Julian Garcia-Feijoo

Safety of posterior chamber phakic intraocular lenses for the correction of high myopia: Anterior segment changes after posterior chamber phakic intraocular lens implantation

OBJECTIVE To assess the safety of posterior chamber phakic intraocular lens (PCPIOL) implantation in patients with high myopia. DESIGN Prospective, noncomparative, interventional case series. PARTICIPANTS Twenty eyes of 10 patients were included. INTERVENTION Staar Collamer Implantable Contact Lens PCPIOLs were implanted for the correction of high myopia. MAIN OUTCOME MEASURES Intra- and postoperative complications were recorded. Specular microscopy, lens fluorophotometry, laser flare-meter, and ultrasound biomicroscopy were performed before surgery and at different stages of the follow-up period to evaluate endothelial cell density, crystalline lens transmittance, aqueous flare, and anatomic relations of the implanted lenses with the other structures of the anterior segment. RESULTS There were no intraoperative complications. One patient experienced pupillary entrapment by the lens in the immediate postoperative period, which was resolved without incident. Pigmentary dispersion or cataracts did not appear during the postoperative period. All the lenses remained correctly centered, and no patient reported night halos or glare. Anterior chamber depth showed a statistically significant reduction, between 9% and 12%. Central endothelial density was significantly decreased after surgery. The percentages of cell loss after 3, 6, 12, 18, and 24 months were 4.41%, 4.83%, 5.17%, 5.46%, and 6.57%, respectively. Aqueous flare increased by 49.19% in the first postoperative month in relation to preoperative values. Afterward, it decreased and then remained above preoperative values for the entire follow-up period (33.76% at month 3, 27.81% at month 6, 27.65% at month 12, 23.39% at month 18, and 27.27% at month 24). Crystalline lens transmittance decreased by 0.72% at month 3, by 1.44% at month 6, by 1.95% at month 12, by 2.25% at month 18, and by 2.24% at month 24. Finally, by ultrasound biomicroscopy it was observed that the PCPIOL and the crystalline lens were in contact on the peripheral level in 12 patients (60%) and in the center in another three patients (15%) during at least one checkup. In all the patients, contact between the PCPIOL and the posterior iris surface could be observed. CONCLUSIONS Posterior chamber phakic IOL implantation for the surgical correction of high myopia is a safe procedure with regard to immediate visual and refractive results. The short-term clinical benefit and lack of immediate surgical complications are impressive. However, the increase in flare, the endothelial cell loss, the decrease in crystalline lens transmittance, and the iris-PCPIOL and crystalline lens-PCPIOL contact are findings that suggest caution regarding the long-term safety of this lens implant.

Selective vs argon laser trabeculoplasty: hypotensive efficacy, anterior chamber inflammation, and postoperative pain

AbstractPurpose To compare selective laser trabeculoplasty (SLT) with conventional argon laser trabeculoplasty (ALT) in terms of hypotensive efficacy, anterior chamber inflammation, and pain reported by the patients treated.Methods A prospective study performed on 40 consecutive patients. Group I (n=20): SLT 180°. Group II (n=20): ALT 180°. Intraocular pressure, flare (Laser-Flare-Meter, Kowa FM-500, Japan), and pain (Visual Analogue Scale) were measured before treatment and 1 h, 24 h, 1 week, and 1, 3 and 6 months after treatment. Statistically significant differences were determined by an independent-sample Students t-test.Results At 6 months after treatment, pressure reduction was similar in both groups: SLT 22.2% (range 0–36.3%) and ALT 19.5% (range 0–30.2%), P=0.741. The energy released during treatment was significantly lower in SLT (48.3 SD 7.4 mJ) than in ALT (4321 SD 241.7 mJ), P<0.001. At 1 h after treatment, anterior chamber flare was also lower in SLT (13.3 SD 6.3 vs 20.7 SD 7.4 photons/ms), P=0.003. Pain reported by the patients during the treatment was significantly lower in SLT (2.0 SD 0.7 vs 4.3 SD 1.3), P<0.001.Conclusions The hypotensive efficacy of both lasers at the end of follow-up was similar. The energy released during treatment and inflammation produced in the anterior chamber in the immediate postoperative period were significantly lower for SLT. The SLT procedure was better tolerated, producing less discomfort during treatment than conventional trabeculoplasty with argon.

