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 pro, gressive 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), tonome-try, 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. (Am J Ophthalmol 2009;148:844-851. (C) 2009 by Elsevier Inc. All rights reserved.)
PURPOSE:To investigate late-onset downward decentration of iris-fixated phakic intraocular lenses (pIOL) resulting from progressive shifting of the haptics through the iris and its influence on the position of the pIOL and the amount of enclavated iris tissue. DESIGN:Institutional, prospective, observational case series. METHODS:Six patients (9 eyes) from among 368 eyes had 1 shifted haptic during long-term follow-up. Anterior segment optical coherence tomography (AS-OCT) was used to measure the distance between the edges of the pIOL and the corneal endothelium. Slit-lamp photography imaged the pIOL after implantation and after decentration. The images were analyzed to determine decentration and amount of iris tissue at the enclavation sites. RESULTS:Shifting of the haptics occurred in 2.4% and was discovered at a mean follow-up of 4.8 years (range, 3 to 7 years). Mean downward decentration was 0.28 +/- 0.15 mm. Mean edge-distances on the nasal, temporal, superior, and inferior side were 1.71 +/- 0.30 mm, 1.86 +/- 0.31 mm, 1.86 +/- 0.31 mm, and 1.58 +/- 0.34 mm, respectively. Mean enclavated iris tissue on the nasal and temporal side was smaller after decentration when compared with that directly after surgery (P = .033 and P = .017, respectively). Shifting of the haptics did not result in a decreased uncorrected and best-corrected visual acuity. CONCLUSIONS:Late-onset downward decentration resulting from progressive shifting of the haptics occurred in 2.4% and was associated with a decrease in enclavated iris tissue. AS-OCT showed a mean distance between the edge of the pIOL and the endothelium greater than the advised safety distance of 1.5 mm.
PURPOSE:To evaluate higher-order aberrations (HOAs) after implantation of Artiflex phakic intraocular lenses (pIOLs).SETTING:Department of Ophthalmology, Academic Hospital Maastricht, Maastricht, The Netherlands.METHODS:This retrospective comparative case series comprised 27 eyes (14 patients) that had Artiflex pIOL implantation and 22 eyes (13 patients) that had Artisan pIOL implantation. Refractive data, pupil size, IOL decentration, and HOA values were recorded and compared. Laboratory analysis was performed. Follow-up was 1 year.RESULTS:In the Artiflex group, the mean spherical equivalent (SE) changed from -9.95 diopters (D) +/- 1.43 (SD) (range -6.75 to -12.13 D) to -0.30 +/- 0.53 D (range -1.94 to 0.56 D). Postoperatively, trefoil-y increased (increase factor 1.73) and spherical aberration decreased (increase factor 0.55). The mean pIOL decentration was 0.24 +/- 0.12 mm; 96.3% were decentered 0.5 mm or less. There was a significant correlation between pIOL decentration and postoperative spherical aberration and coma-y. In the Artisan group, the mean SE changed from -9.90 +/- 2.74 D (range -4.00 to -14.50 D) to -0.20 +/- 0.42 D (range -0.75 to 0.50 D). Postoperatively, trefoil-y and spherical aberration increased (increase factors 3.32 and 6.84, respectively). Laboratory analysis confirmed the negative and positive spherical aberration profile of the Artiflex pIOL and Artisan pIOL, respectively.CONCLUSIONS:Artiflex pIOL implantation decreased spherical aberration, while Artisan pIOL implantation increased spherical aberration. Trefoil-y increased in both groups. These changes might be explained by incision size differences in relation to trefoil and differences in optic design in relation to spherical aberration.
