Timothy V. Roberts

Primary phacoemulsification for uncontrolled angle-closure glaucoma

PURPOSE To report the results of primary phacoemulsification to treat uncontrolled angle-closure glaucoma. SETTING Private practice and teaching hospital department. METHODS This retrospective interventional case series assessed 3 patients having phacoemulsification and posterior chamber intraocular lens implantation for uncontrolled intraocular pressure (IOP) after acute primary angle-closure glaucoma. RESULTS Intraocular pressure control was achieved in all patients postoperatively. CONCLUSIONS Primary phacoemulsification with the option of future trabeculectomy should be considered in selected patients with persistent appositional angle closure and uncontrolled IOP after angle-closure glaucoma.

Capsular block syndrome associated with femtosecond laser-assisted cataract surgery.

UNLABELLED We report intraoperative capsular block syndrome occuring during the first 50 femtosecond laser-assisted cataract surgeries performed in our facility. Two patients had uneventful combined laser fragmentation, capsulotomy, and corneal incision procedures. In both cases, following transfer to the operating room and manual removal of the laser-cut capsulotomy, posterior capsule rupture was noted during hydrodissection, resulting in posterior dislocation of the lens. Pars plana vitrectomy, removal of the crystalline lens, and sulcus implantation of an intraocular lens were performed in both patients with good visual outcomes. Femtosecond laser-assisted cataract surgery changes the intraoperative environment with the generation of intracapsular gas and laser-induced changes in the cortex. With awareness of the changed intraocular environment following laser lens fragmentation and capsulotomy and a modification of the surgical technique, no additional cases of intraoperative CBS have been seen in more than 600 laser-assisted cataract surgery procedures performed to date at our facility. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.

Femtosecond laser cataract surgery: technology and clinical practice

The recent introduction of femtosecond lasers to cataract surgery has generated much interest among ophthalmologists around the world. Laser cataract surgery integrates high‐resolution anterior segment imaging systems with a femtosecond laser, allowing key steps of the procedure, including the primary and side‐port corneal incisions, the anterior capsulotomy and fragmentation of the lens nucleus, to be performed with computer‐guided laser precision. There is emerging evidence of reduced phacoemulsification time, better wound architecture and a more stable refractive result with femtosecond cataract surgery, as well as reports documenting an initial learning curve. This article will review the current state of technology and discuss our clinical experience.The recent introduction of femtosecond lasers to cataract surgery has generated much interest among ophthalmologists around the world. Laser cataract surgery integrates high-resolution anterior segment imaging systems with a femtosecond laser, allowing key steps of the procedure, including the primary and side-port corneal incisions, the anterior capsulotomy and fragmentation of the lens nucleus, to be performed with computer-guided laser precision. There is emerging evidence of reduced phacoemulsification time, better wound architecture and a more stable refractive result with femtosecond cataract surgery, as well as reports documenting an initial learning curve. This article will review the current state of technology and discuss our clinical experience.

Outcomes of Femtosecond Laser Cataract Surgery With a Diffractive Multifocal Intraocular Lens

PURPOSE To report the visual and refractive outcomes in an initial series of eyes undergoing femtosecond laser cataract surgery with implantation of a diffractive multi-focal intraocular lens (IOL). METHODS The first 61 consecutive eyes undergoing femtosecond laser cataract surgery and ReSTOR (Alcon Laboratories Inc) +3.00-diopter (D) add IOL implantation between May and July 2011 were enrolled in the study (LCS group). The control group consisted of a retrospective consecutive cohort of 29 eyes that underwent manual phacoemulsification cataract surgery and ReSTOR +3.00-D add IOL implantation (MCS group) between December 2010 and April 2011. Visual and refractive parameters were collected pre- and postoperatively at 1 and 3 months. RESULTS Mean postoperative spherical equivalent refraction was -0.01±0.35 D and -0.06±0.30 D in the LCS and MCS groups, respectively (P=.492). Mean absolute refractive prediction error (PE) was 0.26±0.25 D for the LCS group and 0.23±0.16 D for the MCS group (P=.489). Mean arithmetic refractive PE was 0.06±0.44 D and -0.02±0.30 D for the LCS and MCS groups, respectively (P=.388). No significant difference was noted in mean postoperative uncorrected distance visual acuity or uncorrected near visual acuity between groups. No eyes in either group had surgical complications or loss of corrected distance visual acuity in the follow-up period. CONCLUSIONS Mean spherical equivalent refraction and visual acuity of our initial group of patients undergoing laser cataract surgery are comparable to the manual phacoemulsification cohort for the AcrySof ReSTOR +3.00-D add IOL.

The effect of laser-assisted in situ keratomileusis on retinal nerve fiber layer measurements obtained with scanning laser polarimetry.

PurposeScanning laser polarimetry provides indirect measurements of retinal nerve fiber layer thickness by measuring the retardation of polarized laser light as it passes through the retinal nerve fiber layer. Laser-assisted in situ keratomileusis is a refractive technique by which corneal stromal photoablation is achieved by the structural and refractive changes induced by the excimer laser. Both techniques are becoming widely performed and there is some evidence that scanning laser polarimetry measurements are significantly changed after laser-assisted in situ keratomileusis. The authors performed a larger study to determine whether laser-assisted in situ keratomileusis induces predictable and consistent alterations in the measurement of retinal nerve fiber layer thickness. MethodsRetinal nerve fiber layer thickness measurements using scanning laser polarimetry were performed 1 week before and 1 week after laser-assisted in situ keratomileusis in 30 consecutive eyes (16 patients) undergoing the procedure at The Eye Institute. ResultsMean ± SD preoperative spherical equivalent refraction was −4.66 ± 2.40 D, mean ablation depth was 73.0 ± 36.23 &mgr;m, and mean patient age was 40.6 ± 8.7 years. Six of 12 retinal nerve fiber layer thickness measurements showed significant change (P < 0.05) after laser-assisted in situ keratomileusis. There was no correlation with corneal ablation depth (P > 0.05) for all parameters. ConclusionLaser-assisted in situ keratomileusis significantly affects retinal nerve fiber layer thickness measurements obtained by scanning laser polarimetry. Sequential images should be interpreted with caution and new postoperative baseline images should be obtained.

