Zeba A. Syed

Intraocular pressure fluctuation and glaucoma progression: what do we know?

While mean intraocular pressure (IOP) has long been known to correlate with glaucomatous damage, the role of IOP fluctuation is less clearly defined. There is extensive evidence in the literature for and against the value of short-term and long-term IOP fluctuation in the evaluation and prognosis of patients with glaucoma. We present here the arguments made by both sides, as well as a discussion of the pitfalls of prior research and potential directions for future studies. Until a reliable method is developed that allows for constant IOP monitoring, many variables will continue to hinder us from drawing adequate conclusions regarding the significance of IOP variation.

Cataract surgery outcomes at a UK independent sector treatment centre

Background/Aims The goal of this study was to review cataract surgery outcomes at three independent surgery treatment centres established by the UK Specialist Hospitals (UKSH) and to compare these outcomes with recognised benchmarks. Methods All patients who underwent cataract surgery at UKSH between July 2005 and March 2013 were included. Complication rates were obtained using annual quality reports, logbooks kept in operating theatres and outpatient departments, and electronic medical records. Refractive outcomes and biometry results between December 2010 and March 2013 were obtained from electronic medical records. Results were compared with previously published benchmarks. Results This study reviewed 20 070 cataract surgeries. UKSH had lower rates of several operative complications compared with the Cataract National Dataset benchmark study. These included choroidal haemorrhage, hyphaema, intraocular lens complications, iris damage from phacoemulsification, nuclear fragment into the vitreous, phacoemulsification wound burn, posterior capsule rupture or vitreous loss or both, vitreous in anterior chamber, and zonular dialysis. UKSH had lower rates of postoperative complications including corneal decompensation, cystoid macular oedema, iris to wound, posterior capsule opacification with yttrium aluminium garnet indicated, raised intraocular pressure, retained soft lens matter, uveitis, vitreous to section, and wound leak. Biometry outcomes at UKSH were significantly better than recently published benchmarks from the National Healthcare Service. Conclusions This is the first large-scale retrospective study of cataract surgery outcomes in the UK independent sector. The results indicate comparable or lower rates for most complications as compared with data collected in a previously published study.

Non-topography-guided photorefractive keratectomy for the correction of residual mild refractive errors after ICRS implantation and CXL in keratoconus.

PURPOSE To evaluate the safety and clinical outcomes of non-topography-guided photorefractive keratectomy (PRK) for the treatment of residual mild refractive errors 6 months after sequential intracorneal ring segment (ICRS) implantation and corneal collagen cross-linking (CXL) in stable keratoconus. METHODS This retrospective study included 17 eyes of 14 patients with mild to moderate keratoconus. The ICRS implantation and CXL were performed sequentially with a 4-week interval and non-topography-guided PRK was performed at least 6 months after CXL. Data were collected preoperatively and at the 6-month follow-up visits. RESULTS ICRS implantation and CXL induced a significant decrease in keratometry and refraction and an increase in visual acuity. At the 6-month follow-up after ICRS implantation and CXL, uncorrected and corrected distance visual acuity (UDVA and CDVA) significantly improved from 1.17 ± 0.38 and 0.44 ± 0.09 logMAR preoperatively to 0.45 ± 0.11 and 0.17 ± 0.08 logMAR (P = .001) postoperatively, respectively. The mean spherical error decreased from -5.45 ± 1.64 to -2.57 ± 1.15 D (P = .01) and the mean cylinder from 3.86 ± 1.15 to 2.13 ± 1.11 D (P = .01). At the 6-month follow-up after PRK, UDVA significantly improved to 0.18 ± 0.06 logMAR and CDVA was 0.15 ± 0.05 logMAR. The mean spherical error and mean cylinder significantly decreased to -1.10 ± 0.41 D (P = .02) and 0.98 ± 0.37 D (P = .046), respectively. No intraoperative or postoperative complications occurred. CONCLUSIONS At the 6-month follow-up, non-topography-guided PRK after ICRS implantation and CXL was found to be an effective and safe option for correcting residual refractive error and improving visual acuity in patients with moderate keratoconus.

