Dry ice in the eye: A rare occupational hazard!

Superficial corneal foreign bodies (FBs) are a common occupational ocular hazard and can cause visually important astigmatism. A 23-year-old male working in a factory, which produced dry ice (solid carbon dioxide), presented to our emergency unit with symptoms of whitish discolouration of the right cornea for 1 day. Visual acuity in both eyes was 20/20 and slit-lamp examination of the right eye revealed an irregularly shaped whitish superficial FB in the inferior paracentral cornea with surrounding superior nebular opacity. Its gentle removal with a moistened cotton bud revealed an underlying epithelial defect with residual whitish changes. At 1-month of follow-up, the patient had nebulo-macular corneal opacity with stromal thinning at the site of impacted dry ice. We speculate that dry ice causes corneal damage due to its extremely cold temperatures and the formation of carbonic acid.

Topographic distribution of retinal neovascularization in proliferative diabetic retinopathy using ultra-wide field angiography.

Purpose: To analyze the topographic distribution of neovascularization (NV) and capillary nonperfusion (CNP) using ultra-wide field fluorescein angiography (UWFFA) in patients with proliferative diabetic retinopathy (PDR). Methods: This was a prospective, single-center, observational study in which all patients who presented between March 2019 and December 2020 and satisfied the inclusion criteria were recruited. In our study, patients with treatment-naïve PDR without any fibrovascular proliferation underwent UWFFA. The images were analyzed qualitatively for the topographic distribution of NV and the CNP area was quantified. The number of lesions picked by UWFFA was compared with 7 standard field (7SF) image using overlay of 7SF. The main outcome measure was characteristics of neovascularization, such as the number, location, and area of CNP, measured using UWFFA, which was considered with 95% confidence intervals (CI). Results: Two hundred and fifty-three eyes of 187 patients with a mean age of 56.03 ± 8 years were included. Mean neovascularization elsewhere (NVE) was 2.91 ± 3.43. Maximum NVEs were seen in the superotemporal (ST; 0.9 ± 1.13) quadrant, followed by the inferotemporal (IT; 0.7 ± 1.08), inferonasal (IN; 0.66 ± 1.02) and superonasal (SN; 0.66 ± 1.01) quadrants. Maximum CNP area was seen in the SN (13.75 ± 8.83 disc diameter square [DD2]) quadrant, followed by the IN (13.48 ± 8.59 DD2), IT (11.34 ± 8.37 DD2), and ST (11.3 ± 8.34 DD2) quadrants. Mean CNP area was maximum in patients with only neovascularization of disc (NVD; 64.99 ± 41.47 DD2), followed by both NVD and NVE (61.37 ± 35.61 DD2), and was minimum in patients with only NVE (36.44 ± 22.03 DD2). Eighty-one (32%) eyes out of 253 had NVE and 189 (75%) out of 253 had CNP area outside 7SF (overlay) of Early Treatment Diabetic Retinopathy Study (ETDRS). Conclusion: Diabetic NV lesions and CNP areas are distributed asymmetrically throughout the retina and are not restricted to the posterior pole. Compared to conventional 7SF imaging, UWFFA reveals significantly more retinal vascular pathology in patients with PDR.

Vitreous hemorrhage - Causes, diagnosis, and management.

Vitreous hemorrhage is associated with a myriad of conditions such as proliferative diabetic retinopathy, proliferative retinopathy following vascular occlusion and vasculitis, trauma, retinal breaks, and posterior vitreous detachment without retinal break. Multiple pathological mechanisms are associated with development of vitreous hemorrhage such as disruption of abnormal vessels, normal vessels, and extension of blood from an adjacent source. The diagnosis of vitreous hemorrhage requires a thorough history taking and clinical examination including investigations such as ultra-sonography, which help decide the appropriate time for intervention. The prognosis of vitreous hemorrhage depends on the underlying cause. Treatment options include observation, laser photo-coagulation, cryotherapy, intravitreal injections of anti-vascular endothelial growth factor, and surgery. Pars plana vitrectomy remains the cornerstone of management. Complications of vitreous hemorrhage include glaucoma (ghost cell glaucoma, hemosiderotic glaucoma), proliferative vitreoretinopathy, and hemosiderosis bulbi.

