T. Neuhann

Development, advantages, and methods of the continuous circular capsulorhexis technique.

ABSTRACT The development of the continuous circular capsulorhexis (CCC) technique has contributed significantly to the safety and effectiveness of cataract extraction and intraocular lens implantation. This technique facilitates every, size of smooth, circular, capsular opening, and it produces a strong capsular rim that resists tearing even when stretched during lens material removal or lens implantation. Maintaining the general integrity of the eye and facilitating such procedures as hydrodissection, endolenticular phacoemulsification, capsule polishing, and safe lens implantation in both adults and children are some of the advantages of CCC. This procedure can be performed in several ways, and it has been proven to be consistently reproducible by experienced surgeons.

Retinal detachment after phacoemulsification in high myopia : Analysis of 2356 cases

PURPOSE: To determine the incidence of and risk factors for rhegmatogenous retinal detachment (RD) in highly myopic eyes after cataract surgery. SETTING: Two ophthalmology centers in Munich and Ahaus, Germany. METHODS: This retrospective medical chart review comprised 1519 consecutive patients (2356 eyes) with an axial length (AL) greater than 27.0 mm who had planned phacoemulsification and intraocular lens implantation in the capsular bag. In addition, all patients and/or the referring ophthalmologist were contacted regarding the occurrence of RD and laser capsulotomy and the date of occurrence. RESULTS: Follow‐up was longer than 24 months in 84% of eyes. Because some cases of RD were questionably related to the preceding cataract surgery, the absolute incidence of postoperative RD was determined as highest (2.2%) and lowest (1.5%). Sex, history of laser capsulotomy, and increasing AL had no statistically significant effect on the rate of RD. The risk for postoperative RD was significantly higher in eyes of younger patients and eyes with preoperative prophylactic treatment for retinal degeneration. CONCLUSIONS: The risk for postoperative RD in this study (1.5% to 2.2%) corresponds to the incidence of pseudophakic RD and idiopathic RD in myopia described in the literature. The risk profile for postoperative RD in this series cannot be distinguished from the risk profile for idiopathic RD in myopia of this extent. The true effect of prophylactic treatment of degenerative lesions remains to be elucidated.

Determination of Valid Benchmarks for Outcome Indicators in Cataract Surgery : A Multicenter, Prospective Cohort Trial

OBJECTIVE To evaluate a systematic approach to derive valid benchmarks for 2 outcome indicators intended to ascertain quality in cataract surgery and to propose benchmark levels drawn from the study results. DESIGN Prospective, multicenter cohort trial. PARTICIPANTS A total of 1685 patients (206-239 eyes per trial site) were recruited consecutively at 7 study sites. The patients featured age-related cataracts and were undergoing unilateral cataract surgery in the period between January 2007 and August 2008. METHODS Only patients with uncomplicated age-related cataracts were included. Cataract surgery was performed by phacoemulsification. The SN60AT (Alcon, Inc., Fort Worth, TX) intraocular lens (IOL) was used as a study lens. The IOL power was calculated using the SRK-T formula with a standardized A constant. Biometry was performed with the IOL Master (Carl Zeiss Meditex, Jena, Germany). Only highly experienced senior surgeons were involved. MAIN OUTCOME MEASURES The outcome indicators 1 month and 3 months after surgery were the respective achievement of: (1) maximum absolute deviation of 0.5 diopter (D) between target refraction and postoperative spherical equivalent (primary end point, refractive accuracy); (2) best-corrected visual acuity of at least 0.8 (secondary end point, visual acuity outcome). RESULTS In the pooled data, maximum absolute deviation of ± 0.5 D from target refraction was achieved in 80% (95% confidence interval, 78%-82%) of cases. Visual acuity of 0.8 or more was reached in 87% (95% confidence interval, 80%-93%) of cases. The results from the trial centers differed significantly in the outcomes of the primary and secondary end points (P<0.001). CONCLUSIONS The study quantified benchmark levels for 2 outcome indicators in a standardized cataract surgery procedure. External confounding factors such as the comorbidity of patients, which cannot be influenced by the surgeon, were excluded. The derived benchmarks selectively illustrate the quality of the surgery and are superior to success rates published in the literature from unspecific data collections. This method is more suited for improving outcome quality by benchmarking. General methodologic problems are discussed, leading to recommendations for future study designs. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Treatment of myopia and myopic astigmatism by customized laser in situ keratomileusis based on corneal topography.

