Retinal safety evaluation of two-photon laser scanning in rats.

Safe use of retinal imaging with two-photon excitation in human eyes is crucial, as the effects of ultrashort pulsed lasers on the retina are relatively unknown. At the time of the study, the laser safety standards were inadequate due to the lack of biological data. This article addresses the feasibility of two-photon retinal imaging with respect to laser safety. In this study, rat retinas were evaluated at various laser exposure levels and with different laser parameters to determine the effects of laser-induced optical damage. The results were experimentally verified using confocal reflectance imaging, two-photon fluorescein angiography, immunohistochemistry, and correlated to the IEC 60825-1 laser safety standard.

Haptic tuck for reverse optic capture of a single-piece acrylic toric or other single-piece acrylic intraocular lenses.

We describe a new technique for capsule fixation of 1-piece acrylic toric intraocular lens (IOL) or other 1-piece acrylic IOLs in the presence of a large posterior capsule tear resulting in an open capsule. To keep the thick haptics out of the sulcus, reverse optic capture is necessary, with the haptics below the capsule and the optic edges above the capsule. This is done by placing the IOL in the sulcus and if it is a toric IOL, with the toric marks on the optic aligned with the corneal marks. Then, each haptic is separately tucked through the anterior continuous curvilinear capsulorhexis (CCC) opening, leaving the optic edges above the capsule. This technique achieves reverse optic capsulorhexis capture without the challenge of injecting the IOL through the CCC with an open posterior capsule. We propose the term haptic tuck for reverse optic capture for this technique.

Incidence of implantable Collamer lens-induced cataract.

OBJECTIVE: Although the literature on the implantable Collamer lens (ICL) suggests an increasing rate of anterior subcapsular cataract (ASC) development with increasing age and decreasing anterior chamber depth (ACD), the exact correlation is not known. We performed a retrospective observation study of 1653 eyes and calculated the incidence of ICL removal with cataract extraction and intraocular lens placement (CE-IOL) as a result of ASC, in correlation to patient's age and ACD. DESIGN: Retrospective observation study. SETTING: The Gimbel Eye Centre, Calgary, Alberta, Canada. METHODS: We analyzed ICL V4 model (Visian ICL; STAAR Surgical, Monrovia, CA) implanted in 1653 eyes with myopia from 2000 to 2012 at the Gimbel Eye Centre, Calgary. Myopic patients aged 19 years and older with no history of cataracts were included. The rate of ICL removal with cataract extraction was calculated. Parameters such as age, sex, refractive sphere, refractive cylinder, length of follow-up, and ACD were collected. Cataract-free survival with comparison of FDA and non-FDA cohorts was conducted using Kaplan-Meier survival curves with the log-rank test. In addition, covariates adjusted hazards ratios and 95% confidence intervals were calculated using Cox regression. RESULTS: Of the 1653 eyes included in this study, a total of 46 eyes underwent ICL removal with CE-IOL. The length of follow-up varied between 2 and 14 years. CONCLUSIONS: This retrospective study demonstrated that the rate of developing ASCs positively correlated with age and negatively correlated with ACD.

In vivo two-photon imaging of retina in rabbits and rats.

The purpose of this study was to evaluate the retina using near-infrared (NIR) two-photon scanning laser ophthalmoscopy. New Zealand white rabbits, albino rats, and brown Norway rats were used in this study. An autofluorescence image of the retina, including the retinal cells and its associated vasculatures was obtained by a real-time scan using the ophthalmoscope. Furthermore, the retinal vessels, nerve fiber layers and the non-pigmented retina were recorded with two-photon fluorescein angiography (FA); and the choroidal vasculatures were recorded using two-photon indocyanine green angiography (ICGA). Two-photon ICGA was achieved by exciting a second singlet state at ∼398 nm. Simultaneous two-photon FA and two-photon ICGA were performed to characterize the retinal and choroidal vessels with a single injection. The minimum laser power threshold required to elicit two-photon fluorescence was determined. The two-photon ophthalmoscope could serve as a promising tool to detect and monitor the disease progression in animal models. Moreover, these high-resolution images of retinal and choroidal vessels can be acquired in a real-time scan with a single light source, requiring no additional filters for FA or ICGA. The combination of FA and ICGA using the two-photon ophthalmoscope will help researchers to characterize the retinal diseases in animal models, and also to classify the types (classic, occult or mixed) of choroidal neovascularization (CNV) in macular degeneration. Furthermore, the prototype can be adapted to image the retina of rodents and rabbits.

