Long-term topical steroid treatment improves graft survival following normal-risk penetrating keratoplasty.

PURPOSE: To assess the impact of duration of topical steroid treatment on the incidence of endothelial graft rejection after normal-risk penetrating keratoplasty (PK). DESIGN: Prospective, institutional, longitudinal, randomized interventional trial including 406 eyes (age 52 +/- 19 years; follow-up 42 +/- 18 months). METHODS: Postoperative treatment started with prednisolone acetate 1% eye drops five times daily and was tapered over the first six months. Patients were then randomized into either short-term (stop topical steroid treatment) or long-term treatment (continue steroids once daily for 12 months). RESULTS: During follow-up, 29 eyes (7.1%) developed an episode of endothelial graft rejection. Graft rejections were significantly more common in the short-term (19 of 202; 9.1%) compared with the long-term treatment group (10 of 204: 4.9%; P = .001). CONCLUSIONS: Long-term, low-dose topical steroid treatment protects against immunologic graft rejections.

Reading performance with low-vision aids and vision-related quality of life after macular translocation surgery in patients with age-related macular degeneration.

PURPOSE: The aim of the present study was to evaluate the power of magnification required, reading performance with low-vision aids and vision-related quality of life with reference to reading ability and ability to carry out day-to-day activities in patients after macular translocation. METHODS: This study included 15 patients who had undergone macular translocation with 360-degree peripheral retinectomy. The mean length of follow-up was 19.2 +/- 10.8 months (median 11 months). At the final examination, the impact of visual impairment on reading ability and quality of life was assessed according to a modified 9-item questionnaire in conjunction with a comprehensive clinical examination, which included assessment of best corrected visual acuity (BCVA), the magnification power required for reading, use of low-vision aids and reading speed. Patients rated the extent to which low vision restricted their ability to read and participate in other activities that affect quality of life. Responses were scored on a scale of 1.0 (optimum self-evaluation) to 5.0 (very poor). RESULTS: In the operated eye, overall mean postoperative BCVA (distance) was not significantly better than mean preoperative BCVA (0.11 +/- 0.06 and 0.15 +/- 0.08, respectively; p = 0.53). However, 53% of patients reported a subjective increase in visual function after treatment. At the final visit, the mean magnification required was x 7.7 +/- 6.7. A total of 60% of patients needed optical magnifiers for reading and in 40% of patients closed-circuit TV systems were necessary. All patients were able to read newspaper print using adapted low-vision aids at a mean reading speed of 71 +/- 40 words per minute. Mean self-reported scores were 3.2 +/- 1.1 for reading, 2.5 +/- 0.7 for day-to-day activities and 2.7 +/- 3.0 for outdoor walking and using steps or stairs. Patients' levels of dependency were significantly correlated with scores for reading (p = 0.01), day-to-day activities (p < 0.001) and outdoor walking and using steps (p = 0.001). CONCLUSIONS: The evaluation of self-reported visual function and vision-related quality of life in patients after macular translocation is necessary to obtain detailed information on treatment effects. Our results indicated improvement in patients' subjective evaluations of visual function, without significant improvement in visual acuity. The postoperative clinical benefits of treatment coincide with subjective benefits in terms of reading ability, quality of life and patient satisfaction. Our study confirms the importance and efficiency of visual rehabilitation with aids for low vision after surgery.

Surgery-related factors influencing corneal neovascularization after low-risk keratoplasty.