OBJECTIVE To evaluate the predictability, efficacy, and safety of customized laser in situ keratomileusis (LASIK) based on corneal topography in myopia and myopic astigmatism. DESIGN Prospective, noncomparative interventional case series. PARTICIPANTS One hundred fourteen patients (eyes) with myopia of -1 to -6 diopters (D) and astigmatism of 0 to -4 D (low myopia group), and 89 patients (eyes) with myopia of -6.10 to -12.00 D and astigmatism of 0 to -4.00 D (high myopia group). INTERVENTION LASIK was performed with the Hansatome Microkeratome and the Keracor 217 spot-scanning excimer laser (Bausch & Lomb Surgical Technolas, Munich, Germany). Individual ablation patterns were calculated on the basis of elevation data obtained with the Orbscan II corneal topography system (Bausch & Lomb Surgical, Irvine, CA). MAIN OUTCOME MEASURES Manifest spectacle refraction, visual acuity, and change in visual acuity at 3 months after surgery. RESULTS At 3 months, 51 patients in the low myopia group and 40 patients in the high myopia group were available. In the low (high) myopia group, 96.1% (75.0%) were within +/-0.50 D of emmetropia, and uncorrected visual acuity was 20/20 or better in 82.4% (62.5%), 20/25 or better in 98.0% (70.0%), and 20/40 or better in 100% (95.0%). A loss of two or more lines of spectacle-corrected visual acuity occurred in 3.9% of the low and 5. 0% of the high myopia group. In low myopia, spectacle-corrected visual acuity was 20/12.5 or better in 5.9% preoperatively and in 13.7% at 3 months and 20/15 or better in 37.3% and 47.1%, respectively. Differences were statistically significant. CONCLUSIONS The customized LASIK based on corneal topography used in this study showed high predictability and efficacy in myopia and myopic astigmatism of -1.00 to -6.00 D, and could possibly improve spectacle-corrected visual acuity in myopia of -1.00 to -6.00 D. Predictability and efficacy were somewhat lower in myopia and myopic astigmatism of -6.10 to -12.00 D. In both groups, a small number of patients lost two or more lines of spectacle-corrected visual acuity.

Age-related behavior of posterior chamber lenses in myopic phakic eyes during accommodation measured by anterior segment partial coherence interferometry

PURPOSE: To evaluate age‐related position shifts of the crystalline lens and the implantable contact lens (ICL, Staar Surgical) by a new, commercially available, anterior segment partial coherence interferometer, the ACMaster (Carl Zeiss Meditec), during accommodation in myopic eyes. SETTING: ALZ Augenklinik, Munich, Germany. METHODS: Fifty‐three eyes of 29 consecutive patients were measured after myopic ICL implantation before and during subjective accommodation to a stimulus of 3 diopters (D) by anterior segment partial coherence interferometry (PCI). Nine eyes were also measured with a 5.00 diopters (D) stimulus; 14 eyes were measured repeatedly at different visits. The mean patient age was 33 years ± 9 (SD) (range 21 to 59 years). The preoperative mean sphere was −7.6 ± 1.9 D (range −5.0 to −11.5 D) and the cylinder, −1.4 ± 1.1 D (range 0 to −4.25 D). RESULTS: Older patients had a tendency toward smaller vaults on desaccommodation between the ICL and the crystalline lens compared to younger individuals. In younger patients, there was a decrease of the vault on accommodation, whereas it increased in older persons (P = .005). During accommodation, the more the anterior lens surface shifted forward, the more the ICL bulged (P = .005). The change in vaulting was significantly larger at 5.00 D than at 3.00 D accommodation stimulus (P = .012). CONCLUSIONS: The behavior of ICLs in relation to the crystalline lens during accommodation varied with age and could be shown by PCI. The position shift of the ICL depended on the initial vault at desaccommodation and the ability of the anterior lens surface to bulge forward. Even though the crystalline lens stiffened, and therefore accommodation deteriorated with age, there was still a movement of the ICL, pointing to the role of the ciliary muscle movement in accommodation.

