Detection of SARS-CoV-2 in conjunctival secretions from patients without ocular symptoms.

PURPOSE: To evaluate the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in conjunctival secretions from patients without ocular symptoms. METHODS: Conjunctival swabs were prospectively collected from laboratory-confirmed Coronavirus disease 2019 (COVID-19) patients without ocular symptoms for reverse transcription-polymerase chain reaction (RT-PCR) and viral culture. RESULTS: A total of 158 conjunctival swabs were obtained from 49 laboratory-confirmed COVID-19 patients. The median duration of illness when the first conjunctival swab was obtained was 10 days (range 2-27 days). Four conjunctival swabs from four different patients (4/49, 8.2%) were positive for SARS-CoV-2 RNA by RT-PCR. The Ct values ranged from 32.7 to 37.7 (mean 35.4). Viral cultures were negative for all four RT-PCR-positive conjunctival swabs. CONCLUSION: Conjunctival secretions of a minority of COVID-19 patients without ocular symptoms may contain relatively low levels of SARS-CoV-2 RNA, but their infectiousness remains undetermined. Appropriate infection control measures should be implemented during ophthalmological assessment of COVID-19 patients to prevent potential nosocomial transmission of SARS-CoV-2.

Early intraocular pressure change after peripheral iridotomy with ultralow fluence pattern scanning laser and Nd:YAG laser in primary angle-closure suspect: Kowloon East Pattern Scanning Laser Study Report No. 3.

PURPOSE: Our purpose was to assess the early intraocular pressure (IOP) changes of ultralow fluence laser iridotomy using pattern scanning laser followed by neodymium:yttrium-aluminum-gamet (Nd:YAG) laser. METHODS: This is a prospective interventional study. Thirty-three eyes of 33 adult Chinese primary angle-closure suspect subjects were recruited for prophylactic laser peripheral iridotomy. Sequential laser peripheral iridotomy was performed using pattern scanning laser followed by Nd:YAG laser. Visual acuity (VA) and IOP were measured before treatment, at 1 h, 1 day, 1 week, 1 month, 3 months and 6 months after laser. Laser energy used and complications were documented. Corneal endothelial cell count was examined at baseline and 6 months. Patency of the iridotomy was assessed at each follow-up visit. RESULTS: All subjects achieved patent iridotomy in a single session. The mean energy used was 0.335+/-0.088 J for the pattern scanning laser, and 4.767+/-5.780 mJ for the Nd:YAG laser. The total mean energy was 0.339+/-0.089 J. None of the eyes developed a clinically significant IOP spike (≥ 8 mmHg) at 1 h and 1 day after laser use. Only four eyes developed higher IOP at 1 h and all were ≤3 mmHg compared to baseline. The mean IOP was 13.8+/-2.5 mmHg at 1 h and 11.5+/-2.2 mmHg at 1 day, both were significantly lower than baseline (15.8+/-2.1 mmHg) (P < 0.001). Mean VA (logMAR) was similar at 1 h post laser compared to baseline (0.23 vs 0.26). There was also no statistically significant difference in mean VA at other follow-up visits compared to baseline. Peripheral iridotomy closure was encountered in two (6.1%) eyes, one at 1 month and another at 6 months follow-up. There were no complications including hyphema, peripheral anterior synechia formation nor prolonged inflammation throughout the follow-up period. There was no significant loss in corneal endothelial cell counts at 6 months (2255+/-490) compared to baseline (2303+/-386) (P = 0.347). CONCLUSIONS: Sequential LPI using an ultralow fluence pattern scanning laser, followed by a Nd:YAG laser, is safe and efficacious, and produces no IOP spike in dark irides of primary angle-closure suspects. Further studies to investigate its role in the treatment of other angle-closure conditions are warranted.

Optical coherence tomography angiography wide-field montage in branch retinal vein occlusion before and after anti-vascular endothelial-derived growth factor injection.

The wide-field montage technique of optical coherence tomography angiography provides good delineation of the improvement in microvascular disturbance associated with branch retinal vein occlusion after treatment with anti-vascular endothelial-derived growth factor injection. It may be further evaluated for the assessment of treatment progress in patients with retinal vein occlusion.

Differential microvascular assessment of retinal vein occlusion with coherence tomography angiography and fluorescein angiography: a blinded comparative study.