Femtosecond laser cataract surgery: challenging cases.

Purpose of review Emerging data in the peer-reviewed literature indicate that femtosecond laser-assisted cataract surgery (LCS) is a well tolerated and effective alternative to conventional phacoemulsification. Initial reports have largely been based on findings from an optimal patient selection. As confidence with the technology has grown, clinical indications have expanded and the benefit of LCS in high-risk patients with complex cataracts is increasingly being considered. Recent findings We discuss challenging cataract surgery cases, citing the currently available literature alongside experience from over 3000 completed LCS cases at our centre. Summary Current experience is limited. However, LCS platforms are continuously evolving and improving. The results collected to date would suggest that the precision and safety offered by LCS may improve outcomes in these challenging cases.

Laser-assisted cataract surgery following insertion of a pupil expander for management of complex cataract and small irregular pupil

We report a case in which laser-assisted cataract surgery was performed safely and successfully following manual division of posterior synechiae and mechanical dilation of the pupil with a Malyugin ring in a patient with an irregular, small stuck-down pupil.

Prevalence of nocturnal oxygen desaturation and self-reported sleep-disordered breathing in glaucoma

PurposeTo evaluate the prevalence of nocturnal oxygen desaturation and sleep-disordered breathing symptoms within a glaucoma population. Patients and MethodsOne hundred and twelve subjects (glaucoma=52, control=60) aged between 45 and 80 years were recruited for the study. Clinical assessment included overnight ambulatory pulse oximetry monitoring and administration of a self-reported sleep-disordered breathing questionnaire. ResultsThere were no differences in age, sex, body mass index, or prevalence of systemic hypertension between the groups. The mean oxygen desaturation index of the glaucoma group (8.6) did not differ significantly from that of the control group (9.6) (P=0.715). The prevalence of moderate to severe respiratory dysfunction (oxygen desaturation index >20) in the glaucoma group (17%) was similar to that in the control group (12%) (P=0.463). The severity of sleep-disordered breathing symptoms was similar between the groups (P=0.157). ConclusionsNo statistically significant association was found between glaucoma and either nocturnal oxygen desaturation or sleep-disordered breathing. Although this study cannot exclude the possibility of either impaired optic nerve head autoregulation or hypoxic damage occurring secondary to sleep apnea syndrome, the findings do not support the routine use of pulse oximetry in the workup of individuals with glaucoma.

A comparison of cataract surgery under topical anaesthesia with and without intracameral lignocaine

Purpose: To compare the efficacy of intracameral unpreserved lignocaine with placebo during cataract surgery under topical anaesthesia.

Incidence of cystoid macular edema: Femtosecond laser–assisted cataract surgery versus manual cataract surgery

cation were included in the study. Nonsmokers were defined as those who had never smoked. Chronic smokers showed significant increases in the corneal resistance factor (CRF) and corneal hysteresis (CH) values. This increase in corneal stiffness might originate from compounds found in cigarette smoke that enhance corneal biomechanics; for example, formaldehyde crosslinks the cornea and experimentally increases the tissue’s resistance to collagenases. The dynamic bidirectional applanation device also measures IOP, and it compensates the measured IOP (Goldmann-correlated IOP) for corneal thickness (corneal-compensated IOP). To determine a potential relationship between chronic smoking and IOP, we continued and extended our initial study (66 eyes of nonsmokers and 61 age-matched eyes of chronic smokers). Patient ages ranged from 20 to 71 years. The nonsmokers had a mean age of 45.8 years and a median age of 46.2 years. Smokers had a mean age of 44.9 years and a median age 43.9 years. Patients were recruited at the Institute for Refractive and Ophthalmic Surgery, Zurich, Switzerland. Institutional review board approval was obtained from the Ethical Committee of the Canton of Zurich. Univariable and multivariable analyses were performed for factors related to IOP and to adjust for potential correlations. Because measurements in both eyes of the same subject are likely to correlate, generalized estimating equations with robust standard errors (Huber-White sandwich variance estimator) were used to account for the fact that both eyes of an individual were included in the analysis. Data analysis was performed using the Student t test. In smokers, there were statistically significant increases and distinct increases (O2 mm Hg) in not only the Goldmann-correlated IOP but also in the corneal-compensated IOP (P Z .0003 and P Z .002, respectively) (Table 1). The CRF showed an increase similar to the one observed previously.When adjusting for age, smoking status, CH,CRF, and corneal thickness, smoking had a statistically significant correlation with the Goldmann-correlated IOP (R Z 1.925, PZ.034) and corneal-compensated IOP (R Z 1.655, P Z .034). This finding might indicate that the increase in IOP in smokers is independent of the previously reported increase in biomechanical resistance. One possible mechanism is an elevation in choroidal thickness caused by chronic smoking, which in return can cause an elevation in the episcleral venous pressure and IOP. We found a higher mean IOP in chronic long-term smokers than in nonsmokers. This increase seems to be independent of corneal biomechanical properties and of variations in central corneal thickness (CCT) because the corneal-compensated IOP has been repeatedly shown to independent of the CCT. In light of an estimated 1.2 billion smokers worldwide in 2010, more extensive studies are needed to further investigate this relationship.