PURPOSE: To identify the speed of corneal neovascularization (CNV) after penetrating keratoplasty (PK) and to evaluate the influence of surgery-related factors on postkeratoplasty CNV in keratoconus patients. DESIGN: Prospective, longitudinal, observational, case series study. METHODS: All consecutive primary PKs performed for keratoconus by four experienced surgeons between January 1, 2000 and December 31, 2002 at our department were included (n=66 patients). Standardized corneal photographs taken preoperatively and at 6 weeks, 3, 6, 12, 18, and 24 months postoperatively were evaluated. Limbus suture distance (LSD), limbus graft distance (LGD), inner suture angle (ISA), and maximal extension of CNVs in digitized pictures with 100-fold magnification were measured at each of the 16 suture turning points at every timepoint. RESULTS: Forty-four (67%) out of 66 corneal grafts developed some degree of CNV after PK, most commonly from around the 12 o'clock position. The mean speed of CNV growth was 114 microm/month with the fastest growth occurring during the first six weeks after PK. There was an inverse correlation between CNV and LSD, LGD, and ISA (all P<.001). Ninety percent of all CNVs developed with LSD<406 microm and with LGD<1000 microm. Superior limbal localization between 11 and 1 o'clock is an independent risk factor for postoperative neovascularization, too (P<.001). CONCLUSIONS: Small LSD, small LGD, and narrow stitching with small ISA were identified as potentially modifiable surgical risk factors for CNV after PK. The speed of CNV outgrowth was most pronounced in the first weeks after PK making early postoperative controls for CNV growth and initiation of antiangiogenic treatment important.

Eye Movement Training and Suggested Gaze Strategies in Tunnel Vision - A Randomized and Controlled Pilot Study.

PURPOSE: Degenerative retinal diseases, especially retinitis pigmentosa (RP), lead to severe peripheral visual field loss (tunnel vision), which impairs mobility. The lack of peripheral information leads to fewer horizontal eye movements and, thus, diminished scanning in RP patients in a natural environment walking task. This randomized controlled study aimed to improve mobility and the dynamic visual field by applying a compensatory Exploratory Saccadic Training (EST). METHODS: Oculomotor responses during walking and avoiding obstacles in a controlled environment were studied before and after saccade or reading training in 25 RP patients. Eye movements were recorded using a mobile infrared eye tracker (Tobii glasses) that measured a range of spatial and temporal variables. Patients were randomly assigned to two training conditions: Saccade (experimental) and reading (control) training. All subjects who first performed reading training underwent experimental training later (waiting list control group). To assess the effect of training on subjects, we measured performance in the training task and the following outcome variables related to daily life: Response Time (RT) during exploratory saccade training, Percent Preferred Walking Speed (PPWS), the number of collisions with obstacles, eye position variability, fixation duration, and the total number of fixations including the ones in the subjects' blind area of the visual field. RESULTS: In the saccade training group, RTs on average decreased, while the PPWS significantly increased. The improvement persisted, as tested 6 weeks after the end of the training. On average, the eye movement range of RP patients before and after training was similar to that of healthy observers. In both, the experimental and reading training groups, we found many fixations outside the subjects' seeing visual field before and after training. The average fixation duration was significantly shorter after the training, but only in the experimental training condition. CONCLUSIONS: We conclude that the exploratory saccade training was beneficial for RP patients and resulted in shorter fixation durations after the training. We also found a significant improvement in relative walking speed during navigation in a real-world like controlled environment.

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.

Combined use of frequency doubling perimetry and polarimetric measurements of retinal nerve fiber layer in glaucoma detection.

PURPOSE: The aim of this study was to evaluate the diagnostic usefulness of the combined use of frequency-doubling technology (FDT) perimetry and polarimetry of the retinal nerve fiber layer. DESIGN: Cross-sectional study. METHODS: Seventy ocular hypertensive patients (normal optic disk and standard perimetry, elevated intraocular pressure [>21 mm Hg]), 59 patients with "preperimetric" open-angle glaucoma (glaucomatous optic disk atrophy, elevated intraocular pressure [>21 mm Hg], no visual field defect in standard perimetry), 105 patients with "perimetric" open-angle glaucoma (glaucomatous optic disk atrophy and clearly marked visual field defect), and 73 control subjects had FDT screening (protocol: C-20-5) and polarimetric measurements (GDx). Criteria for exclusion: optic disks larger than 4 mm(2), media opacities, patients younger than 33 years or older than 66 years. None of the subjects had earlier FDT perimetry. One eye of each patient and control subject entered the statistical evaluation. Database and statistical software were used for case-wise recalculation of all missed localized probability levels to create a FDT screening score. RESULTS: At a predefined specificity of 94.5% in control eyes, discrimination between "perimetric" glaucoma and normal subjects is superior using the FDT perimetry (sensitivity = 84.8%) in comparison to polarimetry (sensitivity = 63.8%), whereas sensitivity is similar with both methods in "preperimetric" patients (GDx, FDT: 25.4%). In several cases, patients classified as glaucomatous by the GDx are not the same patients as identified by the FDT perimetry. Therefore, a two-dimensional discrimination analysis can increase correct positive classification. Using a linear combination of the present FDT screening score and polarimetry ("the number"), 92.4% of "perimetric" glaucoma eyes and 44.1% of "preperimetric" glaucoma eyes have been classified as glaucomatous. CONCLUSION: Joint usage of polarimetry and FDT perimetry indicate that a combination of different techniques which can uncover different glaucoma properties, might be helpful in early glaucoma detection.