PURPOSE: To compare the imaging of retinal vein occlusion (RVO) with optical coherence tomography angiography (OCTA) and fluorescein angiography (FA) and evaluate their roles in clinical management. METHODS: RVO patients who underwent imaging with both FA and OCTA from 1 June 2015-31 December 2015 were enrolled. An independent retinal specialist blinded from patient identity assessed the FA and OCTA reports. The pixel counting technique was used for FAZ size measurement. A significant level of p < 0.05 was taken for correlation and agreement analysis. RESULTS: On OCTA, the mean FAZ size was 0.382 ± 0.152 mm2 and 0.606 ± 0.136 mm2 for the superficial and deep retinal layers, respectively, with significant correlation (p = 0.004). On FA, the mean FAZ size was 0.352 ± 0.158 mm2, better correlated with OCTA at the superficial (p = 0.062) than the deep retinal layer (p = 0.122). Between FA and OCTA, good agreement was found for microaneurysms (100%, p = 0.001) and venous congestion (83.33%, p = 0.028), but not capillary non-perfusion (p = 0.217) and venous tortuosity (p = 0.546). OCTA also revealed more capillary non-perfusion than FA (91.67 vs. 58.33%). The presenting best-corrected visual acuity was significantly correlated with capillary non-perfusion on OCTA (p = 0.001). CONCLUSION: OCTA and FA are complementary tools in RVO assessment. While OCTA is more precise in the assessment of FAZ and capillary non-perfusion, FA offers better vascular imaging of the peripheral retina.

Intracameral cefuroxime in the prevention of postoperative endophthalmitis: an experience from Hong Kong.

PURPOSE: The purpose was to study the effect of introducing intracameral cefuroxime, which was compounded by a hospital pharmacy, on postoperative endophthalmitis in a tertiary eye centre in Hong Kong. METHODS: All cases that underwent cataract surgeries over a 12-year period (January 2004 to December 2015) were included. The routine use of intracameral cefuroxime at the end of cataract surgery was introduced at our centre after April 2010. All cefuroxime aliquots were prepared by the hospital pharmacy using an aseptic compounding technique. The rates of postoperative endophthalmitis before April 2010 (Group 1, no intracameral cefuroxime) and after April 2010 (Group 2, routine use of intracameral cefuroxime) were compared. RESULTS: A total of 30,428 eyes (7,332 in Group 1 and 23,096 in Group 2) were studied. Eight cases developed postoperative endophthalmitis (1.09 in 1000; 0.11 %) in Group 1 whereas no cases developed endophthalmitis (0 %) in Group 2. The rate of reduction was statistically significant (p < 0.0001). Seven out of eight cases of endophthalmitis were confirmed by positive culture. Organisms identified were Group G Streptococcus (two cases), Group B Streptococcus, Staphylococcus aureus, Serratia marcescens, and coagulase-negative Staphylococcus (two cases). Antibiotic susceptibility testing results were available in six cases. Four out of six organisms were susceptible to the penicillin group. No adverse events related to the use of intracameral cefuroxime were encountered. CONCLUSIONS: The use of intracameral cefuroxime could significantly reduce the rate of postoperative endophthalmitis in a tertiary centre in Hong Kong. The use of aseptic compounding to prepare cefuroxime aliquots by hospital pharmacy appeared to be safe and efficacious.

Is it necessary to cover the macular hole with the inverted internal limiting membrane flap in macular hole surgery? A case report.

BACKGROUND: To report a case of late closure of idiopathic full-thickness macular hole (FTMH) after vitrectomy with the inverted internal limiting membrane (ILM) technique. CASE PRESENTATION: A 68-year-old lady with a stage IV FTMH underwent pars plana vitrectomy with 25 gauge plus transconjunctival system, ILM peeling and gas tamponade. The inverted ILM flap technique was adopted, except that no extra surgical manipulation was used to cover the macular hole with the ILM flap. Surgical outcome was monitored with serial optical coherence tomography (OCT). Complete closure of the FTMH with resolution of intraretinal cystic changes was confirmed on OCT at 16 months postoperatively. Visual acuity improved from a baseline level of 0.1 to 0.4. CONCLUSION: Idiopathic macular hole closure could be delayed to beyond 1 year following the inverted ILM flap technique, especially if the macular hole was not covered with the ILM flap. Not all macular holes that fail to close in the early postoperative period need to be re-operated and there may be no risk of further visual deterioration.

A prospective study on neonatal ophthalmic injuries associated with forceps delivery.

BACKGROUND: Assisted delivery by forceps is needed to expedite vaginal delivery in certain maternal and fetal conditions. The aim of this study was to evaluate the incidence and the extent of ophthalmological injuries in neonates after forceps delivery. METHODS: Women with cephalic fetuses delivered vaginally by forceps from July 2020 to June 2022 were recruited prospectively. Ophthalmologists would be consulted when there were signs of external ophthalmic injuries, such as periorbital forceps marks or facial bruising. Demographic data, pregnancy characteristics, delivery details, and perinatal outcomes were evaluated to identify any associated risk factors for neonatal ophthalmological injuries. RESULTS: A total of 77 forceps deliveries were performed in the study period, in which 20 cases (26%) required ophthalmological consultations. There were more right or left occipital fetal head positions in the group requiring ophthalmological assessment than those that did not require assessment (35% vs 12.3% [P = 0.023]). The degree of moulding of the fetal head was more marked in the former group (65% vs 28% [P = 0.001]). The overall incidence of detectable ophthalmological lesions was 16.9% (13/77). All ophthalmic injuries were mild, and most resolved with conservative management. CONCLUSIONS: In our study cohort, external ophthalmic injuries were common after forceps delivery. We recommended ophthalmological consultation in newborns delivered by forceps with evidence of compressive trauma to rule out serious ophthalmological trauma.

