Joshua C. Teichman

Fixation stability using radial gratings in patients with age-related macular degeneration

BACKGROUND The fixation stability of patients with macular atrophy is generally worse than that of people without pathology. METHODS The effects of 2 types of high-contrast fixation stimuli on fixation stability were compared between patients with longstanding age-related macular degeneration (AMD) and control subjects with normal vision. One stimulus was a 9-cycle square-wave radial grating measuring 5 degrees in diameter and the other a white 0.5 degrees disc. A video-based infrared eye tracker with remote optics was used to record eye position while participants fixated the stimuli in primary position of gaze for 6 to 7 s. Fixation stability was measured with a bivariate contour ellipse area (BCEA). RESULTS For patients with AMD, fixation stability for the radial grating was largely independent of visual acuity, whereas fixation stability for the disc diminished with acuity. For the control observers, there were no differences in fixation stability for the 2 kinds of stimuli. INTERPRETATION In clinical and research settings, radial gratings can be useful targets for fixation for patients with macular disease since they provide enough visual information to help maintain fixation stability. These findings have important implications for the design of clinical tests and procedures such as perimetry, multifocal electroretinography, and optical coherence tomography for patients with macular atrophies.

Transepithelial phototherapeutic keratectomy combined with implantation of a single inferior intrastromal corneal ring segment and collagen crosslinking in keratoconus

Purpose To evaluate the efficacy of phototherapeutic keratectomy (PTK) combined with implantation of a single inferior intrastromal corneal ring segment (ICRS) and riboflavin with ultraviolet‐A collagen crosslinking (CXL) performed sequentially on the same day in the management of keratoconus. Setting Cornea Unit, Toronto Western Hospital, Toronto, Ontario, Canada. Design Case series. Methods This retrospective review comprised consecutive patients with progressive keratoconus having transepithelial PTK followed by femtosecond laser–enabled placement of a single inferior ICRS and CXL on the same day by the same surgeon between December 2010 and August 2011. The main outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), mean refraction spherical equivalent, keratometry (K), and total higher‐order aberrations. Results Sixteen eyes of 13 patients were included in the study. Six months after same‐day PTK combined with implantation of a single inferior ICRS and CXL, there was a significant improvement in UDVA, CDVA, and the mean and steep K values. No patient lost CDVA lines. Conclusion Phototherapeutic keratectomy combined with implantation of a single inferior ICRS and CXL on the same day was a safe, effective treatment for improving visual acuity in select patients with progressive keratoconus. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Intraocular lens choices for patients with glaucoma.

Purpose of review To discuss the unique functional and structural changes in glaucoma and the impact on intraocular lens (IOL) selection. Recent findings Glaucoma is a common ocular disease. Functional and structural changes associated with glaucoma require special consideration in the patient who is undergoing cataract/IOL surgery. Decreased contrast sensitivity found in glaucoma may be enhanced by the use of aspheric IOLs. Small pupils and weakened zonules necessitate meticulous surgical technique and increase the risk of IOL dislocation, as does anterior capsular contraction. Posterior capsular opacification is a common postoperative complication and may be related to IOL material and design. Both anterior chamber depth and axial length may change in patients who have had trabeculectomy and should be considered in the preoperative plan. Multifocal IOLs may afford spectacle independence for patients; however, there is a paucity of data for their use in concurrent ocular disease. Summary Although there are challenges in performing cataract surgery in patients with glaucoma, excellent outcomes may be obtained with proper preoperative planning, meticulous intraoperative technique, and appropriate selection of IOL design.

Sutureless intrascleral fixation of a custom-tailored iris prosthesis with an intraocular lens

UNLABELLED We describe a technique for sutureless intrascleral fixation of a 3-piece intraocular lens (IOL) and custom silicone iris prosthesis complex to address the optical and functional issues of aphakia and aniridia, as well as to restore excellent cosmesis. The 3-piece IOL is anchored to the iris prosthesis using the belt-loop technique. We believe the intrascleral haptic fixation is overall a more robust fixation method in patients with aphakia and aniridia, who are often younger and require a long-lasting anterior segment reconstruction. FINANCIAL DISCLOSURE Dr. Ahmed is a consultant to Alcon Laboratories, Inc., and Abbott Medical Optics, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

Type 1 Boston keratoprosthesis: outcomes at two Canadian centres

OBJECTIVES To report the outcomes of patients who underwent Boston type 1 keratoprosthesis (Kpro) surgery at the University Health Network (Toronto, Ont.) and the University of Ottawa Eye Institute (Ottawa, Ont.) between June 2008 and July 2013. DESIGN Retrospective case series. PARTICIPANTS Forty-four eyes of 43 patients who underwent Kpro surgery. METHODS A retrospective review was conducted of all Kpro procedures performed by 4 attending cornea surgeons. The preoperative characteristics and postoperative course of each patient were analyzed. RESULTS In 31 eyes (70%), the primary indication for a Kpro was failed corneal transplantation. The remaining 13 eyes (30%) had Kpro as a primary procedure. In all eyes, preoperative visual acuity (VA) was 20/150 or worse, with 39 eyes (89%) having a VA of counting fingers, hand movement, or light perception. Mean follow-up time was 21 ± 12 months (range 12-57 months). The retention rate at the last follow-up was 95%. Best-achieved median VA was 20/100 (range 20/20 to no light perception [NLP]), with 37% of patients achieving a VA of >20/40 at some point during their postoperative course. At the last follow-up, median VA was 20/400 (range 20/30 to NLP). The 2 most common complications included retroprosthetic membrane formation (23 eyes, 52%) and elevated intraocular pressure (10 eyes, 23%). There were 5 cases (11%) of stromal melt and 1 case (2%) of infective keratitis. CONCLUSIONS This study demonstrates that Kpro improves VA in a majority of cases, and is a viable option in situations in which there is a poor prognosis for traditional penetrating keratoplasty.

