Lymphatic vessels in vascularized human corneas: immunohistochemical investigation using LYVE-1 and podoplanin.

PURPOSE: To determine whether lymphatic vessels exist in vascularized human corneas, by using immunohistochemistry with novel markers for lymphatic endothelium. METHODS: Human corneas exhibiting neovascularization secondary to keratitis, transplant rejection, trauma, and limbal insufficiency (n = 21) were assessed for lymphatic vessel content by conventional transmission electron microscopy and by immunostaining and immunoelectron microscopy with antibodies specific for the lymphatic endothelial markers, lymphatic vessel endothelial hyaluronan receptor (LYVE-1) and the 38-kDa integral membrane glycoprotein podoplanin. In addition, corneas were stained for the lymphangiogenic growth factor VEGF-C, and its receptor VEGFR3 by immunohistochemistry and in situ RNA hybridization, respectively. RESULTS: Thin-walled, erythrocyte-free vessels staining with lymphatic markers (LYVE-1 and podoplanin) were found to constitute 8% of all vessels, to be more common in the early course of neovascularization, to be always associated with blood vessels and stromal inflammatory cells, and to correlate significantly with the degree of corneal hemangiogenesis (r = 0.6; P = 0.005). VEGF-C, VEGFR3, podoplanin, and LYVE-1 colocalized on the endothelial lining of lymphatic vessels. With immunogold labeling, LYVE-1 and podoplanin antigen were found on endothelial cells lining vessels with ultrastructural features of lymph vessels. CONCLUSIONS: Immunohistochemistry with novel lymph-endothelium markers and ultrastructural analyses indicate the existence of lymphatic vessels in vascularized human corneas. Human corneal lymphangiogenesis appears to be correlated with the degree of corneal hemangiogenesis and may at least partially be mediated by VEGF-C and its receptor VEGFR3.

Matrix metalloproteinases and their inhibitors in aqueous humor of patients with pseudoexfoliation syndrome/glaucoma and primary open-angle glaucoma.

PURPOSE: To determine the presence, activity, and quantitative differences of matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs) in aqueous humor and serum samples of patients with pseudoexfoliation (PEX) syndrome, PEX glaucoma (PEXG), primary open-angle glaucoma (POAG), and cataract. METHODS: Aqueous humor and serum samples were collected from 100 patients with PEX syndrome, PEX glaucoma (PEXG), POAG, and cataract, respectively. Levels of MMP-1, -2, -3, -7, -9, and -12 and TIMP-1 and -2 were determined by zymography, Western blot analysis, and specific immunoassays. Activity assay kits were used to quantitate levels of endogenously activated MMP-2 and -9. RESULTS: MMP-2, -3, -7, -9, and -12 and TIMP-1 and -2 were identified in human aqueous humor samples from all groups of patients with a six to sevenfold molar excess of TIMPs over MMPs. Whereas serum samples showed no significant differences, total MMP-2 and -3 and TIMP-1 and -2 were detected at significantly higher concentrations in aqueous samples from PEX eyes with and without glaucoma compared with cataractous eyes. MMP-2 and -3 and TIMP-1 were also detected in higher, but not significantly different, amounts in aqueous samples of POAG eyes. However, levels of endogenously activated MMP-2 were significantly decreased in both PEX and POAG samples. The ratio of MMP-2 to its principal inhibitor TIMP-2 was balanced in cataract samples, but was decreased in samples from patients with PEXG, resulting in an excess of TIMP-2 over MMP-2. CONCLUSIONS: The findings suggest that complex changes in the local MMP-TIMP balance and reduced MMP activity in aqueous humor may promote the abnormal matrix accumulation characteristic of PEX syndrome and may be causally involved in the pathogenesis of both PEX glaucoma and POAG.

Theoretical and measured pseudophakic accommodation after implantation of a new accommodative posterior chamber intraocular lens.