Gamma-irradiated corneas as carriers for the Boston type 1 keratoprosthesis: advantages and outcomes in a surgical mission setting.

Purpose: The Boston keratoprosthesis (KPro) is the most commonly used KPro worldwide. There are limited data on the outcomes when irradiated corneas are used as KPro carriers. We report a retrospective analysis of corneal transplantations performed in a regular surgical mission setting in Beirut, Lebanon, using the Boston KPro type 1 and gamma-irradiated carrier corneas, and we describe visual outcomes, complications, and retention percentage. Methods: We conducted a retrospective analysis of 17 consecutive eyes from 16 patients who underwent Boston KPro type 1 implantation at the Beirut Eye Specialist Hospital between December 2010 and July 2012. Patient medical records were reviewed for preoperative, intraoperative, and postoperative details. Results: Postoperatively, 9 (52.9%), 5 (29.4%), and 2 (11.7%) eyes had a corrected visual acuity of 20/400 or better, 20/100 or better, and 20/40 or better, respectively, at the most recent follow-up visit. A total of 16 eyes (94.1%) improved in corrected visual acuity over the course of follow-up. Overall, 13 eyes (76.4%) developed at least 1 complication after surgery. Retroprosthetic membrane formation was the most common complication, occurring in 10 eyes (58.8%). Neither infectious keratitis nor corneal stromal necrosis was noted during the follow-up period. The retention percentage was 94.1%. Conclusions: The visual acuity outcomes, incidence of complications, and retention percentage of the KPro using gamma-irradiated carrier corneas are comparable with the outcomes of KPro implantation reported in the literature using fresh grafts as carriers. KPro with irradiated corneal carrier grafts seems to be an effective option to increase the supply of transplantation suitable corneas in remote areas, where fresh corneal grafts may be scarce.

Dynamic Intraductal Meibomian Probing: A Modified Approach to the Treatment of Obstructive Meibomian Gland Dysfunction

PURPOSE Obstructive meibomian gland dysfunction is a leading cause of ocular morbidity and its treatment remains a challenge. Meibomian gland probing was initially described in 2010. Here, the authors describe a modified technique, dynamic intraductal meibomian probing, which offers several advantages over the traditional approach including increased magnification, greater eyelid stabilization, enhanced anesthesia, and easier identification of gland orifices through the expression of meibum. METHODS The authors conducted a retrospective chart review of 70 eyelids with treatment-resistant obstructive meibomian gland dysfunction undergoing dynamic intraductal meibomian probing between January 2013 and April 2015. RESULTS Immediately after the procedure, 91.4% of cases experienced symptomatic improvement, and no complications were noted. CONCLUSIONS Dynamic intraductal meibomian probing is an effective and safe treatment for obstructive meibomian gland dysfunction that is resistant to traditional therapies.

Novel Treatments for Corneal Angiogenesis

Corneal neovascularization (CNV) is a commonly encountered clinical finding that represents the cornea’s natural healing and defense response when threatened, allowing for an amplified immunity in the face of harm. Most pathologic processes leading to CNV can be categorized into 1 of 3 groups: (1) hypoxia; (2) inflammation; and (3) loss of the limbal barrier function. Specific scenarios that are often seen clinically include herpes simplex virus infection, Acanthamoeba infection, hypoxia related to contact lens wear, limbal stem cell deficiency, chemical burns, ocular surface neoplasia, corneal allograft rejection, persistent corneal edema, and atopic keratoconjunctivitis. CNV is not necessarily harmful when limited in size and duration in the typically avascular cornea.1 Indeed, situations where CNV may be beneficial include the clearing of fungal and other chronic microbial infections, wound healing, and arresting some forms of corneal stromal melts.1 Furthermore, cornea specialists will often use CNV to guide treatment; for example in herpes simplex virus-related interstitial keratitis, CNV activity is sometimes used clinically to guide steroid dosing. In contrast, CNV can complicate the management of autoimmune and alloimmune responses, and in chronic circumstances CNV has the potential for serious visual consequences due to the deposition of lipid and induction of corneal scarring. The presence of neovessels increases corneal edema and leads to lipid deposition, hemorrhage, and scarring, decreasing corneal clarity and visual acuity. In 1 study, CNV was present in 35 (4.14%) of 845 consecutive eye clinic patients and resulted in a decrease in visual acuity in 12% of these cases.2 Furthermore, after keratoplasty CNV facilitates graft rejection by overcoming the natural immune privilege of the cornea. A meta-analysis demonstrated that in