Identification of the optic nerve head with genetic algorithms

OBJECTIVE This work proposes creating an automatic system to locate and segment the optic nerve head (ONH) in eye fundus photographic images using genetic algorithms. METHODS AND MATERIAL Domain knowledge is used to create a set of heuristics that guide the various steps involved in the process. Initially, using an eye fundus colour image as input, a set of hypothesis points was obtained that exhibited geometric properties and intensity levels similar to the ONH contour pixels. Next, a genetic algorithm was used to find an ellipse containing the maximum number of hypothesis points in an offset of its perimeter, considering some constraints. The ellipse thus obtained is the approximation to the ONH. The segmentation method is tested in a sample of 110 eye fundus images, belonging to 55 patients with glaucoma (23.1%) and eye hypertension (76.9%) and random selected from an eye fundus image base belonging to the Ophthalmology Service at Miguel Servet Hospital, Saragossa (Spain). RESULTS AND CONCLUSIONS The results obtained are competitive with those in the literature. The methods generalization capability is reinforced when it is applied to a different image base from the one used in our study and a discrepancy curve is obtained very similar to the one obtained in our image base. In addition, the robustness of the method proposed can be seen in the high percentage of images obtained with a discrepancy delta<5 (96% and 99% in our and a different image base, respectively). The results also confirm the hypothesis that the ONH contour can be properly approached with a non-deformable ellipse. Another important aspect of the method is that it directly provides the parameters characterising the shape of the papilla: lengths of its major and minor axes, its centre of location and its orientation with regard to the horizontal position.

Combined iStent trabecular micro-bypass stent implantation and phacoemulsification for coexistent open-angle glaucoma and cataract: a long-term study

Aims To evaluate the long-term efficacy and safety of combined cataract surgery and Glaukos iStent implantation for coexistent open-angle glaucoma and cataract. Methods Prospective, non-comparative, uncontrolled, non-randomised, interventional case series study. Subjects older than 18 years with coexistent uncontrolled mild or moderate open-angle glaucoma (including pseudoexfoliative and pigmentary) and cataract underwent phacoemulsification and intraocular lens implantation along with ab-interno gonioscopically guided implantation of one Glaukos iStent. The variables recorded during a minimum of 3 years of follow-up were: intraocular pressure (IOP), number of antiglaucoma medications and best-corrected visual acuity. Results The 19 patients enrolled were 58–88 years old (mean age 74.6±8.44 years). Mean follow-up was 53.68±9.26 months. Mean IOP was reduced from 19.42±1.89 mm Hg to 16.26±4.23 mm Hg (p=0.002) at the end of follow up, indicating a 16.33% decrease in IOP. The mean number of pressure-lowering medications used by the patients fell from 1.32±0.48 to 0.84±0.89 (p=0.046). In 42% of patients, no antiglaucoma medications were used at the end of follow-up. Mean best-corrected visual acuity significantly improved from 0.29±0.13 to 0.62±0.3 (p<0.001). No complications of surgery were observed. Conclusion Combined cataract surgery and Glaukos iStent implantation seems to be an effective and safe procedure to treat coexistent open-angle glaucoma and cataract.

Ultrasound biomicroscopy examination of posterior chamber phakic intraocular lens position

OBJECTIVE To better elucidate the in vivo position of the Collamer posterior chamber phakic intraocular lens (PCPIOL) and its relationship to the iris and the crystalline lens and to analyze possible variations over time. DESIGN Prospective observational case series. PARTICIPANTS Eighteen eyes of nine patients were included. INTERVENTION A Staar Collamer implantable PCPIOL was implanted for the correction of high myopia. MAIN OUTCOME MEASURES The eyes were studied with a 50-MHz ultrasound biomicroscopy UBM 840. The exact PCPIOL position and the distances between it and the crystalline lens were measured at 3, 6, and 12 months after surgery. RESULTS There were no intraoperative complications. In 13 eyes (72.22%), contact between the PCPIOL and the crystalline lens was found at some time during follow-up. In 3 eyes (16.6%), central contact could be demonstrated. We also observed that the contact zone and its extension can vary over time. In 2 eyes, rotation of the lens was observed. CONCLUSIONS We found contact between the PCPIOL and the crystalline lens in a high percentage of cases. There was also mobility of the lens in the posterior chamber, especially in the anteroposterior plane, and, as a consequence, both the contact zone and its extension would vary over time.

