Therapeutic Challenges and Prognosis of Descemet's Membrane Endothelial Keratoplasty in Herpes Simplex Eye Disease

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.

Clinical Manifestations and Long-term Outcomes of Endothelial Keratoplasty in Patients with Proven VZV-related Endothelial Decompensation

PURPOSE

To report the clinical manifestations, postoperative complications and long-term outcomes of endothelial keratoplasty in VZV-related endothelial decompensation.

METHODS

In this retrospective study, thirteen eyes undergoing endothelial keratoplasty (EK) for VZV-related endothelial decompensation were compared with controls for Fuchs endothelial dystrophy or pseudophakic bullous keratopathy.

RESULTS

Twelve patients did not have typical dermal pain or blisters. Ten patients had obvious iris abnormalities. Glaucoma was noted in eight patients before surgery. The best spectacle-corrected visual acuity improved from 1.12 ± 0.47 to 0.39 ± 0.43 (p = .002), whereas endothelial cell (EC) loss was 65% ±15% at 12 months that higher than that in the controls (p < .05). Postoperative complications included graft detachment (2/13), recurrence of endotheliitis (3/13), neurotrophic ulcer (1/13) and scleritis (1/13).

CONCLUSIONS

The onset of VZV-related endothelial decompensation is generally insidious. Iris segmental atrophy, glaucoma and pigment KPs are highly suspected to be associated with VZV. EK is a reasonable option to rehabilitate vision.

Predictive factors of graft detachment and rebubbling after descemet membrane endothelial keratoplasty

PURPOSE

To identify risk and predictive factors associated with the need of rebubbling in the eye of patients who underwent a descemet membrane endothelial keratoplasty (DMEK).

METHODS

The records of patients who underwent DMEK were retrospectively analyzed. Data regarding comorbidities, intraoperative characteristics, and postoperative treatments or complications were collected. The central corneal thickness (CCT) was measured by optical coherence tomography before and the day after DMEK. Univariate and multivariate analyses were performed.

RESULTS

Of the 333 DMEK, rebubbling was performed in 119 cases (36%). Preoperative subepithelial fibrosis and a history of penetrating keratoplasty (PK) were associated with significantly more graft detachment [OR of 3.55 (2.02-6.32; P < 0.001) and 5.89 (2.00-21.86; P = 0.003), respectively]. A decreased CCT the day after surgery reduced by 5.7-fold the risk of rebubbling (sensitivity/specificity of 0.42/0.93). Conversely, a 20% increase in the CCT the day after surgery increased by 4.5-fold the risk of rebubbling (sensitivity/specificity of 0.42/0.91).

CONCLUSION

Variation of the CCT could be used as a predictive factor of rebubbling after DMEK. Patients with a 20% increase of CCT the day after surgery are at higher risk of graft detachment. Conversely, a reduced CCT the day after the surgery is associated with a reduced risk of rebubbling. Subepithelial fibrosis and history of PK were also identified as risk factors for rebubbling. Those predictive factors may help develop a customized approach for patients undergoing DMEK surgery.

Management of an unresponsive case of HSV keratouveitis with trabeculectomy and DSAEK: A case report

Introduction and importance

This case demonstrates an unusual presentation of Herpes simplex virus (HSV) ocular infection and the challenges faced during the management of its complications.

Presentation of the case

A thirty year-old lady, a steroid responder with HSV keratouveitis, was referred for non-response to treatment with the prophylactic dose of oral acyclovir and acetazolamide. She presented with large epithelial bullae, anterior chamber reaction, and raised intraocular pressure in her right eye. Initially, she responded to the therapeutic dose of oral acyclovir, but on follow-up visits, she developed high intraocular pressures of up to 45 mmHg on maximum medical therapy. Hence, trabeculectomy with mitomycin-C was performed. One year later, she developed corneal endothelial decompensation, for which a Descemet's stripping automated endothelial keratoplasty (DSAEK) was done. Eight months post-operatively, she had a best corrected visual acuity of 20/20, clear corneal graft, quiet anterior chamber, and well-controlled intraocular pressures.

Discussion

HSV trabeculitis is associated with inflammation of the anterior chamber, endothelitis and raised intra-ocular pressure. A combination of anti-viral, anti-inflammatory, and anti-glaucoma medications helps in the management. However, glaucoma filtration surgery is often needed to the control intra-ocular pressure. Chronic recurrent episodes eventually lead to endothelial failure and demand endothelial keratoplasty (EK). It is prudent to adopt certain measures to perform EK in these phakic eyes without causing any iatrogenic damage to the filtration bleb as well as to the clear crystalline lens.

Conclusion

This case highlights the difficulties of treating HSV-related keratouveitis with uncontrolled glaucoma, problems of associated steroid response, and complexities in performing corneal endothelial procedures in young phakic patients especially post-trabeculectomy.

