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Objective: To evaluate the initial safety and efficacy of femtosecond laser-assisted minimally invasive lamellar keratoplasty (FL-MILK) for advanced keratoconus. Methods: It was a case series study. Patients with advanced keratoconus who underwent FL-MILK between August 2017 and April 2020 at Shandong Eye Hospital were prospectively included. The femtosecond laser was used to create an intrastromal pocket in the recipient cornea and a lamellar cornea in the donor. The lamellar cornea was then gently inserted into the intrastromal pocket through the incision and flattened. Clinical measurements included best-corrected visual acuity, 3-mm anterior corneal mean keratometry, anterior and posterior central corneal elevation, central corneal thickness, corneal biomechanics, and endothelial cell density. The follow-up was conducted at 1 month, 12 months, and 24 months after the operation. Results: There were 33 patients (35 eyes) in the study. Twenty-six patients were male and 7 patients were female. The mean age was (20.34±5.24) years old. All patients completed 12 months of follow-up, and 25 patients (27 eyes) completed 24 months of follow-up. No epithelial ingrowth, infection, or allogeneic rejection was observed. Compared with the preoperative data, the anterior central corneal elevation significantly decreased ( P <0.001), the mean keratometry significantly decreased ( P <0.05), and the central corneal thickness significantly increased ( P <0.001). The corneal biomechanical strength was significantly improved, with the deformation amplitude ratio at 2.0 mm decreasing from 1.39±0.14 preoperatively to 1.21±0.10 at 24 months postoperatively ( P <0.001) and the stiffness parameter at the first applanation increasing from 41.49±11.47 preoperatively to 88.41±18.17 at 24 months postoperatively ( P <0.001). There were no significant changes in the mean best-corrected visual acuity, posterior corneal elevation, mean spherical equivalent, and endothelial cell density (all P >0.05). Conclusions: FL-MILK may be a feasible option for advanced keratoconus. This procedure may provide a new resolution for keratoconus.

Objective: To evaluate the clinical effect of rigid permeable contact lenses (RGPCL) in the correction of irregular astigmatism after keratoplasty. Methods: Retrospective case study. From June 2012 to December 2016, 31 patients (37 eyes) who underwent corneal transplantation were tested and fitted with RGPCL. The patients' data of primary disease, interval from keratoplasty to contact lens fitting, uncorrected visual acuity, best spectacle-corrected visual acuity, best RGPCL-corrected visual acuity, contrast visual acuity before and after RGPCL wear, corneal topography and corneal endothelium parameters before and after RGPCL wear were collected, including ocular complications and comfort of contact lenses. Results: Among the 31 patients, 24 were male and 7 were female, with age of (31.3±5.8) years. The mean interval between grafting and initial contact lens fitting was (4.6±2.3) years. Uncorrected visual acuity, best spectacle-corrected visual acuity, and best RGPCL-corrected visual acuity were 0.81±0.21, 0.54±0.13, and 0.10±0.07, respectively ( t= 7.170, 16.617, 17.866; all P< 0.05). The average astigmatism was -5.76±2.23 D and -0.83±0.47 D before and after wearing RGPCL ( t= 8.531, P< 0.05). After wearing RGPCL, the contrast visual acuity of 100%, 25%, 10%, and 5% was increased from 0.95±0.33, 1.18±0.21, 1.40±0.00, and 1.40±0.00 to 0.12±0.15, 0.37±0.17, 0.65±0.25, and 0.96±0.29, respectively ( t= 5.972, 8.473, 9.243, 5.104; all P< 0. 05). There were no obvious changes of corneal endothelium parameters during the observation period. No obvious corneal allograft rejection or other complications occurred, and 94.6% (35/37) of the patients felt comfortable with wearing RGPCL. Conclusions: RGPCL wear is safe and effective in correcting irregular astigmatism after corneal transplantation. We can obtain good corrected vision and improve contrast visual acuity, especially for patients who can not wear spectacles. (Chin J Ophthalmol, 2019, 55: 413-418) .

Objective: To study the relationship between corneal neovascularization and various biological factors in corneal stroma of rats., Methods: It was an experimental study. Corneal neovascularization was induced by alkali burn in 40 rats. Transforming growth factor-beta1 (TGF-beta1), alpha-smooth muscle actin (alpha-SMA) and fibroblast activation protein (FAP) in the stroma surrounding corneal neovascularization were detected by immunohistochemical studies on day 1, 3 and 7 after chemical burn. Platelet-endothelial cell adhesion molecule-1 (CD31) was used to identify the vascular endothelial cells. RT-PCR was used to identify FAP in the cornea 3 and 7 days after chemical burn. Picrosirius staining and polarization microscopy were used to detect changes of collagen types I and III in the cornea., Results: After alkali burn, TGF-beta1 was first expressed in the cornea stroma. Then, some stroma cells expressed both alpha-SMA and FAP. The FAP(+) keratocytes were found surrounding the CD31(+) endothelium of angiogenesis. RT-PCR study showed that FAP mRNA was only present in neovascularized cornea and not in normal cornea. Polarization microscopy revealed that the collagen types I and III were rearranged in neovascularized cornea., Conclusions: Various biological factors in corneal stroma are changed when the cornea shows neovascularization. FAP(+) keratocytes are present in the stroma, and the appearance of these cells parallels the growth of vascular endothelial cells. Collagen types I and III are rearranged during the process of angiogenesis.

Microbial keratitis is one of the major causes of blindness in China. The rapid and unequivocal identification of the causative organism is the key point for the rational antimicrobial therapy and restoration of the vision. It is difficult for the physician to choice the first step in the management of microbial keratitis: starting antimicrobial therapy after the identification of the causative organism, or starting therapy even there is no organism identification. The authors thought that it is urgent to start the antimicrobial therapy for microbial keratitis, however, the causative organism identification should be performed in time. This steps are necessary for the high diagnostic rate and cure rate of microbial keratitis, also for improving physician's consciousness of causative organism diagnosis.