Angle-supported phakic intraocular lenses for the correction of myopia: Three-year follow-up.

PURPOSE: To evaluate patient safety and refractive outcomes in eyes with an angle-supported phakic intraocular lens (pIOL), and to assess the correlation between rotation and corneal endothelial cell damage. SETTING: Gimbel Eye Centres, Calgary and Edmonton, Alberta, Canada. DESIGN: Retrospective cohort study. METHODS: This study included patients with moderate to high myopia (range -6.50 to -19.50 diopters [D]) who received the Acrysof Cachet pIOL. Outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity, manifest refraction spherical equivalent (MRSE), endothelial cell density (ECD), and IOL rotation. RESULTS: This study evaluated 119 eyes of 61 patients. The mean ECD decrease from preoperative measurements was 3.11% (n = 46), with a mean IOL rotation of 10.6 degrees (n = 35) at the 3-year postoperative visit. Of the 49 eyes at the 3-year visit measured for UDVA, 98.0% were 20/40 or better and 77.6% were 20/20 or better. The MRSE improved from a preoperative mean of -9.26 diopters (D) ± 2.43 (SD) (range -19.50 to -5.63 D) to -0.33 ± 0.61 D (range -3.12 to +0.71 D) at the 3-year visit. The residual refractive error was within ±0.50 D of the target refraction for 78.4% and within ±1.00 D for 92.2% of the 51 eyes. The study included one bilateral pIOL removal due to endothelial cell loss, one case of synechia, and one case of subtle pupil ovalization. CONCLUSIONS: No correlation between IOL rotation and ECD decrease was found (R(2) = 0.0143); the pIOL provided promising refractive outcomes and acceptable safety in patients with moderate to high myopia. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Suture refixation and recentration of a subluxated capsular tension ring-capsular bag-intraocular lens complex.

We describe a 3-point ab externo technique to refixate and recenter a subluxated Cionni capsular tension ring (CTR)-intraocular lens (IOL)-capsular bag complex to the sclera. A 9-0 polypropylene suture on a curved needle is looped through the eyelet of the CTR and back through a Hoffman scleral tunnel. Two other sutures passed in a similar fashion through the fibrotic continuous curvilinear capsulorhexis (CCC) edge are used to complete a tripod fixation, which centers and stabilizes the IOL. This surgical approach avoids the surgical trauma of removing and replacing a subluxated CTR-IOL-capsular bag complex, retains the optimal anatomical position, and ensures centration of the IOL.

Assessment of axial length before and after myopic LASIK with the IOLMaster.

PURPOSE: To assess the relationship between theoretical ablation depth and axial length change after LASIK with the IOLMaster (Carl Zeiss Meditec, Dublin, CA). METHODS: Ninety-nine eyes were examined preoperatively and 1 and 3 months after LASIK. RESULTS: Mean ± standard deviation (SD) spherical equivalent before LASIK was -4.06 ± 1.91 diopters (D). Mean ± SD ablation depth was 83.13 ± 30.31 µm. Mean ± SD postoperative axial length of 25.11 ± 0.14 mm at 1 month was significantly shorter than mean ± SD preoperative axial length of 25.20 ± 0.14 mm (P < .001) with no subsequent change thereafter (P = .450). An increase in ablation depth of 1 µm led to a decrease in axial length of 0.00118 ± 0.00005 mm. Ablation depth correlated strongly with change in axial length (adjusted R(2) = 0.9039). CONCLUSIONS: The IOLMaster showed a decrease in axial length after LASIK that correlated well with theoretical ablation depth.

Reverse optic capture to stabilize a toric intraocular lens.

