Clinical profile and microbiological trends of therapeutic keratoplasty at a network of tertiary care ophthalmology centers in India

Indications and Outcomes of Emergency Keratoplasty in a Major New Zealand Eye Tertiary Referral Center, 2000 to 2021

PURPOSE

To report the indications and outcomes of emergency keratoplasty over a 21-year period in Greenlane Clinical Centre, the major tertiary eye referral center in Auckland, New Zealand (Aotearoa).

METHODS

A retrospective review of medical records of all emergency keratoplasties performed in Greenlane Clinical Centre from January 2000 to September 2021 was conducted. Demographic, preoperative, intraoperative, and 1-year postoperative data were collected.

RESULTS

Emergency keratoplasty was performed in 102 eyes of 97 patients (54 men), comprising 5.6% of transplants performed (N = 1830) in this period. The mean age was 53 years (range = 4-95 years, SD = 20). Patients of Māori ethnicity were overrepresented (31%). Corneal perforation was present in 90% of eyes, and microbial keratitis was the most common indication. Bacteria were the most commonly isolated organisms (38%). The mean preoperative and 12-month postoperative best potential corrected distance visual acuity was 1.6 and 1.2 (logMAR), respectively. All cases of therapeutic keratoplasty achieved initial therapeutic success, with no eyes lost or requiring repeat emergency keratoplasty. Complications included nonhealing epithelial defects (19%), cataract (19%), glaucoma (15%), allograft rejection (13%), and corneal melting (5%). Fifteen cases (15%) had documented graft failure at 12 months. Multivariate analysis revealed that younger age was the only statistically significant factor associated with failure at 12 months.

CONCLUSIONS

Emergency keratoplasty was the indication for 5.6% of keratoplasties performed. Our results compare favorably with those in the literature, possibly because of early intervention and lower incidence of fungal keratitis. The reported overrepresentation of Māori has important implications for health access and delivery in New Zealand.

Evolving indications and surgical techniques for corneal transplantation at a tertiary eye care center in southern China

BACKGROUND

This retrospective study aimed to analyze the evolution of primary indications and surgical techniques for corneal transplantation in Southern China from 2012 to 2021.

METHODS

The medical charts of all patients who underwent keratoplasty between January 2012 and December 2021 at Zhongshan Ophthalmic Centre, Sun Yat-Sen University, Guangzhou, Southern China were reviewed. We collected and analyzed the primary indications for corneal transplantation and the surgical methods used in each keratoplasty.

RESULTS

The total number of corneal transplantations was 7,286 during this decade, increasing from 210 cases in 2012 to 1054 cases in 2021. The primary indications for keratoplasty included acquired nontraumatic corneal diseases (56.2%), congenital corneal abnormalities (16.4%), acquired traumatic corneal diseases (14.0%), and regraft (13.4%). Infectious keratitis was the leading indication among all keratoplasties (18.5%), followed by regraft (13.4%). Over the decade, the proportion of infectious keratitis gradually decreased (P = 0.013), while the proportion of regraft increased (P = 0.019). The predominant surgical technique was penetrating keratoplasty (PKP), accounting for 56.7%. However, the number of deep anterior lamellar keratoplasty (DALK) and endothelial keratoplasty (EK) significantly increased from 2012 to 2021 (P = 0.007 and P = 0.002).

CONCLUSIONS

The annual number of corneal transplants significantly increased from 2012 to 2021. In the past decade, infectious keratitis and regraft have become the leading primary indications for corneal transplantation. Although the use of customized lamellar techniques has dramatically increased, PKP remains the predominant surgical technique for keratoplasty.

Herpes simplex virus keratitis: electronic medical records driven big data analytics report from a tertiary eye institute of South India

OBJECTIVE

To describe the demographics and clinical profile of Herpes Simplex Virus (HSV) Keratitis in patients presenting to a multi-tier ophthalmology hospital network in South India.

METHODS

We have reviewed the medical records of all patients having a clinical diagnosis of any form of HSV keratitis, seen between May 2012 and August 2020 across the L V Prasad Eye Institute network. All the further analyses of the groups were performed using the keywords used for making the diagnosis of HSV keratitis and the data were collected from the electronic medical record system.

RESULTS

There were a total of 8308 (N = 8897 eyes) patients. Male: female ratio was 5368 (64.61%):2940 (35.39%). Unilateral involvement was in 7719 (92.91%) patients. The most common age group affected was between the third to fifth decades of life with 1544 (18.58%). 3708 (1.68%) eyes had mild visual impairment (< 20/70) while the rest of them had moderate to severe visual impairment as observed mainly (p ≤ 0.01) in Necrotizing stromal keratitis. 7314 (82.21%) eyes had normal intraocular pressure (10-21 mm Hg) while raised most commonly in keratouveitis (P ≤ 0.01). Epithelial Keratitis, Immune Stromal Keratitis, Endotheliitis, Neurotrophic keratopathy and Keratouveitis were observed in 1875 (17.22%) eyes, 5430 (61.03%) eyes, in 129(1.45%) eyes, 1188 (13.35%) eyes, 148 (1.66%) eyes and 256 (2.88%) eyes respectively.

CONCLUSION

Based on our institute-based data, the most common type of HSV keratitis is Immune stromal keratitis followed by epithelial keratitis. Although not representative of the general population, this data provide useful insights related to HSV keratitis from India.

Pythium insidiosum Keratitis: Past, Present, and Future

Pythium insidiosum (PI) is an oomycete, a protist belonging to the clade Stramenopila. PI causes vision-threatening keratitis closely mimicking fungal keratitis (FK), hence it is also labeled as "parafungus". PI keratitis was initially confined to Thailand, USA, China, and Australia, but with growing clinical awareness and improvement in diagnostic modalities, the last decade saw a massive upsurge in numbers with the majority of reports coming from India. In the early 1990s, pythiosis was classified as vascular, cutaneous, gastrointestinal, systemic, and ocular. Clinically, morphologically, and microbiologically, PI keratitis closely resembles severe FK and requires a high index of clinical suspicion for diagnosis. The clinical features such as reticular dot infiltrate, tentacular projections, peripheral thinning with guttering, and rapid limbal spread distinguish it from other microorganisms. Routine smearing with Gram and KOH stain reveals perpendicular septate/aseptate hyphae, which closely mimic fungi and make the diagnosis cumbersome. The definitive diagnosis is the presence of dull grey/brown refractile colonies along with zoospore formation upon culture by leaf induction method. However, culture is time-consuming, and currently polymerase chain reaction (PCR) method is the gold standard. The value of other diagnostic modalities such as confocal microscopy and immunohistopathological assays is limited due to cost, non-availability, and limited diagnostic accuracy. PI keratitis is a relatively rare disease without established treatment protocols. Because of its resemblance to fungus, it was earlier treated with antifungals but with an improved understanding of its cell wall structure and absence of ergosterol, this is no longer recommended. Currently, antibacterials have shown promising results. Therapeutic keratoplasty with good margin (1 mm) is mandated for non-resolving cases and corneal perforation. In this review, we have deliberated on the evolution of PI keratitis, covered all the recently available literature, described our current understanding of the diagnosis and treatment, and the potential future diagnostic and management options for PI keratitis.