Viral Keratitis, Surgical Intervention in Viral Keratitis, Challenges in Diagnosis and Treatment of Viral Keratitis, HSV, HZV.

Viral keratitis is a significant cause of ocular morbidity and visual impairment worldwide. In recent years, there has been a growing understanding of the pathogenesis, clinical manifestations, and diagnostic modalities for viral keratitis. The most common viral pathogens associated with this condition are adenovirus, herpes simplex (HSV), and varicella-zoster virus (VZV). However, emerging viruses such as cytomegalovirus (CMV), Epstein-Barr virus (EBV), and Vaccinia virus can also cause keratitis. Non-surgical interventions are the mainstay of treatment for viral keratitis. Antiviral agents such as Acyclovir, Ganciclovir, and trifluridine have effectively reduced viral replication and improved clinical outcomes. Additionally, adjunctive measures such as lubrication, corticosteroids, and immunomodulatory agents have alleviated symptoms by reducing inflammation and facilitating tissue repair. Despite these conservative approaches, some cases of viral keratitis may progress to severe forms, leading to corneal scarring, thinning, or perforation. In such instances, surgical intervention becomes necessary to restore corneal integrity and visual function. This review article aims to provide an overview of the current perspectives and surgical interventions in managing viral keratitis. The choice of surgical technique depends on the extent and severity of corneal involvement. As highlighted in this article, on-going research and advancements in surgical interventions hold promise for further improving outcomes in patients with viral keratitis.

Decision-making in Herpes Simplex viral keratitis grafts.

Background: Keratoplasty after healed herpes simplex viral keratitis is a challenge due to problems arising preoperatively, intraoperatively, and postoperatively. Purpose: In this video, we describe the necessary challenges and the steps, which can be taken to prevent and manage those cases of healed herpes simplex virus (HSV) keratitis that would require a keratoplasty. Synopsis: The video talks about both the typical and atypical features of HSV keratitis, clinical examination, the scenarios which would require a keratoplasty, problems arising intraoperatively and how to manage them, and finally how to approach these high-risk grafts postoperatively. Highlights: Our video highlights the diagnosis of HSV keratitis, which cases are ready for surgery, and preoperative, intraoperative, and postoperative considerations before corneal transplantation in healed HSV keratitis. Decision-making before corneal transplant in HSV grafts can become more structured if these points are followed. Video Link: https://youtu.be/xMT7Ki8vuc4.

Evidence in the prevention of the recurrence of herpes simplex and herpes zoster keratitis after eye surgery.

OBJECTIVE: Herpetic keratitis, either due to herpes simplex keratitis (HSK) or herpes zoster ophthalmicus (HZO), can recur after eye surgery.º Prophylaxis is postulated as necessary to avoid it. The objective of this study was to review the scientific evidence on the preventive methods used in the perioperative period in patients previously affected by HSK/HZO. METHODS: An exhaustive search was carried out in the PubMed and Web of Science databases to identify relevant articles on prophylaxis and risk of recurrence of HSK/HZO in patients undergoing eye surgery up to 31 December 2019. RESULTS: There is strong evidence that oral prophylaxis should be recommended after penetrating keratoplasty in patients who have previously had HSK/HZO. For other types of surgery, the evidence is less compelling. However, a latent period of inactivity should be considered between disease and oral prophylaxis. CONCLUSIONS: Penetrating and lamellar keratoplasty, corneal crosslinking, cataract surgery, and photorefractive and phototherapeutic surgery cause an alteration of the subbasal nerve plexus of the cornea. Due to surgical trauma, as well as the modulation of the ocular immune response caused by steroids applied in the postoperative period, it is possible to induce the reactivation of HSK/HZO, which is common in some cases. Within this article, we discuss the available evidence for HSK/HZO prophylaxis in eye surgery. Further studies are necessary to define the real risk of HSK/HZO recurrence after ocular surgeries, particularly in cataract surgery, and to confirm the efficacy of perioperative prophylaxis with anti-HSK/HZO antivirals.