PURPOSE: To describe a technique for stabilizing a rotationally unstable toric intraocular lens (IOL). METHOD: Case report and literature review. RESULTS: Surgical technique and long-term follow-up for a patient who underwent repositioning and stabilization of a mobile 1-piece acrylic toric IOL using reverse optic capture (ROC) are described. This patient presented with early, more than 70° off-axis rotation. The IOL was repositioned but was very mobile within the bag and tended to rotate off-axis; hence, it was stabilized in the desired position by capturing the optic through the anterior continuous curvilinear capsulorhexis, leaving the haptics in the bag. The immediate and 2-year postoperative follow-up revealed a stable and on-axis IOL with no visual, refractive or ocular complications. CONCLUSIONS: ROC is a useful and safe technique to address the problem of toric IOLs that tend to rotate at the time of surgery or are not stable postoperatively.

Bilateral Implantation of Scleral-Fixated Cionni Endocapsular Rings and Toric Intraocular Lenses in a Pediatric Patient with Marfan's Syndrome.

The management of ectopia lentis in Marfan's syndrome is challenging. Multiple disease-associated factors conspire to deprive these patients of adequate vision. While optical correction with glasses and contact lenses is usually advocated early on, the irregular astigmatism and even partial aphakia that accompanies advanced cases generally warrant surgical intervention. Several surgical strategies have been devised to manage these challenging cases, including the combination of endocapsular or pars plana lensectomy and iris or scleral fixation of the intraocular lens (IOL) or IOL-bag complex. All of the reported cases have been implanted with IOLs that correct for myopia only. With toric lenses, it is now possible to correct for corneal astigmatism in these patients as well, provided that the capsular bag is maintained and can be properly centered. We report the combination of scleral-fixated Cionni endocapsular rings and toric IOLs in a pediatric patient with bilateral ectopia lentis secondary to Marfan's syndrome.

Necrotizing keratitis after laser refractive surgery in patients with inactive inflammatory bowel disease.

Two cases of necrotizing keratitis following laser refractive corneal surgery, with stable and controlled Crohn's disease are described. A 40-year-old woman developed bilateral stromal inflammation and inferior thinning in the right eye along the flap edge within 1 day of uneventful bilateral IntraLase laser-assisted in situ keratomileusis. The other case is a 30-year-old man who also developed bilateral inferior stromal infiltrates 2 days following photorefractive keratectomy. Both cases were aggressively treated with systemic and topical corticosteroids. The infiltrates in both patients gradually resolved, with one relapse during the 7 months period of follow-up in the first case. These cases highlight the importance of taking precautions considering this and similar autoimmune conditions as a relative contraindication to refractive surgery.

Toric implantable collamer lens implantation in a case with bilateral primary peripheral iris cysts.

The authors describe a patient who was found to have bilateral, peripheral iris cysts during preoperative ultrasound biomicroscopy (UBM) assessment prior to toric implantable collamer lens (TICL) implantation. TICL implantation was undertaken with no intraoperative or postoperative complications. The TICLs remained in stable position over a follow-up period of 15 months. The presence of solitary temporal iris cysts had no impact on final visual outcome or TICL position.

Toric collagen copolymer phakic intraocular lens to correct myopic astigmatism in eyes with pellucid marginal degeneration.

PURPOSE: To evaluate the clinical outcomes of implantation of the Implantable Collamer Lens collagen copolymer toric phakic intraocular lens (pIOL) to correct myopic astigmatism in eyes with mild pellucid marginal degeneration (PMD). SETTING: Gimbel Eye Centre, Calgary, Alberta, Canada. DESIGN: Retrospective chart review. METHODS: All consecutive cases with PMD that had implantation of the toric pIOL from January 1, 2003, to May 30, 2011, were retrospectively reviewed for postoperative outcomes. Perioperative variables of interest included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction, and corneal topography. RESULTS: The study comprised 10 eyes of 5 patients. The mean age was 37.4 years ± 2.6 (SEM). The mean CDVA was 0 ± 0.03 logMAR (20/20) preoperatively and -0.04 ± 0.03 logMAR (20/18) postoperatively. The mean postoperative UDVA was +0.14 ± 0.05 logMAR (20/28). The mean spherical equivalent (SE) was -6.71 ± 0.9 diopters (D) preoperatively and -0.58 ± 0.1 D at the last follow-up. All eyes had improved CDVA after surgery. One patient reported severe glare and halos in 1 eye postoperatively, requiring removal and replacement of the toric pIOL because of a hyperopic refractive surprise. The new toric pIOL was subsequently repositioned because of high residual astigmatism related to changes in corneal topography postoperatively and a small shift in the position of the toric pIOL. The final manifest refraction for this eye was plano -1.00 × 160. CONCLUSIONS: Implantation of the collagen copolymer toric pIOL was a safe, effective surgical procedure for the correction of myopic astigmatism in eyes with mild PMD.