Static and dynamic rotational eye tracking during LASIK treatment of myopic astigmatism with the Zyoptix laser platform and Advanced Control Eye Tracker.

PURPOSE To evaluate the amount of cyclotorsion and the effect of static and dynamic rotational eye tracking with the Advanced Control Eye Tracker (Bausch & Lomb) based on iris recognition in the treatment of myopic astigmatism with LASIK. METHODS All patients with myopic LASIK and attempted cylinder correction >0.75 diopters (D) on the Zyoptix 217z100 excimer laser platform between May 2005 and May 2007 were identified retrospectively through the existing databank. Pre- and postoperative refraction and the amount of cyclotorsion during treatment were extracted and analyzed in 828 eyes with >3-month follow-up. RESULTS Preoperative mean manifest refraction spherical equivalent (MRSE) was -4.31+/-1.84 D (range: -0.37 to -9.50 D), and mean cylinder was -1.27+/-0.87 D (range: -0.75 to -6.75 D). Mean static rotation was 3.96+/-2.96 degrees (maximum 14.8 degrees ). Median dynamic rotation was 1.32+/-1.85 degrees (maximum 24 degrees). At 3 months postoperatively, MRSE was -0.10+/-0.36 D (range: -2.25 to +1.25 D), and mean cylinder was -0.33+/-0.35 D (range: -2.00 to 0 D). Predictability was 90.2% within +/-0.50 D and 98.2% within +/-1.00 D (MRSE), and 82.5% within +/-0.50 D and 96.9% within +/-1.00 D (cylinder). The efficacy ratio was 0.99. Safety was 99.4% (5 dry eyes), reaching 100% at 12 months. Stability from 3 to 12 months (n=275) was 98.2% for sphere, 95.3% for cylinder, and 96.0% for MRSE. CONCLUSIONS Our study demonstrates that significant cyclotorsion occurs before and during treatment. By using the dynamic rotational eye tracker presented, the efficacy of cylinder correction can be improved compared to those studies not performing cyclotorsional correction.

Posterior limbal incision

Background: Sutureless cataract incisions should ideally remain sealed with increased intraocular pressure and be able to withstand increased external pressure to the posterior aspect. Cadaver eye studies have shown that meeting these criteria requires an internal corneal lip of at least 1.5 mm and a square wound. Scleral incisions can meet these criteria but sacrifice aesthetics and surgical efficiency. Clear corneal incisions provide aesthetics and surgical efficiency but not wound stability. An ideal incision would combine stability with aesthetics and efficiency. Methods: We tested a posterior limbal incision to assess its stability, aesthetics, and efficiency. The incision originated at the posterior limbus within the conjunctiva, gaining about 1.0 mm in tunnel length over a clear corneal incision. This was enough to obtain a square profile for 3.0 × 3.0 mm wide incisions, while providing the aesthetics and surgical efficiency of a clear corneal incision. We compared a 3.0 × 2.0 mm posterior limbal with a 3.0 × 2.0 mm clear corneal incision. Each was tested in stepped, paracentesis, and hinged profiles. Results: The hinged incision performed better than the stepped incision, which was superior to the paracentesis incision. In all cases, the limbal incision performed better than the corneal incision, even when both incisions were equally rectangular. Conclusions: When compared with the clear corneal incision, the posterior limbal incision is equal in aesthetics and surgical efficiency, slightly superior in patient comfort, and far more stable.

