Intraocular pressure screening during high-volume cataract surgery outreach in Ethiopia.

INTRODUCTION: Glaucoma is the leading cause of irreversible blindness worldwide and is often undetected in resource-limited settings. Early screening and treatment of elevated intraocular pressure (IOP) reduces both the development and progression of visual field defects. IOP screening in developing countries is limited by access to ophthalmic equipment, trained ophthalmic staff, and follow up. High-volume cataract surgery outreaches in resource-limited countries provide ample opportunity for glaucoma screening, intervention and follow up. METHODS: This prospective cross-sectional study took place during a cataract outreach campaign sponsored by the Himalayan Cataract Project (HCP) in partnership with Felege Hiwot Hospital in Bahir Dar, Ethiopia, during April 5th - April 10th 2021. IOP was measured on the surgical eye of patients before undergoing small incision cataract surgery (SICS) using rebound tonometry with an iCare tonometer model IC100. RESULTS: Intraocular pressure (IOP) was measured in 604 eyes of 595 patients who received SICS. Mean IOP was 12.1 mmHg (SD = 5.0 mmHg). A total of 29 patients had an IOP greater than 21 mmHg representing 4.8% of total IOP measurements. A total of 17 patients received oral acetazolamide prior to surgery to acutely lower IOP. Six of these patients had their surgery delayed due to elevated IOP and 9 patients received excisional goniotomy at the time of SICS. A temporal approach during SCIS was taken for all patients with elevated IOP to allow for possible trabeculectomy at a future date. DISCUSSION: IOP screening during high-volume cataract outreach campaigns can be performed safely, accurately and on a large scale with minimal resources and supplemental training. Pre-operative IOP measurement can improve surgical care at the time of cataract surgery as well as help establish long-term follow up for patients with glaucoma.

NECROSIS OF THE RETINA AND UVEAL TRACT SECONDARY TO EXPANDING GAS TAMPONADE.

PURPOSE: To present a case of retinal and uveal necrosis caused by expanding gas tamponade after pars plana vitrectomy. METHODS: Single case report. RESULTS: An otherwise healthy 66-year-old woman underwent pars plana vitrectomy with intended 20% sulfur hexafluoride (SF6) tamponade for macular hole repair of her pseudophakic left eye. She developed intractable nausea, emesis and increasing left eye pain in association with gas expanded to totally fill the left eye, just hours after surgery. Extremely elevated intraocular pressure was lowered with a successful paracentesis but recurred within a few hours. She then underwent vitrectomy evacuation of all vitreous cavity gas, reformation of the anterior chamber, and silicone oil placement, normalizing intraocular pressure. Three weeks later, the left eye had no light perception, and devitalization of the retina, choroid, and iris was evident. CONCLUSION: We present a case of blindness and intraocular tissue dissolution/disorganization after vitrectomy with intended 20% SF6. To our knowledge, this is the most detailed report of the under-recognized complication of expanding gas tamponade. Institutions hosting vitrectomy surgery should consider enacting a formal "Time Out" that requires all team members to witness accurate fractionation of potentially expansile gas. In the event of acute postoperative glaucoma in such eyes, a single small volume paracentesis cannot be relied upon to protect against continued gas expansion.

Postoperative Complications of Ab Interno Gelatin Microstent.

PURPOSE: To report 4 previously undescribed postoperative complications in 4 cases of ab interno XEN45 Gel Stent (XEN) implantation following uncomplicated surgeries. PATIENTS AND METHODS: A total of 51 consecutive XEN implantations performed between July 1, 2017 and April 30, 2018 were reviewed. All cases were performed by 7 experienced glaucoma surgeons affiliated with the William Beaumont Hospital, Department of Ophthalmology. Cases with postoperative complications were identified, and a literature review was performed on PubMed.gov between April 5, 2018 and June 2, 2018 to identify previously unreported XEN complications. RESULTS: Case 1 consisted of an 86-year-old woman who suffered a suprachoroidal hemorrhage and associated rhegmatogenous retinal detachment following XEN implantation. One month after sclerotomy drainage and pars plana vitrectomy repair, an amputated XEN was found to have eroded through the conjunctiva. Case 2 consisted of a 68-year-old man with persistent elevated intraocular pressure due to recurrent Tenon's capsule fibrosis who developed complete XEN retraction into the subconjunctival space. Cases 3 and 4 consisted of a 68-year-old man and a 78-year-old woman who developed occlusion of the microstent's internal ostium by a partially detached Descemet's membrane. Case 3 maintained normal intraocular pressure on timolol, whereas case 4 resulted in bleb failure, despite Nd:YAG laser lysis of the occluded XEN internal ostium. CONCLUSIONS: Although the XEN is a promising new surgical option for the management of primary open-angle glaucoma, it can present unique postoperative challenges that are still being elucidated. Timely intervention or prevention of these complications can be improved by early surgeon recognition and effective communication with comanaging ophthalmologists.

