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M Küchle

Publications and source records attributed to M Küchle.

At least 19 recordsLinked to original sources
PubMed2005

[Toric intraocular lenses for correction of persistent corneal astigmatism after penetrating keratoplasty].

PURPOSE: Cataract extraction with implantation of toric intraocular lenses (tIOL) is a new surgical option for correction of residual astigmatism following penetrating keratoplasty and cataract with only minimal direct manipulation of the graft. PATIENTS AND METHODS: We implanted an individually manufactured backtoric tIOL in 11 eyes of 9 patients. TIOL power calculation was done using vergence transformation in a paraxial space. RESULTS: Implantation and intraoperative alignment of tIOL were uneventful in all patients. Uncorrected visual acuity increased from 0.1+/-0.06 preoperatively to 0.47+/-0.18 (p=0.006) postoperatively. Best-corrected visual acuity changed from 0.23+/-0.18 preoperatively to 0.6+/-0.14 postoperatively (p=0.002). The refractive cylinder could be reduced from 7.0+/-2.6 D to 1.63+/-1.5 D (p=0.001) after surgery. We observed a small mean deviation from the target axis of 4.1+/-2.9 degrees (0-8 degrees ) after a mean follow-up time of 3.5 (2-7) months. CONCLUSION: TIOL implantation is a promising option for correction of high astigmatism following penetrating keratoplasty with only minimal direct surgical manipulation of the graft. Regular and symmetric corneal topography is essential for successful implantation of tIOL.

Aged↗
PubMed2005

[Blunt ocular trauma. Part II. Blunt posterior segment trauma].

This review presents typical patterns of posterior segment injuries as well as diagnostic and therapeutic considerations after ocular contusion or rupture of the globe. Vitreal prolapse is associated with retinal detachment (20%), iridodialysis or ciliary body cleft (43%), and contusion cataract (41%). Berlin's edema (35%) and retinal detachment (5-7%) are frequent after ocular contusion. In cases of central Berlin's edema, choroidal infarction (Hutchinson-Siegrist-Neubauer syndrome) or choroidal rupture, macular hole or choroidal neovascularization should be ruled out. A central choroidal rupture is often associated with choroidal neovascularization (14-20%). Globe ruptures (5% of blunt injuries) are associated with hyphema grades III and IV (58 vs 5% in ocular contusions). The prognosis of globe ruptures to develop a visual function <20/200 is 51 times more frequent than in eyes with contusion. The risk of trauma-induced globe ruptures is higher in eyes after cataract surgery (27 x) (in females 5 x).

Adult↗
PubMed2004

Accommodation after Nd: YAG capsulotomy in patients with accommodative posterior chamber lens 1CU.

PURPOSE: After initial encouraging results with the accommodative 1CU posterior chamber lens (PCIOL), we investigated the rate, the postoperative time point of posterior capsular opacification (PCO) necessitating YAG capsulotomy and the accommodative range after Nd: YAG capsulotomy in patients with 1CU-PCIOL. PATIENTS AND METHODS: This prospective clinical study included 65 patients who underwent phacoemulsification and implantation of the accommodative 1CU-PCIOL with postoperative follow-up from 3 to 24 months. Postoperative examination was performed 3, 6 and 12 months after surgery, then before and 6 weeks after Nd: YAG capsulotomy. Measurements included: the best corrected distance visual acuity, distance refraction, near visual acuity (Birkhauser charts in 35 cm) obtained with best distance correction, accommodative range measured by subjective near point with an accodommometer and defocusing with a visual acuity fall to 0.4. RESULTS: Both best corrected distance visual acuity (1.1+/-0.1) and near visual acuity with best distance correction (0.4+/-0.1) remained stable over the follow-up period until 12 months postoperatively. The accommodative range determined by near point was stable (mean 2.0+/-0.5 D). Also, the defocusing range remained stable over 12 months (1.8+/-0.4 D). A clinically relevant posterior capsule opacification with a significant decrease of visual acuity (0.4+/-0.2) and a need for Nd: YAG capsulotomy was diagnosed in 12 patients between 15 and 22 (mean 20+/-4, median 20) months postoperatively. All capsulotomies were performed without complication. Six weeks after capsulotomy, best corrected distance visual acuity was improved (1.1+/-0.1), near visual acuity with best distance correction was 0.4+/-0.1 and the accommodative range determined by near point was 1.95+/-0.6 D and by defocusing was 1.88+/-0.47 D. Six weeks after capsulotomy, measurements of the accommodative range did not show any statistical difference to the 12-month results before the occurrence of PCO (P>0.5). CONCLUSIONS: A clinically relevant PCO with a significant decrease of visual acuity necessitating Nd: YAG capsulotomy occurred mainly after 15 postoperative months in patients with 1CU. Our results indicate that Nd: YAG capsulotomy may not affect the accommodation ability of the 1CU. Nevertheless, long-term studies are needed to further analyze the accommodative properties.