OBJECTIVE: To analyze different techniques of measuring accommodation after implantation of a new accommodative posterior chamber intraocular lens (PCIOL). METHODS: In this comparative, nonrandomized interventional study, we analyzed 15 eyes of 15 patients (aged 44-84 years) at 6 months after cataract surgery and PCIOL implantation (Akkommodative 1CU; HumanOptics AG, Erlangen, Germany) and compared these results with those of an age-matched control group (n = 15). We used the following methods to measure accommodation: dynamic measurement with objective (videorefractometry [PowerRefractor; PlusOptix, Erlangen] and streak retinoscopy) and subjective (subjective near point [push-up test and accommodometer] and defocusing) techniques, as well as static measurement of the change in anterior chamber depth (ACD) using the IOLMaster (Zeiss, Jena, Germany) after pharmacological stimulation using 2% pilocarpine eye drops. MAIN OUTCOME MEASURES: Theoretical accommodation calculated from the forward shift of the lens optics (decrease of ACD) using paraxial geometrical optics and measured accommodation amplitude. RESULTS: Accommodation amplitude (mean +/- SD; range; median) results after 6 months in the study and control groups were as follows: 1.00 +/- 0.44; 0.75-2.13; 1 diopter (D); and 0.35 +/- 0.26; 0.10-0.65; 0.25 D, respectively, using the PowerRefractor; 0.99 +/- 0.48; 0.13-2.00; 0.88 D; and 0.24 +/- 0.21; -0.13-0.75; 0.25 D, respectively, using retinoscopy; 1.6 +/- 0.55; 0.50-2.56; 1.7 D; and 0.42 +/- 0.25; 0.00-0.75; 0.50 D, respectively, using subjective near point; and 1.46 +/- 0.53; 1.00-2.50; 1.75 D; and 0.55 +/- 0.33; 0.25-0.87; 0.50 D, respectively, using defocusing. Anterior chamber depth decreased in the study and control groups as follows: 0.78 +/- 0.12; 0.49-1.91; 0.65 mm; and 0.16 +/- 0.09; 0.00-0.34; 0.18 mm, respectively, after applying 2% pilocarpine eyedrops, indicating an accommodation of 1.16 +/- 0.22; 0.72-1.88; 1.05 D vs 0.22 +/- 0.13; 0.00-0.47; 0.23 D (P =.001). CONCLUSIONS: Accommodation after implantation of a presumably accommodative PCIOL can be measured with clinical methods or derived from the biometric data of the eye and the measured ACD decrease using geometrical optics. For clinical purposes, pseudophakic accommodation should be assessed with a variety of different techniques, including subjective and objective measurements. The theoretical approach using geometrical optics may be an additional indicator for the accommodative response in patients with pseudophakic eyes and may allow a subdivision of the measured accommodation into true pseudophakic accommodation and pseudoaccommodation.

Nonmechanical Q-switched erbium:YAG laser trephination for penetrating keratoplasty: experimental study on human donor corneas.

OBJECTIVE: To assess the alterations in human donor corneal tissue induced by Q-switched erbium (Er):YAG laser corneal trephination. METHODS: Thirty human corneoscleral donor buttons unsuitable for transplantation were placed in an artificial chamber on an automated rotation device. Corneas were trephined with a Q-switched Er:YAG laser (wavelength, 2.94 microm; pulse duration, 400 nanoseconds) along (donor and recipient) aluminum silicate (ceramic) open masks. A spot diameter of 0.65 mm, energy setting of 50 mJ/pulse, and repetition rate of 5 Hz were used. Corneal thermal damage and cut regularity were quantitatively assessed in 24 corneas processed for light microscopy and by transmission and scanning electron microscopy. RESULTS: The stromal thermal damage was the highest (mean [SD], 8.0 [2.7] microm) at a 150-microm cut depth and decreased downward. Cut regularity was very good and did not significantly differ between donors and recipients. Scanning electron microscopy confirmed that the cuts were highly regular; transmission electron microscopy revealed 2 distinctive subzones within the stromal thermal damage zone. CONCLUSIONS: Thermal damage induced by Q-switched Er:YAG nonmechanical corneal trephination was low, and the regularity of the cuts was very good. CLINICAL RELEVANCE: The Q-switched Er:YAG laser may have the potential to become an alternative to the excimer laser for nonmechanical penetrating keratoplasty.

Implantation of a new accommodative posterior chamber intraocular lens.

