Tectonic deep anterior lamellar keratoplasty in impending corneal perforation using cryopreserved cornea

Customized therapeutic deep anterior lamellar keratoplasty in perforated Mooren's ulcer: A novel technique

We describe customized therapeutic deep anterior lamellar keratoplasty (DALK) for treating a perforated Mooren's ulcer. Slit-lamp biomicroscopy revealed corneal perforation (3.5 mm × 3.0 mm) with iris prolapse. The corneal melt extended from 9.0 o'clock to 4.0 o'clock. The peripheral edge of the ulcer was sloping, whereas the medial edge showed undermining. Immunological tests did not reveal any evidence of systemic autoimmune disease. In view of extensive peripheral corneal melt with large corneal perforation, the patient needed tectonic keratoplasty. The penetrating graft is not only technically demanding but also results in a poor visual outcome. We advised customized tectonic DALK. We used two different-sized trephines to obtain appropriate-sized donor tissue and avoided manual dissection. The post-surgery period was uneventful. He was prescribed topical steroids and oral methotrexate. He achieved 6/9 aided visual acuity at 4 months and maintained it until the last follow-up at 36 months.

Tectonic Descemet's stripping automated endothelial keratoplasty for corneal perforation

We report the use of Descemet stripping automated endothelial keratoplasty (DSAEK) for the treatment of sterile corneal perforation after trauma. In an eye with corneal perforation and cataract due to trauma, cataract surgery and DSAEK were performed. Corneal integrity was promptly restored and the patient avoided tectonic anterior lamellar and penetrating keratoplasty. DSAEK may be performed for the management of corneal perforation.

Tectonic Eccentric Penetrating Sclerokeratoplasty à chaud as Treatment for Peripheral Perforated or Predescemetal Corneal Ulceration

BACKGROUND

Tectonic eccentric sclerokeratoplasty à chaud is a very complex corneal operation and aims to preserve the eyeball and possibly to improve visual acuity in patients with peripheral corneal ulcerations or perforating corneal trauma.

METHODS

1650 eyes received corneal transplants in our clinic between 2006 and 2019. 14 of these 1650 eyes (0.8%) had a perforated or predescemetal peripheral corneal ulceration and these were treated between 2006 and 2019 with a tectonic eccentric sclerokeratoplasty à chaud. The mean age of the 8 women and 6 men included in this case series was 63 years (22 - 91 years).

RESULTS

In the postoperative follow-up period, most complications and reoperations occurred in the first 6 months. Re-ulceration was observed in 2 cases as well as early suture loosening in 12 patients. These 2 cases were treated with a partial conjunctival flap. Additionally, prolonged superficial wound healing process was shown in 12 patients. Therefore 27 amniotic membrane transplantations, 12 suture replacements, and 6 partial conjunctival flaps were performed in total. No re-keratoplasties were required in this case series. All eyes could be stabilised through the sclerokeratoplasty as well as subsequent operations and intensive local or even systemic treatment. After removal of the corneal suture, the best-corrected visual acuity improved only insignificantly to hand movement in 1 case, finger counting in 3 cases, 0.1 in 5 cases, 0.2 in 4 cases and 0.5 in 1 case. Preservation of the eyeball with pain relief was achieved in all 14 eyes.

CONCLUSIONS

Eccentric sclerokeratoplasty is a very demanding surgical procedure and is extremely rarely performed. The goal is to preserve the eye.

Tectonic Mini-DSAEK Facilitates Closure of Corneal Perforation in Eyes With Healthy Endothelium

PURPOSE

The purpose of this study was to report a surgical technique for closure of a traumatic corneal perforation in a patient with healthy endothelium.

