Excimer laser phototherapeutic keratectomy for the treatment of clinically presumed fungal keratitis

Phototherapeutic keratectomy: Indications, methods and decision making

Phototherapeutic keratectomy (PTK) involves treating anterior corneal lesions by superficial corneal ablation using an excimer laser (193 nm). Some of the commonly treated conditions include recurrent corneal erosions (RCE), corneal dystrophies, spheroidal degeneration, keratoconus, and corneal scars. We discuss various techniques of PTK including large area PTK, focal PTK, and multifocal PTK and alternatives to PTK. Masking agents like hyaluronate, methylcellulose, and dextran are recommended to help achieve a better outcome when ablating irregular corneal surfaces. Antifibrotic agents like mitomycin C reduce the chances of recurrence of the disease, apart from minimizing the postoperative scarring. Some of the complications include induced hyperopia and irregular astigmatism, haze, recurrence, and corneal thinning. However, earlier postoperative recovery, possibility of a repeat procedure, and ability to control the depth of ablation make PTK a promising, minimally invasive alternative to keratoplasty in cases with anterior corneal pathologies.

A recognition survey of granular corneal dystrophy type 2 genetic detection in China

AIM

To evaluate the feasibility of promoting genetic detection for granular corneal dystrophy type 2 (GCD₂) by a questionnaire conducted among citizens in five cities in China.

METHODS

The data were collected by questionnaire, and analyzed by Chi-square test and one-tailed t test in IBM SPSS statistics.

RESULTS

Based on the survey data on the awareness of GCD₂ genetic detection in this study and the positive predictive analysis report of the citizens in five cities in China, the vast majority (84.2%) of respondents had never heard of it and did not know that GCD₂ patients have been prohibited from performing excimer surgery that can deteriorate GCD₂ patients' condition even leading to blindness. Though 3.4% of patients understood GCD₂ very much, they have no idea that GCD₂ could not be 100% accuracy diagnosed by the conventional inspection methods.

CONCLUSION

It is feasible and necessary to use GCD₂ genetic detection as an excimer preoperative examination project. In order to promote the development of detection project, a few improvements should be carried out in terms of the promoting efforts, costs, and research progress.

Full-thickness conjunctival flap covering surgery combined with amniotic membrane transplantation for severe fungal keratitis

Fungal keratitis is a severe and common ocular infectious disease. The present study evaluated the efficiency of full-thickness conjunctival flap covering surgery with amniotic membrane transplantation (FCCS + AMT) as a transitional surgery for severe fungal keratitis. A total of 17 patients with severe fungal keratitis without corneal perforation underwent FCCS + AMT between January 2010 and December 2015. The pathogenic factors, preoperative diagnosis and postoperative prognosis of FCCS + AMT at 3 months were evaluated. Subsequently, 7 patients received sclerokeratoplasty, and the best-corrected visual acuity (BCVA) and recurrence ratio were analyzed at 1 month postoperatively. The primary risk factor was agricultural trauma (7 cases), followed by a non-agricultural object entering the eye (3 cases). Preoperatively, there were 10 cases of fungal keratitis positively identified using confocal microscopy and 9 cases positively identified by corneal scrapings. A total of 3 months following FCCS + AMT, the percentage of cases resulting in preservation of the eyeball was 88.24%, with 15/17 patients demonstrating complete conjunctival re-epithelization and a smooth conjunctival surface without any complications. A total of 2 (11.76%) patients experienced melting of the conjunctival flap and development of endophthalmitis, and subsequently underwent ocular evisceration surgery. A total of 7 patients underwent sclerokeratoplasty and the mean logarithm of the minimum angle of resolution BCVA at 1 month was significantly improved (0.689±0.121; P<0.001) compared with preoperative values (2.459±0.037) and BCVA values following FCCS + AMT (2.529±0.066). No recurrence was observed in any of the cases during the follow-up period. Conclusively, FCCS + AMT may be a preferable treatment for severe fungal keratitis of the entire corneal ulcer without perforation, and may save the eyeball and provide a greater opportunity for corneal transplantation.