[Deep anterior lamellar (DALK) vs. penetrating keratoplasty (PKP): a clinical and statistical analysis]. / Tiefe lamelläre Keratoplastik vs. perforierende Keratoplastik: Klinische und statistische Analyse.

PURPOSE: Results of deep anterior lamellar keratoplasty (DALK) have been analysed regarding the BCVA, cylinder values, endothelial cell counts and complications both clinically and statistically. An answer to the question is sought as to whether DALK is an equal or better alternative to penetrating keratoplasty (PKP) given all indications with intact corneal endothelium. PATIENTS AND METHOD: A consecutive series on 166 eyes is compared to a group of 566 consecutive PKP eyes regarding visual acuity, astigmatism, stability of refraction and endothelial cell count. The operations were performed in one centre by the same surgeon with the same trephine (Guided Trephine System, GTS) and special instrumentation for DALK (Geuder, Heidelberg). All transplants were of a diameter of 8 mm, the fixation was done with the double-running antitorque suture with one exception. All cases of DALK and PKP were analysed first as two overall groups, then subgroups were broken down for keratoconus and endothelial cell counts (ECC). The subgroups comprised 135 DALK and 76 PKP eyes. RESULTS: BCVA was identical over the whole follow-up of 5 years for the overall groups of DALK and PKP. Statistically significant differences could only be found for the first 3 months favouring DALK (Median 0.5 to 0.35, p = 0.001), whereas for both groups BCVA was without statistically significant differences from month 6 through to 5 years. In the subgroups DALK versus PKP in keratoconus none of the medians from the 1st month to the 5th year were statically significantly different. Between the 1st and 2nd year a maximal BCVA of median 0.7 was reached. The analysis of the endothelial cell count shows both for the comparison of the overall groups and the subgroups keratoconus highly significant differences favouring DALK for all time intervals. CONCLUSION: Since stable ECC suggest an unlimited lifetime of DALK and there is no clinical difference in the outcomes of BCVA or cylinders it must be concluded that with the data presented the DALK operation should be preferred over PKP in eyes that preoperatively have normal endothelial cell counts.

[Excimer laser treatment in deep lamellar keratoplasty 100 micrometer over Descemet's membrane]. / Excimerlaserbehandlung bei tiefer lamellärer Keratoplastik (TLKP) 100 micrometer über der Descemet.

BACKGROUND: Possible improvements of best corrected visual acuity (BCVA) and the stability of the endothelium in deep lamellar keratoplasty (DLKP) assisted by Excimer laser polishing were evaluated. PATIENTS AND METHODS: A 59-year-old male patient was treated 1 year after DLKP with the intention of improving is BCVA. Excimer laser treatment was performed on the deep layers of the graft and on the posterior lamellae of the recipient's cornea 100 micrometer over the endothelium. RESULTS: BCVA improved from 20/100 to 20/22 within 9 months. Refraction remained identical pre- and post-laser treatment at +1.25 sph=-2.0 cyl/17 degrees The endothelium remained unchanged with regard to its cell count of 2,100 cells/mm(2) and the normal morphology. CONCLUSION: Smoothing of the interface by Excimer scanning laser treatment may be recommended in such cases of DLKP in which postoperatively the resulting visual acuity does not correspond to the retinal resolution. Use of scanning or flying-spot lasers are the prerequisite for the maintenance of the endothelium.

Perforating keratoplasty with an intracorneal ring.

PURPOSE: We evaluated the clinical feasibility of an intracorneal ring for penetrating keratoplasty (PKP) designed to decrease postoperative corneal astigmatism. MATERIAL AND METHODS: A steel alloy ring was used for 8-mm PKP. The prospective study was comprised of 15 consecutive patients who underwent PKP for different corneal pathologies. The mean age was 52 years (range, 20-74 years). The Guided Trephine System was used in all cases for the preparation of the donor button and the recipient bed to ensure identical dimensions. The donor button with the surrounding ring in place was sutured in place with a 10-0 nylon double-running suture. RESULTS: Except for one patient who had an allergic reaction to alloy components, no significant complications were observed. Mean reepithelialization occurred within an average of 4 days (range, 3-5 days). In 80% of the cases, stromal graft edema and Descemet's folds disappeared at 14 days after surgery. Average removal time of the intracorneal ring was 6 months (range, 3-9 months). Mean corneal astigmatism was 2.71 (standard deviation [SD], 1.37) diopters (D) before surgery compared to 2.10 (SD, 1.09) D at 1 month, 2.07 (SD, 1.26) D at 3 months, 2.29 (SD, 0.86) D at 6 months, and 2.94 (SD, 1.05) D at 12 months. In four eyes (27%), ruptures of one of the double-running antitorque sutures required resuturing. CONCLUSION: The intracorneal ring prevented the donor button from distortions related to peripheral changes or suture traction. A sutured intracorneal ring appears to be a safe and effective aid in keratoplasties. Further evaluation in a multicenter study with larger patient numbers and indication-specific longer follow-ups is under way.