Ocular Features and Autism Spectrum Disorder: A 10-Year Retrospective Review.

We reviewed the medical records of our pediatric ophthalmology and strabismus clinic of our hospitals for the period 1 January, 2009 to 31 December, 2018, to identify children with autism spectrum disorder (ASD). We found that refractive errors (62%) and strabismus (63%) were the most common ocular manifestations in children with ASD. With timely management, amblyopia and strabismus could have favorable outcome. As amblyopia was significantly associated with intellectual disability (P=0.02), early ophthalmic monitoring via multidisciplinary approach is warranted.

What Is the Cause of Toxicity of Silicone Oil?

PURPOSE: To investigate the toxicity of the low-molecular-weight components (LMWCs) in ophthalmic silicone oils (SilOils) on retinal cell lines. METHODS: The toxicity of six types of LMWCs were studied and compared with conventional SilOil 1000 cSt. In vitro cytotoxic tests of LMWCs, in both liquid and emulsified forms, on three retinal cell lines (Müller cells (rMC-1), photoreceptor cells (661W) and retinal pigment epithelial cells (ARPE-19)) were conducted using a transwell cell culturing system. The morphology and viability of cells were assessed by light microscopy and Cell Counting Kit-8 (CCK-8) assay at different time points (6, 24 and 72 h). The ARPE-19 apoptotic pathway was investigated by Mitochondrial Membrane Potential/Annexin V Apoptosis Kit at different time points (6, 24 and 72 h). RESULTS: Apart from dodecamethylpentasiloxane (L5), all liquid LMWCs showed varying degrees of acute cytotoxicity on retinal cell lines within 72 h. Emulsified LMWCs showed comparable cytotoxicity with liquid LMWCs on retinal cell lines. Cyclic LMWCs, octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) had significantly higher cytotoxicity when compared with their linear counterparts decamethyltetrasiloxane (L4) and L5 with similar molecular formula. Using ARPE-19 cells as an example, we showed that LMWCs induce the apoptosis of retinal cells. CONCLUSIONS: Most LMWCs, in both liquid and emulsified forms, can induce acute cytotoxicity. In addition, cyclic LMWCs are suspected to have higher cytotoxicity than their linear counterparts. Therefore, LMWCs are suspected to be the main cause of the long-term toxicity of ophthalmic SilOil, due to their toxicity and propensity to cause ophthalmic SilOil to emulsify. The amount of LMWCs should be considered as the paramount parameter when referring to the quality of SilOil.

Combined Phacoendoscopic Cyclophotocoagulation versus Combined Phacotrabeculectomy in the Management of Coexisting Cataract and Glaucoma: A Comparative Study.

PURPOSE: To compare the surgical outcome of combined phacoemulsification and endoscopic cyclophotocoagulation (phacoECP) versus combined phacoemulsification and mitomycin C-augmented trabeculectomy (phacoTbx) in patients with coexisting glaucoma and visually significant cataract. METHODS: A retrospective review of 89 eyes of 89 patients who received phacoECP (N=49) and phacoTbx (N=40) was carried out at a tertiary eye center in Hong Kong. The minimum follow-up period was 6 months. Criterion of success was reduction of IOP at least 30% or absolute IOP of 15 mmHg or below without (complete success) or with (qualified success) antiglaucomatous medication. RESULTS: PhacoTbx had more reduction of antiglaucomatous medication (4 vs 1, P < 0.001). At postoperative year one, there was more IOP reduction for phacoTbx than phacoECP (8 mmHg vs 3 mmHg, P=0.012). The one-year complete success rate was also higher for phacoTbx (46.2% vs 8.2%, P < 0.001), while qualified success was comparable between the 2 groups (74.4% vs 73.5%, P=0.925). Operation time was shorter for phacoECP (37 vs 73 minutes, P < 0.001). The number of postoperative follow-up visits was less (6 vs 11.5, P < 0.001) for phacoECP. Additional surgical procedures were more common in phacoTbx (55% vs 0%, P < 0.001). There was no postoperative cystoid macula edema, hypotony, or endophthalmitis reported in both groups. CONCLUSIONS: PhacoECP is significantly less effective than phacoTbx in reduction of both IOP and number of antiglaucomatous medications for patients with medically uncontrolled glaucoma and cataract. Its complete success rate is also significantly lower than that of phacoTbx. With its comparable qualified success, shorter operation time, less number of postoperative visits, and secondary surgical intervention, phacoECP may still have a role in very selected cases.