PURPOSE:To compare a handheld and a digital pupillometer in determining pupil size in a population of refractive surgery candidates (group 1) and after implantation of an Artisan phakic intraocular lens (PIOL) for correction of myopia (group 2).METHODS:Pupil size was measured with the Colvard and Procyon pupillometers in 121 eyes in group 1 and 83 eyes in group 2. Pupil sizes measured with the Colvard device were compared with the scotopic, mesopic-low and mesopic-high measurements taken with the Procyon pupillometer in both groups. Analysis of comparison between pupil measurements was performed according to methods described by Bland and Altman.RESULTS:The mean Colvard scotopic pupil diameter, scotopic, mesopic-low and mesopic-high Procyon pupil diameters were 5.86 +/- 0.81 mm, 6.42 +/- 0.88 mm, 5.55 +/- 0.95 mm and 4.21 +/- 0.73 mm in group 1 and 5.32 +/- 0.67 mm, 6.14 +/- 0.81 mm, 5.33 +/- 0.78 mm and 4.02 +/- 0.55 mm in group 2, respectively. The Colvard diameter compared most favourably with the Procyon mesopic-low diameter (group 2; p = 0.78).CONCLUSIONS:Measurements of pupil diameter with the Colvard pupillometer correlated best with measurements taken by the Procyon pupillometer under standardized mesopic-low light conditions. We believe that digital binocular infrared pupillometry is advantageous for obtaining standardized measurements of pupil size.
We report 2 patients who had radial keratotomy (RK) to correct myopia. The first patient developed a postoperative hyperopic shift and cataract. Nine years post RK, she had intracapsular cataract extraction and implantation of an Artisan aphakic intraocular lens (IOL). Twenty years post RK, hyperopia and astigmatism progressed to +7.0 -5.75 x 100 with a best corrected visual acuity (BCVA) of 20/20. Due to contact lens intolerance, the Artisan aphakic IOL was exchanged for an Artisan toric aphakic IOL. Three months later, the BCVA was 20/20 with +1.0 -0.50 x 130. The second patient demonstrated residual myopic astigmatism 6 years after bilateral RK and had become contact-lens intolerant. An Artisan toric phakic IOL was implanted in both eyes. Four months later, the BCVA was 20/25 with a refraction of +0.25 -1.0 x 135 and 20/20 with a refraction of -1.0 x 40. Both patients were satisfied with the visual outcomes.
We describe a 54-year old man who developed a severe cell deposition 1 week after implantation of a foldable Artiflex phakic intraocular lens (pIOL) (Ophtec B.V.) with a silicone optic and poly(methyl methacrylate) (PMMA) haptics in the left eye for the correction of high myopia. Nine months after implantation, many cell deposits remained visible on the posterior surface of the IOL, causing severe glare, especially during daylight conditions. We explanted the Artiflex pIOL and exchanged it for a PMMA Artisan pIOL. One month after the exchange, the uncorrected visual acuity was 20/20 and the patient's glare complaints had disappeared. Slitlamp examination showed no signs of inflammation in the anterior segment or cell deposits on the PMMA Artisan pIOL. Scanning electron microscopy demonstrated multiple cell deposits on the explanted Artiflex pIOL.
PURPOSE:To determine patient satisfaction after Artisan phakic intraocular lens (PIOL) implantation to correct myopia.DESIGN:Non-comparative prospective case series.METHODS:One hundred twenty eyes of 60 patients who had undergone Artisan PIOL implantation to correct myopia were analyzed. A validated questionnaire that consisted of 66 satisfaction items were self-administered by patients 12 months after surgery. Clinical parameters (PIOL decentration, the difference between pupil size and PIOL optical zone, and optical aberrations) were measured. Main outcome measures of satisfaction scale scores (global satisfaction, quality of uncorrected and corrected vision, night vision, glare, day and night driving) were analyzed. Correlations with clinical parameters were obtained.RESULTS:After surgery, 98.3% of patients were satisfied, and 73.3% of patients considered their night vision to be the same or better; 44.1% of patients reported more bothersome glare. The night vision score correlated with spheric aberration (r = -0.303; P = .020). The glare score correlated with the difference between scotopic pupil size and PIOL optical zone (r = -0.280; P = .030) and vertical coma (r = -0.337; P = .009). The night driving score correlated with postoperative spheric equivalent (r = 0.375; P = .009), total root mean square aberrations (r = -0.337; P = .017), higher order root mean square aberrations (r = -0.313; P = .027), and vertical coma (r = -0.297; P = .036).CONCLUSION:Overall satisfaction after Artisan PIOL implantation for myopia is excellent. The quality of night vision and night driving were related to scotopic pupil size, individual higher order aberrations, and residual refractive error.