Outcome of Lamellar Graft Patching for the Treatment of Noninfectious Corneal Perforations.

PURPOSE: The aims of this study were to evaluate the clinical outcome of lamellar graft patching used for treating noninfectious corneal perforations and to determine the clinical factors affecting tectonic integrity. METHODS: This retrospective study includes a total of 71 eyes of 67 patients who underwent lamellar graft patching for the treatment of corneal perforations due to persistent epithelial defects secondary to limbal stem cell deficiency (LSCD, 21 eyes; 29.6%), peripheral ulcerative keratitis (17 eyes; 23.9%), neurotrophic keratitis due to herpes simplex keratitis (HSK, 14 eyes; 19.7%), and other causes (19 eyes; 26.8%). We evaluated the tectonic integrity of the globe, visual outcomes, and postoperative complications. RESULTS: Tectonic integrity was achieved in 53 eyes (74.6%). The survival proportions of eyes that achieved clear grafts were 77.8% and 65.2% at 12 and 24 months, respectively. Graft failure was observed in 19 eyes (26.8%). The survival rate of tectonic integrity and eyes that finally achieved a clear graft was significantly worse in eyes with LSCD compared with those without ( P < 0.001). The logarithm of minimal angle resolution improved significantly from 1.79 ± 0.98 to 1.22 ± 0.87 at 12 months and 1.08 ± 0.81 at 24 months. Postoperative complications included cataract formation (32 eyes, 45.1%), intraocular pressure rise (23 eyes, 32.4%), recurrent perforations (15 eyes, 21.1%), infectious keratitis (14 eyes, 19.7%), recurrence of herpes simplex keratitis (7 eyes, 9.9%), and traumatic graft dehiscence (1 eye, 1.4%). CONCLUSIONS: Lamellar graft patching is an effective and safe surgical treatment for noninfectious corneal perforations; however, careful attention to severe complications is necessary, especially in eyes with LSCD.

Herpes Simplex Virus Keratitis in a University Tertiary Referral Centre - Clinical Features and Surgical Approaches.

PURPOSE: To assess prevalence, clinical manifestations, required keratoplasties, follow-up, and outcome in patients with Herpes Simplex Virus Keratitis (HSK) attending a University Tertiary Referral Center. DESIGN: Retrospective (12 years), descriptive, observational study. METHODS: A total of 817 eyes with clinical diagnosis of HSK from 779 patients were classified by the type of presentation. We gathered data on the visual acuity, refraction, IOP, and required surgical procedures. RESULTS: Stromal involvement including scars represented the most common diagnosis in our department and the main indication of penetrating keratoplasty (PKP). Epithelial keratitis (16%) presented with the best visual acuity at the first visit. Necrotizing keratitis represented 17% of the patients, 78% of whom required PKP; this group also had the worst visual acuity at first examination and was the main indication for emergency PKP. Among all eyes, 288 (35%) required PKP. A total of 230 (28%) PKPs were elective procedures and 58 (7%) PKPs were performed as emergency procedures. Two patients with quiet endothelial decompensations after recurrent HSV endotheliitis were treated with DMEK and had good visual outcomes without HSV recurrence at last follow-up. CONCLUSIONS: HSK is a prevalent disease with severe consequences when not treated appropriately and on time. Even when making an accurate diagnosis, the disease can be extremely aggressive, with all the implications it brings to the patients and health system. Elective PKP had better outcomes in terms of visual acuity and clear graft percentage compared to emergency PKP.

Extracellular matrix changes in corneal opacification vary depending on etiology.