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.

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.

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.

Impact of preoperative corneal curvature on the outcome of penetrating keratoplasty in keratoconus.

PURPOSE: To assess the impact of the patient's preoperative corneal curvature on the refractive outcome after penetrating keratoplasty (PK) in keratoconus before and after suture removal. PATIENTS AND METHODS: In this retrospective cross-sectional clinical study, 236 keratoconus patients (mean age 37 +/- 11 years) were divided into four groups based on their preoperative keratometric (K-) readings: group 1, <50 diopters (D) (n = 24); group 2, <60 D (n = 52); group 3, > or =60 D (n = 101); group 4, irregular corneal shape with unmeasurable K-reading (n = 59). An 8.0/8.1-mm central round PK was performed using 193 nm Meditec excimer laser trephination along metal masks with eight "orientation teeth/notches." A 16-bite double running cross-stitch suture was applied in all cases. Postoperative examinations were performed before removal of the first suture (ie, 12 months) and after removal of the second suture (ie, 18 months). The outcome measures included central power (C-power), keratometric astigmatism (AST), surface regularity index (SRI), surface asymmetry index (SAI), spherical equivalent (SEQ), refractive cylinder (Cyl), and best corrected visual acuity (BCVA). In addition, the regularity of Zeiss keratometry mires was classified semiquantitatively (0, regular; 1, mildly irregular; 2, moderately irregular; 3, unmeasurable). RESULTS Before/after suture removal, median C-power was 43.4/43.3 D; AST was 3.0/3.0 D; SAI was 0.6/0.6; SRI was 0.9/0.9; Cyl was 2.5/2.5 D; BCVA was 0.7/0.7. After suture removal, the percentage of regular keratometry mires increased from 37% to 61%. Comparisons among the four groups revealed no significant differences for any parameters tested either before or after suture removal. CONCLUSIONS With laser trephination and a double running suture, the refractive and visual outcome of PK for keratoconus seems to be independent on the patient's preoperative corneal curvature or irregularity. Suture removal did not effect an increase of corneal astigmatism but did increase the proportion of regular keratometry mires. Thus, our policy of not performing PK in keratoconus eyes before the patient becomes contact lens intolerant is well supported.

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.

New glaucoma classification method based on standard Heidelberg Retina Tomograph parameters by bagging classification trees.

PURPOSE: In this article we propose and evaluate nonparametric tree classifiers that can handle non-normal data and a large number of possible predictors using the full set of standard Heidelberg Retina Tomograph measurements for classifying glaucoma. METHODS: The classifiers were trained and tested using standard Heidelberg Retina Tomograph parameters from examinations of 98 subjects with glaucoma and 98 normal subjects of the Erlangen Glaucoma Registry. All patients and control subjects were evaluated by 15 degrees -optic disc stereographs, Heidelberg Retina Tomograph measurements, standard computerized white-in-white perimetry, and 24-hour-intraocular pressure profiles. The subjects were matched by age and sex. Standard classification trees as well as bagged classification trees were used. The classification outcome of the trees was compared with the classification by two published linear discriminant functions based on Heidelberg Retina Tomograph variables with respect to their cross-validated misclassification error. RESULTS: The bagged classification tree had the lowest misclassification error estimate of 14.8% with a sensitivity of 81.6% at a specificity of 88.8%. The cross-validated error rates of the two linear discriminant function procedures were 20.4% (sensitivity 82.6%, specificity 76.7%) and 20.6% (sensitivity 81.4%, specificity 77.3%) for our set of observations. Bagged classification trees were able to reduce the misclassification error of glaucoma classification. CONCLUSIONS: Bagged classification trees promise to be a new and efficient approach for glaucoma classification using morphometric 2- and 3-dimensional data derived from the Heidelberg Retina Tomograph, taking into account all given variables.