[Depth of lamellar keratoplasty with the guided trephine system for transplantation of full-thickness donor sections]. / Tiefe lamelläre Keratoplastik mit dem geführten Trepan System zur Ubertragung von Spenderscheiben in ganzer Dicke.

BACKGROUND: Despite the fact that deep lamellar keratoplasty (DLKP) is less invasive than to penetrating keratoplasty (PKP), this procedure is rarely performed. We therefore investigated whether or not the DLKP technique we employed can achieve stable improvement of visual acuity. MATERIALS AND METHODS: Thirty-three eyes underwent TLKP for treatment of superficial corneal pathology. The donor tissue transplanted was suitable for PKP. The donor lenticule was obtained on the artificial chamber of the guided trephine system (GTS). The recipient cornea was trephined with the same trephine to a depth of 680 microns. Manual dissection was performed with a bevel-up blade. The donor lenticule with the endothelium peeled off was then sutured in with a 10 x 0 nylon double-running antitorque suture. Cortisone-antibiotic eye drops were administered postoperatively. RESULTS: Throughout the series no complications occurred. The mean best corrected visual acuity (BSCVA) over glasses was 0.29 (+/- 0.21) preoperatively, 0.1 (+/- 0.11) at 1 week, 0.33 (+/- 0.14) at 1 month, 0.5 (+/- 0.13) at 6 months, 0.61 (+/- 0.16) at 1 year and 0.63 (+/- 0.15) at 2 years. Clinically, we observed two subpopulations. In the first group of 87% of the cases, mean BSCVA was 0.67 (+/- 0.07) at 6 months. The remaining cases (BSCVA < or = 0.25 at 6 months) achieved a mean BSCVA of only 0.2 (+/- 0.04) at 1 year. Mean corneal astigmatism measured 2.93 D (+/- 1.62) preoperatively, 2.69 D (+/- 1.18) at 1 month, 2.09 D (+/- 1.07) at 1 year, and 2.22 D (+/- 1.11) at 2 years. We did not observe any graft rejection. CONCLUSION: The technique reported for DLKP provides excellent matching of donor lenticule and recipient bed. Separation of donor and recipient stroma prevents interface healing. DLKP appears to be a safe procedure for the surgical treatment of superficial corneal pathology and may offer a clinically applicable alternative to PKP.

Blunt, bent needle for continuous curvilinear capsulorhexis.

We describe an anterior continuous curvilinear capsulorhexis (CCC) technique that uses a dull needle. The needle's blunt tip prevents inadvertent tearing of the anterior capsule, and its rough surface allows the surgeon to transmit a power vector of different amplitude and direction to the edge of the capsulorhexis to continue the tear as desired. For biomechanical reasons, we prefer an arcade-shaped CCC because this configuration provides a greater circumference than a circular CCC. The blunt needle allows one to perform a single-step capsulorhexis in a safe and controlled manner and reduces surgical time. Even in cases of white and liquified cortex, the dull needle has proved a useful, safe tool.

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.

[Live epikeratophakia and deep lamellar keratoplasty for I-III stage-specific surgical treatment of keratoconus]. / Lebend-Epikeratophakie und Tiefe Lamelläre Keratoplastik zur Stadiengerechten chirurgischen Behandlung des Keratokonus (KK) I-III.

