25 research outputs found

    A new technique for rigid gas permeable contact lens fitting following penetrating keratoplasty

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    Rigid gas-permeable contact lens fitting in LASIK patients for the correction of multifocal corneas

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    Treatment of negative dysphotopsia with supplementary implantation of a sulcus-fixated intraocular lens

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    PURPOSE: Our aim was to evaluate the resolution of negative dysphotopsia supplementary implantation of a sulcus-fixated intraocular lens (IOL). This was a retrospective case series. Patients with severe negative were treated with supplementary implantation of the Rayner Sulcoflex (653 L) IOL. Primary outcome measurements were subjectively reported of dysphotopsia, best corrected distance visual acuity (CDVA), iris-IOL anterior chamber depth (ACD) and volume (ACV), angle opening distance trabecular-iris space area at 500 and 750 mum. RESULTS: A Rayner was implanted in seven patients (nine eyes) with negative dysphotopsias. resolved completely in six eyes, partially in one eye and remained two eyes. We did not find any significant changes in CDVA. Angle opening distance, ACD, ACV and iris-IOL distance reduced significantly after IOL implantation. CONCLUSIONS: Supplementary implantation of a Sulcoflex successfully treat negative dysphotopsia. The decrease in anterior dimensions in combination with the displacement of light rays by the edges of a Sulcoflex IOL may contribute to the resolution of symptoms

    Wavefront-guided versus standard laser in situ keratomileusis to correct low to moderate myopia.

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    To evaluate the 6-month refractive outcomes of wavefront-guided laser in situ keratomileusis (LASIK) (Zyoptix, Bausch & Lomb) versus standard LASIK (PlanoScan, Bausch & Lomb).Department of Ophthalmology, University Hospital Maastricht, Maastricht, The Netherlands.In a prospective randomized study, 12 patients with myopia had Zyoptix wavefront-guided LASIK in 1 eye and PlanoScan LASIK in the contralateral eye. The safety, efficacy, predictability, stability, optical zone size, and ablation depth were evaluated.The mean preoperative spherical equivalent (SE) of the subjective manifest refraction was -3.88 diopters (D) +/- 1.92 (SD) (Zyoptix) and -4.35 +/- 2.11 D (PlanoScan). Six months postoperatively, 8% of PlanoScan patients and 16% of Zyoptix patients gained at least 2 lines of best corrected visual acuity; the safety index was 1.12 in the Zyoptix group and 1.08 in the PlanoScan group. An SE of +/-1.00 D and +/-0.50 D was achieved by 100% and 92%, respectively, in both groups. There were 2 undercorrections in the Zyoptix group and 1 undercorrection in the PlanoScan group. In the Zyoptix group, 100% had a UCVA of 20/40 and 67% of 20/20 and in the PlanoScan group, 100% and 83%, respectively. The efficacy index was 0.87 and 0.93 in the Zyoptix group and PlanoScan group, respectively. The mean optical zone 6 months postoperatively was 6.16 +/- 0.34 mm in the PlanoScan group and 6.23 +/- 0.41 mm in the Zyoptix group (P =.67). The ablation depth per diopter of defocus equivalent was 13.5 +/- 4.6 microm/D and 8.6 +/- 4.4 microm/D, respectively (P =.01).An excellent safety index was achieved with the Zyoptix and PlanoScan treatments. The efficacy index was marginally lower for Zyoptix treatments as a result of 2 undercorrections. The ablation depth in the Zyoptix group per diopter of defocus equivalent was significantly lower than in the PlanoScan group. Further refinements in defining the ablation algorithms may increase the efficacy index

    Functional outcomes and patient satisfaction after laser in situ keratomileusis for correction of myopia.

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    Item does not contain fulltextPURPOSE: To determine subjective patient satisfaction and self-perceived quality of vision after laser in situ keratomileusis (LASIK) to correct myopia and myopic astigmatism. SETTING: Department of Ophthalmology, Academic Hospital Maastricht, Maastricht, The Netherlands. METHODS: A validated questionnaire consisting of 66 items was self-administered by 142 consecutive patients. Seven scales covering a specific aspect of quality of vision were formulated. Aspects included global satisfaction, quality of uncorrected and corrected vision, quality of night vision, glare, daytime driving, and night driving. Main outcome measures were responses to individual questions and scale scores, and correlations with clinical parameters including refractive outcome, uncorrected visual acuity, best corrected visual acuity, ablation depth, and scotopic pupil-optical zone disparity were obtained. RESULTS: The mean score for the overall satisfaction was 4.1 +/- 0.71 (SD) (scale 0 to 5.0). A total of 92.2% of patients were satisfied or very satisfied with their surgery, 93.6% considered their main goal of surgery achieved, and 92.3% would choose to have LASIK surgery again. Satisfaction with uncorrected vision was 3.03 +/- 0.71. The mean score for glare was 3.0 +/- 0.9. At night, glare from lights was believed to be more important than before surgery by 47.2%. Glare from oncoming car headlights after surgery was reported by 58.4% and was believed to be more bothersome for night driving than before surgery by 52.8%. Night driving was rated more difficult than before surgery by 39.4%, whereas 59.3% had less difficulty driving at night. There was a significant correlation between the uncorrected vision score and the postoperative spherical equivalent (r = 0.245) and postoperative astigmatism (r = 0.265). There was no correlation between the glare or night vision scores and the degree of correction, the amount of ablation depth, or the disparity between the scotopic pupil and the optical zone. CONCLUSIONS: Self-perceived uncorrected vision after LASIK surgery for the correction of myopia and myopic astigmatism appears to be very good and is related to the postoperative residual error. Although the majority of patients postoperatively experienced glare, particularly with driving at night, this was not related to the pupil-optical zone disparity or degree of correction