Electron microscopy of silicone irrigation/aspiration tips involved in posterior capsule rupture.

We describe 2 cases of posterior capsule rupture caused by Alcon reusable silicone irrigation/aspiration (I/A) tips. Scanning electron microscopy and reflected light microscopy of these tips revealed burring of the inner metallic shafts and tears in the silicone sleeves. A review of surgical video revealed that posterior capsule ruptures caused by the I/A tips occurred when the posterior capsule was aspirated either through the aspiration port or through a tear in the silicone sleeve. Contact of the posterior capsule with the sharp metallic burrs on the inner metal tube can result in posterior capsule rupture.

Clinical Trial of Thermal Pulsation (LipiFlow) in Meibomian Gland Dysfunction With Preteatment Meibography.

OBJECTIVES: Thermal pulsation (LipiFlow) has been advocated for meibomian gland dysfunction (MGD) treatment and was found useful. We aimed to evaluate the efficacy and safety of thermal pulsation in Asian patients with different grades of meibomian gland loss. METHODS: A hospital-based interventional study comparing thermal pulsation to warm compresses for MGD treatment. Fifty patients were recruited from the dry eye clinic of a Singapore tertiary eye hospital. The ocular surface and symptom were evaluated before treatment, and one and three months after treatment. Twenty-five patients underwent thermal pulsation (single session), whereas 25 patients underwent warm compresses (twice daily) for 3 months. Meibomian gland loss was graded using infrared meibography, whereas function was graded using the number of glands with liquid secretion. RESULTS: The mean age (SD) of participants was 56.4 (11.4) years in the warm compress group and 55.6 (12.7) years in the thermal pulsation group. Seventy-six percent of the participants were female. Irritation symptom significantly improved over 3 months in both groups (P<0.01), whereas tear breakup time (TBUT) was modestly improved at 1 month in only the thermal pulsation group (P=0.048), without significant difference between both groups over the 3 months (P=0.88). There was also no significant difference in irritation symptom, TBUT, Schirmer test, and gland secretion variables between patients with different grades of gland loss or function at follow-ups. CONCLUSIONS: A single session of thermal pulsation was similar in its efficacy and safety profile to 3 months of twice daily warm compresses in Asians. Treatment efficacy was not affected by pretreatment gland loss.

Ultrasonic evaluation of bone quality in cadaver ilia.

Several imaging modalities have traditionally been utilized to assess bone health. However, none of these standards is capable of providing a clear rendition or display of the damaged bone layers caused, for instance, by osteoporosis. This study examines the use of ultrasound for non-invasive monitoring of bone quality in bone samples with various degrees of porosity. A user-defined region of interest (ROI) in the iliac portion of extracted human cadaver coxal bones is monitored and quantified. Raster C-scan images of the ROI were acquired and compared to basic physical measurements, and to bone scans using dual energy X-ray absorptiometry (DXA). A quantitative measure of the superficial sub-surface composite matrix (ScM) content was analyzed using linear regression with all physical and DXA measures. The trend in the degree of percent bone loss (PBL) measured by ultrasound (US) was found to be closely paralleled with that measured by DXA (R(2) = 0.82, p < .0005). Also, the trend in which PBL (US) correlated with bone mineral density (BMD) (R(2) = 0.62, p < .01) was found to exhibit a similar behavior when the latter was compared to dry mass density (DmD) of the bone samples (R(2) = 0.63, p < .01). However, when PBL (DXA) was compared to DmD, it did reveal a better linearity (R(2) = 0.69, p < .005) than the one obtained when PBL (US) was compared with the same DmD (R(2) = 0.45, p < .05). A similar outcome was observed when PBL (US) was compared with percent porosity (R(2) = 0.51, p < .05), as opposed to the better linearity exhibited between PBL (DXA) and porosity (R(2) = 0.86, p < .0005). Despite these slight variations, further analyses on the statistical significance between these correlations suggest that ultrasound can be an effective imaging technique in assessing the degree of bone damage, and can be used to assess the structural integrity of bones.