Purpose: The purpose of this study is to examine the expression of tenascin-C and matrilin-2 in three different disorders, which frequently require corneal transplantation. These pathological conditions include bullous keratopathy (BK), Fuchs' endothelial corneal dystrophy (FECD), and corneal scarring in herpetic keratitis. Methods: Histological sections of corneal buttons removed during keratoplasty were analyzed in BK (n = 20), FECD (n = 9), herpetic keratitis (n = 12), and cadaveric control (n = 10) groups with light microscopy following chromogenic immunohistochemistry. The sections were evaluated by three investigators, and semiquantitative scoring (0 to 3+) was applied according to standardized methods at 400X magnification. Each layer of the cornea was investigated; moreover, the stroma was subdivided into subepithelial, middle, and pre-Descemet's membrane areas for more detailed analysis. Results: Excessive epithelial and stromal expression of tenascin-C was identified in all investigated conditions; the results were most pronounced in the pre-Descemet's membrane. Regarding matrilin-2, when examined in BK, there was increased labeling intensity in the epithelium (p<0.001) and stromal layers (p<0.05), and a decrease in the endothelium (p<0.001). In the other investigated conditions, only a low degree of stromal localization (p<0.05) of matrilin-2 was detected. Conclusions: The expression of tenascin-C and matrilin-2 differs when examined in various corneal pathologies resulting in opacification. Both molecules seem to be involved in regeneration and wound healing of the corneal matrix in these diseases.

Corneal Graft Success Rates in HSV Keratitis: A Systematic Review.

Herpes Simplex Virus (HSV) has worldwide prevalence. The primary objective of this systematic review was to compare penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) regarding the efficacy and complications of the treatment of corneal scarring caused by herpes simplex keratitis. Out of the 469 articles identified during the combined search of the literature based on the PubMed and Cochrane libraries, 10 retrospective and 2 prospective studies published from January 2010 to December 2019 were included. The study outcomes indicated that both surgical approaches resulted in a comparable improvement of visual acuity (VA). However, DALK demonstrated fewer complications in the majority of studies. Higher graft survival rates were associated with higher acyclovir (ACV) doses (above 800 mg/day), topical steroid and antibiotic drops. In conclusion, in terms of postoperative VA, both PK and DALK demonstrate comparable efficacy. However, DALK, which is applied in less severe HSK cases, is associated with fewer complications and better graft survival rates. High dosages of ACV, topical steroids and antibiotics contribute significantly to improved postoperative outcomes.

Ocular surgery after herpes simplex and herpes zoster keratitis.

PURPOSE: The recurrence of herpetic stromal keratitis (HSK) and herpes zoster ophthalmicus (HZO) has been reported after a variety of ocular surgeries. The aim of this study was to review the evidence on the preventive methods employed in the perioperative period in patients having undergone HSK/HZO. METHODS: The PubMed and Web of Science databases were the main resources used to conduct the medical literature search. An extensive search was performed to identify relevant articles concerning the prophylaxis against and risk of HSK/HZO recurrence in patients undergoing ocular surgery up to December 31, 2019. RESULTS: The disturbance of the corneal nerve plexus occurs during several ocular surgeries including penetrating keratoplasty, lamellar keratoplasty, corneal cross-linking, cataract surgery, as well as photorefractive and phototherapeutic procedures. Such trauma, as well as modulation of the ocular immunological response caused by steroids applied postoperatively, might engender the HSK/HZO reactivation which is not uncommon. There is strong evidence that oral prophylaxis should be recommended just after surgery in patients undergoing penetrating keratoplasty and having suffered from HSK/HZO. For other types of surgeries, the evidence is less compelling; nevertheless, a period of disease quiescence and oral prophylaxis should still be considered. CONCLUSIONS: Within the article, we discuss the available evidence for HSK/HZO prophylaxis in ocular surgery. Additional studies would be required to define the real risk of HSK/HZO recurrence following eye surgeries, and particularly cataract surgery, and to confirm the utility of perioperative HSK/HZO prophylaxis.

Initial High-Dose Prophylaxis and Extended Taper for Mushroom Keratoplasty in Vascularized Herpetic Scars.