Accommodation, Ocular↗
PubMed2004

[Results of the first 1,000 consecutive elective nonmechanical keratoplasties using the excimer laser. A prospective study over more than 12 years].

BACKGROUND AND PURPOSE: The purpose of this prospective clinical cross-sectional study was to analyse indications, intraoperative, perioperative and postoperative pecularities and complications as well as postoperative functional and morphologic results of the first 1000 consecutive elective round laser keratoplasties. PATIENTS AND METHODS: The age of the 480 females and 520 males (362 x keratoconus), who had been operated on between 07/1989 and 04/2002 ranged from 20 to 92 years (mean 55+/-19). A total of 6 microsurgeons performed 718 x PK only, 222 x a triple procedure and 60 x additional IOL manoeuvres. Recipient and donor trephinations were accomplished with an 193 nm excimer laser (Carl Zeiss Meditec, Jena, Germany) from the epithelial side. RESULTS: In 895 eyes with perioperative corneal erosion, epithelial healing took not more than 3 days in half of cases. During a follow-up period of 1.9+/-1.5 years, in 35 eyes episodes of acute diffuse (8 irreversible) and in 12 eyes episodes of chronic focal (5 irreversible) endothelial immunologic graft reactions (4.7%) occurred between 6 weeks and 4.7 years after PK. Before/after suture removal, median values of astigmatism were 1.5 diopters (D)/2.5 D refractive, 3.0 D/3.3 D keratometric, and 4.0 D/4.2 D topographic. Best-corrected visual acuity was 0.50/0.60, respectively. CONCLUSIONS: More than 12 years of experience with this new technique indicate that besides optical advantages, nonmechanical trephination does not cause intraoperative or postoperative disadvantages for the patient. Under standardised surgical conditions a massive increase of astigmatism after suture removal seems to be avoidable with laser trephination in most cases due to reduction of decentration,"vertical tilt" and especially "horizontal torsion".

Adult↗
PubMed2004

[Blunt ocular trauma. Part I: blunt anterior segment trauma].

Blunt ocular traumas include contusions and ruptures of the globe--open and closed globe injuries. Characteristic damage results in anterior and posterior segment trauma. Typical patterns of injuries are combinations of (1) hyphema grade II-IV, iris-lens injury, vitreal bleeding--choroidal rupture and increased risk of rebleeding, (2) angle recession >180 degrees--secondary open-angle glaucoma, and (3) vitreal prolapse and lens dislocation-retinal detachment. Patients with blunt eye trauma should be under steady observation by an ophthalmologist to handle late complications.

Adult↗
PubMed2004

Q-switched erbium:YAG laser corneal trephination: thermal damage in corneal stroma and cut regularity of nonmechanical Q-switched erbium:YAG laser corneal trephination for penetrating keratoplasty.