Capsule membrane suture fixation of decentered sulcus intraocular lenses.

Different surgical methods are used to fixate the subluxated sulcus intraocular lens (IOL) in the absence of in-bag fixation, ranging from iris and scleral suturing to optic capture of the IOL. A new technique, which we have termed capsule membrane suture fixation, provides an additional method for securing a subluxated or decentered sulcus-based IOL to the remnant capsule or a capsular membrane. This method can also be used in secondary surgery for fixation, repositioning, or removal and replacement of IOLs. In this technique, the IOL haptics are sutured to the fibrotic elements of the capsular membrane to center and secure the IOL to the capsular membrane and prevent complications associated with uveal touch.

Neurosyphilis Masquerading as an Acute Adie's Tonic Pupil: Report of a Case.

We describe the case of a male patient who presented with anisocoria, and was initially diagnosed with an acute Adie's tonic pupil. On subsequent laboratory testing, he was found to have neurosyphilis. Magnetic resonance imaging demonstrated enhancement of the right oculomotor nerve. This case underscores the importance of considering this diagnosis in patients with acute onset internal ophthalmoplegia and hypersensitivity to dilute pilocarpine, even in the absence of other oculomotor nerve findings.

Estimation of corneal power after myopic laser refractive surgery: comparison of methods against back-calculated corneal power.

PURPOSE: To compare methods of corneal power estimation after myopic laser refractive surgery with back-calculated corneal power (K). SETTING: Private practice, Edmonton, Alberta, Canada. DESIGN: Case series. METHODS: Patients with previous myopic laser surgery followed by cataract extraction were studied. Back-calculated K obtained with the Holladay IOL Consultant was compared with that obtained by the clinical history method (CHM), the modified Maloney method, an adaptation of the Maloney method using individualized Orbscan IIz-derived posterior corneal power values, Orbscan IIz quantitative area topography, and the Gaussian optics formula. A mixed effects linear model was used for analysis. RESULTS: The mean spherical equivalent (SE) before laser treatment was -6.43 diopters (D) ± 3.52 (SD). The estimated means of all methods except those obtained with the CHM, modified Maloney method, 2.0 mm total axial map, 1.5 mm total mean map, and 1.5 mm total optical map were significantly different from the mean of the back-calculated K. Estimates from the 1.5 mm total mean map were generally 0.06 D higher. The 2.0 mm total axial map, modified Maloney method, 1.5 mm total optical map, and CHM underestimated corneal power by 0.11 D, 0.13 D, 0.22 D, and 0.26 D, respectively. Unit increases in optical zone and pre-laser myopic SE were associated with decreases in corneal power of 1.58 D (P = .047) and 0.55 D (P = .0001), respectively. CONCLUSION: The modified Maloney method, 2.0 mm total axial map, 1.5 mm total mean map and 1.5 mm total optical map of the Orbscan IIz may provide estimates closer to the back-calculated K than the CHM. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Scleral fixation of a subluxated intraocular lens-capsular bag complex through a fibrotic continuous curvilinear capsulorhexis.

UNLABELLED: Several strategies have been devised to manage in-the-bag intraocular lens (IOL) subluxation. We describe a method of fixating the IOL-capsular bag complex to the sclera using the fibrotic ring that develops around the continuous curvilinear capsulorhexis (CCC). Two, preferably 3, double-armed 10-0 polypropylene sutures are passed around the fibrotic CCC rim of the capsule and out the Hoffman scleral pockets and then tied in the scleral tunnels to center the IOL-bag complex. This technique provides an alternative approach to repositioning and fixating the IOL-bag complex that is especially useful in cases in which removal and replacement of the IOL would be difficult. It also provides more than 2-point fixation to achieve perfect IOL centration. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Consequences of waiting for cataract surgery.