A comprehensive review of intravitreal immunosuppressants and biologicals used in ophthalmology.

Systemic immunosuppressants and biologicals have been a valuable tool in the treatment of inflammatory diseases and malignancies. The safety profile of these drugs has been debatable, especially in localized systems, such as the eye. This has led to the search for fairly local approaches, such as intravitreal, subconjunctival, and topical route of administration. Immunosuppressants have been used as a second-line drug in patients intolerable to corticosteroids or those who develop multiple recurrences on weaning corticosteroids. Similarly, biologicals have also been used as the next line of therapy, when adequate control of inflammation could not be attained or immunosuppressants were contraindicated to patients. Intravitreal immunosuppressants, such as methotrexate and sirolimus, have been extensively studied in noninfectious posterior uveitis, whereas limited studies have established the efficacy of intravitreal biologicals, such as infliximab and adalimumab. Most of these drugs have shown good safety profile and tolerability in animal studies alone and have not been studied further in human subjects. However, most of the studies in literature are single-case reports or case series which limits the level of evidence. In this comprehensive review, we discuss the mechanism of action, pharmacodynamics, pharmacokinetics, indications, efficacy, and side effects of different intravitreal immunosuppressants and biologicals that have been studied in literature.

Comparison of two protocols of subthreshold micropulse yellow laser treatment for non-resolving central serous chorioretinopathy.

Purpose: To study the effect of subthreshold micropulse yellow laser treatment on central serous chorioretinopathy (CSC) and to compare two laser protocols. As per our knowledge, there are no studies comparing the two protocols of subthreshold laser. Methods: Twenty-three patients with non-resolving CSC of at least three months duration were treated with subthreshold laser (577 nm). Ten patients were treated with 5% duty cycle (group A) and 13 patients with 10% duty cycle (group B). At one month, best corrected visual acuity (BCVA), central macular thickness (CMT), subretinal fluid (SRF), choroidal thickness (CT) and choroidal vascularity index (CVI) were evaluated. Results: In group A, BCVA improved from 0.508 ± 504 to 0.174 ± 0.171 (P = 0.0058), CMT improved from 349.8 ± 168.9 micrometers (µm) to 183.3 ± 70.312 µm (P = 0.0093) and SRF reduced from 202.4 ± 158.024 to 43.8 ± 46.599 µm (P = 0.0069). In group B, BCVA improved from 0.437 ± 0.426 to 0.289 ± 0.470 (P = 0.0026), CMT improved from 280.846 ± 72.668 to 196.769 ± 72.62 µm (P = 0.0002) and SRF reduced from 110.385 ± 57.687 µm to 52.538 ± 52.111 µm (P = 0.0064). No significant difference was found in BCVA and CMT between the groups (P = 0.8716 and P = 0.8523, respectively). CSC completely resolved in 50% of cases in group A and in 69.2% of cases in group B. This difference was not statistically significant (0.423); however, the odds ratio of resolution was 2.25 times more with 10% duty cycle. No change was observed on fundus autofluorescence (FAF) following laser. Conclusion: Subthreshold micropulse laser can lead to resolution of SRF in 60.87% of cases (groups A and B combined). Ten per cent duty cycle had higher odds of resolution without causing any RPE damage.

Vitrectomy without encircling band for rhegmatogenous retinal detachment with inferior break utilizing 3D heads up viewing system.