BACKGROUND: Perforating keratoplasty (PKP) for the treatment of keratoconus is a temporary procedure that sacrifices the healthy recipient endothelium. As an alternative to PKP we perform live-epikeratophakia (L-EPI) in keratoconus I-II and deep lamellar keratoplasty (DLKP) in keratoconus II-III. PATIENTS AND METHODS: 20 patients with keratoconus were operated on either with L-EPI for keratoconus I-II (n = 10) or DLKP for keratoconus II-III (n = 10) respectively. In all cases, corneal tissue eligible for corneal transplantation was used. L-EPI: The corneal lenticule was prepared by means of the Barraquer-Krumeich-Swinger (BKS) set. The recipient cornea was trephined to a depth of 0.3 mm with the Guided-Trephine-System (GTS). The incision was extended manually (inner diameter 7.0 mm, outer diameter 9.0 mm). No keratectomy was performed. The lenticule was fixed with a 10 x 0 nylon double-running anti-torque suture (DRA). DLKP: The recipient cornea was trephined with the 8.0 mm GTS to a depth of 0.68 mm. A lamellar removal of the upper layers was performed by hand. After mechanical removal of the graft endothelium, the remaining full thickness donor cornea was sutured into the bed with a 10 x 0 nylon DRA suture. RESULTS: L-EPI: Within this series, there was no disturbance of the healing process. Spherical equivalent and corneal astigmatism remained stable from the first month on. Visual acuity of 20/40 or better was obtained in 40% of the cases at 1 month, 53% at 6 months, and 100% at 1 year and 2 years. We did not observe any late decline of VA. Two patients with kerato-conus borderline stage II did not reach useful VA due to insufficiently reduced pre-existing irregular corneal astigmatism. These patients successfully underwent DLKP at 8 and 10 months respectively. DLKP: Except for 1 case (neurodermatitis), all lenticules remained stable with respect to refraction and radii up to the longest follow-up of 2 years. Starting from the first month on, refraction was stable. Visual acuity of 20/40 or better was reached in 33% of the cases at 1 month, in 56% at 6 months, and in 89% at 1 and 2 years. We did not administer systemic cyclosporine-A in either group. In the lamellar techniques presented, we did not observe any graft rejection. According to corneal topography, corneal astigmatism, spherical equivalent, and keratometry we did not observe any late re-onset of a progression of the cone. CONCLUSION: In patients with keratoconus stage I to III, L-EPI or DLKP appeared to be very useful therapies. Both procedures seem to end progression of the disease and allow to preserve the healthy recipient endothelium. If unsuccessful, either procedure may be repeated. Neither procedure precludes possibly later needed PKP.

The suction bridge for radial keratotomy may avoid late hyperopic shift.

BACKGROUND: Radial keratotomy may induce late hyperopic shift. We present data on 140 consecutive eyes with a follow-up of up to 3 years that underwent radial keratotomy with the RK suction bridge. METHODS: We conducted a retrospective study of 140 consecutive eyes that had radial keratotomy between 1987 and 1994. Mean preoperative spherical equivalent was -5.21 D (range -2.00 to -9.75 D). All operations were performed by one surgeon (JHK) with the RK suction bridge. A suction ring maintaining physiological intraocular pressure immobilized the eye and left a peripheral rim of uncut cornea. The ring incorporated an eccentric bridge that guided the radial keratotomy knife. The knife setting was 90% of the central corneal thickness, measured by pachymetry. Spherical equivalent refraction and spectacle corrected visual acuity were measured at 1 week, 1, 3, 6 months, 1 year, and 3 years after radial keratotomy. RESULTS: The mean preoperative spherical equivalent refraction of -5.21 D dropped to -0.43 D at 1 week (n = 136), -0.71D at 1 month (n = 120), -0.85 D at 3 months (n = 95), -0.74 D at 6 months (n = 73), -0.77 D at 12 months (n = 79), and -0.85 D at 3 years (n = 67). Compared to 1 month spherical equivalent, at 3 years three eyes (4.4%) had moved > = or 1.00 D toward hyperopia. One eye (1.4%) shifted by 1.25 D. Paired t-tests of mean spherical equivalent refraction did not reveal significant shifts toward hyperopia. Mean preoperative spectacle-corrected visual acuity was slightly diminished at 1 week and was equal or better thereafter. CONCLUSIONS: Our 3-year data suggest that a late hyperopic shift following radial keratotomy may be prevented if an intact peripheral rim is maintained and cutting depth does not exceed 90% of the lowest corneal thickness.

Improved technique of circular keratotomy for the correction of corneal astigmatism.