PURPOSE: A new, potentially accommodative posterior chamber lens (PCIOL) was designed based on principles elaborated by Hanna using finite element computer simulation methods. We report 3-month postoperative results in patients. METHODS: In a prospective study, 12 eyes of 12 patients (age 45 to 87 yr) underwent phacoemulsification for cataracts and PCIOL implantation. The PCIOL, 1 CU, has haptics designed for anterior optic movement following ciliary muscle contraction. Patients were examined postoperatively after 1 and 2 days, 1, 2 and 6 weeks, and 3 months, and results were compared with a control group of 12 eyes that received standard PMMA or acrylic PCIOLs. RESULTS: Surgery was uncomplicated and all PCIOLs were well-tolerated and stable with good centration in the capsular bag. The results were (mean +/- SD [range] and median; 1 CU versus control PCIOL): near visual acuity (Birkhäuser reading chart at 35 cm) with best distance correction 0.34 +/- 0.17 (0.2 to 0.6), 0.3 (J10-J1, median J7) versus 0.15 +/- 0.07 (0.1 to 0.3), 0.15 (J16-J7, median J13), P=.001; subjective near point 59 +/- 10 cm (40 to 100 cm), 53.5 cm versus 93 +/- 20 cm (64 to 128 cm), 86 cm, P=.004; retinoscopic accommodative range 1.2 +/- 0.4 D (0.63 to 1.5 D), 1.2 D versus 0.2 +/- 0.19 D (-0.25 to 0.5 D), 0.25 D, P < .001; decrease of anterior chamber depth after 2% pilocarpine 0.63 +/- 0.16 mm (0.40 to 0.91 mm), 0.63 mm versus 0.15 +/- 0.05 mm (0.08 to 0.20 mm), 0.17 mm, P < .001. CONCLUSIONS: The new PCIOL appears to be safe at short to medium term. Our results indicate pseudophakic accommodation secondary to focus shift with this PCIOL. Additional larger and long-term studies are necessary for exact evaluation of safety and accommodative power of this new PCIOL.

Short-term blood-aqueous barrier breakdown after implantation of the 1CU accommodative posterior chamber intraocular lens.

PURPOSE: To quantify intraocular inflammation after phacoemulsification with implantation of an accommodative posterior chamber intraocular lens (IOL). SETTING: Department of Ophthalmology, University of Erlangen-Nürnberg, Erlangen, Germany. METHODS: Twenty cataractous eyes of 20 patients without preexisting blood-aqueous barrier (BAB) deficiencies or previous intraocular surgery were included in this study. The mean age of the patients was 64.6 years +/- 16.0 (SD). A single surgeon performed phacoemulsification through a superior sclerocorneal tunnel incision and implantation of a 1CU IOL (HumanOptics AG) though a 3.2 mm incision. The haptics of the single-piece acrylic 1CU lens are designed for anterior optic movement following ciliary muscle contraction. The postoperative treatment was standardized. Postoperative BAB breakdown was quantified by laser flare photometry (FC-1000, Kowa) at 1 day, 1 and 4 weeks, and 3 and 6 months. RESULTS: The mean aqueous flare was 6.3 photons/ms +/- 3.0 (SD) (range 4.0 to 12.2 photons/ms) 1 day postoperatively, with 64% of patients having normal aqueous flare values (<8.0 photons/ms). One week after surgery, the mean aqueous flare was 5.3 +/- 2.8 photons/ms (range 2.0 to 10.5 photons/ms). Four weeks postoperatively, aqueous flare was normal in all patients and remained stable below the normal limit for up to 6 months (mean 3.3 +/- 1.2 months; range 2.0 to 5.4 months). The number of aqueous cells did not increase at any follow-up and was normal in all eyes. No postoperative complications such as fibrin formation, synechias, macrophages on the IOL optic, or endophthalmitis were observed. CONCLUSIONS: Phacoemulsification with implantation of the 1CU accommodative IOL led to minimal and short-lasting BAB alteration. No signs of persistent inflammation or pigment dispersion were detected.

Stability of refraction, accommodation, and lens position after implantation of the 1CU accommodating posterior chamber intraocular lens.