PURPOSE: To report the outcomes of initial high-dose and extended taper of antiviral and steroid prophylaxis for the treatment of eyes with high-risk vascularized herpetic corneal scars that underwent 2-piece mushroom keratoplasty (MK). DESIGN: Prospective interventional case series. METHODS: In this single-center study, 52 consecutive eyes with vascularized (≥2 quadrants) herpetic corneal scars underwent 2-piece microkeratome-assisted MK. Initial high-dose and extended taper of combined oral and topical antiviral and steroid prophylaxis was administered. Outcome measures were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism (RA), endothelial cell density, immunologic rejection, herpetic recurrence, and graft failure rates. RESULTS: Excluding patients with vision-impairing comorbidities, baseline BSCVA (1.73 ± 0.67 logMAR) significantly improved annually during the first 2 years (P < .001, P = .016), reaching 0.17 ± 0.18 logMAR at year 2, and remaining stable up to 10 years (P = .662). At 2 years, 86% of eyes saw ≥20/40, 55% saw ≥20/25, and 18% saw ≥20/20 Snellen BSCVA. RA exceeded 4.5 diopters in 7% of cases after wound revision for high-degree astigmatism in 7 cases. Endothelial cell loss was 40.9% at 1 year with an annual decline of 3.1% over 10 years. The 10-year cumulative risk for immunologic rejection, herpetic recurrence, and graft failure was 9.7%, 7.8%, and 7.6%, respectively. CONCLUSIONS: Initial high dose and extended taper of antiviral and steroid prophylaxis for MK in high-risk, vascularized herpetic corneal scars achieves clinical outcomes that remain stable for up to 10 years after surgery with minimal risk of immunologic rejection, herpetic recurrence and graft failure.

Conjunctival Epithelial Ingrowth After Penetrating Keratoplasty.

PURPOSE: To report a case of conjunctival epithelial ingrowth after penetrating keratoplasty. METHODS: A 57-year-old woman with herpetic corneal keratitis, endotheliitis, and bullous keratopathy underwent penetrating keratoplasty (PKP) and secondary cataract surgery. One month after cataract surgery, an epithelial ingrowth was observed at the 5 o'clock donor host junction. Ingrowth extended into the anterior chamber and along the iris surface by 9 months. Another PKP was performed, and the excised graft was submitted for histopathology. RESULTS: The graft showed CK13-positive and CK3-negative cells lining the endothelial surface, indicating the conjunctival origin of ingrown epithelium. Ten months postoperatively, no recurrence of ingrowth was observed. CONCLUSIONS: We experienced a rare case of conjunctival epithelial ingrowth after penetrating keratoplasty. There was no recurrence of the ingrowth after surgical removal, and the conjunctival origin may explain the relatively benign course of the complication.

Descemet Membrane Endothelial Keratoplasty in Irreversible Corneal Edema Due to Herpes Simplex Virus Endotheliitis.

PURPOSE: To report the clinical outcome and postoperative course of Descemet membrane endothelial keratoplasty (DMEK) in irreversible corneal edema due to herpes simplex virus (HSV) endotheliitis. METHODS: This is a retrospective, noncomparative, interventional case series. Nineteen eyes of 19 patients underwent standard DMEK combined with cataract surgery (triple DMEK) between May 2016 and April 2018. All patients received perioperative oral acyclovir (ACV) and prednisolone. Patients were followed up on day 1, on day 7, at 1 month, and then at 3 monthly intervals. Preoperative and postoperative best spectacle-corrected visual acuity (BSCVA), graft clarity, pachymetry, and endothelial cell loss after 1 year were recorded. Postoperative complications and HSV recurrence were noted until the last follow-up visit. RESULTS: All eyes were phakic with variable grades of cataract with a preoperative BSCVA of 1.0 logarithm of the minimum angle of resolution or worse. The mean follow-up period was 19.3 ± 5.4 months. After 1 year, 14 (73.7%) eyes achieved a BSCVA of 0.3 or better. Seventeen (89.5%) patients had a clear graft at the last visit without any rejection episode. One graft failed after 16 months. After 3 months, the mean pachymetry reduced from 667.1 ± 62.1 to 512.8 ± 27.1 µm (P < 0.001). The mean endothelial cell loss after 1 year was 36.7 ± 13.4%. Three (15.8%) eyes had recurrence: one with recurrent endotheliitis and 2 with dendritic keratitis despite oral ACV, which responded to oral valacyclovir and ACV eye ointment. One patient had re-recurrence of endotheliitis after 20 months. CONCLUSIONS: DMEK in persistent corneal edema after HSV endotheliitis remains challenging but has encouraging outcomes. The postoperative course may be complicated by HSV recurrence. Prophylactic oral antivirals for 1 year or more and topical antivirals are useful for the prevention of recurrence.