PURPOSE: To assess stromal thermal damage and cut regularity induced by nonmechanical Q-switched Er:YAG laser corneal trephination for penetrating keratoplasty. METHODS: Corneal trephination was performed in 80 enucleated porcine eyes by Q-switched (2.94-microm) Er:YAG laser, along with donor and recipient masks made of metal or ceramic. All combinations of 0.65- or 0.96-mm spot diameter and 45- or 50-mJ/pulse energy setting were used with each of the masks at a 5-Hz repetition rate. Corneas were processed for histologic examinations. Stromal thermal damage was quantified on PAS-stained slides, and cut regularity was assessed semiquantitatively on a scale from 0 (regular) to 3 (highly irregular). Transmission electron microscopy and scanning electron microscopy were performed on selected specimens. RESULTS: The least thermal damage (mean +/- SD = 6.2 +/- 0.7 microm) was found in the donor ceramic group with 50-mJ/pulse energy and 0.65-mm spot diameter, while the best regularity of the cut (1.2 +/- 0.4) was found in the donor ceramic group with 45-mJ pulse energy and 0.65-mm spot diameter. Thermal damage was less pronounced in donor than in recipient corneas (P < 0.01). Smaller spot diameter (0.65 mm) led to less thermal damage (P < 0.01) than the use of a 0.96-mm spot diameter. The differences in thermal damage between ceramic and metal masks were minimal. CONCLUSIONS: After Q-switched Er:YAG laser corneal trephination for nonmechanical penetrating keratoplasty, reproducible high cut regularity and low concomitant thermal damage were observed. This is an encouraging finding in the search for a nonmechanical trephine for penetrating keratoplasty combining high precision and low cost.

Animals↗
PubMed2003

[Impact of an Er:YAG laser beam control on cut quality of non-mechanical corneal trepanation for penetrating keratoplasty].

BACKGROUND: Results of non-mechanical corneal trepanation using the excimer laser enhance the morphological and functional results for penetrating keratoplasty. Searching for alternative laser sources we assessed the impact of an automatic laser beam control for the Er:YAG solid-state laser on the cut performance and thermal damage zone in non-mechanical corneal trepanation. METHODS: We compared the cut quality of A) a manually guided laser beam, B) a semiautomatically guided laser beam and C) a fully PC-controlled laser beam positioning system (q-switched, repetition rate 5 Hz, pulse energy 65 mJ, spot size 0.7 mm) along slit aperture masks on 28 rabbit eyes using macroscopic images and histological sections (PAS staining). RESULTS: The manually guided laser beam control (A) induced the broadest thermal damage zone in the corneal stroma (19.3+/-8.7 microm) compared to the semi-automatic mode (B) (8.8+/-3.0 microm, p=0.03) and the PC-controlled laser beam control (C) (7.0+/-3.0 microm, p=0.016). CONCLUSION: The fully automatic PC-controlled laser beam positioning system for the Er:YAG solid-state laser with a small spot size and fixed low repetition rate allows a precise laser beam guidance and a significant enhancement of the cut performance compared to a manual laser beam control via micromanipulator in experimental nonmechanical corneal trepanation.

Animals↗
PubMed2003

Pericyte recruitment in human corneal angiogenesis: an ultrastructural study with clinicopathological correlation.

BACKGROUND/AIM: During angiogenesis-that is, the outgrowth of new from pre-existing blood vessels, new capillaries undergo a period of "fine tuning" when vascular endothelial cells become apoptotic if sufficient supply of angiogenic factors is lacking. Morphologically, this period correlates with the absence of pericyte coverage of new vessels. Mature, pericyte covered vessels, in contrast, do not depend on elevated levels of angiogenic factors for survival. This study analyses whether, and if so when, pathological vessels in human corneal neovascularisation (CN) acquire pericyte coverage. This can be of importance for future angioregressive therapeutic strategies. METHODS: Vascularised human corneas obtained by keratoplasty were evaluated by electron microscopy for pericyte coverage of new vessels. These data were correlated with the duration of CN (mean 73 (SD 95) (range 0.5-360) months; n = 15). CN was secondary to keratitis, transplant rejection, aniridia, or trauma. RESULTS: Overall, 196 blood vessels were analysed ultrastructurally (72 (37%) capillaries, 122 (62%) venules, and two (1%) arterioles). Electron microscopically, 170 (87%) vessels were covered by pericytes and two (1%) in addition by smooth muscle cells. Pericyte recruitment increased with time, evolving between clinically noted onset of CN and keratoplasty. Already 2 weeks after onset of CN, more than 80% of new vessels were covered by pericytes. CONCLUSION: Pathological new vessels in human corneal angiogenesis are rapidly covered by pericytes. Therapeutic strategies aimed at regression of immature, not yet pericyte covered vessels by antagonising angiogenic factors should thus be most effective if applied very early in the course of corneal neovascularisation.