BACKGROUND: Based on Gauss' law governing the comparison of hyperbaric pressure in the eye and atmospheric pressure, the authors present a procedure to correct astigmatism. The present paper describes an improvement of a technique for circular keratotomy that was published previously. METHODS: We present data on a consecutive series of 32 eyes with a mean corneal astigmatism of 4.66 diopters (D) (range -2.25 to -6.00 D) with a variety of clinical diagnoses. The astigmatic cornea was trephined with a diameter of 7 mm and a depth of 300 microns. After deepening of the trephination with a diamond knife to 550 microns over the steeper semimeridians, the intraocular pressure created a rounding of the cornea. The amount of astigmatic correction and extent of deepening were controlled intraoperatively with a keratoscope. No sutures were placed. RESULTS: In 32 consecutive eyes, corrections were between 50 and 90% of the initial cylindrical values after 1 week to 1 month. In 29 eyes (91%), the results obtained remained stable during a 1-year follow-up; in two eyes (6%), the 1-month results worsened by more than 1.00 D and in one eye (3%), results improved by more than 1.00 D. There were no complications during or after surgery. Wound gaping resulting in epithelial plugs did not occur. No patient lost one or more lines of spectacle-corrected visual acuity, but 13 eyes (40%) gained one or more lines. CONCLUSION: The technique of correcting corneal astigmatism by trephining to a depth of 300 microns, with deepening of the wound to 550 microns along the steep meridian and using no sutures can correct up to 10.00 D of astigmatism with reasonable stability.

Closed-system technique for implantation of iris-supported negative-power intraocular lens.

BACKGROUND: The iris-supported claw lens can reversibly correct a wide range of ametropia and aniseikonia with excellent predictability and stability. However, concerns regarding its potential harm to the corneal endothelium have prevented its widespread use. Our experience with the closed-system surgical technique and the spreader device used in 180 cases between 1987 and 1993 has led us to conclude that potential complications are more likely due to the technique of implantation rather than to the properties of the lens itself. METHOD: We conducted a prospective study of 35 eyes of 20 consecutive patients (mean age, 38 years; range, 21 to 55 years) operated on between August 1993 and August 1994. Preoperative spherical equivalent refractions ranged from -6.00 to -21.25 diopters (D) (mean, -12.50 D). Follow up was 6 months (86% of eyes) to 1 year (57% of eyes). Spectacle-corrected visual acuity and endothelial cell density were measured prior to, and 1, 6, and 12 months following lens implantation. All data were analyzed using the paired t-test. RESULTS: Mean endothelial cell density dropped insignificantly (p > .10):by 1.22% at 1 month (n = 34), by 2.25% at 6 months (n = 27), and by 1.21% at 12 months (n = 18). Spectacle-corrected visual acuity increased significantly (p < .001): from a mean of 0.61 preoperatively to 0.77 at 1 month, 0.84 at 6 months, and 0.93 at 12 months postoperatively. At 12 months, 15 eyes (75%) had a refraction within +/-0.50 D, 19 eyes (95%) within +/-1.00 D, and 20 eyes (100%) within +/-2.00 D of emmetropia. CONCLUSIONS: Our results suggest that the closed-system approach using the spreader device allows safe implantation of the Worst iris-supported claw lens.

Circular keratotomy for the correction of astigmatism.

BACKGROUND: Mathematical and physical considerations that are contained in Gauss' law lead to the concept of a circular cut for the correction of corneal astigmatism. METHODS: The method applied is the coupling of the aspheric corneal surface to the spherical obturator of the Guided Trephine System and cutting of 90% of the parenchyma. Nineteen human eyes were treated with this technique, using a double-running suture closure. RESULTS: Results of reduction of astigmatism can regularly be obtained but are of different amounts depending on the origin of astigmatism. Mean preoperative refractive astigmatism was 5.41 diopters and mean postoperative refractive astigmatism was 1.34 D. Six eyes required additional tranverse arcuate keratotomy. CONCLUSIONS: The procedure is effective, but the results are variable. It may be improved by the use of obturators that fit the radius of curvature of the cornea.

[Non-freeze epikeratophakia (live epikeratophakia)]. / Non-freeze-Epikeratophakie (Lebend-Epikeratophakie).

Instruments for the production of non-freeze epikeratophakia lenticules allow the surgeon to produce his own live lenticules from -35 to +25 dptr using the Barraquer-Krumeich-Swinger set. 29 myopic cases differ to the refractive target plus/minus 15% and reach contact lens visual acuity values after 2-5 weeks. 58 consecutive cases off epikeratophakia correction of aphakia result between 5 and 15% of the target. Optimal visual acuity is generally reached between 4 and 8 weeks postop. In 6 cases the epikeratophakia lenticule had to be removed and replaced.

Nonfreeze epikeratophakia for the correction of myopia.

We developed a procedure for preparing epikeratophakia tissue lenses for the correction of myopia from unfrozen tissue using a newly developed artificial anterior chamber and the BKS-1000 (Barraquer-Krumeich-Swinger) refractive set. The results of 23 clinical cases involving tissue that was not frozen or lyophilized demonstrate a correlation coefficient of 0.90 in terms of accuracy of correction and good visual acuity results.