Training to improve reading speed in patients with juvenile macular dystrophy: a randomized study comparing two training methods.

PURPOSE: In this study, we examined the clinical application of two training methods for optimizing reading ability in patients with juvenile macular dystrophy with established eccentric preferred retinal locus and optimal use of low-vision aids. METHOD: This randomized study included 36 patients with juvenile macular dystrophy (35 with Stargardt's disease and one with Best's disease). All patients have been using individually optimized low-vision aids. After careful ophthalmological examination, patients were randomized into two groups: Group 1: Training to read during rapid serial visual presentation (RSVP) with elimination of eye movements as far as possible (n = 20); Group 2: Training to optimize reading eye movements (SM, sensomotoric training) (n = 16). Only patients with magnification requirement up to sixfold were included in the study. Training was performed for 4 weeks with an intensity of ½ hr per day and 5 days a week. Reading speed during page reading was measured before and after training. Eye movements during silent reading were recorded before and after training using a video eye tracker in 11 patients (five patients of SM and six of RSVP training group) and using an infrared reflection system in five patients (three patients from the SM and two patients of RSVP training group). RESULTS: Age, visual acuity and magnification requirement did not differ significantly between the two groups. The median reading speed was 83 words per minute (wpm) (interquartile range 74-105 wpm) in the RSVP training group and 102 (interquartile range 63-126 wpm) in the SM group before training and increased significantly to 104 (interquartile range 81-124 wpm) and 122, respectively (interquartile range 102-137 wpm; p = 0.01 and 0.006) after training, i.e. patients with RSVP training increased their reading speed by a median of 21 wpm, while it was 20 wpm in the SM group. There were individual patients, who benefited strongly from the training. Eye movement recordings before and after training showed that in the RSVP group, increasing reading speed correlated with decreasing fixation duration (r = -0.75, p = 0.03), whereas in the SM group, increasing reading speed correlated with a decreasing number of forward saccades (r = -0.9, p = 0.01). CONCLUSION: Although the median effect of both training methods was limited, individual patients benefited well. Our results may indicate a difference in the training effect between both methods on the reading strategy: the RSVP method reduces fixation duration, the SM method decreases the number of forward saccades. Patients can apply their newly learned reading strategy in the natural reading situation, e.g. in page reading without special presentation of the text. These results can be used as a basis for further improvement in training methods for optimizing reading performance in patients with a central scotoma.

The photopic negative response of the blue-on-yellow flash-electroretinogram in glaucomas and normal subjects.