METHODS

A 69-year-old male patient presented to Southend University Hospital with a 2.5 mm round temporal corneal perforation caused by a metallic foreign body from an industrial accident. Best-corrected visual acuity at presentation was 6/36. The patient received a tectonic small diameter Descemet stripping automated endothelial keratoplasty (mini-DSAEK) to close the perforation. The patient subsequently developed traumatic cataract and underwent cataract surgery 8 months later. Clinical outcomes at 1 week, 1 month, 3 months, 6 months, and 9 months were evaluated. The primary outcomes of interest were successful sustained closure of the perforation and surgical complications, with secondary outcomes of best-spectacle corrected visual acuity (BSCVA, Snellen) and keratometric astigmatism (KA, Pentacam).

RESULTS

The anterior chamber was reformed by the graft, restoring the globe's mechanical integrity. The bare stroma reepithelized by 1 week. Neither intraoperative nor postoperative surgical complications were reported. The anterior chamber remained deep and formed during subsequent follow-ups through 9 months. At the 9-month follow-up, final best spectacle-corrected visual acuity was 6/6-1 (Snellen fraction). Keratometric astigmatism was 1.1 diopters.

CONCLUSIONS

Tectonic mini-Descemet stripping automated endothelial keratoplasty is a safe technique in the management of corneal perforations too large for tissue adhesives, with a low astigmatic profile and rapid visual recovery.

Mechanical Stability of Cryopreserved Split-Thickness Tectonic Corneal Grafts

PURPOSE

To evaluate the influence of cryopreservation on the pressure-strain relationship of microkeratome dissected anterior stromal grafts (ASGs).

METHODS

Partial thickness ASGs were created from 7 pairs of human corneas and randomized to immediate grafting or grafting after 3 months of cryopreservation at -80°C into a whole globe ex vivo corneal perforation model. High frequency ultrasound speckle tracking was used to calculate the cross-sectional axial and lateral strains in each graft at increasing intraocular pressure (IOP) from 5 to 30 mm Hg. The mean axial and lateral strains were compared between the paired groups.

RESULTS

The mean axial and lateral strains were not significantly different between the cryopreserved and noncryopreserved ASGs. The mean lateral strains at 30 mm Hg in the noncryopreserved and cryopreserved grafts were 2.4% ± 2.1% and 1.4% ± 0.7% (P = 0.294), respectively. The mean axial strains at 30 mm Hg in the noncryopreserved and cryopreserved grafts were -7.8% ± 3.3% and -5.5% ± 3.0% (P = 0.198), respectively. A linear pressure-strain relationship was found for all grafts at physiologic IOP.

CONCLUSIONS

ASGs cryopreserved at -80°C maintain their IOP-strain relationship compared with noncryopreserved ASGs at physiologic pressures, supporting the potential use of cryopreserved human corneal stroma for patch grafting procedures.

Update on surgical management of corneal ulceration and perforation

Corneal ulcerations are a medical emergency, and in recalcitrant cases, leading to perforation, a surgical ophthalmological emergency. The urgency of the treatment is dictated by the necessity of preventing complications that can lead to serious ocular morbidities. Medical treatment represents the first therapeutic approach and is a defining step in the further management of a patient with corneal ulceration. Multiple surgical strategies are available, but the option depends on the etiology and parameters of the ulceration: size, depth, and location.

Methods of cadaver donor cornea evaluation for keratoplasty (literature review)

At present time, a large amount of patients with corneal diseases require keratoplasty, therefore there is a quite high demand of constant donor cornea stock. In present article, methods of cadaver donor corneal material analysis are described in a sequence that is necessary for its qualitative assessment before surgery or for the choice of the optimal method of preservation in the Eye Bank conditions. It is known that corneal endothelial cells and their viability play a main role in the maintenance of transparency of transplanted corneal flap after penetrating keratoplasty or endothelial keratoplasty. It is for these types of keratoplasty that the highest quality of donor material with preservation of a large number of viable corneal endothelial cells is needed. Corneal flaps with poorer quality of corneal endothelial layer could be successfully used for different types of anterior lamellar keratoplasty and interlamellar keratoplasty. Therefore the adequate evaluation of donor corneal material before surgery allows reducing the risk of postoperative complications associated with failure of the corneal endothelial layer, and increasing graft survival in patients after surgery. In addition, the choice of the optimal type of preservation is of great relevance for maintaining the corneal material as viable in the long run for various types of transplantations.

