Results of penetrating keratoplasty after epikeratophakia for keratoconus in the nationwide study

Pneumatic Dissection for Large-Diameter (9-mm) Deep Anterior Lamellar Keratoplasty in Eyes With Previous Anterior Lamellar Keratoplasty

PURPOSE

To evaluate the surgical and 3-year clinical outcomes of modified big-bubble 9-mm deep anterior lamellar keratoplasty (DALK) in eyes with previous ALK (ALK).

METHODS

In this interventional case series, 21 consecutive eyes with unsatisfactory vision after ALK (superficial ALK n = 9; laser-assisted ALK n = 7; and epikeratophakia n = 5) underwent large-diameter (9-mm) DALK. The surgery involved deep trephination based on the anterior segment optical coherence tomography pachymetry measurement at 9-mm diameter, pneumatic dissection from the base of the trephination and limited stromal clearance of the optical zone (6 mm). Main outcome measures were success rates of pneumatic dissection, best spectacle-corrected visual acuity, and complication rates.

RESULTS

Pneumatic dissection with type 1 bubble formation succeeded in 19 (90%) eyes. In the 2 remaining cases, the 6-mm optical zone was cleared by manual dissection. Perforation occurred in one of the latter cases; no procedure was converted to penetrating keratoplasty. One month after complete suture removal, the preoperative mean best spectacle-corrected visual acuity (0.75 ± 0.23 logMAR) improved to 0.09 ± 0.10 logMAR (P < 0.001) and remained stable up to 3 years after surgery. At the final follow-up, refractive astigmatism was ≤4.5 and <6 D in 20 (95%) and 21 (100%) eyes, respectively. Stromal rejection was observed in 2 eyes (10%) and was treated successfully with steroids.

CONCLUSIONS

Even in eyes with previous ALK, pneumatic dissection can be achieved through a modified DALK technique with a low risk of complications and excellent visual and refractive outcomes.

Corneal grafting for keratoconus in mentally retarded patients

PURPOSE

To compare the results of penetrating and non-penetrating corneal grafting procedures in mentally retarded keratoconus patients.

METHODS

In the years 1974-2000 41 mentally retarded patients with keratoconus (33 with Down syndrome) were operated with corneal grafting. Mean age at operation was 36.7+/-10.8 years. Three different surgical procedures were used (no randomization): penetrating keratoplasty (n=16), lamellar keratoplasty (n=5) and epikeratophakia (n=20). In a retrospective study, the non-penetrating procedures (lamellar keratoplasty and epikeratophakia) were compared to the penetrating keratoplasties with regard to graft survival and frequency of serious complications. Mean follow-up time of all grafting procedures was 80+/-58 months.

RESULTS

All cases of serious complications (irreversible rejection, wound leakage or perforation) occurred in the penetrating keratoplasty group (p=0.0005). Older age at operation (p=0.011) adversely influenced the frequency of serious complications. Overall five-year survival was 74.9%. Graft survival was not related to surgical procedure, but rather to age at operation (poorer survival in older age, p=0.012) and degree of retardation (poorer survival in patients with more severe retardation, p=0.051).

CONCLUSIONS

Because of the safety and low frequency of complications, epikeratophakia is recommended as the grafting procedure of choice in the majority of mentally retarded with keratoconus. In selected cases (good cooperation, age < or =40 years, and a good peripheral corneal thickness) penetrating keratoplasty may be performed, which, if uncomplicated, often will give better functional/optical results.

Live-epikeratophakia for keratoconus

PURPOSE

To assess the clinical feasibility of refractive live-epikeratophakia (L-EPI) for early keratoconus to cap, rather than reverse, the ectatic cornea.

SETTING

Eye Department, Martin-Luther-Hospital, Bochum, Germany.

METHODS

Twenty-seven consecutive cases with keratoconus stage I-II had L-EPI. Lenticules were obtained from eye-bank eyes. The lenticules were cut on the artificial anterior chamber bench of the Barraquer-Krumeich-Swinger set. Optical power was generated over refractive dies to achieve postoperative emmetropia. The lenticule was sutured into a peripherally undermined 7.0 mm trephination with a double-running torque suture.

RESULTS

Re-epithelialization was complete within 4 to 6 days. In all but three cases that had corneal ulcers and experienced partial melting of tissue following severe neurodermatitis, all lenticules remained stable during the 10 year follow-up. The 1 month spherical equivalent remained almost stable over the entire follow-up. There was no sign of progression of keratoconus as induced myopia or astigmatism indicated by keratometry readings. Mean best spectacle-corrected visual acuity (BSCVA) was 0.45 (n = 27) preoperatively and 0.19 (n = 25) at 1 week, 0.39 (n = 26) at 1 month, 0.53 (n = 20) at 6 months, 0.58 (n = 13) at 1 year, and 0.64 (n = 8) at 2 years. Preoperative BCVA was achieved or improved in 13 eyes at 1 month. Postoperative astigmatism was < or = 3.25 diopters. Neither rejection nor lenticule opacification was observed.

CONCLUSIONS

Live-epikeratophakia is a safe and minimally invasive extraocular procedure suitable for keratoconus stage I-II. Progression of keratoconus may be arrested. If unsuccessful, the procedure is complementable and there is no interference with a later penetrating keratoplasty.

Management of perforations during epikeratoplasty for keratoconus

Epikeratoplasty (EKP) in keratoconus generally has few intraoperative complications. Perforations during EKP are rare but may force the surgeon to abandon the procedure. We developed a special suture technique to manage this problem. Several deep mattress sutures are placed by taking shallow bites of the central corneal rim and deep bites of the peripheral corneal rim. This leaves the peripheral corneal rim projecting forward by approximately one third the corneal thickness. Slight stretching of this peripheral corneal rim allows adaptation of the epilenticule to form a smooth tissue plane. This method was used in two patients with significant corneal scarring and led to satisfactory visual results.

Wedge resection in the cone after failed refractive surgery in a patient with keratoconus

A 30-year-old man with keratoconus in the right eye had radial keratotomy in the left eye. Two pairs of corneal relaxing incisions (CRIs) were made in the right eye to flatten the central cornea and reduce high astigmatism. The right eye required an enhancement, and two additional arcuate CRIs were made. A corneal ulcer developed in the right eye, with infiltrates in the incision and corneal thinning. Although the second set of CRIs resulted in more regular astigmatism, the corneal thinning and ulcer caused regression at two months postoperatively. A wedge resection was performed to even the irregular astigmatism. The results are presented.