PURPOSE: To investigate stability of refraction, anterior chamber depth (ACD), and accommodation up to 12 months after implantation of the 1CU accommodating posterior chamber intraocular lens (PC IOL). SETTING: Department of Ophthalmology, University Erlangen-Nürnberg, Erlangen, Germany. METHODS: In a prospective study, 15 eyes of 15 patients (mean age 62.2 years +/- 13.4 [SD] [range 44 to 86 years]) had phacoemulsification and PC IOL implantation. Distance refraction, accommodative range measured by the near point with an accommodometer, ACD measured with the IOLMaster (Carl Zeiss Meditec), and near visual acuity with best distance correction (Birkhäuser charts at 35 cm) were determined after 3, 6, and 12 months and analyzed for signs of systematic changes. RESULTS: After 3, 6, and 12 months, the mean distance refraction was -0.28 +/- 0.54 diopters (D), -0.29 +/- 0.52 D, and -0.21 +/- 0.54 D, respectively; the mean accommodative range, 1.93 +/- 0.47 D, 1.85 +/- 0.62 D, and 2.02 +/- 0.38 D, respectively; the mean ACD without pharmacological induction of ciliary muscle contraction, 4.40 +/- 0.44 mm, 4.35 +/- 0.50 mm, 4.25 +/- 0.53 mm, respectively; and the mean near visual acuity with best distance correction, 0.41 +/- 0.15, 0.37 +/- 0.12, and 0.39 +/- 0.11, respectively. There were no statistically significant changes in any measurement during the follow-up (P>.1). CONCLUSIONS: Refraction, ACD, and accommodative range remained stable without indication of a systemic trend toward myopia, hyperopia, PC IOL dislocation, or regression of accommodative properties. The 1CU accommodating PC IOL provided stable refraction, accommodation, and PC IOL position for up to 1 year.

Measurement of accommodation after implantation of an accommodating posterior chamber intraocular lens.

PURPOSE: To analyze techniques of measuring accommodation after implantation of an accommodating posterior chamber intraocular lens (PC IOL). SETTING: Department of Ophthalmology and University Eye Hospital, University Erlangen-Nürnberg, Erlangen, Germany. METHODS: This prospective study analyzed 23 eyes of 23 patients (aged 41 to 87 years) after cataract surgery and PC IOL implantation (1 CU, HumanOptics) 4 weeks and 3 and 6 months after surgery. The results were compared to those in an age-matched control group (n = 20) 6 months after surgery. The following methods were used to measure accommodation: dynamic with objective techniques (PlusOptix PowerRefractor videorefractometry, streak retinoscopy) and subjective techniques (subjective near point [push-up test, accommodometer], defocusing); static with pharmacologic stimulation after pilocarpine 2% eyedrops directly (conventional refractometry); indirectly (change in the anterior chamber depth [ACD] with Zeiss IOLMaster). RESULTS: Results at 6 months, given as mean +/- SD (range), in the study and control groups, respectively, were as follows: near visual acuity (Birkhäuser reading charts at 35 cm) with distance correction, 0.32 +/- 0.11 (0.20 to 0.60) and 0.14 +/- 0.10 (0.05 to 0.30); accommodation amplitude (diopters) by PowerRefractor, 1.00 +/- 0.44 (0.75 to 2.13) and 0.35 +/- 0.26 (0.10 to 0.65), by retinoscopy, 0.99 +/- 0.48 (0.13 to 2.00) and 0.24 +/- 0.21 (-0.13 to +0.75), by subjective near point, 1.60 +/- 0.55 (0.50 to 2.56) and 0.42 +/- 0.25 (0.00 to 0.75), and by defocusing, 1.46 +/- 0.53 (1.00 to -2.50) and 0.55 +/- 0.33 (0.25 to 0.87). The mean ACD decrease (mm) was 0.78 +/- 0.12 (0.49 to 1.91) and 0.16 +/- 0.09 (0.00 to 0.34) after pilocarpine 2% eyedrops, indicating a mean accommodation of 1.40 D and 0.29 D, respectively, based on Gullstrand's model eye (P =.001). The lowest fluctuation between follow-ups was with the subjective near point and the defocusing techniques followed by ACD decrease with the IOLMaster. CONCLUSIONS: Accommodation after implantation of an accommodating PC IOL should be assessed with several techniques, including subjective and objective, to differentiate true pseudophakic accommodation from pseudoaccommodation. Researchers should be aware of the different variability and consistency of measurements with each technique over time.

Corneal neovascularization after nonmechanical versus mechanical corneal trephination for non-high-risk keratoplasty.

