Quality and applicability of cadaveric donor eyes for molecular biology research: An Indian experience

PURPOSE

Human ocular tissue banking plays an important part in the advancement of translational research for identifying the molecular processes involved in disease etiology and pathogenesis. Timely obtaining a good-quality ocular tissue from a cadaveric donor is exceedingly difficult, especially in remote areas, with a variable transportation time (within 12-24 h), raising concerns about RNA quality and its subsequent applications. Therefore, we assessed the utility of retinal tissues from cadaver donor and enucleated eyes based on the RNA quality and gene expression by real-time polymerase chain reaction (PCR).

SETTINGS AND DESIGN

Prospective study.

METHODS

Retina tissues were separated from the donor/enucleated eyes received in the eye bank within 24 h of death (n = 15) and within an hour from OR (n = 3), respectively, and stored immediately at -80 degree. RNA was isolated using trizol, and the quantity and quality were assessed using Qubit and agarose gel electrophoresis, respectively. QPCR was performed for measuring the expression of different retinal-specific genes. The cellular viability of the retina was assessed by establishing explant primary cell cultures.

STATISTICAL ANALYSIS

The data were calculated as an average of normalised Ct values ± standard error of the mean.

RESULTS

RNA obtained from cadaveric tissues despite being partially degraded showed a uniform strong gene expression of several retinal-specific genes such as PAX6, RHO, TUBB3, CRX, and ALDH1L1. The primary cultures established from cadaveric tissues showed viable cells.

CONCLUSION

The cadaver donor tissues collected within 24 hours of death can be effectively utilized for gene expression profiling.

Neurotization of the human cornea - A comprehensive review and an interim report

We present a comprehensive review of existing literature on surgical corneal neurotization (SCN) as a treatment modality for neurotrophic keratopathy (NK) with an interim report of seven cases where SCN was performed using the indirect approach and followed up till 18 months postoperatively to look for improvement in ocular surface, corneal sensations, and nerve regeneration by using in vivo confocal microscopy (IVCM). A literature search was performed for publications with keywords “corneal nerves,” “neurotization,” “esthesiometry,” “corneal anesthesia,” and “neurotrophic keratopathy.” All literature available till December 31, 2020 was reviewed and included to describe NK and its management options, particularly SCN. NK is associated with absent or reduced corneal sensations and is managed using a step-ladder algorithm ranging from medical management for symptomatic relief to surgical corneal neurotization. Both direct and indirect approaches of SCN have a favorable outcome with reduced surgical morbidity in the indirect approach using sural nerve graft. Post neurotization, corneal sensation recovery may take up to 3–6 months, while nerve regeneration on confocal microscopy can take as long as 6 months–1 year.

Choroidal Thickness in Thyroid Eye Disease: Comparison With Controls and Application in Diagnosing Non-Inflammatory Active Disease

Introduction

Choroidal thickness is known to vary in various systemic diseases. In the current study, we aim to report the differences in choroidal thickness in thyroid eye disease (TED) and normals and its discriminatory value for differentiating various stages of TED.

Methods

Prospective, cross-sectional, non-interventional imaging study. In an institutional practice, 102 eyes of 51 patients were included and divided into five groups: normal controls (C), inactive TED (I), active TED (A), non-inflammatory active TED (NIA) and systemic thyroid disorder but no TED (SYS). Choroidal images were acquired using the swept-source optical coherence tomography (Topcon DRI OCT Triton) with automatic layer segmentation which provided an automatic measurement of the subfoveal choroidal thickness and the mean in nine subfields based on the Early Treatment Diabetic Retinopathy Study (ETDRS) grid. One-way analysis of variance (ANOVA), Youden index and area under the receiver operating characteristic curves (AUROC) were reported.

Results

Central choroidal thickness in the A group was 279±37.52 microns and in the NIA group was 302.5±59.22 microns. Both were comparable to each other and significantly higher than the C, I and SYS groups (p<0.001). All ETDRS sub-fields showed significant AUROC to distinguish NIA from I. Most significant Youden index was for the inner nasal and central ETDRS subfields (0.55 and 0.61 respectively). Inner nasal sub-field showed 100% specificity while the central sub-field, showed 86.5% for predicting NIA. At a choroidal thickness of >266 microns, the central sub-field had the strongest discriminatory potential to predict NIA. 

Conclusion

Choroidal thickness is greater in active and non-inflammatory active TED. The inner nasal and central ETDRS sub-fields have value in differentiating the non-inflammatory active TED eyes from the inactive eyes.

Rhino-orbital mucormycosis following COVID-19 in previously non-diabetic, immunocompetent patients

PURPOSE

To report a series of 13 immunocompetent patients who developed new-onset uncontrolled diabetes mellitus (DM) following COVID-19 infection and presented as rhino-orbital mucormycosis (ROM).

METHOD

Retrospective study.

RESULTS

A total of 127 patients of COVID-19 Associated Mucormycosis (CAM) were evaluated at four centres in India. All patients underwent endoscopic sinus debridement surgery and received systemic amphotericin-B therapy. Five patients (5/13; 38.4%) received retrobulbar amphotericin-B injections. Orbital exenteration was performed in advanced orbital involvement or progression of orbital disease in spite of maximal medical therapy. In his cohort, 13/127 (10.2%) patients presented with new onset DM, where one patient had bilateral disease. The mean age was 35.9 years (range: 20-51 years) and the mean duration from diagnosis of COVID-19 to the diagnosis of mucormycosis was 14.2 days. While 7/13 (53.8%) of the patients received systemic corticosteroids during the course of their treatment for COVID-19, six patients received no steroids or immunomodulators. The mean follow-up period was 9.2 weeks (range: 3-18 weeks) following discharge. Life salvage was possible in 100% of the cases. While overall globe salvage was possible in 42.8% (6/14 eyes), the globe could be preserved in 4/5 patients who received retrobulbar amphotericin-B injections.

CONCLUSIONS

Those involved in the care of COVID-19 patients should be aware about the possibility of recent-onset DM, even in patients without a history of corticosteroid therapy. Rarely, recent-onset DM following COVID-19 may present as rhino-orbital mucormycosis, which requires aggressive surgical and medical intervention.

Isolated peripunctal sebaceous gland carcinoma in a young adult: An unusual presentation

Sebaceous gland carcinoma (SGC) of the eyelid is one of the leading peri-ocular eyelid malignancies in Asian-Indians. It usually affects elderly women and has a high rate of local recurrence, regional and distant metastasis. This is partly attributable to a delay in clinical diagnosis since it mimics more benign conditions of the eyelid like chalazia. To the best of our knowledge, this is the first case report of a peri-punctal SGC. Atypical location and the young age of the patient resulted in a relatively conservative excisional biopsy under frozen section control and eyelid reconstruction with a favorable outcome.

Customized 3D printing: A novel approach to migrated orbital implant

This paper describes a novel approach to treat migrated orbital implants post socket surgery. Implant migration may hinder the final aesthetic outcome of a custom ocular prosthesis. Once an implant migrates within the orbit there tends to be fibrosis around the implant. This fibrosis does not allow for centeration of the implant during repeat surgery. Hence treatment of a migrated implant traditionally involves implant removal with dermis fat grafting. Dermis fat graft though an option, needs a second site surgery that may be unacceptable to many patients. Also the rate of graft necrosis is as high as 40%. This paper describes a technique to create a custom orbital implant that allows recenteration of the migrated implant centrally, using 3-dimension (3D) printing and rapid prototyping to construct the patients affected orbit. This orbit is used as a mould to create the custom orbital implant that aids in volume augmentation as well as recenteration of the migrated orbital implant.