Successful Descemet Membrane Endothelial Keratoplasty in Proven Herpetic Endothelial Decompensation Requires Intensive Antiviral Therapy.

PURPOSE: To report the outcomes of Descemet membrane endothelial keratoplasty (DMEK) with intensive antiviral therapy for corneal edema secondary to herpes simplex virus type 1 (HSV-1)-mediated endotheliitis. METHODS: All eyes with polymerase chain reaction positive for HSV-1 undergoing DMEK for endothelial decompensation between January 2014 and January 2018 were followed up prospectively at our tertiary referral center. All eyes had been free of active inflammation for a minimum of 9 months and were treated prophylactically with high-dose systemic and topical antivirals, which were continued for a prolonged period of time. Primary outcomes were the occurrence of immunological rejection and/or recurrence of endotheliitis, eventually resulting in graft failure. Secondary outcomes were best spectacle-corrected visual acuity and endothelial cell loss. RESULTS: Four consecutive eyes of 4 patients were included with a mean (±SD) patient age of 68.5 ± 15.1 years. The postoperative follow-up averaged 22 months. No eyes exhibited any signs of immunologic rejection, recurrence of endotheliitis, or graft failure. Mean (±SD) decimal best spectacle-corrected visual acuity improved from 0.2 ± 0.1 to 0.7 ± 0.2 (P = 0.007), whereas mean (±SD) endothelial cell loss was 56% ± 10.2% at the final postoperative follow-up. CONCLUSIONS: DMEK is an effective option to treat corneal edema secondary to HSV-1-related endotheliitis. Intensive antiviral prophylaxis may reduce the risk of recurrence and subsequent graft failure.

Herpetic Corneal Keratopathy Management Using Ipsilateral Supratrochlear Nerve Transfer for Corneal Neurotization.

BACKGROUND: Neurotrophic keratopathy (NK) is a potentially sight-threatening condition caused by impairment in the trigeminal corneal innervations with decrease or loss of corneal sensitivity. This prospective study aimed to evaluate the outcomes of surgical neurotization of the cornea using ipsilateral supratrochlear nerve transfer in patients with herpes-induced NK. METHODS: An ophthalmologist and a plastic surgeon performed an interdisciplinary corneal neurotization in 13 eyes of 13 patients after preoperative exclusion of forehead sensation impairment. A 3-cm supra-eyebrow incision allowed for microsurgical supratrochlear nerve dissection, and a subconjunctival tunneling was performed for the nerve transfer. Neurotrophic keratopathy was assessed preoperatively and every 3 months postoperatively using slit-lamp microscopy, the corneal sensitivity test, specular microscopy, and in vivo confocal microscopy. RESULTS: The surgeries had no major complications. The average disease duration from cornea denervation to surgery was 15.2 years. The mean follow-up duration was 18.5 ± 6 months. The symptoms exhibited subjectively improved visual acuity, and objectively improved visual analog scale and NK grading. The subepithelial corneal nerve plexus was found at 9 months postoperatively. The corneal thickness decreased and the corneal endothelial count increased postoperatively. CONCLUSIONS: This is the largest series of corneal neurotization using direct ipsilateral supratrochlear nerve transfer. It is a minimally invasive method to restore corneal sensitivity and treat NK successfully within 1 year without a sural nerve graft. A long-term follow-up is needed for further assessment.

