Feasibility and clinical utility of handheld fundus cameras for retinal imaging.

BACKGROUND/OBJECTIVES: Handheld fundus cameras are portable and cheaper alternatives to table-top counterparts. To date there have been no studies comparing feasibility and clinical utility of handheld fundus cameras to table-top devices. We compare the feasibility and clinical utility of four handheld fundus cameras/retinal imaging devices (Remidio NMFOP, Volk Pictor Plus, Volk iNview, oDocs visoScope) to a table-top camera (Zeiss VisucamNM/FA). SUBJECTS/METHODS: Healthy participants (n = 10, mean age ± SD = 21.0 ± 0.9 years) underwent fundus photography with five devices to assess success/failure rates of image acquisition. Participants with optic disc abnormalities (n = 8, mean age ± SD = 26.8 ± 15.9) and macular abnormalities (n = 10, mean age ± SD = 71.6 ± 15.4) underwent imaging with the top three scoring fundus cameras. Images were randomised and subsequently validated by ophthalmologists masked to the diagnoses and devices used. RESULTS: Image acquisition success rates (100%) were achieved in non-mydriatic and mydriatic settings for Zeiss, Remidio and Pictor, compared with lower success rates for iNview and oDocs. Image quality and gradeability were significantly higher for Zeiss, Remidio and Pictor (p < 0.0001) compared to iNview and oDocs. For cup:disc ratio estimates, similar levels of bias were seen for Zeiss (-0.09 ± SD:0.15), Remidio (-0.07 ± SD:0.14) and Pictor (-0.05 ± SD:0.16). Diagnostic sensitivities were highest for Zeiss (84.9%; 95% CI, 78.2-91.5%) followed by Pictor (78.1%; 95% CI, 66.6-89.5%) and Remidio (77.5%; 95% CI, 65.9-89.0%). CONCLUSIONS: Remidio and Pictor achieve comparable results to the Zeiss table-top camera. Both devices achieved similar scores in feasibility, image quality, image gradeability and diagnostic sensitivity. This suggests that these devices potentially offer a more cost-effective alternative in certain clinical scenarios.

Impact of COVID-19 pandemic and lockdown on eye emergencies.

BACKGROUND: To characterise and compare ocular pathologies presenting to an emergency eye department (EED) during the COVID-19 pandemic in 2020 against an equivalent period in 2019. METHODS: Electronic patient records of 852 patients in 2020 and 1818 patients in 2019, attending the EED at a tertiary eye centre (University Hospitals of Leicester, UK) were analysed. Data was extracted over a 31-day period during: (study period 1 (SP1)) COVID-19 pandemic lockdown in UK (24th March 2020-23rd April 2020) and (study period 2 (SP2)) the equivalent 2019 period (24th March 2019-23rd April 2019). RESULTS: A 53% reduction in EED attendance was noted during lockdown. The top three pathologies accounting for >30% of the caseload were trauma-related, keratitis and uveitis in SP1 in comparison to conjunctivitis, trauma-related and blepharitis in SP2. The overall number of retinal tears and retinal detachments (RD) were lower in SP1, the proportion of macula-off RD's (84.6%) was significantly (p = 0.0099) higher in SP1 (vs 42.9% in SP2). CONCLUSION: COVID-19 pandemic related lockdown has had a significant impact on the range of presenting conditions to the EED. Measures to stop spread of COVID-19 such as awareness of hand hygiene practices, social distancing measures and school closures could have an indirect role in reducing spread of infective conjunctivitis. The higher proportion of macula-off RD and lower number of retinal tears raises possibility of delayed presentation in these cases. Going forward, we anticipate additional pressures on EED and other subspecialty services due to complications and associated morbidity from delayed presentations.

Visualization of aqueous shunt position and patency using anterior segment optical coherence tomography.