Successful femtosecond LASIK flap creation despite multiple suction losses

We present a case of successful completion of a laser in situ keratomileusis (LASIK) procedure despite 5 episodes of suction loss during femtosecond flap creation in a 30-year-old man with no risk factors. The patient had an uncorrected distance visual acuity of 20/20 in both eyes at his 2-month follow-up visit. Our experience in this case shows that multiple suction losses during femtosecond LASIK flap creation do not preclude completion of a successful procedure with excellent visual outcomes. Caution and technique modification are advised if multiple laser passes are applied to avoid creating multiplanar flaps.

Case 19: Zone I Open Globe Injury with Traumatic Cataract Requiring Secondary Lens Extraction in a Pediatric Case

A 10-year-old male presented with a Zone I corneal laceration with possible lens violation of the left eye on pre-operative evaluation. Given the limitations of the pre-operative examination and intra-operative view of the lens, the globe corneal laceration was repaired primarily without lens extraction. As the corneal edema improved, the view to the lens improved and it was clear the patient had a traumatic cataract with lens violation. Subsequently, secondary cataract extraction and lens implantation was performed with safe lens positioning into the capsular bag 9 days after open globe repair. The patient’s vision slowly improved over time as the corneal wound continued to heal. The pediatric ocular trauma score (POTS) has been devised to predict visual prognosis after pediatric eye injury, and may be a useful tool when counseling families.

Peripheral Endothelial Cell Count Is a Predictor of Disease Severity in Advanced Fuchs Endothelial Corneal Dystrophy

Purpose: In advanced Fuchs endothelial corneal dystrophy (FECD), central endothelial changes do not correlate with disease severity. The peripheral endothelial cell count (ECC) has not been studied as a marker of FECD severity. The goal of this study was to determine the relationship between the peripheral ECC and known clinical markers of FECD in advanced cases. Methods: Patients with FECD examined between January 1, 2013, and September 1, 2016, by 1 cornea specialist were identified. Medical records from all previous visits were reviewed to include eyes with high-quality central and peripheral in vivo confocal microscopy images performed on the same day as a clinical evaluation. Endothelial photographs were used to perform manual cell counts centrally and peripherally. Clinical grading of FECD from 1 to 4 was performed at the slit-lamp. Results: We identified 154 eyes of 126 patients that met criteria for inclusion. With higher disease grades, central ECC and peripheral ECC decreased, visual acuity worsened, and central corneal thickness (CCT) increased (all P < 0.05). In patients with advanced disease (defined as either grade 3 or 4, CCT >700, or central ECC <350), the peripheral ECC was the best predictor of disease severity and had the highest number of statistically significant correlations with other clinical markers compared with competing variables. Conclusions: In advanced FECD, severity is best determined by the peripheral ECC compared with the central ECC, visual acuity, clinical disease grade, and CCT. The peripheral ECC should be added to the clinical parameters used to evaluate FECD severity.

Detection of Glaucoma Progression with Alternation Flicker

Glaucoma is a progressive optic neuropathy characterized by functional visual loss and underlying optic nerve deterioration. Optic nerve imaging, achieved using photography and scanning ophthalmic laser diagnostic imaging techniques, is an important aspect of glaucoma diagnosis and management. Alternation flicker is a technique in which serial optic nerve photographs, typically taken one or more years apart, are aligned and alternated in order to allow the observer to easily detect change over time. Alternation flicker has been shown to improve several aspects of optic nerve evaluation and has been demonstrated to correlate with traditional glaucoma risk factors, with some limitations. In this review, we consider the literature with respect to flicker for the evaluation and monitoring of glaucomatous optic neuropathy.