-year-old woman presented with intermittent blurred vision in the right eye for 1 year. She was using three AGMs. Anterior segment was severely distorted. Fundus examination showed a cup–disc ratio of 0.5:1. The patient underwent synechiolysis, Descemet membrane stripping, iridectomy up to root of iris with a vitrector, phacoemulsification with intraocular lens implantation followed by DSAEK. Postoperative course was unremarkable. At the last follow-up, the graft was clear, the best corrected visual acuity was 20/25, with a well-controlled IOP and cup–disc ratio of 0.5:1 (figure 3A, B).

Figure 3.

(A) Anterior segment optical coherence tomography (AS-OCT) images of patient 3 showing large areas of iridocorneal contact in all angles. (B) Postoperative images of the right eye at the last follow-up visit of 4 years after YAG laser capsulotomy.

Results

Table 1 summarises the salient clinical features and outcomes in the three patients. Mean age was 35 years. Prior to EK, the IOP was in the range of 12–15 mm Hg. Two eyes (patients 1 and 2) had a glaucoma drainage device (AGV) and in one eye, the IOP was in normal range with two AGMs. One patient (patient 2) had advanced disc damage prior to EK. Post-EK, the IOP control and the disc status was maintained till the mean last follow-up duration of 50.25 (range 24–72) months. Two patients (patients 1 and 3) needed a YAG laser capsulotomy and one patient (patient 2) had a cataract surgery after EK.

Table 1.

Clinical features, demographics and outcomes of the patients

Patient	Age/ gender	Preop vision	Salient clinical features (prior to EK)	Anti-glaucoma medications before EK	Anti-glaucoma medications after EK	Duration between AGV and EK	Follow-up (months) after EK	Postop BCVA (at last follow-up)	ECD, cells/ mm2 baseline LF up
1	28/f	20/320	Iridocorneal touch 3/4th of chamber, AGV at inferotemoral location with tube in sulcus, lens clear, cdr 0.3:1, IOP=15 mm Hg	Timolol maleate	Timolol maleate	3 months	70	20/30	2994	2235
2	41/f	Hand motions	Near total iridocorneal contact, anterior stromal scar with facet, lens clear, exotropia, s/post Trab, s/post AGV in superotemoral location with tube in posterior chamber, cdr 0.9:1, IOP=12 mm Hg	Brimonidine, Timolol maleate	Brimonidine, Timolol maleate	7 years	30	20/80	2500	1887
3	37/f	20/80	Near total iridocorneal touch, lens clear, cdr 0.5:1, IOP=13 mm Hg	Dorzolamide Timolol maleate	Timolol maleate	–	60	20/25	2631	2632

AGV, Ahmed glaucoma valve; cdr, cup–disc ratio; EK, endothelial keratoplasty; ECD, endothelial cell density; intraocular pressure; LF, up-last follow-up.

AGV, Ahmed glaucoma valve; cdr, cup–disc ratio; ECD, endothelial cell density; EK, endothelial keratoplasty; IOP, intraocular pressure; LF, up-last follow-up.

None of the patients complained of glare. The BCVA at the last follow-up visit ranged from 20/25 to 20/80. Patient 2 had exotropia and subnormal vision in the affected eye since early childhood.

The overall mean endothelial cell density at the last follow-up visit was 2251 cells/mm².

Outcome and follow-up

All the grafts were clear and IOP was normal till the mean last follow-up duration of 50.25 (range 24–72) months.

Discussion

DSAEK in ICE syndrome is surgically challenging when associated with an extremely crowded anterior chamber.^{3 4} The outcomes of DSAEK is variably reported.^5–8 Ao et al⁷ reported a failure rate of 55% with a mean estimated survival of 23.4 months. A recent study by Mohamed et al⁹ has reported a more favourable success rate of 60% at 5 years follow-up period.

The surgical approach for keratoplasty in ICE syndrome is governed by the status of the anterior chamber. Those eyes with a fewer synechiae can be managed by synechiolysis followed by insertion of posterior lamellar graft. In some eyes with relatively preserved anterior chamber, Descemet membrane EK was attempted with good surgical outcomes.^{10 11} However, in eyes with broad synechiae and large area of iridocorneal contact, anterior segment reconstruction is needed first to create adequate space for insertion of posterior lamellar graft. In such eyes after performing synechiolysis and Descemet membrane removal, the iris tissue is notably friable and floppy. The posterior lamellar graft insertion, manipulation and air bubble management in that situation is challenging. Further, retaining floppy and friable iris tissue eventually leads to reformation of postoperative synechiae with the graft edges. With our simplified approach of management via performing an iridectomy up to the root of iris, there are threefold advantages—first, the graft insertion into the anterior chamber and air bubble tamponade is facilitated. Second, the abnormal endothelial membrane that had proliferated on the angle and iris surface is removed more completely during iridectomy thereby; possibly preventing the progression of the disease later that is known to occur in some cases after keratoplasty. Third, synechiae that occur in the postoperative period due to retained floppy iris tissue is avoided.

One aftermath of this approach is the potential of glare due surgical aniridia. However, none of the patients reported any glare associated disability in their routine work. Second, the occlusion of the trabecular meshwork from the iris remnants is a possibility. Two patients presented here already had tubes with a good IOP control and one patient (patient 3), medical therapy with one AGM (timolol maleate 0.5%) was effective in maintaining the IOP in the postoperative period.

The clinical outcomes with this approach in the three patients described here seem favourable. The corneal clarity was restored and maintained. IOP and disc findings were stable in the postoperative period ranging from 30 to 70 months.

Learning points.

• Iridocorneal endothelial syndrome can cause a severe disorganisation of anterior chamber with corneal oedema. Endothelial keratoplasty can be technically challenging in such eyes. Management in these situations requires a difference from those with relatively preserved anterior segment.

• The surgical approach in these eyes involves anterior segment reconstruction, via extensive (near complete) iridectomy up to the root of the iris, followed by cataract extraction (when needed) and insertion of the posterior lamellar graft.

• The outcomes of Descemet stripping automated endothelial keratoplasty with this approach was favourable in this case series of three eyes with a mean follow-up of 53 (range 30–72) months.