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HSV infecting the uveal tract is likely to infect the endothelium and trabecula.

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HSV trabeculitis is associated with endothelitis and high intraocular pressure, which is not controlled with maximum medical management.

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Glaucoma filtration surgery helps in controlling intraocular pressure.

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Chronic cases develop endothelial dysfunction and demand endothelial keratoplasty.

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Endothelial keratoplasty in a phakic eye needs a strategical approach intra-operatively.

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.

Outcomes after Descemet membrane endothelial keratoplasty over a period of 7 years at a tertiary referral center: endothelial cell density, central corneal thickness, and visual acuity

Purpose

To better assess clinical trajectories of patients with or without ocular comorbidity after Descemet membrane endothelial keratoplasty. Background: To report on the outcomes of eyes with differing starting conditions following surgery. Design: Retrospective study at a University Eye Hospital. Participants: 361 eyes separated into group 1 (n=229; eyes with endothelial disease only) and group 2 (n=132; eyes with additional ocular comorbid conditions, such as herpetic eye disease 18/132 (13.6%), glaucoma 16/132 (12.1%), dry age-related macular degeneration 14/132 (10.6%), epiretinal membranes 10/132 (7.6%), and wet age-related macular degeneration 9/132 (6.8%)).

Methods

Consecutive eyes that underwent Descemet membrane endothelial keratoplasty over a follow-up period of up to 7 years at a tertiary referral center were reviewed. Main outcome measures were best-corrected visual acuity, postoperative complications, graft survival, central corneal thickness, and endothelial cell density.

Results

Postoperative best-corrected visual acuity at year 1 improved in both groups significantly (Wilcoxon signed rank test: group 1, p =.002; .63 to .23 logMAR; group 2, p <.001; 1.15 to .87 logMAR) with a group difference in favor of group 1 (p =.009, Mann-Whitney-Wilcoxon). A decrease of the endothelial cell density and central corneal thickness was noted at postoperative year 1 for both groups (paired t-tests (group 1, p <.001; group 2, p =.045) and paired t-tests (group 1, p <.001; group 2, p =.003). Complications were less common, and graft longevity was superior in group 1.

Conclusion

Eyes with different starting conditions might experience a visual improvement and benefit from surgery. Descemet membrane endothelial keratoplasty is a valid treatment for endothelial disorders in manifold of eyes. Further long-term studies are required.

Corneal graft failure: an update

Corneal graft surgery is one of the most successful forms of human solid-tissue transplantation, and nowadays, there is a worldwide expansion of the surgical volume of corneal grafts. This surgery is continuously evolving, with new surgical techniques and postoperative treatments that have considerably increased the chance of survival for the grafts. Despite the high rate of success, corneal transplantation is still complicated by a relevant risk of graft failure. This study investigates the causes that lead to the failure of the different corneal graft surgical techniques and provides an updated synthesis on this topic. A comprehensive review of the main pathological pathways that determine the failure of corneal grafts is provided, analysing the main risk factors and disclosing the survival rates of the principal form of corneal grafts. Our results revealed that penetrating keratoplasty has higher failure rates than lamellar keratoplasty, with immunological rejection being the leading cause of graft failure, followed by late endothelial failure (LEF) and ocular surface disorders. Postoperative glaucoma and dehiscence of the surgical wound represent other important causes of failure. Endothelial keratoplasty showed the lowest rates of failure in the mid-term, with LEF, detachment of the graft and primary graft failure representing the most common pathological reasons for failure.

Protective effect of total flavonoids from Ixeris Sonchifolia on herpes simplex virus keratitis in mice

Background

To investigate the protective effect of Ixeris Sonchifolia (Bae.) Hance (ISH) extract on herpes simplex virus keratitis (HSK) in mice.

Methods

A mouse model of HSK was established by inoculating 60 mice (60 right eyes) with herpes simplex virus type 1 (HSV-1) by corneal scratch. The other 15 mice as blank control only received corneal scratch but without HSV-1. From the 2nd day after the successful modeling, the experimental group was fed with ISH total flavonoids (50, 100 and 200 mg/kg) orally, twice a day for 14 days. The model group and control group were given the same amount of normal saline. The pathological changes of cornea were observed once a day by slit lamp microscopy combined with fluorescein staining. The corneal histopathological examination, the survival status and the serum levels of interleukin-2 (IL-2), IL-4 and interferon-gama (INF-γ) were performed at the end of the experiment.

Results

The result showed that ISH could significantly improve the corneal lesion degree, increase mice survival rate, and markedly increase the levels of IL-2 and INF-γ, reduce the levels of IL-4 in serum of mice.

Conclusions

ISH could increase the anti-virus ability, promote the healing of corneal inflammation and alleviate the pathological damage of cornea, which suggested that ISH has a potential and valuable therapeutic effect on the HSK.