Coexistent primary open-angle glaucoma and cataract: Preliminary analysis of treatment by cataract surgery and the iStent trabecular micro-bypass stent

IntroductionReducing intraocular pressure (IOP) is the only proven treatment modality for reducing the risk of glaucomatous progression. In this study, we evaluated the safety and efficacy of a new tool in IOP reduction, implanted with cataract surgery: the Glaukos iStent trabecular micro-bypass stent.MethodsThis was a prospective, 24-month, uncontrolled, non-randomised, multicentre study. Subjects with uncontrolled primary open-angle glaucoma (including pseudoexfoliation and pigmentary) and a cataract underwent clear cornea phacoemulsification cataract extraction with ab-interno gonioscopically guided implantation of the study stent. Subjects who had completed at least 6 months of follow-up were included in this interim analysis (n=47).ResultsAt baseline, mean (±standard deviation) IOP was 21.5±3.7 mmHg, and subjects were taking a mean of 1.5±0.7 ocular hypotensive medications. Six months after implantation of the study stent the mean IOP was 15.8± 3.0 mmHg, a mean IOP reduction of 5.7±3.8 mmHg (25.4%, P<0.001). The mean number of patient medications after 6 months was 0.5±0.8 medications, a mean decrease of 1.0±0.8 medications (66.7%, P<0.001). Most subjects (70%) were able to discontinue all glaucoma medications. There were no complications traditionally associated with filtering surgery, and no serious adverse events were reported.ConclusionIn this interim analysis of subjects with glaucoma and cataracts, this novel stent implantation in subjects undergoing cataract surgery represents a new surgical approach to provide clinically significant decreases in IOP and drug burden.

A Randomized Trial of a Schlemm's Canal Microstent with Phacoemulsification for Reducing Intraocular Pressure in Open-Angle Glaucoma

PURPOSE To assess the safety and effectiveness of the Hydrus Microstent (Ivantis, Inc, Irvine, CA) with concurrent cataract surgery (CS) for reducing intraocular pressure (IOP) in open-angle glaucoma (OAG). DESIGN Prospective, multicenter, randomized, single-masked, controlled clinical trial. PARTICIPANTS One hundred eyes from 100 patients 21 to 80 years of age with OAG and cataract with IOP of 24 mmHg or less with 4 or fewer hypotensive medications and a washed-out diurnal IOP (DIOP) of 21 to 36 mmHg. METHODS On the day of surgery, patients were randomized 1:1 to undergo CS with the microstent or CS alone. Postoperative follow-up was at 1 day, 1 week, and 1, 3, 6, 12, 18, and 24 months. Washout of hypotensive medications was repeated at 12 and 24 months. MAIN OUTCOME MEASURES Response to treatment was defined as a 20% or more decrease in washed out DIOP at 12 and 24 months of follow-up compared with baseline. Mean DIOP at 12 and 24 months, the proportion of subjects requiring medications at follow-up, and the mean number of medications were analyzed. Safety measures included change in visual acuity, slit-lamp observations, and adverse events. RESULTS The proportion of patients with a 20% reduction in washed out DIOP was significantly higher in the Hydrus plus CS group at 24 months compared with the CS group (80% vs. 46%; P = 0.0008). Washed out mean DIOP in the Hydrus plus CS group was significantly lower at 24 months compared with the CS group (16.9±3.3 mmHg vs. 19.2±4.7 mmHg; P = 0.0093), and the proportion of patients using no hypotensive medications was significantly higher at 24 months in the Hydrus plus CS group (73% vs. 38%; P = 0.0008). There were no differences in follow-up visual acuity between groups. The only notable device-related adverse event was focal peripheral anterior synechiae (1-2 mm in length). Otherwise, adverse event frequency was similar in the 2 groups. CONCLUSIONS Intraocular pressure was clinically and statistically significantly lower at 2 years in the Hydrus plus CS group compared with the CS alone group, with no differences in safety.