[Methods of preserving donor corneas]

Corneal transplantation is the most successful and frequently performed allotransplantation procedure. Benign outcome of penetrating and posterior keratoplasty depends on viability of the corneal tissue and presence of the proper endothelial layer, which retaining is one of the main objectives of preservation of donor material. Methods designed to reach this goal may be classified according to storage duration as short-term (storage in a moist chamber), medium-term (hypothermia), long-term (organ cultivation) and unlimited (cryopreservation). While there are reports of successful application of cryo-conserved corneas for penetrating keratoplasty, its use for this type of transplantation is limited due to complexity of the method and very high requirements for the quality of donor material. However, being a method of unlimited storage, it still attracts the attention of researchers. Taking into account the ongoing development of innovative keratoplasty technologies and the tendency for predominant use of layered grafts that in some cases do not need viable endothelium, methods of preservation of such material for anterior lamellar and intralamellar keratoplasties become relevant. In this context, cryopreservation without the use of cryoprotective agents is promising because it allows simple and fast accumulation of large amount of material with long storage time. Further research on the development of preservation methods of the corneal endothelial layer at sub-zero temperatures may allow storing the material by cryopreservation that will be suitable for penetrating and posterior keratoplasty.

Differences in Surgical Management of Corneal Perforations, Measured over Six Years

Purpose. To report the surgical approach, anatomical and functional results, and complications in the group of patients with corneal perforation. Materials and Methods. 247 eyes with corneal perforation were operated on between January 2010 and July 2016. The three surgical procedures, dependent on size and location of perforation, were performed: full-sized penetrating keratoplasty, corneoscleral patch graft, and anterior lamellar keratoplasty. The eyes underwent the minimum 6-month follow-up visit. Results. Between January 2010 and July 2016, 247 surgeries were performed: 116 penetrating keratoplasties, 117 corneoscleral patch grafts, and 14 anterior lamellar keratoplasties. More than one procedure was necessary in 32 eyes. Final improvement of the visual acuity, within a gain of 2 or more lines with the Snellen test, was achieved in 56 operated eyes. To achieve better final visual acuity, 75 eyes required successive surgical treatment. Complications of the surgery comprised persistent epithelial defect, glaucoma or ocular hypertension, corneal oedema, graft melting, loose corneal sutures, reinfection, anterior synechiae and fibrinoid membranes, and endophthalmitis. In 26 eyes, the treatment failure was reported. Conclusions. There is no one general-purpose surgical technique to treat corneal perforations. The complex nature of this pathology remains the individual, careful but also very distinct and multifactorial approach.

Tectonic DSAEK for the Management of Impending Corneal Perforation

Purpose. To report a case of severe corneal thinning secondary to dry eye treated with a tectonic Descemet stripping automated lamellar keratoplasty (DSAEK) and amniotic membrane graft. Methods. A 72-year-old man with a history of long standing diabetes mellitus type 2 and dry eye presented with 80% corneal thinning and edema on the right eye and no signs of infectious disease, initially managed with topical unpreserved lubrication and 20% autologous serum drops. Eight weeks after, the defect advanced in size and depth until Descemetocele was formed. Thereafter, he underwent DSAEK for tectonic purposes. One month after the procedure, the posterior lamellar graft was well adhered but a 4 mm epithelial defect was still present. A multilayered amniotic membrane graft was then performed. Results. Ocular surface healed quickly and reepithelization occurred over a 2-week period. Eight months after, the ocular surface remained stable and structurally adequate. Conclusion. Tectonic DSAEK in conjunction with multilayered amniotic graft may not only provide structural support and avoid corneal perforation, but may also promote reepithelization and ocular surface healing and decrease concomitant inflammation.