Purpose: This study aimed to determine the anatomical and functional outcomes of pars plana vitrectomy without encircling band for primary rhegmatogenous retinal detachments with inferior breaks utilizing 3D heads up viewing system. Method: This prospective, single-center study included 22 consecutive eyes with primary rhegmatogenous retinal detachments with only inferior breaks with proliferative vitreoretinopathy (PVR) CP2 or less, who underwent pars plana vitrectomy without encircling band, with silicon oil as tamponade. All surgeries were performed by a single surgeon. The single operation success rate was recorded after silicon oil removal. Results: The patient population consisted of 08 women (36%) and 14 men (64%) with a mean age of 56.6 +/- 14.7 years. The mean follow-up period was 8 months. A single break was present in 13 cases (59%), and 2-4 breaks were present in 9 cases (40.9%). The mean time for the surgical procedure was 35 min (range: 25-50). The macula was found to be detached in 19 cases (86.36%) and attached in 3 cases (13.6%). Single operation success rate (SOSR) of vitrectomy, after silicon oil removal without encircling band, for primary rhegmatogenous retinal detachment (RRD) with inferior breaks was 95.4%. One case redetached due to PVR changes and underwent re-surgery. Final reattachment was achieved in all 22 cases (100%). Mean best-corrected visual acuity (BCVA) significantly improved from 1.43 ± 0.59 logarithm of the minimum angle of resolution (logMAR) to postoperative BCVA was 0.48 ± 0.34 logMAR (P = 0.001). Conclusion: Pars plana vitrectomy without encircling band, utilizing 3D heads up the system in RRDs with inferior breaks in eyes with PVR grade C2 or less, provides good outcome.

Role of optical coherence tomography-angiography in diabetes mellitus: Utility in diabetic retinopathy and a comparison with fluorescein angiography in vision threatening diabetic retinopathy.

PURPOSE: To determine the utility of optical coherence tomography-angiography (OCT-A) in diabetic retinopathy (DR) and comparison versus fluorescein angiography (FA) in vision-threatening diabetic retinopathy (VTDR). METHODS: In this cross-sectional observational study, 60 eyes with no DR (NDR), 60 eyes with non-proliferative diabetic retinopathy (NPDR), and 60 eyes with proliferative diabetic retinopathy (PDR) underwent OCT-A. FA was done in VTDR. OCT-A of the NDR eyes was analyzed by two independent retina specialists. Vessel density (VD) (mm/mm2), perfusion density (PD) (%), and foveal avascular zone (FAZ) (mm2) area was analyzed among the groups. Montage angiography with vitreoretinal interface (VRI) segmentation was done in PDR. A qualitative comparison was done between OCT-A and FA for features of DR. RESULTS: OCT-A detected 16.66% of the eyes with microaneurysm and 57.5% of the patients with capillary non-perfusion (CNP) areas in the NDR group. The inter-grader coefficient between the two observers was 0.820 for microaneurysm and 0.880 for CNP. The mean VD in NDR, NPDR, and PDR was 16.865, 13.983, and 11.643 mm/mm2. The mean PD in NDR, NPDR, and PDR was 30.595, 26.853, and 23.193%. The VD and PD values were statistically significant (P < 0.001). The mean FAZ area was not statistically significant (NPDR and PDR) (P > 0.05). The VRI showed elevated neovascularization in four eyes. OCT-A delineated microaneurysm and FAZ in 97/97 eyes who underwent FA. The FA failed to delineate FAZ in 2/37 NPDR eyes and 13/60 PDR eyes. The CNP areas (OCT-A) were detectable in all eyes. The FA demonstrated CNP areas in 17/37 and 36/60 eyes in NPDR and PDR, respectively. The FA could show peripheral CNP. CONCLUSION: The OCT-A helps in the early diagnosis of DR by providing vascular indices which are consistent with disease progression. OCT-A is non-invasive and ideal for follow-up. FA is a dynamic test with a larger field of view.

Pediatric idiopathic macular hole - A case report and review of literature.

Macular hole in the pediatric age group is usually post-traumatic unlike, the adult counterpart. Herein we describe a case of idiopathic macular hole occurring in a 9-year-old male who presented to us with complaints of diminution of vision in OD (oculus dextrus) for 2 months. The child underwent 25-gauge pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling. On follow-up his best-corrected visual acuity improved with type 1 closure of macular hole.