Short-term results of acellular porcine corneal stroma keratoplasty for herpes simplex keratitis.

BACKGROUND: Corneal transplantation is a common surgical intervention for restoring vision loss due to corneal damages. However, for cultural reasons, there is a huge shortage of donor corneas in China. Acellular porcine corneal stromas (APCSs) can be used as corneal substitutes in lamellar keratoplasty for corneal ulcers. This study was conducted to analyze the results of APCS use for herpes simplex keratitis (HSK). METHODS: The study involved HSK patients who underwent keratoplasty with APCSs from February 2016 to October 2017 in the second affiliated hospital of Zhejiang University. Patient data were collected at 7 days, 1 month, 3 months, 6 months, and at the last follow-up (7-25 months) postoperative. The corneal transparency, neovascularization, visual acuity, and graft stability were observed. RESULTS: Thirteen patients with HSK including five patients with corneal perforation were included in this study, nine patients underwent deep anterior lamellar keratoplasty (DALK) and five perforation patients underwent double lamellar keratoplasty. There were nine men and four women with an average age of 62.5 ± 5.6 years old (ranging from 52 to 70 years old). The mean postoperative follow-up duration was 15.1 ± 5.8 months (ranging from 7 to 25 months). At the last visit, visual acuity improved in nine patients (69.2%) compared with preoperative (P = 0.008).The grafts of seven individuals (53.8%) were completely transparent or slightly opaque; their corneal transparency score had improved significantly compared with before the surgery (P = 0.010). Various degrees of neovascularization were present in 11 of the 13 patients (84.6%), most neovascularization gradually stabilized. Graft dissolution occurred in three eyes (23.1%) during the observation period, two underwent regrafting, the other one became stable after treatment. Three patients underwent second allograft transplantation, two of which encountered APCS graft dissolution and one of the patients requested a human donor allograft transplantation due to transparency issues despite the absence of adverse issues. CONCLUSION: Acellular porcine corneal stroma seems to be effective in the treatment of HSK and can be used in HSK with corneal perforation by using double lamellar keratoplasty in an emergency.

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

PURPOSE: To describe the functional outcome, postoperative complications, and complication management of Descemet's membrane endothelial keratoplasty (DMEK) in corneal decompensation secondary to Herpes simplex eye disease (HED). METHODS: This retrospective interventional case series included 17 eyes that received DMEK for endothelial decompensation secondary to HED. Complete ophthalmological examination, including corrected-distance visual acuity (CDVA), anterior segment slit-lamp, and optical coherence tomography assessment, were performed preoperatively and postoperatively at regular follow-up intervals. Visual outcome and complication rates were compared with those of 72 consecutive eyes that received DMEK for Fuchs endothelial corneal dystrophy (FECD) and pseudophakic bullous keratopathy (PBK) during the same period. RESULTS: Mean follow-up time was 11.1 ± 5.9 months (range 6-27). CDVA improved from 1.16 ± 0.46 logMAR to 0.62 ± 0.44 logMAR (P = 0.001). Corneal pachymetry significantly decreased from 695 ± 53 µm at day 1 to 569 ± 88 µm at 2 months (P < 0.001). Postoperative complications occurred in 12 eyes, including primary graft failure (12%), endotheliitis (29%), corneal ulcers (35%), and cystoid macular edema (18%). Most complications occurred shortly after surgery, with a median delay of 2.5 months. In comparison, the complication rates for DMEK in FECD and PBK were significantly lower (no graft failure, P = 0.005; no endotheliitis, P < 0.001; no corneal ulcers, P < 0.001 and 3% cystoid macular edema, P = 0.046). CONCLUSIONS: DMEK surgery significantly improved CDVA in patients with endothelial decompensation due to HED. The rate of postoperative complications was higher than for FECD and PBK. Close follow-up is mandatory and the rate of postoperative inflammatory events suggests that patients should be kept on high doses of oral valacyclovir.