The photopic negative response of the flash-electroretinogram driven by the middle- and long-wavelength cones has been shown to be reduced in non-human primates with experimental glaucoma and in human patients with glaucoma. The photopic negative response for the blue-sensitive response has been studied using a blue-green silent-substitution-technique on a red background. The aim of this study was to re-evaluate the value of the photopic negative response of the blue-sensitive pathway in glaucoma using a conventional flash-electroretinogram. In 37 eyes of 37 controls (age: 53 +/- 13.6 years) and 37 eyes of 37 patients with open-angle glaucoma of different perimetric visual field defects (age: 58.3 +/- 10 years; MD: 11.7 +/- 6.7 dB) of the Erlangen glaucoma registry Ganzfeld flash-electroretinograms (LKC, UTAS 3000) were recorded using blue Xenon-flashes of increasing photopic luminance (0.013, 0.018, 0.030, and 0.052 cd s/m(2); 440 nm) on a bright yellow background (238 cd/m(2); 550 nm) after 2 min of light adaptation. Amplitudes and implicit times of the photopic negative response and of L&M-cone- and S-cone-driven b-waves were compared between glaucomas and controls for all flash energies (unpaired t-test). The amplitudes of the photopic negative response were significantly reduced in glaucoma patients for all flash energies (P < 0.001). The implicit times of L&M-cone-driven b-wave (0.013, 0.018, 0.030, and 0.052 cd s/m(2)) and S-cone-driven b-wave (0.030 and 0.052 cd s/m(2)) were significantly prolonged in glaucoma patients (P < 0.05). The changes in these implicit times, however, are very small (1.5 ms or less). The other measures did not differ significantly. The amplitude of the photopic negative response and the implicit times of the L&M-cone and S-cone b-wave in the same responses of the blue-on-yellow flash-electroretinogram are potentially useful in the evaluation of inner-retinal function in glaucoma.

Long-term refractive and visual outcome after penetrating keratoplasty only versus the triple procedure in Fuchs' dystrophy.

BACKGROUND: Long-term refractive and visual outcome after penetrating keratoplasty (PK) only and the triple procedure in eyes with Fuchs' endothelial dystrophy were assessed and compared. DESIGN: Retrospective, non-randomized, cross-sectional, clinical, single-centre study. METHODS: Ninety-two eyes of 87 patients were divided into two groups. Group 1 consisted of 28 eyes (mean age 62+/-13 years) that had undergone PK only and group 2 consisted of 64 eyes (mean age 69+/-10 years) that had undergone the triple procedure. Inclusion criteria were: (1) Fuchs' dystrophy, (2) central nonmechanical trephination, (3) double-running suturing technique and (4) availability of 'two-sutures-out' findings. In all eyes, a central trephination was performed (donor trephination from the epithelial side) using the 193-nm excimer laser along metal masks with eight 'orientation teeth/notches'. A double-running 10-0 nylon suture was applied in all eyes. Subjective refractometry (trial glasses), standard keratometry (Zeiss) and corneal topography analysis (TMS-1, Tomey) were performed in all eyes with 'two-sutures-in', 'one-suture-out', and 'two-sutures-out'. Main outcome measures included refractive cylinder, keratometric and topographic net astigmatism, keratometric and topographic central power, best-corrected visual acuity (BCVA), spherical equivalent (SE) of manifest refraction, surface regularity index (SRI), surface asymmetry index (SAI), and regularity of keratometry mires. RESULTS: The results were compared between the two groups (i.e. group 1 vs group 2) at various stages (i.e. 'two-sutures-in', 'one-suture-out', 'two-sutures-out'). Refractive cylinder in dioptres [D] was 2.5/2.0/2.5 vs 2.0/1.5/3.0, keratometric astigmatism [D] was 3.5/2.6/3.0 vs 3.5/3.1/3.5 and topographic astigmatism [D] was 3.9/4.1/4.9 vs 4.2/5.0/5.1. Keratometric central power [D] was 41.7/42.4/43.8 vs 41.5/41.9/43.3 and topographic central power [D] was 42.3/43.6/43.7 vs 42.6/41.8/44.3. BCVA was 0.5/0.6/0.6 vs 0.5/0.5/0.5. SE [D] was 0.0 /0.0/-0.5 vs -0.5/-0.5/-1.1. SRI was 1.5/1.1/1.0 vs 1.4/1.4/1.2 and SAI was 1.0/0.8/1.0 vs 1.3/1.2/1.0. The proportion of 'regular' and 'mildly irregular' keratometry mires was 44% / 69% / 68% vs 29% / 46% / 66%. The differences between the two groups did not reach statistical significance at any of the stages. CONCLUSIONS: Refractive and visual outcome after the triple procedure did not differ significantly from that after PK only. Therefore, we recommend the triple procedure in elderly patients with Fuchs' dystrophy and cataract to avoid delayed visual rehabilitation and a second surgical procedure.

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.

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.