Actins↗
PubMed2002

[Microsurgical quality assurance exemplified by cataract surgery].

BACKGROUND: The new German laws demand comprehensive quality assurance in all hospitals. The prerequisite for this in ophthalmic microsurgery is the complete documentation of all relevant surgical details including patient comorbidity. METHODS: Since 1989 we have documented all microsurgical procedures using a computer-based surgery recording system. To analyze the changing spectrum of cataract surgery in a university eye hospital, we evaluated 12,653 consecutive cataract extractions divided into 5 periods between 1990 and 1999. RESULTS: Within these periods the patients' age changed significantly (p < 0.001), whereas the gender showed no significant change (p = 0.34). Furthermore, there was an increase in the number of simultaneous surgical procedures (p < 0.01) as well as the frequency of the pseudoexfoliation syndrome (p < 0.001). In addition the mean duration of cataract procedures decreased (p < 0.001) and the occurrence of vitreous loss also decreased (p < 0.001). CONCLUSIONS: Long-term documentation of all relevant patient data enables valid evaluation of the patient spectrum. Furthermore, this monitoring helps to manage the challenge of quality assurance in ophthalmology.

Aged↗
PubMed2002

[Relevance of the pseudoexfoliation syndrome for the glaucomas].

Secondary chronic open-angle glaucoma associated with pseudoexfoliation (PEX) syndrome accounts for approximately 25% of all glaucomas and represents the most common identifiable cause of glaucoma overall. The underlying disorder, PEX syndrome, is a generalized process of the extracellular matrix characterized by production and progressive accumulation of an abnormal extracellular material in many intra- and extraocular tissues. Recent data support the pathogenetic concept of PEX syndrome as a type of elastosis affecting particularly elastic microfibrils. Active involvement of the trabecular meshwork in this characteristic matrix process may lead to glaucoma development in 40-60% of the patients. In addition, PEX syndrome also represents an important risk factor for a broad spectrum of spontaneous or intra- and postoperative ocular complications as well as for systemic cardiovascular diseases. PEX-associated open-angle glaucoma represents a relatively severe and progressive type of glaucoma with a generally poor prognosis due to high intraocular pressure levels and fluctuations in the diurnal pressure curve. The primary cause of chronic pressure elevation appears to be local production of PEX material by trabecular meshwork cells and Schlemm's canal cells with subsequent degenerative changes of Schlemm's canal and juxtacanalicular tissues. Additional pathogenetic factors contributing to pressure increase include pronounced melanin dispersion, increased protein concentrations of the aqueous humor, vascular factors, and connective tissue alterations of the lamina cribrosa. Other types of glaucoma, such as acute open-angle glaucoma, provoked by melanin showers during diagnostic mydriasis, or secondary angle closure glaucoma due to pupillary or ciliary block, are also common in PEX patients. The pathogenetic factors TGF-beta1 and TIMP-1/2 appear to be causally involved in this fibrotic process and thus may represent potential targets for specific, rational therapeutic approaches.

Exfoliation Syndrome↗
PubMed2002

[Two years experience with the new accommodative 1 CU intraocular lens].