Evaluation of image quality after implantation of 2 diffractive multifocal intraocular lens models

PURPOSE: To compare the visual quality after implantation of multifocal intraocular lenses (IOLs). SETTING: Departments of Ophthalmology, Hospital Quirón and Hospital Clínico San Carlos, Madrid, Spain. METHODS: In a prospective nonrandomized consecutive trial, patients had bilateral implantation of Acri.LISA 366D (Group A) or Tecnis ZM900 (Group B) multifocal IOLs. One eye of each patient was included in the study. Three months postoperatively, uncorrected and corrected distance and near visual acuities, pupil diameter, and refraction were assessed. The modulation transfer function (MTF), point‐spread function (PSF), and light scattering were calculated using the double‐pass Optical Quality Analysis System for distance vision with a 4.0 mm pupil diameter. RESULTS: Each IOL group comprised 20 patients. No statistically significant differences were found between the 2 groups in postoperative mean spherical equivalent or mean monocular corrected distance or near visual acuity. The PSF variables were slightly lower in Group B, although the difference between groups was not statistically significant. The MTF parameters (double‐pass value at 100%, 20%, and 9% contrast) were slightly higher in Group A (P = .07, P = .04, and P = .09, respectively). The mean objective scatter index was 1.83 ± 0.91 (SD) in Group A and 2.00 ± 0.74 in Group B (P = .43). CONCLUSIONS: Both diffractive multifocal IOLs improved functional visual capacity at distance and near. Although the visual quality variables were slightly better in Group A than in Group B, the differences were not statistically significant.

Intravitreal Ranibizumab for Myopic Choroidal Neovascularization: Factors Predictive of Visual Outcome and Need for Retreatment

PURPOSE To identify predictive factors for visual outcome and need for retreatment after treating myopic choroidal neovascularization (CNV) with ranibizumab. DESIGN A prospective interventional case series. METHODS Sixty-seven eyes of 67 patients with myopic CNV were treated with 3 intravitreal ranibizumab injections given monthly. Best-corrected visual acuity (BCVA) and optical coherence tomography-determined central macular thickness (CMT) were recorded monthly during follow-up. Fluorescein angiography changes and the number of injections needed were also assessed. RESULTS Mean follow-up was 15.9 months. Mean BCVA improved by 7.8 letters after the first injection, 12.5 letters after 3 injections, and 12 letters by end follow-up. In 53 eyes (79.1%), BCVA improved; 40.3% gained more than 15 letters. No differences were detected in visual outcome between treatment-naïve and previously treated patients. Myopic CNV area and greatest linear dimension had diminished at the study end. The mean reduction in CMT was 93.6 μm. The mean number of injections given was 4.2. A total of 53.7% of eyes received only 3 injections. Through regression analysis, baseline BCVA (P = .006) and myopic CNV location (P = .026) were significantly correlated with BCVA at the end of follow-up. Myopic CNV location (P = .023) and prior treatment (P = .047) were significantly linked to the number of injections given. No major complications arose. CONCLUSION An initial treatment regimen of 3 monthly ranibizumab injections seems effective and safe to treat myopic CNV. Baseline BCVA and myopic CNV location emerged as predictive factors for visual outcome. A need for retreatment was associated with myopic CNV location and prior treatment.

Ultrasound biomicroscopy of silicone posterior chamber phakic intraocular lens for myopia

Purpose: To study the intraocular position and anatomic relationships of PRL‐III (phakic refractive lens) (PRL) posterior chamber phakic intraocular lens (PCP IOL) for high myopia using ultrasound biomicroscopy (UBM). Setting: Centro Oftalmológico Real Vision, and Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain. Methods: Sixteen phakic myopic eyes that had had PRL implantation were examined by UBM 1 month after surgery. The PRL position, PRL–crystalline lens peripheral distance, and central distance between the corneal endothelium and the PRL were measured. Results: Both haptics were on the zonule in 6 eyes, in the ciliary sulcus in 5 eyes, and impacted in the ciliary body in 1 eye. In the 4 remaining eyes, the haptics were in mixed positions. The mean PCP IOL crystalline lens peripheral distance in the minor axis was 588.1 &mgr;m ± 232.5 (SD), and the mean PCP IOL–endothelium central distance was 2082.8 ± 277.6 &mgr;m. Conclusions: Phakic refractive lens implantation should be done carefully because of the sulcus location of the haptics in many cases. This, with the iris–PRL contact, suggests caution for the long‐term outcome.