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.
Background: The hereditary Reis–Bückler dystrophy is one of the anterior localised corneal dystrophies with superficial reticulated opacities, sometimes in combination with recurrent attacks of corneal erosion. Phototherapeutic keratectomy (PTK) is now the first method to consider for managing this disease when intervention is required.
BACKGROUND:Laser in situ keratomileusis (LASIK) has recently become the most commonly performed refractive surgery procedure. Results are promising in correcting low to moderate myopia. Most complications occur during the surgeon's learning curve. One of the complications is a decentration of the ablated area that causes monocular diplopia and a nocturnal halo phenomenon due to a multifocality of the corneal surface overlying the entrance pupil. The corneal shape is significantly altered after LASIK. We evaluate the efficacy of rigid gas-permeable contact lens designs and fitting techniques used in eight eyes with multifocal LASIK ablations to correct haloes and impaired night vision complaints.METHODS:We used large-diameter tetra-curved rigid gas-permeable (RGP) contact lenses for visual recovery in eight eyes of seven LASIK patients. We used the power on the transition zone of the corneal topographic map, 0.2 mm outside the ablated refractive area, for selection of the back optic zone radius of the RGP contact lenses. Procedures for lens fitting are described. Visual acuity (high-contrast logarithm of the minimum angle of resolution, LogMAR) was measured before- and 6 months after contact lens fitting.RESULTS:Large-diameter tetra-curve RGP lenses with a mean diameter of 11.85 (SD 0.16) mm were successfully used in LASIK patients with multifocal corneas. Mean best spectacle-corrected visual acuity was +0.3 LogMAR (SD 0.19; in Snellen equivalent, 20/40) and improved significantly with the contact lenses to +0.08 LogMAR (SD 0.11; in Snellen equivalent, 20/25, P=<0.01). During the follow-up period of 16.7 months, the average daily wearing time of the lenses was 12.5 h. Contact lenses with a standard geometry were not useful due to excessive movement and inadequate centration.CONCLUSIONS:Contact lenses with large diameters, in combination with selection of the back optic zone radius 0.2 mm peripheral of the refractive ablation zone, facilitate contact lens fitting to restore best-corrected visual acuity in LASIK patients with multifocal corneas.
We performed a phototherapeutic keratectomy using excimer laser 193-nm ablation in a patient with granular dystrophy of the cornea. The hyperopic shift caused by the 5-mm diameter tissue ablation could effectively be corrected by a high oxygen-transmissible, aspheric, rigid contact lenses 1 week after treatment. Corneal topographic analysis was used to monitor the changes in corneal shape after excimer treatment. The 3.5-D hyperopic shift did not change after 4 months, but corneal shape altered during this period. It was not necessary to adjust lens parameters. The central corneal area was clear, and visual acuity improved from 20/40 to 20/20.
Trial contact lenses, flexible and rigid, are possible vectors for the transmission of micro-organisms between patients inthe contact lens practice. The large variation in contact lens materials and the vast choice of disinfection systems can lead to confusion. The renewed interest in achieving complete disinfection is mainly due to the possible threat of HIV transmission. A bacteriological and virological investigation, mimicking the storage procedure of professional practice, confirms the reliability of a one-step sodium dichloroisocyanurate (Polyclor or Softab) system, especially when used in combination with proper cleaning, and demonstrates some advantages over other disinfection systems.