After marked improvement of optical rehabilitation of cataract patients during the last decades due to small incision surgery and foldable intraocular lenses (IOL), presbyopia is now one of the great unsolved questions in ophthalmology. During recent years a new accommodative IOL, the 1CU lens, has been developed based on the concepts of K.D. Hanna and on finite element computer simulation models. The 1CU IOL is designed to transform contracting forces of the ciliary muscle into anterior movement of the IOL optic (optic-shift concept). After the first implantation of a 1CU IOL in Erlangen in June 2000, we have now successfully implanted the 1CU IOL in over 90 patients. Our experiences and the results of several clinical studies indicate good and safe implantability, good centration, no IOL-specific complications, and good distance visual acuity. In comparison to control groups with conventional IOL, patients with the 1CU enjoyed significantly better distance-corrected near visual acuity, a larger accommodative range, and increased anterior and posterior axial movement of the lens optic after medical stimulation or inhibition of the ciliary muscle. We interpret our results as confirmation of the optic-shift concept of the 1CU IOL. Overall, the concept of accommodative IOL appears attractive and may have a great potential in the future. Additional studies including randomized blind multicenter evaluation of the 1CU IOL are necessary to further evaluate long-term and accommodative results.

Accommodation, Ocular↗
PubMed2002

[Corneal neural paralysis after block excision including the 3 and 9 o'clock meridian].

PURPOSE: Corneal innervation is mainly supported by the long posterior ciliary nerves. Anatomically, the long ciliary nerves run with the long ciliary arteries at 3 and 9 o'clock. The aim of this retrospective study was to find out if block excision of anterior uveal tumors or epithelial ingrowth located at the 3 or 9 o'clock position of the limbal circumference causes corneal neuroparalysis. PATIENTS AND METHODS: Between 1980 and May 1999, a total of 151 block excisions were performed in our department (92 block excisions because of anterior uveal tumors and 59 because of cystic epithelial ingrowth to the anterior chamber). In 27 patients, anterior uveal tumors or cystic epithelial ingrowth were located at the 3 or 9 o'clock position of the limbal circumference (14 patients with cystic epithelial ingrowth and 13 patients with anterior uveal tumors). Mean age of all patients was 54.4 +/- 15.7 years at the time of surgery. Mean diameter of the block excision was 10.7 +/- 4.5 mm for tumor-patients and 9.0 +/- 1.2 mm for patients with anterior chamber cysts. Mean follow-up time was 93.6 +/- 43 months. RESULTS: Only 1 of 27 patients exhibited a moderate neuroparalytic corneal ulcer during the follow-up time. In the remaining 26 patients, no signs of clinically relevant corneal neuroparalysis such as epithelial disorders or neuroparalytic ulcers were found. CONCLUSION: Block excision of tumors or cystic epithelial ingrowth located at the 3 or 9 o'clock position of the limbal circumference did not lead to severe neuroparalytic disorders of the host cornea. This may be an important factor in postoperative management of patients undergoing block excision and corneoscleral grafting.

Adult↗
PubMed2002

[Eye contusions caused by a bottle cap. A retrospective study based on the Erlangen Ocular Contusion Register (EOCR)].

BACKGROUND: Perforating ocular injuries due to exploding beverage bottles are well known. However, bottle caps alone may also induce severe ocular damage due to ocular contusions while opening carbon dioxide-containing beverage bottles. We studied this type of ocular contusion. PATIENTS AND METHODS: Retrospectively, we examined all findings, operations, and tension profiles of 400 consecutive patients with ocular contusion who had been hospitalized in the Department of Ophthalmology, University Erlangen-Nürnberg, using the Erlangen ocular contusion registry (EOCR). RESULTS: Seven patients were injured by bottle caps (1.8%) while attempting to open a beverage bottle. The bottle caps were screw caps in six patients and crown corks in one patient. The patient age was 34 +/- 22 years (range: 16-68 years). Four patients were female, three male. We found the following morphological changes: hyphema (seven patients), iridodialysis (two patients), traumatic cataract (two patients), vitreous prolapse (one patient), vitreous hemorrhage (two patients), and retinal detachment (two patients). Intraocular pressure was higher than 21 mmHg in three patients. Visual acuity was hand motion in two patients, lower then 0.4 in two, and 1.0 in three on the admission day. Five patients read 1.0 on the day of discharge. CONCLUSIONS: Bottle cap injuries are not as harmless as supposed. Bottle caps may induce severe ocular damage due to the high-impact energy.