PURPOSE: To analyze the influence of mechanical versus nonmechanical trephination of donor and host corneas on superficial, peripheral corneal neovascularization occurring after non-high-risk keratoplasty. METHODS: Patients of the prospective Erlangen non-high-risk keratoplasty study with standardized corneal photographs taken preoperatively and 1 year later were analyzed (n = 184). Slides of these photographs were projected (magnification x100) and corneal vessels graded in a standardized semiquantitative fashion into five categories with regard to limbus, sutures, and host-graft junction in each of 12 corneal sectors. Degree (total increase of grades in the 12 sectors) and maximal extent of corneal neovascularization (maximal centripetal extension of blood vessels) were analyzed. In 32 patients mechanical (17%) and in 152 nonmechanical trephination of host and donor tissue was performed (193-nm excimer laser, 83%). Statistical analysis was done using Fisher's exact and Mann-Whitney test. RESULTS: Corneal neovascularization within the first postoperative year was lower in the nonmechanical [73 of 152 (48%)] compared with mechanical trephination group [24 of 32 (75%); p< 0.01; Mann-Whitney test]. Maximal extent of neovascularization (i.e., vessels reaching the interface or growing beyond) was not yet significantly different between nonmechanical (8%) and mechanical (17%) trephination (p = 0.074). CONCLUSIONS: Nonmechanical trephination using the 193-nm excimer laser in non-high-risk keratoplasties might reduce corneal neovascularization occurring within the first postoperative year. This indicates that in the non-high-risk setting, development of postoperative corneal neovascularization may be affected by the trephination technique and subsequent wound-healing response.

Histopathology of corneal changes in lecithin-cholesterol acyltransferase deficiency.

PURPOSE: Lecithin-cholesterol acyltransferase (LCAT) deficiency is a rare entity. This dyslipoproteinemia may lead to corneal opacity, renal failure, and arteriosclerosis. METHODS: Presentation of a 66-year-old man with bilateral corneal opacification due to LCAT deficiency caused by a single-nucleotide exchange in codon 123 of gene. An extracapsular cataract extraction combined with full-thickness corneal transplantation was performed. The corneal specimen was analyzed by light and transmission electron microscopy. RESULTS: All stromal layers showed extracellular vacuoles with acid mucopolysaccharide contents measuring up to 2.5 microm. Amyloid deposits measuring up to 12 microm in diameter were detected in the stroma and especially predescemetally. CONCLUSION: To our knowledge, this is the first histologic description of secondary amyloidosis in a full-thickness corneal specimen with LCAT deficiency. The disease is associated with anemia, proteinuria, a lack of plasma high-density lipoprotein, and the presence of target cells. Bilateral corneal opacification is a characteristic of the disease and may allow early detection of homozygous LCAT deficiency by the ophthalmologist.

Long-term follow-up of intraocular pressure after penetrating keratoplasty for keratoconus and Fuchs' dystrophy: comparison of mechanical and Excimer laser trephination.

PURPOSE: In the literature, the incidence of "secondary glaucoma" after penetrating keratoplasty (PK) is reported to range from 10% to 42%, depending on the diagnosis and the complexity of surgery. The purpose of this study was to assess the impact of the trephination method and simultaneous cataract surgery on the early and long-term intraocular pressure (IOP) after PK in eyes without previous surgery and glaucoma. METHODS: Inclusion criteria for this prospective, randomized, longitudinal clinical study were (1) one surgeon (G.O.H.N.), (2) primary central PK, (3) Fuchs' dystrophy (7.5/7.6 mm) or keratoconus (8.0/8.1 mm), and (4) 16-bite double running diagonal suture. Exclusion criteria were (1) previous intraocular surgery, (2) preoperative glaucoma, and (3) postoperative trauma or endophthalmitis. In 170 patients (mean age, 51 +/- 18 years), PK was performed with use of either a 193-nm excimer laser (Excimer patients) along metal masks with eight orientation teeth/notches (50 keratoconus, 32 Fuchs') or motor trephination (Control patients; 53 keratoconus, 35 Fuchs'). In 27% of Excimer patients and 29% of Control patients a triple procedure was performed. The perioperative systemic acetazolamide application and the postoperative topical steroid therapy were standardized. RESULTS: Maximal IOP during the first week after PK was 15.7 +/- 3.6 mm Hg (7% > 21; maximum, 28) in the Excimer group and 16.2 +/- 3.5 mm Hg (7% > 21; maximum, 30) in the Control group. During a mean follow-up of 3.4 +/- 1.3 years (maximal, 6.0), an IOP >21 mm Hg and/or application of topical antiglaucomatous medication was documented in 9% of Excimer patients versus 15% of Control patients (p = 0.32), in 15% of Fuchs' dystrophy versus 11% of keratoconus cases (p = 0.41), and in 11% of PK-only versus 15% of triple-procedure cases (p = 0.68). The IOP elevation started an average of 3.7 +/- 2.8 months (1 week to 9 months) after PK and ended an average of 6.5 +/- 3.1 months (6 weeks to 12 months) after PK. Mean maximal IOP during follow-up was 16.6 +/- 3.5 mm Hg (12-38) in the Excimer group and 17.2 +/- 3.2 mm Hg (12-30) in the Control group. Only one patient, who had undergone a triple procedure for Fuchs' dystrophy and had an elevated IOP, needed topical medication, from 32 months after PK to the end of follow-up. Glaucomatous optic disc damage was clinically detected in none of the patients. CONCLUSIONS: Temporary secondary ocular hypertension after PK is rare in eyes with keratoconus or Fuchs' dystrophy without previous surgery. There was no detectable impact from the trephination method, the diagnosis, or simultaneous cataract surgery. With meticulous microsurgical technique, careful suturing, and peripheral iridotomy, the development of secondary glaucoma with disc cupping seems to be the exception.

