Trachipleistophora hominis: molecular characterization of a rare pathogen causing microsporidial stromal keratitis.

The authors report the clinical and microbiological findings of a unique case of stromal keratitis caused by a rare microsporidium, Trachipleistophora hominis. This case of stromal keratitis was in a 49-year-old male with a history of COVID-19 infection and diabetes mellitus. Corneal scraping specimens revealed numerous microsporidia spores upon microscopic examination. PCR of the corneal button revealed the presence of T. hominis infection, which could be controlled by penetrating keratoplasty surgery. The graft was clear with no recurrence of infection until the last follow-up 6 weeks postsurgery. This is the first case of human stromal keratitis caused by this organism in a post-COVID infection, confirmed by molecular diagnosis.

Rejection of Acellular Porcine Corneal Stroma Transplantation During Coronavirus Disease 2019 Pandemic.

ABSTRACT: To report 2 successfully managed cases of graft rejection with acellular porcine corneal stroma (APCS) transplantation in patients with fungal corneal ulcer. Two patients were diagnosed with fungal corneal ulcer and received APCS transplantation. Graft rejection developed due to the lost follow-up during the period of coronavirus disease 2019 outbreak. Amniotic membranes transplantation and cauterization of neovascularization was performed, respectively. The graft failure resolved successfully after the procedure. To the best of our knowledge, amniotic membranes transplantation and cauterization of new vessels are the firstly reported in treating APCS graft failure. Amniotic membranes transplantation or cauterization of neovascularization appear to be a safe and costeffective method for treating graft failure.

Evaluation of a Telemedicine Model for Following Keratoconus Patients in the Era of COVID-19 Pandemic.

Purpose: To evaluate the diagnostic accuracy and reliability of a telemedicine approach for detecting keratoconus patients' progression in the era of coronavirus disease 2019 (COVID-19) pandemic. Materials and Methods: A retrospective study, comparing the office and telemedicine evaluations in determining whether keratoconus patients were at risk of progression and indicated for further treatment of corneal crosslinking, was conducted. The clinic examination included best spectacle corrected visual acuity measurement and manifest refraction, full ophthalmic examination, and corneal topography, which provided with the gold-standard diagnosis. The remote assessment included two decisions of keratoconus progression or stability: the first evaluation after revealing patient demographics and topography images, and the second with the manifest refraction and clinical findings as documented in the outpatient clinic visit. Results: Two-hundred and four eyes of 102 keratoconus patients were included. There was an agreement of assessment between the in-person and the remote diagnostic decisions in 192 (94%) of the eyes. Among the remaining 12 eyes, a false-positive diagnosis was made in 8 (3.9%) eyes, whereas a false-negative diagnosis was made in 4 (1.9%) eyes. The remote assessment showed a sensitivity and specificity of 69% and 96%, respectively. In no case was remote diagnostic decision 2 different from remote decision 1. Conclusions: The telemedicine model yielded high specificity, but low sensitivity values, therefore, not suitable as an alternative for keratoconus patient follow-up (Clinical trial number TLV-0363-20).

Late Corneal Stromal Deposits After COVID-19.

ABSTRACT: We present 2 cases of striking stromal corneal infiltrates months after COVID-19 infection. While we cannot prove that these infiltrates are caused by or directly related to COVID-19, we did not find any other plausible cause that could explain these ophthalmic signs. In these cases, the ongoing process was detected in relatively early stages due to scheduled visits with patients and responded positively to prednisolone acetate 1% ophthalmic suspension. However, we do not know the response to treatment in more advanced cases.

Comparison of Wavefront-Guided Femtosecond LASIK and Optimized SMILE for Correction of Moderate-to-High Astigmatism.

PURPOSE: To compare refractive outcomes, higher order aberrations (HOAs), and the changes in contrast sensitivity after wavefront-guided femtosecond laser-assisted in situ keratomileusis (WFG LASIK) and optimized small incision lenticule extraction (SMILE) for moderate-to-high astigmatism correction. METHODS: This prospective, randomized study included 87 eyes: 40 eyes in the WFG LASIK group and 47 eyes in the SMILE group. Manual cyclotorsion compensation by marking the horizontal axis before SMILE surgery was used for optimized SMILE. Refractive diopter, aberrations, and contrast sensitivity were assessed 3 months postoperatively. The Alpins vector analysis method was used to analyze the astigmatic changes after surgery. RESULTS: There were no significant differences in the corrected distance visual acuity and refraction between the two groups after surgery. The fitted curve of surgically induced astigmatism versus target induced astigmatism was described as y = 0.9905 x + 0.0009 in the WFG LASIK group and y = 0.9672 x + 0.0026 in the SMILE group. The percentage of corneal astigmatism axis change within 5 degrees was statistically significant (chi-square test: 10.632, P = .001). HOAs increased in both the WFG LASIK and SMILE groups after surgery (t = -3.655, P = .001, t = -3.784, P = .001, respectively). However, comparison of the changes of HOAs between both groups was not significant (t = -0.565, P = .575). The improvement in contrast sensitivity in the WFG LASIK group was significantly higher than that in the SMILE group. CONCLUSIONS: WFG LASIK and optimized SMILE can achieve similar outcomes for astigmatism correction. Optimized SMILE with marking could achieve good astigmatism correction, even without an eye tracking system. [J Refract Surg. 2021;37(3):166-173.].

Negative polymerase chain reaction for SARS-CoV-2 in aqueous sample of patient with confirmed SARS-CoV-2 and recurrence of herpetic stromal keratitis.

This case report describes a negative result for antigen testing for the SARS-CoV-2 virus in an aqueous sample taken during the management of suspected herpes simplex keratitis from a patient with confirmed SARS-CoV-2 based on antigen testing of high nasal swab. The implications of no viral load detectable in the aqueous sample are discussed in context of routine phacoemulsification surgery during the SARS-CoV-2 pandemic.

Quantitative shadowgraphy of aerosol and droplet creation during oscillatory motion of the microkeratome amid COVID-19 and other infectious diseases.

PURPOSE: To quantify the atomization of liquid over the cornea during flap creation using microkeratome using high-speed shadowgraphy. SETTING: Laboratory study. DESIGN: Laboratory investigational study. METHOD: In an experimental setup, flap creation was performed on enucleated goat's eyes (n = 8) mounted on a stand using One Use-Plus SBK Moria microkeratome (Moria SA) to assess the spread of aerosols and droplets using high-speed shadowgraphy. Two conditions were computed. A constant airflow assumed uniform air velocity throughout the room. A decaying jet assumed that local air velocity at the site of measurements was smaller than the exit velocity from the air duct. RESULTS: With the advancement of the microkeratome across the wet corneal surface, the atomization of a balanced salt solution was recorded on shadowgraphy. The minimum droplet size was ∼90 µm. The maximum distance traversed was ∼1.8 m and ∼1.3 m assuming a constant airflow (setting of refractive surgery theater) and decaying jet condition (setting of an operating theater with air-handling unit), respectively. CONCLUSIONS: The microkeratome-assisted LASIK flap creation seemed to cause spread of droplets. The droplet diameters and velocities did not permit the formation of aerosols. Therefore, the risk of transmission of the virus to the surgeon and surgical personnel due to the microkeratome procedure seemed to be low.