Cytomegalovirus infection is not a major cause of corneal graft failure in the United Kingdom

Herpes simplex keratitis: A brief clinical overview

The aim of our minireview is to provide a brief overview of the diagnosis, clinical aspects, treatment options, management, and current literature available regarding herpes simplex keratitis (HSK). This type of corneal viral infection is caused by the herpes simplex virus (HSV), which can affect several tissues, including the cornea. One significant aspect of HSK is its potential to cause recurrent episodes of inflammation and damage to the cornea. After the initial infection, the HSV can establish a latent infection in the trigeminal ganglion, a nerve cluster near the eye. The virus may remain dormant for extended periods. Periodic reactivation of the virus can occur, leading to recurrent episodes of HSK. Factors triggering reactivation include stress, illness, immunosuppression, or trauma. Recurrent episodes can manifest in different clinical patterns, ranging from mild epithelial involvement to more severe stromal or endothelial disease. The severity and frequency of recurrences vary among individuals. Severe cases of HSK, especially those involving the stroma and leading to scarring, can result in vision impairment or even blindness in extreme cases. The cornea's clarity is crucial for good vision, and scarring can compromise this, potentially leading to visual impairment. The management of HSK involves not only treating acute episodes but also implementing long-term strategies to prevent recurrences and attempt repairs of corneal nerve endings via neurotization. Antiviral medications, such as oral Acyclovir or topical Ganciclovir, may be prescribed for prophylaxis. The immune response to the virus can contribute to corneal damage. Inflammation, caused by the body's attempt to control the infection, may inadvertently harm the corneal tissues. Clinicians should be informed about triggers and advised on measures to minimize the risk of reactivation. In summary, the recurrent nature of HSK underscores the importance of both acute and long-term management strategies to preserve corneal health and maintain optimal visual function.

Cytokine analysis of aqueous humor in patients with cytomegalovirus corneal endotheliitis

PURPOSE

To evaluate cytokine levels of aqueous humor in patients with cytomegalovirus (CMV) corneal endotheliitis and their relationships with CMV DNA load.

METHODS

44 aqueous humor samples were obtained from 26 patients with CMV corneal endotheliitis at various stages of treatment. 33 samples obtained from cataract patients during the same period were selected as a control group. Each sample was used to measure the concentration of the CMV DNA load using real-time quantitative polymerase chain reaction, and to examine the levels of IL-6, IL-8, IL-10, MCP-1, VCAM-1, VEGF, IP-10, G-CSF, ICAM-1 and IFN-γ using a cytometric bead array.

RESULTS

All 10 cytokines were found to have statistically significant differences between the CMV endotheliitis and cataract groups. The Spearman correlation test showed that the concentration of CMV DNA load was significantly associated with the levels of IL-6 (P = 0.005, r = 0.417), IL-8 (P < 0.001, r = 0.514), IL-10 (P < 0.001, r = 0.700), MCP-1 (P = 0.001, r = 0.487), VEGF (P < 0.001, r = 0.690), IP-10 (P = 0.001, r = 0.469), G-CSF (P < 0.001, r = 0.554) and ICAM-1 (P < 0.001, r = 0.635), but not significantly associated with VCAM-1 (P = 0.056) and IFN-γ (P = 0.219).

CONCLUSIONS

There was a combined innate and adaptive immune response in aqueous humor in patients with CMV endotheliitis. Levels of multiple cytokines were significantly correlated with viral particle. Cytokines are potential indicators to help diagnose CMV endotheliitis, evaluate disease activity and assess treatment response.

Cytomegalovirus Corneal Endotheliitis: A Comprehensive Review

Cytomegalovirus (CMV) anterior uveitis and corneal endotheliitis are the most common ocular diseases caused by CMV infections in immunocompetent patients. The incidence of CMV corneal endotheliitis is relatively high in middle-aged men. CMV corneal endotheliitis presents with mild anterior chamber inflammation, corneal edema, keratic precipitates, and elevated intraocular pressure. It resembles Posner-Schlossman syndrome and Fuchs uveitis because of the elevated intraocular pressure. Without proper diagnosis and treatment, it may progress to bullous keratopathy or glaucoma, necessitating keratoplasty or glaucoma surgery. Therefore, early diagnosis and treatment are important for a good prognosis. Aqueous humor analysis can facilitate the diagnosis of CMV corneal endotheliitis, and early antiviral treatment can decrease the risk of corneal compensation or glaucomatous optic atrophy. In this article, we review the epidemiology, pathogenesis, clinical manifestations, diagnosis, treatment, and prognosis of CMV corneal endotheliitis along with the evidence for early clinical diagnosis and active antiviral treatment.