UNLABELLED: PURPOSE OR REVIEW: To conduct a concise review of primary research articles over the preceding year on the subject of the consequences of waiting for cataract surgery. RECENT FINDINGS: Waiting for cataract surgery beyond 6 months may result in increasing vision loss, decrease in quality life, loss of driver's license, depression and adverse events including falls and fractures. The consequences of waiting for cataract surgery not only affect patients, families and surgeons, but also health ministries and public health policy makers. Consequences are both quantitative and qualitative in nature, ranging from progressive vision loss to patients' decrease in quality of life from factors other than vision loss. Cataract wait lists are not unique to North America, and numerous international articles have described a broad variety of consequences. SUMMARY: Consequences of waiting for cataract surgery are multivariate in nature and easily extend beyond the clinical setting into sociodemographic realms and public health costs and policy arenas.

Simplified technique for combined silicone oil removal during phacoemulsification with standard or toric intraocular lens implantation.

We describe a simple automated technique for silicone oil removal at the time of phacoemulsification combined with standard or toric intraocular lens implantation using the phacoemulsification handpiece in irrigation/aspiration mode. No additional corneal or scleral incisions are needed, and no specialized vitreoretinal instrumentation is required.

Early experience with the AcrySof toric IOL for the correction of astigmatism in cataract surgery.

OBJECTIVE: The AcrySof toric IOL (tIOL) became available in Canada in 2006, thereby giving surgeons another option in the correction of astigmatism during cataract surgery. The purpose of this paper is to report the early experience of the acrylic AcrySof tIOL. DESIGN: Observational clinical study. PARTICIPANTS: One hundred eleven eyes, including 41 bilateral patients. METHODS: Patients were implanted with the AcrySoftIOL by 1 surgeon between April and September 2007. The eyes were followed for 6 months and pre- and postrefractive outcomes were summarized. RESULTS: Preoperatively, the mean refractive cylinder was -1.25 D compared with -0.32 D postoperative. At 6 months, 95.5% of eyes remained within 10 degrees of planned axis. Two eyes of 1 patient (1.8%) required bilateral repositioning at 2 weeks postoperative for significant rotation off axis. CONCLUSIONS: Based on our early postoperative experience, we have found the AcrySof tIOL to be successful in reducing moderate levels of astigmatism.

Mitomycin C in photorefractive keratectomy.

PURPOSE: To evaluate the outcome of primary or retreatment photorefractive keratectomy (PRK) or phototherapeutic keratectomy (PTK) with mitomycin C (MMC) 0.02% applied prophylactically intraoperatively for the prevention of haze and regression in cases of significant haze and regression after primary PRK, due to previous radial keratotomy (RK), in primary PRK eyes with high myopia, and in comeas with a previous superficial foreign body scar. METHODS: This was a retrospective evaluation of 34 eyes treated with PRK or PTK and intraoperative MMC. Mitomycin C was applied immediately after laser ablation. Postoperative examinations were conducted 3 and 7 days after surgery and monthly for 6 months. Haze was graded on a standard 0+ (clear cornea) to 4+ (total opacity) scale. Visual acuity was measured as a general baseline indicator. RESULTS: Postoperatively, uncorrected visual acuity (UCVA) was 20/20 or better in 21 eyes and 20/25 in 5 eyes with best spectacle-corrected visual acuity (BSCVA) of 20/20 or better. Three eyes achieved UCVA of 20/30 with BSCVA of 20/20 or better; and 5 eyes had UCVA of 20/40 with BSCVA of 20/20 or better. Nineteen (56%) eyes had grade 0+ haze and 15 (44%) eyes had grade 0.5+ haze (trace haze) at 6-month follow-up. CONCLUSIONS: Mitomycin C 0.02% used prophylactically during PRK or PTK retreatment was effective in preventing significant recurrent haze from developing. In eyes with high myopia or previous RK or scarring, MMC was effective in preventing significant haze formation.