    Value of preoperative phakic intraocular lens simulation using optical coherence tomography

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    PURPOSE: To compare the position of the iris-fixated phakic intraocular lens (pIOL) in preoperative simulation and after implantation using anterior segment optical coherence tomography (AS-OCT). SETTING: Department of Ophthalmology, Academic Hospital Maastricht, Maastricht, The Netherlands. METHODS: In this prospective study, the morphometrics of the anterior chamber were analyzed using preoperative pIOL simulation and postoperative images assessed with AS-OCT. Patients' eyes were examined before and 6 months after pIOL implantation. The measured distances were from the center of the pIOL to the endothelium, from the edge of the pIOL to the endothelium (nasal and temporal side), and from the back of the pIOL to the crystalline lens. RESULTS: Thirty-four eyes (18 patients) were examined. All morphometric parameters showed highly significant correlations and small mean differences between preoperative and postoperative measurements. However, the distance from the nasal edge of the pIOL to the endothelium and the distance from the pIOL to the crystalline lens showed a statistically significant difference between the preoperative simulation and the actual postoperative measurements (P = .045 and P = .001, respectively). The ranges of agreement between all preoperative simulations and postoperative measurements ranged between 0.24 mm and 0.29 mm. CONCLUSIONS: Preoperative simulation was a useful additional tool in the selection of patients considering pIOL implantation and in ensuring the long-term safety of pIOLs. However, clinicians should be aware of the range between the preoperative simulation and the postoperative measurements

    Use of Anterior Segment Optical Coherence Tomography to Study Corneal Changes after Collagen Cross-linking

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    PURPOSE: To investigate the stromal demarcation line after corneal cross-linking using anterior segment optical coherence tomography (AS-OCT) and its influence on the short-term results of cross-linking in patients with progressive keratoconus. DESIGN: Prospective, nonrandomized study. METHODS: Twenty-nine eyes of 29 patients with progressive keratoconus (n = 28) or after laser in situ keratomileusis ectasia (n = 1) were included and treated with corneal cross-linking at our institution. Measurements at 1, 3, 6, and 12 months after corneal cross-linking were: refraction, best-corrected visual acuity (BCVA), tonometry, corneal topography, AS-OCT, specular microscopy, and aberrometry. Demarcation line depth was measured centrally, 2 mm temporally, and 2 mm nasally by two independent observers using AS-OCT and was correlated with clinical parameters. RESULTS: The stromal demarcation line was visible with AS-OCT at 1 month after surgery in 28 of 29 eyes. Pairwise comparisons between the two observers of the AS-OCT measurements did not show a statistically significant difference. After an initial steepening of maximal keratometry values and a decrease in BCVA at 1 month after surgery (both with P < .012), no significant changes were found at 3, 6, and 12 months after surgery compared with before surgery. Refractive cylinder, topographic astigmatism, aberration values, endothelial cell density, and intraocular pressure remained stable during all postoperative visits. A deeper demarcation line depth was associated with a larger decrease in corneal thickness (r = -0.506; P = .012). CONCLUSIONS: AS-OCT is a useful device to detect the stromal demarcation line after corneal cross-linking. At 3 to 12 months follow-up, all clinical parameters remained stable, indicating stabilization of the keratoconic disease

    Evaluation of the Lenstar LS 900 non-contact biometer.

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    Item does not contain fulltextBACKGROUND/AIMS: Evaluation of the reproducibility of the Lenstar LS 900 non-contact biometer, and a comparison with the Visante anterior-segment optical coherence tomography (AS-OCT) and the IOLMaster. METHODS: Central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), keratometry (K) values, corneal diameter (CD) and axial length (AL) were obtained in 38 healthy volunteers (76 eyes) to determine the reproducibility of the Lenstar. CCT, ACD, CD, K values and AL measurements measured with the Lenstar were compared with the AS-OCT and IOLMaster. Intraocular lens (IOL) power calculations were done to study the significance of the difference between AL measurements. RESULTS: The reproducibility of the Lenstar was better than 0.9% for CCT, ACD, LT, K values and AL measurements. Although all correlations were highly significant (p<0.001), all comparisons showed a significant difference, except for the comparison of CD measurements using the Lenstar and IOLMaster (p = 0.175). The differences in IOL power calculations for an AL of 20, 25 and 30 mm with a mean difference between Lenstar and IOLMaster AL measurements of 0.03 mm, were 0.13 D, 0.10 D and 0.08 D, respectively. CONCLUSION: The reproducibility of the Lenstar was excellent. Small but significant differences exist between the Lenstar, Visante OCT and the IOLMaster. Therefore, measurements of the Lenstar, AS-OCT and IOLMaster are not interchangeable. Despite the significant difference between AL measurements, there is no clinically significant difference in the IOL power calculation results.1 januari 201

    Iris-fixated anterior chamber phakic intraocular lens for myopia moves posteriorly with mydriasis.

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    Item does not contain fulltextPURPOSE: To elucidate the physiological characteristics of eyes implanted with iris-fixated anterior chamber phakic intraocular lenses (pIOLs), which are increasingly being used for the correction of higher myopic and hyperopic refractive errors. METHODS: In a case series of 20 patients (39 eyes), the position of the pIOL to the natural lens and the cornea was evaluated under photopic (135 lux) and low mesopic (< 1 lux) circumstances with anterior segment optical coherence tomography. RESULTS: The distance between the pIOL and the natural lens decreased, and congruently, the distance from the pIOL to the corneal endothelium increased under low mesopic circumstances. CONCLUSIONS: The distance between the pIOL and the corneal endothelium increases when the pupil dilates under dark circumstances, contributing to the already excellent safety data available on pIOL implantation
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