Evaluation of a new technique for preparation of endothelial grafts for descemet membrane endothelial keratoplasty.

Purpose: The purpose of this study was to compare the Muraine technique, a relatively new method for preparing endothelial grafts for Descemet membrane endothelial keratoplasty (DMEK), with the current standard submerged cornea using backgrounds away (SCUBA) peeling technique. Methods: This study was a prospective ex vivo investigation. In a wet-lab setting, 20 donor corneas were prepared for DMEK using The Muraine technique and 20 donor corneas using the SCUBA technique. In each of the technique groups, 10 corneas were prepared by a corneal surgeon and 10 were prepared by a corneal fellow. Primary outcome measures were the time needed to prepare endothelial grafts and the number of graft tears. Results: In the SCUBA technique, median time to prepare grafts was shorter for both the surgeon (301 ± 85 seconds) and fellow (523 ± 58 seconds) compared with the Muraine technique (surgeon, 359 ± 83 seconds; fellow, 543 ± 44 seconds). However, these findings were not statistically significant (surgeon, P = 0.33; fellow, P = 0.24; pooled, P = 0.46). There was a statistically significant difference between surgeon time and fellow time for each technique (SCUBA technique, P = 0.0005; Muraine technique, P = 0.002). In the Muraine technique, there were 5 graft tears (surgeon = 2, fellow = 3), and no graft tears in the SCUBA technique, which was statistically significant (P = 0.047). Conclusions: The present study demonstrates that the SCUBA technique may be a more effective technique to prepare endothelial donor grafts for DMEK.

Simple technique to measure toric intraocular lens alignment and stability using a smartphone

&NA; Toric intraocular lenses (IOLs) are commonly implanted to correct corneal astigmatism at the time of cataract surgery. Their use requires preoperative calculation of the axis of implantation and postoperative measurement to determine whether the IOL has been implanted with the proper orientation. Moreover, toric IOL alignment stability over time is important for the patient and for the longitudinal evaluation of toric IOLs. We present a simple, inexpensive, and precise method to measure the toric IOL axis using a camera‐enabled cellular phone (iPhone 5S) and computer software (ImageJ). Financial Disclosure Dr. Ahmed is a consultant to Alcon Laboratories, Inc., and Abbott Medical Optics, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

A Case of Orbital Involvement in IgG4-Related Disease

A 46-year-old male was referred to the Ophthalmology Service for a 7-year history of bilateral proptosis and a presumptive diagnosis of thyroid eye disease. Past medical history was only significant for autoimmune pancreatitis. All laboratory testing including tests of thyroid function were within normal limits. The patient underwent orbital biopsy and was found to have plasma cells containing mainly IgG4 immunoglobulin that was consistent with IgG4-related disease. The patient was treated with oral prednisone and the proptosis resolved within 3 weeks.

Top 5 pearls for implanting premium IOLs in patients with glaucoma.

1. To discuss the issues of patient selection for premium intraocular lens (IOL) implantation and the functional changes in glaucoma that underlie these decisions. 2. To discuss the issues of target refraction and preoperative measurements in glaucoma patients, including combined procedures and cataract surgery after trabeculectomy. 3. To discuss the issues of pseudoexfoliative glaucoma and the structural changes, intraoperative considerations, and complications of cataract extraction in the setting of glaucoma and phacotrabeculectomy. 4. To discuss sources of astigmatism in glaucoma patients and its management. 5. To discuss ocular surface disease in glaucoma patients and its management.

Patient comfort and visual outcomes of mini-scleral contact lenses

OBJECTIVE To evaluate short-term visual outcome, patient acceptance, and tolerance of mini-scleral contact lenses (SCLs) in the management of various corneal pathologies. DESIGN Retrospective case series. PARTICIPANTS Thirty-two patients (40 eyes) who received mini-SCLs. METHODS Single-centre retrospective case series, between February 2010 and January 2013, of 32 patients (40 eyes) with various corneal pathologies who were offered either Maxim 5R, Maxim 7, or Maxim 7 × 11 mini-SCLs for nonsurgical optimization of visual correction. Patients were followed up at 1 and 3 months for assessment of best-corrected visual acuity, comfort, length of daily wear, and complications. RESULTS Thirty-two patients (40 eyes), with a mean age of 41 ± 16 years, opted to receive mini-SCLs. Eighteen patients had previously undergone surgery such as penetrating keratoplasty, deep anterior lamellar keratoplasty, and intraocular lens implantation. The median best-corrected visual acuity improved from 0.3 logMAR (range 0-1.3) before mini-SCLs, to 0.05 logMAR (range 0-1) with mini-SCLs (p < 0.0001). At 1-month follow-up, the median length of wear was 10 hours/day (range 1.5-15). At 3-month follow-up, the median length of wear was 12 hours/day (range 2-15). All eyes were comfortable at initial use of mini-SCLs and 91% were comfortable at 3-month follow-up. CONCLUSION Mini-SCLs may be a comfortable management option for patients with keratoconus and other corneal pathologies who are unable to achieve adequate visual outcome with traditional spectacles or rigid gas-permeable contact lenses.