Frequency-doubling perimetry in patients following penetrating keratoplasty.

PURPOSE: Perimetry using a frequency-doubling technique (FDT perimetry) is becoming established as a new diagnostic tool to detect early visual field losses. The aim of this study was to evaluate the diagnostic usefulness of an FDT perimetry protocol (C-20-5) in patients after penetrating keratoplasty (PK) and to assess whether this method is influenced by postoperative corneal topographic changes. METHODS: Thirty-six patients (age 40 +/- 13, median 41 years) following PK and 68 age-matched controls were included in this study. The postoperative interval was 21 +/- 19, median 14 months. Patients with preexisting glaucoma or any postoperative intraocular pressure elevation were excluded. The indications for PK were keratoconus in 82%, Fuchs dystrophy in 15%, and secondary bullous keratopathy in 3%. In 19 patients keratoplasty was performed in 1 eye. FDT perimetry was evaluated in both eyes to judge intraindividual variability. FDT perimetry was done using the screening strategy, which begins testing at the normal 5% probability level. If a stimulus is not detected, further targets are presented. FDT viewfinder and statistics software were used for case-wise recalculation of all missed localized probability levels. RESULTS: Neither mean overall FDT score (0.8 +/- 1.9, median 0.0 versus 0.9 +/-1.0, median 0.0) nor total test time (44 +/- 4.7, median 44 versus 44 +/- 4.2, median 42 seconds) showed significant differences between patients after PK and controls (P = 0.5). There was also no significant difference of mean FDT score between eyes after keratoplasty (0.8 +/- 1.9, median 0.00) and nonoperated contralateral eyes (0.9 +/- 2.0, median 0.00, P = 0.8) in the same patient. No significant correlation between FDT score and visual acuity as well as corneal keratometric astigmatism could be found in patients after PK and in normals (r < 0.2, P = 0.3). In patients after PK, FDT score and examination time were statistically independent of keratometric astigmatism (P = 0.7), topographic astigmatism (P = 0.4), spherical equivalent (P = 0.5), central corneal thickness (P = 0.7), and interval of postoperative follow-up (P = 0.6). CONCLUSIONS: Perimetry using the FDT protocol (C-20-5) seems to be feasible in patients after PK and does not depend on postoperative topographic changes of the cornea. This method allows valid information on visual field abnormality in patients after PK The results indicate that this method may be helpful as a supplement to detect early glaucomatous damage in patients after PK.

Superficial corneal effects of experimental nonmechanical penetrating keratoplasty using a Q-switched Er:YAG laser.

