Infectious Keratitis After Boston Type 1 Keratoprosthesis Implantation

Causes of Corneal Melt After the Boston Keratoprosthesis Type I: The Chinese People's Liberation Army General Hospital Experience

PURPOSE

The purpose of this study was to evaluate the long-term incidence, risk factors, and the management of corneal melt following Boston type I keratoprosthesis (B-KPro I) implantation.

METHODS

This is a retrospective observational case series. Data were collected regarding demographics, preoperative characteristics, incidence, and outcomes of corneal melt in 102 patients who underwent B-KPro I in the Chinese PLA General Hospital between 2011 and 2018, with a follow-up period ranging from 4 to 11 years.

RESULTS

Chemical burn was the most common indication for B-KPro I (n = 56; 53.8%), followed by ocular trauma (n = 26; 25.0%). During the follow-up period (107 ± 25.7 months), corneal melt occurred in 60 cases among 37 eyes (35.6%), with an incidence of 20.2% at 1 year after surgery. Fourteen cases presented with recurrent corneal melt. Patients with multiple corneal allograft failures had a higher risk of corneal melt. Thermal burns, compared with alkali burns, significantly elevated the odds ratio (OR) of corneal melt (OR, 5.11; 95% confidence interval, 1.05-24.86; P = 0.043).

CONCLUSIONS

Corneal melt significantly reduced the retention time of KPro ( P < 0.01), and its coexistence with other complications further shortened the retention time. A specific pattern of corneal melt occurrence was identified, with a peak incidence at 1 year postoperatively. Our findings suggest variations in the risk of corneal melt among different indications, with thermal burns carrying the highest OR. Moreover, each previous failed keratoplasty doubled the risk of corneal melt after B-KPro I.

Modern Technologies in Diagnosis of Fungal Keratitis (Review)

Traumas and infectious diseases of the eye play a leading role in the development of corneal blindness responsible for 1.5-2 million cases of vision loss per year. To date, the issue of reducing the incidence of fungal keratitis is acute and needs to be solved worldwide. Trauma as a risk factor for corneal fungal disease is thought to be prevalent in developing countries due to agricultural involvement, while in developed countries the onset of the disease is predisposed by medical advances such as contact vision correction and modern ophthalmic surgery. Thorough analysis of the pathogenesis gives the possibility to describe the action of fungal enzymes, biofilm formation, and the resistance mechanism, which on the one hand explains the aggressive course of the disease and difficulties in its diagnosis, and on the other hand, it encourages searching for new methods of diagnosis and treatment. The non-specific clinical picture of fungal keratitis, the variety and availability of antibiotics nowadays become an obstacle for rapid detection of this pathology. Low public awareness and late visit to an ophthalmologist are also a barrier to successful combating the increasing incidence of fungal keratitis. Belated diagnosis, increasing resistance of fungi to antibiotics, and lack of registered antifungal ophthalmic drugs justify poor treatment efficacy resulting in decreased visual acuity or vision loss. Existing diagnostic methods need systematization and detailed comparison, identifying the advantages and disadvantages of each. This review considers causative agents and their influence on pathogenesis of the disease, describes difficulties of fungal keratitis diagnosis and possible ways of overcoming these problems using new developments, and also outlines further prospects of research in this direction.

Vitreoretinal Complications in Boston Keratoprosthesis Type 1

PURPOSE

To evaluate the incidence of vitreoretinal complications, treatment modalities, and the visual outcomes in a large cohort of eyes that underwent Boston Keratoprosthesis (KPro) implantation.

DESIGN

Retrospective, interventional case series.

METHODS

132 eyes of 114 patients who underwent KPro implantation at the Centre Hospitalier de l'Université de Montréal from 2008 to 2017 were included with at least 1 year follow-up. Charts were reviewed and data was collected, including demographics, initial corneal indication for surgery, posterior segment complications, preoperative and postoperative visual acuity.

RESULTS

Mean follow-up was 68.2 months and 61.4% of eyes developed postoperative vitreoretinal complications (VRC). The most common VRC was RPM formation (38.6%, n=51) followed by RD (15.2%, n=20), CME (12.1%, n=16), ERM (9.8%, n=13), endophthalmitis (9.1%, n=12), sterile vitritis (7.6%, n=10), vitreous hemorrhage (6.8%, n=9), choroidal detachment (3.0%, n=4) and central retinal vein occlusion (0.7%, n=1). BCVA improved in the no VRC group from 1.74 ± 0.33 logMAR to 1.33±0.83 logMAR and in the VRC group from 1.74±0.36 logMAR to 1.52±0.83 logMAR, without any statistically significant intergroup differences (p=0.231). RD was the only significant complication associated with poorer visual outcomes (p=0.001).

CONCLUSION

Potentially blinding secondary complications occur in the majority of patients and frequent monitoring is necessary, specifically in the early and intermediate postoperative periods. This study evidenced significant improvements in visual outcomes of KPro eyes, including those that developed postoperative vitreoretinal complications.