Adolescent↗
PubMed2001

Immunohistochemical classification of primary and recurrent macular corneal dystrophy in Germany: subclassification of immunophenotype I A using a novel keratan sulfate antibody.

Macular corneal dystrophy (MCD) is an autosomal recessive disease characterized by abnormal deposition of glycosaminoglycans in corneal stroma, keratocytes, Descemet's membrane and corneal endothelium. According to the presence and distribution of sulfated keratan sulfate (KS)-epitopes in serum and cornea (using mAb 5-D-4), MCD can be classified into three immunophenotypes: type I, I A and II. The purpose of this study is to evaluate the immunophenotype of primary and recurrent MCD and to analyze the reactions of a novel KS-antibody in MCD corneas, which recognizes an epitope localized in the binding region of KS-chains to the core protein (mAb 3D12/H7). Indirect immunohistochemistry for KS (mAbs 3D12/H7 and 5-D-4) was performed on 44 corneas of 37 patients with MCD including two recurrences. Immunogold labeling was used to localize KS ultrastructurally within keratocytes. The serum concentration of KS (cKS) was determined in a serum antigen-inhibition assay. Immunohistochemically, no reaction was observed using mAb 5-D-4 in 18 corneas of 16 patients (43% of 37 patients; immunophenotype I). Positive reactions within single keratocytes but not in the stroma, were seen in 22 corneas of 17 patients (46% of 37 patients; immunophenotype I A) and positive reactions in keratocytes and extracellular stroma were found in four corneas of four patients (11% of 37 patients: immunophenotype II). For analysis of cKS a total of seven samples was available. Whereas in the samples of the five patients with immunophenotypes I and I A cKS was below the limit of detection, in the two sera from patients with immunophenotype II, cKS was normal (cKS = 1243 and 1380 nmol l(-1)). The two recurrences demonstrated immunophenotype II. Using mAb 3D12/H7, MCD immunophenotype I A can be further subclassified in type I A 1 (lacking reaction with mAb 3D12/H7 in keratocytes; 77%) and type I A 2 (positive reaction with mAb 3D12/H7 within keratocytes; 23%). MCD immunophenotype I A can not only be found in Saudi Arabia, but is as common as immunophenotype I in German patients. The only recurrences of MCD necessitating regrafting occurred in two patients with immunophenotype II possibly suggesting a higher risk for recurrence in this immunophenotype. The mAb 3D12/H7 allows a further subclassification of immunophenotype I A into type I A1 and 2. This points to a broader spectrum of MCD immunophenotypes and indirectly to a broader corneal proteoglycan pathology in MCD.

Antibodies, Monoclonal↗
PubMed2001

Role of transforming growth factor-beta1 and its latent form binding protein in pseudoexfoliation syndrome.