PURPOSE: To assess thermal effects of Q-switched Er:YAG laser trephination to corneal epithelium and superficial stroma using different mask types and materials for experimental penetrating keratoplasty. METHODS: Laser trephination was performed in 20 freshly-enucleated porcine eyes (repetition rate 5 Hz, pulse energy 65 mJ, spot size 0.7 mm). We used flat, open-metal and ceramic masks for donor and recipient trephination placed directly onto the corneal surface. Main outcome measures as assessed by light microscopy after PAS staining of 8-microm paraffin sections included: extension of tissue thermal damage at the cut edge in the superficial and basal epithelial layers, the basement membrane and subepithelial stroma, and depth and width of epithelial/stromal involvement in the area of the donor mask contact. RESULTS: The thermal damage in the superficial epithelium was more pronounced in donor (mean extension 61.6 +/- 15.6 microm) than in recipient (29.4 +/- 24.9 microm, p= 0.05) trephination. In donor trephination, thermal damage zone of the superficial epithelial layer was significantly smaller with ceramic than with metal masks (21.0 +/- 23.0 versus 61.6 +/- 15.6 microm, p= 0.014). In contrast, differences at basal epithelial layer (p= 0.44), basement membrane (p= 0.79), and subepithelial stroma (p= 0.2) were not statistically significant. Superficial donor involvement of the cornea adjacent to the paracentral donor mask contact zone was seen neither with ceramic nor with metal masks. CONCLUSION: Superficial corneal alterations adjacent to the mask-cornea contact zone may be minimized by using the Er:YAG laser in a Q-switched mode. Ceramic masks, in contrast to metal masks, further reduce superficial thermal alterations at the cut edge.

Q-Switched 2.94-microm Er:YAG laser trephination with convergent and divergent cut angles for penetrating keratoplasty.

PURPOSE: To study the morphologic properties of perpendicular (P), convergent (C), and divergent (D) cut angles using different speeds of rotations during donor and recipient nonmechanical trephination for experimental penetrating keratoplasty. METHODS: With a Q-switched 2.94-microm Er:YAG laser corneal trephination was performed in 150 enucleated porcine eyes using ceramic open masks with 8 "orientation teeth/notches" and an automated globe rotation device allowing different cut angles [0 degree (P), 10 and 20 degrees (C and D)] toward the optical axis and variation of the rotation speed [3, 7, and 11 rotations per minute (rpm)]. The regularity of the cut (I, regular; II, slightly irregular; III, irregular) was assessed by light microscopy. The area of thermal damage and the number and size of "spikes" in the stroma at the superficial, intermediate and deep level of the excision were analyzed using digital images and the Optimas image processing software. RESULTS: The regularity of the cut was classified as I in 42%/22% of donor/recipient and as II in 41%/56%, respectively. The thermal damage was least expressed with D20 degree cut angle and donor mask (P < 0.01). With all cut angles and speeds of rotation, thermal damage at the deep level of excision was significantly smaller (P < 0.01). With different speeds of donor rotations, the thermal damage showed no significant difference. With recipient trephination, the thermal damage at the deep level was greatest with 7 rpm (P < 0.01). The number and size of spikes of thermal damage with donor and recipient masks were significantly smaller in the deep stroma (P < 0.01). CONCLUSIONS: Q-switched Er:YAG laser trephination with appropriate settings results in low thermal damage zones at the cut margin. Different cut angles and speeds of trephination may affect the cut performance and quality of the excision. In our study, low rotation speed and divergent donor cut angles showed the best results. The cut quality and the small thermal damage with the Q-switched 2.94-microm Er:YAG laser seem to be tolerable for corneal trephination. Therefore, this modality may be a low-cost, easy-to-handle alternative for nonmechanical corneal transplantation in humans.

Quantification of blood-aqueous barrier breakdown after phacoemulsification in Fuchs' heterochromic uveitis.