Managing vitreoretinal surgeries during COVID-19 lockdown in India: Experiences and future implications.

PURPOSE: The study aims to describe the clinical and demographic profile of patients who required vitreoretinal surgeries during the novel coronavirus disease-2019 (COVID-19) lockdown in India. It also reports our operating protocols and initial experience while performing vitreoretinal surgeries during COVID-19 times at a government tertiary eye care hospital. METHODS: This is a retrospective cross-sectional observational study of patients requiring emergent/urgent vitreoretinal surgeries between March 25, 2020 and May 31, 2020. A modified working protocol focussing on the enforcement of standard COVID-19 precautions, OT sterilization, and formation of dedicated infection control and disease surveillance committee was adopted. Patients underwent standard vitreoretinal procedures under general/local anesthesia. Relevant demographic and clinical data were recorded and analyzed. Surveillance data of healthcare workers (HCW) was also analyzed. RESULTS: Eighty six patients were considered for vitreoretinal surgery in this period. Finally, 83 patients underwent surgery. The mean age of the patients was 38.4 ± 20.1 years (Range, 1 month - 75 years). Majority of them were males (66%) and adults (82.6%). Majority of them came from nearby hotspot areas. Most common indications were acute retinal detachment (38.5%) and diabetic vitrectomies (22.9%). Trauma-related cases (14.4%) were less. Surgery was deferred in 3 patients who turned out to be COVID-19 positive. 4 HCWs were quarantined but none of them developed COVID-19 disease. CONCLUSION: During COVID-19 lockdown, vitreoretinal surgeries were most commonly performed for retinal detachment and diabetic complications. Proper implementation of infection control protocols helps in delivering adequate patient care while ensuring the safety of caregivers during this pandemic.

Remodeling an Avascular Bleb.

Large avascular blebs need to be repaired especially if they are associated with leaks or have had episodes of bleb-related infections. We describe a new technique of using an amniotic membrane graft, that is inserted into the bleb through a small incision, helping to reduce the size of the avascularity, providing support to the bleb, and preventing extraneous infections.

Intra-lenticular lens aspiration in paediatric cases with anterior dislocation of lens.

PURPOSE: To assess the outcomes of intra-lenticular lens aspiration (ILLA) in paediatric cases with anterior dislocation of lens. METHODS: A retrospective review of medical records of cases with anterior dislocation of the lens in children (age < 16 years) that underwent ILLA between June 2017 and May 2018 was performed. Corrected distance visual acuity (CDVA), intraocular pressure (IOP), and anterior segment findings were noted at presentation and follow-up. Surgical notes were reviewed for all cases. Post-operative central corneal thickness (CCT) and central macular thickness (CMT) were recorded. RESULTS: Eleven eyes of eight patients with a median age of ten years underwent ILLA. There were four males and four females. The median duration of symptoms was 2 months, CDVA was 1.77 logMAR, and IOP was 16 mm of Hg. Ten eyes had corneo-lenticular touch with corneal oedema, and two had raised IOP at presentation. Homocystinuria (n = 2/8), Microspherophakia (n = 2/8), Marfan syndrome (n = 1/8), Buphthalmos (n = 1/8) and Ectopia lentis et pupillae (n = 1/8) were the identifiable causes for anterior dislocation. There were no intra-operative complications in any case. Immediate post-operative corneal oedema and raised IOP was observed in nine and three cases respectively and was treated with medical therapy. The median post-operative CDVA and IOP at 6-months was 1 logMAR and 15 mm of Hg respectively. The median CCT and CMT were 516 and 248 µm respectively. Five eyes developed a central corneal descemet scar. CONCLUSIONS: ILLA is a safe and effective technique for surgical removal of an anteriorly dislocated lens in paediatric cases.