PURPOSE: To describe the use of anterior segment optical coherence tomography (AS-OCT) to clarify the position and patency of aqueous shunt devices in the anterior chamber of eyes where corneal edema or tube position does not permit a satisfactory view. DESIGN: Noncomparative observational case series. METHODS: Four cases are reported in which aqueous shunt malposition or obstruction was suspected but the shunt could not be seen on clinical examination. The patients underwent AS-OCT to identify the position and patency of the shunt tip. RESULTS: In each case, AS-OCT provided data regarding tube position and/or patency that could not be obtained by slit-lamp examination or by gonioscopy that influenced management. CONCLUSIONS: AS-OCT can be used to visualize anterior chamber tubes in the presence of corneal edema that precludes an adequate view or in cases where the tube is retracted into the cornea. In such cases, AS-OCT is useful in identifying shunt patency and position, which helps guide clinical decision making.

5-Fluorouracil augmented needle revision of trabeculectomy: does the location of outflow resistance make a difference?

PURPOSE: To determine whether the outcome of needle revision of trabeculectomy is influenced by the presumed anatomic location of resistance to aqueous outflow. DESIGN: Retrospective case note review. PARTICIPANTS: Thirty-four eyes of 30 consecutive patients undergoing their first needle revision of trabeculectomy. METHODS: We compared 2 types of needle revision: "type-1 needling," limited to breaking down fibrosis in the subconjuctival-subtenon space, and "type-2 needling," which additionally involved needling underneath the scleral flap. MAIN OUTCOME MEASURES: Unqualified success was defined as a postneedling intraocular pressure (IOP) >4 mm Hg and ≤21 mm Hg at the most recent follow-up without further surgery, medications, or repeat needling. Qualified success was defined as a successful patient who required medications or repeat needling. RESULTS: The mean follow-up period was 2.1 ± 0.1 years (range, 1.0 to 3.8 y). Sixteen type-1 and 18 type-2 procedures were performed at a median of 124 days (22 d to 14 y) after trabeculectomy. IOP decreased from a mean of 28.2±1.3 mm Hg (19 to 52 mm Hg) preneedling to 6.7±0.8 mm Hg (2 to 22 mm Hg) on the first postoperative visit and 15.1±0.7 mm Hg (8 to 27 mm Hg) at the most recent follow-up. The overall success rate was 82.4% (47.1% unqualified and a further 35.3% qualified). There was no significant difference in the success rates between type-1 (14/16) and type-2 (14/18) needle revisions (Fisher exact test, P=0.66). Similar proportions of eyes undergoing type-1 and type-2 needling underwent a second needling procedure. There was no significant difference in the IOP reduction between type-1 and type-2 needling (Mann-Whitney U test, P=0.78). CONCLUSIONS: Needle revision is an effective technique for trabeculectomy bleb remodeling and can result in a sustained reduction in IOP. The location of the obstruction did not influence outcome, with type-1 and type-2 needle revisions equally likely to succeed.

Nonpenetrating glaucoma surgery: a critical evaluation.

PURPOSE OF REVIEW: Nonpenetrating glaucoma surgery is popular in a number of countries because of its perceived superior safety profile to mitomycin-C trabeculectomy. This article critically evaluates recently published literature relating to nonpenetrating glaucoma surgery. RECENT FINDINGS: Recent modifications in nonpenetrating glaucoma surgery, including the use of implants, augmentation with antiproliferatives, and use of laser goniopuncture, appear to result in improved intraocular pressure control. Comparative studies suggest a better safety profile with nonpenetrating glaucoma surgery but higher long-term intraocular pressure than after trabeculectomy. Despite this perception, a difference in intraocular pressure control between mitomycin-C trabeculectomy and nonpenetrating glaucoma surgery, when the most recent modification has been incorporated, has not been demonstrated conclusively in randomized trials conducted over sufficiently long periods to be clinically important. SUMMARY: Nonpenetrating glaucoma surgery continues to evolve. Intraocular pressure-lowering efficacy seems to have improved with recent modifications in technique but the degree and longevity of intraocular pressure-lowering in comparison with trabeculectomy are still uncertain.