Pseudoexfoliation (PEX) syndrome is a common and clinically important systemic condition characterized by the pathologic production and accumulation of an abnormal fibrillar extracellular material in many intra- and extraocular tissues. Recent evidence suggests that it is a type of elastosis associated with the excess synthesis of elastic microfibrillar components such as fibrillin-1. Since transforming growth factor (TGF)-beta is a major modulator of extracellular matrix formation, the potential involvement of TGF-beta and its latent form binding protein (LTBP) in this aberrant matrix process was investigated. The expression of various isoforms of TGF-beta and LTBP was investigated in the anterior segment tissues of PEX and control eyes on the protein and mRNA level by light and electron microscopic immunohistochemistry, in situ hybridization, and semiquantitative RT-PCR. TGF-beta1 and TGF-beta2 levels were measured in aqueous humor and serum of PEX and control patients by ELISA. Cultures of Tenon's capsule fibroblasts were established to study the effect of TGF-beta1 on fibrillin-1 mRNA expression by Northern blot analysis. Significantly increased concentrations of both total and active TGF-beta1 were measured in the aqueous humor of PEX eyes without and with glaucoma as compared to control eyes, whereas levels of TGF-beta2 were not significantly different. The expression of TGF-beta1, LTBP-1, and LTBP-2, but not TGF-beta2, was markedly increased in anterior segment tissues of PEX eyes, particularly in the non-pigmented epithelium of the ciliary body, on both the mRNA and the protein level. Latent TGF-beta1 staining was consistently associated with PEX material deposits and could be released by proteolytic processing. Double immunolabeling revealed clear co-localization of LTBP-1 and -2 with latent TGF-beta1 and with fibrillin-1 on PEX fibrils. The expression of mRNA coding for fibrillin-1 was up-regulated in vitro by TGF-beta1. This study provides evidence for a significant role of TGF-beta1 and the LTBPs 1 and 2 in PEX syndrome. The results suggest that increased levels of latent and active TGF-beta1 in the aqueous humor of PEX patients, derived from enhanced local synthesis and activation, promote the buildup of the abnormal extracellular elastic material characteristic of PEX syndrome. They further support a dual role for LTBPs, both as integral structural components of PEX fibers and as a means of matrix anchorage of latent TGF-beta1, representing one possible mechanism for the regulation of TGF-beta1 activity in PEX eyes. Future therapeutic strategies might focus on TGF-beta1 antagonistic approaches.

Aged↗
PubMed2001

Graft endothelium and thickness after penetrating keratoplasty, comparing mechanical and excimer laser trephination: a prospective randomised study.

PURPOSE: To assess the impact of nonmechanical trephination on the graft endothelium and thickness after penetrating keratoplasty (PK). METHODS: Inclusion criteria for this prospective, randomised, cross-sectional, clinical study were: (1) Treatment between October 1992 and December 1997; (2) one surgeon (G.O.H.N.); (3) primary central PK; (4) Fuchs' dystrophy (diameter 7.5/7.6 mm) or keratoconus (diameter 8.0/8.1 mm); (5) graft oversize 0.1 mm; (6) no previous intraocular surgery; (7) 16-bite double-running diagonal suture. In 179 patients (mean age 51+/-18 years), PK was performed using either the 193-nm Meditec MEL60 excimer laser ("Excimer") along metal masks with eight "orientation teeth/notches" (53 keratoconus, 35 Fuchs' dystrophy) or motor trephination with the Mikrokeratron (Geuder) ("Control": 53 keratoconus, 38 Fuchs' dystrophy). For donor trephination from the epithelial side an artificial anterior chamber was used in both groups. In 27% of the excimer and 29% of the control group a triple procedure was performed. Specular microscopy (EM-1000, Tomey) and pachymetry (SP-2000, Tomey) were performed before removal of the first suture (0.4+/-0.2 years postoperatively), before (1.1+/-0.4 years) and after (1.7+/-0.6 years) removal of the second suture but before any additional surgical intervention. RESULTS: Endothelial cell count: Neither "two-sutures-in" (1953+/-426/1804+/-385 cells/mm2, p=0.13), "one-suture-in" (1629+/-439/1765+/-440 cells/mm2, p=0.27), nor "all-sutures-out" (1259+/-493/1294+/-532 cells/mm2, p=0.83) differed significantly between Excimer and Control. Graft thickness: Neither "two-sutures-in" (527+/-58/524+/-16 mucrom, p=0.89), "one-suture-in" (537+/-72/551+/-40 microm, p=0.86), nor "all-sutures-out" (576+/-53/565+/-62 microm, p=0.38) differed significantly between Excimer and Control. Cell count and corneal thickness were not significantly different comparing Fuchs' dystrophy and keratoconus or comparing PK only and triple procedures. Graft thickness and endothelial cell count correlated highly significantly inversely with "all sutures out" (P<0.0001). CONCLUSIONS: Excimer laser trephination from the epithelial side using an artificial anterior chamber in donors seems to have no disadvantages concerning the graft endothelium after PK. Endothelial cell loss was not increased in eyes with Fuchs' dystrophy compared with keratoconus or after triple procedures compared with PK only.

Adolescent↗