PURPOSE: To quantify the breakdown of the blood-aqueous barrier (BAB) following phacoemulsification with posterior chamber lens implantation in eyes with Fuchs' heterochromic uveitis (FHU). PATIENTS AND METHODS: In this retrospective study, 19 eyes of 19 patients with FHU (mean age 38 +/- 14 years) and 35 eyes of 35 patients with senile cataracts (mean age 63 +/- 9 years) underwent phacoemulsification with one-piece PMMA posterior chamber lens implantation. Aqueous flare was quantified using the laser flare-cell meter (LFCM, Kowa FC-1000) following medical pupillary dilation preoperatively and 1, 3, and 5 days, then 1 and 6 weeks and 6 months postoperatively. RESULTS: Mean preoperative aqueous flare (in photon counts per millisecond) in FHU vs. controls was 11.7 +/- 3.5 vs. 5.8 +/- 1.7. Following cataract surgery, mean aqueous flare increased to 27.8 +/- 4.4 vs. 16.0 +/- 4.5 on day 1, decreased to 23.6 +/- 4.0 vs. 11.8 +/- 3.5 on day 3, and to 18.0 +/- 3.0 vs. 9.5 +/- 1.7 on day 5. In FHU eyes, it was 13.9 +/- 2.7 after 1 week, and had returned to preoperative levels after 6 weeks (10.9 +/- 2.5) and remained stable for up to 6 months (mean 10.3 +/- 2.2). Pre- and postoperatively, aqueous flare values were 2-3 times higher in FHU eyes than in control eyes with senile cataract (p = 0.01). No postoperative complications such as fibrin formation, synechiae, macrophages on the intraocular lens optic or endophthalmitis were observed in any of the patients. CONCLUSIONS: BAB breakdown following phacoemulsification with posterior chamber lens implantation is relatively mild in eyes with FHU and the BAB appears to be fully reestablished to preoperative levels 6 weeks postoperatively, explaining the usually good outcome of cataract surgery in this condition.

Visualization of the hyalo-capsular ligament in the living eye.

BACKGROUND: The presence of a prominent, retrolental line is shown biomicroscopically. METHODS: A 25-year-old patient with a prominent circular retrolental line is reported. Slit-lamp stereophotographs of the lens were obtained. RESULTS: A prominent, circular, retrolental line was observed in a female patient - who showed no evidence of ocular disease other than myopia of -5.0 D - and was photographically documented. CONCLUSION: The prominent retrolental line observed in the patient could correspond to the inner border of the hyalo-capsular ligament of Wieger.

Ocular contusion caused by elastic cords: a retrospective analysis using the Erlangen Ocular Contusion Registry.

PURPOSE: Elastic cords are common tools to secure luggage to the roof of motor vehicles or the carrier of bicycles. In comparison with other variants of ocular contusion, patients with elastic cord injuries appear to suffer more severe ocular damage. METHODS: The charts of 398 consecutive patients of the Erlangen Ocular Contusion Registry who had been hospitalized for ocular contusion over a 10-year period were retrospectively reviewed. The acute clinical findings of 23 patients with elastic cord injury were compared with 375 patients with other contusions. Open globe injuries were excluded. RESULTS: A total of 5.8% of the patients were injured by elastic cords; their mean age was 36.6 +/- 17.0 years (range 8-66; median 34 years). The following morphological changes were documented in elastic cord injuries versus other ocular contusions: hyphema 100% versus 75%; angle recession 92% versus 72%; iridodialysis 17% versus 9%; traumatic cataract 14% versus 10%; lens dislocation 38% versus 13%; choroidal rupture 19% versus 6%; peripheral Berlin's oedema 57% versus 35%; and central Berlin's oedema 29% versus 12%. The difference of the incidence was significant for lens dislocation (P < 0.01), choroidal rupture (P = 0.024), and central (P = 0.029) and peripheral Berlin's oedema (P = 0.043). The final visual outcome was lower in patients with elastic cords injuries (P = 0.008). CONCLUSION: Elastic cord injuries induce more severe ocular damage than most other contusions. The elastic cords producing industry is called on to develop safer luggage fixation systems and warn against the potential harmful consequences of injury to the eye.

Cutaneous melanoma metastasizing to the iris and choroid: a case report.

BACKGROUND: Cutaneous melanoma is a primary tumour that rarely produces intraocular metastases. We report on a 47-year-old woman who was referred to our outpatient department because of anisocoria. METHODS: A cutaneous melanoma of the upper left arm had been excised 21 months ago with subsequent polychemotherapy for lymph node involvement. Visual acuity and intraocular tension were normal. The left iris showed a brownish, parapupillary, prominent nodule. In both eyes, multiple circumscribed whitish choroidal sub-pigment epithelial tumours were observed. RESULTS: General metastasis to lymph nodes, pleura, lungs, mucosa and skin was diagnosed. The patient died 2 months later. CONCLUSION: Metastases of cutaneous melanoma to the iris are extremely rare. The ophthalmologist may be helpful in monitoring treatment by quantitative documentation at follow-up.