Cataract surgery and aniridia.

Purpose of review In the past years, several new options have been developed for the surgical management of aniridia in the course of cataract surgery. Recent findings The lens capsule may be altered – thinned – in aniridia, requiring particular attention in order to avoid complications with possible consequences for the surgical plan. Iris prosthetic devices for complete or partial restoration of an iris diaphragm have been developed and their use described. There are options for intracapsular placement as well as for fixation without using a capsular bag and options for improved cosmetic appearance have been created. Corneal tattooing is still an option for selected cases and has been refined technically. Complications attributable with the iris prostheses are relatively infrequent and manageable. Summary Cataract surgery offers an opportunity to manage associated partial or (sub)total aniridia of all origins with good to excellent functional and esthetic results with a relatively low and manageable complication potential.

Intraocular lens calcification after keratoplasty.

Purpose: To report calcification of intraocular lenses (IOLs) after various keratoplasty procedures. Methods: Clinical data of all cases with calcified IOLs after keratoplasty procedures were analyzed. A total of 6 explanted IOLs were analyzed with light microscopy before and after staining with 1% alizarin red and the von Kossa method. Results: A total of 7 cases occurred after Descemet stripping automated endothelial keratoplasty, 1 case after deep anterior lamellar keratoplasty, and 2 cases after penetrating keratoplasty. Median time interval from keratoplasty to first notice of IOL opacification was 6.5 months (minimum 3 months, maximum 51 months). A total of 3 IOLs had been placed at the time of keratoplasty and 7 IOLs before keratoplasty. All affected IOLs were hydrophilic acrylic and comprised IOLs from at least 3 different polymer sources. Common clinical aspects were some amount of inflammation in the anterior chamber during the postoperative period and use of air at the end of surgery in 8 of the 10 cases. Histochemical analysis demonstrated the presence of fine granular deposits located within the very superficial optic material in all cases. The deposits stained positive for calcium with alizarin red and the von Kossa method. Conclusions: IOL calcification associated with keratoplasty in our series does not seem to be a problem related to a specific IOL model or polymer. The process of calcification may be mediated by inflammation, which also may be related to multiple injections of air into the anterior chamber.

Results with the Boston keratoprosthesis

BACKGROUND The Boston keratoprosthesis (BKP) is a surgical therapeutic option in patients with corneal disease and poor prognosis for penetrating keratoplasty. The purpose of this study was to summarize our results with this surgical technique which we have employed at our institution since November 2009. METHODS All patients who underwent the BKP procedure at our institution between November 2009 and August 2011 were identified retrospectively and the data were analyzed. The surgical procedure and postoperative treatment were performed following the recommendations of the developers of the BKP. RESULTS A total of 14 patients were included in the study and the patient age ranged from 36 to 78 years. All patients had superficial and stromal corneal opacification with loss of the normal corneal surface (conjunctivalization). In 13 patients the BKP was implanted after at least 1 penetrating keratoplasty (including 3 matched grafts) and in 1 patient it was performed as a primary procedure. The underlying diseases were Stevens-Johnson syndrome, chemical injury, chronic atopic dermatitis in neurodermitis, keratoconus, granulomatous uveitis, congenital glaucoma and eyeball injury/burn. The follow-up ranged from 1 to 21 months. Postoperative complications consisted of prolonged inflammatory anterior chamber reaction with synechia, deposits on the intraocular lens, posterior capsule opacification, secondary glaucoma, hypotension, conjunctival growth over the keratoprosthesis and cystoid macular edema. All cases had overall improvement of visual acuity at the last follow-up visit. The maximum improvement was from counting fingers to 0.7. CONCLUSION Until now all BKPs have been preserved. At our institution the BKP is becoming increasingly more important even in such cases with a (very) poor prognosis for matched limbal and/or corneal grafts. Reimbursement for the BKP must, however be organized on a case by case basis.