Secondary Endothelial Keratoplasty-A Narrative Review of the Outcomes of Secondary Corneal Endothelial Allografts

BACKGROUND

We review the literature on the efficacy and safety outcomes of secondary Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Literature search of English-written publications up to September 27, 2020 in PubMed database, using the terms "endothelial keratoplasty" in combination with keywords "secondary" or "repeat." In addition, we manually searched the references of the primary articles.

RESULTS

Twenty-seven studies (n = 651 eyes) were retained and reviewed, including 10 studies on repeat DSEK, 8 studies on repeat DMEK, 6 studies of DMEK following DSEK, and 3 studies of DSEK after failed DMEK. All studies reported significant improvement in visual acuity after secondary endothelial keratoplasty (EK). Twelve studies compared visual outcomes between primary and secondary EK, reporting conflicting findings. Sixteen studies reported endothelial cell loss rates after secondary EK, and only 1 study reported significantly increased endothelial cell loss rates compared with primary EK. Allograft rejection episodes occurred in 1.8% of eyes (range, 0%-50%). Six studies compared complication rates between primary and secondary EK eyes, and only 1 study found a higher median number of complications. However, 2 studies reported higher regraft failure rates compared with primary EK eyes.

CONCLUSIONS

Secondary EK is surgically feasible and renders significant visual improvement after failed primary EK, although it is not clear whether visual outcomes and allograft survival are comparable with primary EK, raising the question of whether secondary EK eyes are "low risk" as primary EK eyes. Further larger, prospective studies are encouraged to obtain additional quality data on secondary corneal endothelial allotransplantation.

Post-keratoplasty Infectious Keratitis: Epidemiology, Risk Factors, Management, and Outcomes

Post-keratoplasty infectious keratitis (PKIK) represents a unique clinical entity that often poses significant diagnostic and therapeutic challenges. It carries a high risk of serious complications such as graft rejection and failure, and less commonly endophthalmitis. Topical corticosteroids are often required to reduce the risk of graft rejection but their use in PKIK may act as a double-edged sword, particularly in fungal infection. The increased uptake in lamellar keratoplasty in the recent years has also led to complications such as graft-host interface infectious keratitis (IIK), which is particularly difficult to manage. The reported incidence of PKIK differs considerably across different countries, with a higher incidence observed in developing countries (9.2-11.9%) than developed countries (0.02-7.9%). Common risk factors for PKIK include the use of topical corticosteroids, suture-related problems, ocular surface diseases and previous corneal infection. PKIK after penetrating keratoplasty or (deep) anterior lamellar keratoplasty is most commonly caused by ocular surface commensals, particularly Gramme-positive bacteria, whereas PKIK after endothelial keratoplasty is usually caused by Candida spp. Empirical broad-spectrum antimicrobial treatment is the mainstay of treatment for both PKIK, though surgical interventions are required in medically refractory cases (during the acute phase) and those affected by visually significant scarring (during the late phase). In this paper, we aim to provide a comprehensive overview on PKIK, encompassing the epidemiology, risk factors, causes, management and outcomes, and to propose a treatment algorithm for systematically managing this challenging condition.

The incidence and influence of the donor corneas positive for herpesviridae DNA in keratoplasty

Purpose

We detected the DNA of herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), varicella-zoster virus (VZV), cytomegalovirus (CMV), and Epstein-Barr virus (EBV) in donor corneas and assessed the clinical outcomes of recipients who received virus-positive grafts.

Method

All donor corneas were analyzed for the presence of HSV-1, HSV-2, VZV, CMV, and EBV by real-time PCR from April 2017 to July 2019. The medical records of the transplant patients who received virus-positive grafts were reviewed.

Result

Twenty-three (2.44%) donor cornea buttons tested positive for herpesviridae DNA. The positivity rates of HSV-1, CMV, VZV, and EBV were 0.74%, 0.85%, 0.64%, and 0.21%, respectively.

Conclusion

We suggest that the corneas from donors who had cancer, donors who were inpatients, and donors who had immunodeficiency or who were on immunosuppressive therapy should be tested for herpesviridae DNA before transplantation. Finally, HSV-1 can be transmitted from graft to recipient, but that CMV cannot be transmitted according to our observations. The donor corneas found to be HSV-1-positive have to be discarded and not used for keratoplasty.