Purpose: To describe several essential surgical techniques that overcome difficulties in performing Descemet membrane endothelial keratoplasty (DMEK) for inexperienced surgeons, especially those who perform DMEK on eyes of Asian patients. Methods: Nine eyes of 9 Asian patients with bullous keratopathy who underwent DMEK were analyzed retrospectively. All patients were given a diuretic such as d-mannitol or acetazolamide shortly before surgery, with retrobulbar anesthesia and a Nadbath facial nerve block. Core vitrectomy before DMEK was performed in several cases in which a high vitreous pressure during surgery was predicted. The donor graft was stained with trypan blue, and a 25-G anterior chamber maintenance cannula was used to maintain the anterior chamber depth during graft insertion in all eyes. Results: The cornea became clear in all eyes. The best spectacle-corrected visual acuity had improved significantly 6 months after the surgery compared with preoperative values (P = 0.026). The corneal endothelial cell density was 1371 cells per square millimeter at postoperative 6 months. Conclusions: Although DMEK is technically difficult, especially for inexperienced surgeons who operate on eyes of Asian patients, controlling anterior chamber pressure using various manipulations may help to prevent iatrogenic primary graft failure and lead to successful DMEK.

We aimed to predict keratoconus progression and the need for corneal crosslinking (CXL) using deep learning (DL). Two hundred and seventy-four corneal tomography images taken by Pentacam HR^® (Oculus, Wetzlar, Germany) of 158 keratoconus patients were examined. All patients were examined two times or more, and divided into two groups; the progression group and the non-progression group. An axial map of the frontal corneal plane, a pachymetry map, and a combination of these two maps at the initial examination were assessed according to the patients’ age. Training with a convolutional neural network on these learning data objects was conducted. Ninety eyes showed progression and 184 eyes showed no progression. The axial map, the pachymetry map, and their combination combined with patients’ age showed mean AUC values of 0.783, 0.784, and 0.814 (95% confidence interval (0.721–0.845) (0.722–0.846), and (0.755–0.872), respectively), with sensitivities of 87.8%, 77.8%, and 77.8% ((79.2–93.7), (67.8–85.9), and (67.8–85.9)) and specificities of 59.8%, 65.8%, and 69.6% ((52.3–66.9), (58.4–72.6), and (62.4–76.1)), respectively. Using the proposed DL neural network model, keratoconus progression can be predicted on corneal tomography maps combined with patients’ age.

The optical density of the cornea can be evaluated quantitatively by “densitometry” using a rotating Scheimpflug camera. Densitometry allows evaluation of corneal opacity in the anterior segment of the eye by quantitative measurement of scattering light. In the present investigation, we evaluate quantitatively minimal subclinical corneal edema after cataract surgery using densitometry. Fifty four eyes of 34 patients who underwent cataract surgery were enrolled. Measurement of corneal density was performed using Pentacam® before and on days 1, 3 and 7 after surgery. Densitometry scores increased from 18.12 ± 1.76 before cataract surgery to 21.03 ± 3.84 on day 1 (P < 0.001) and 19.90 ± 2.46 on day 3 (P = 0.018), but recovered to 19.44 ± 1.58 on day 7 (P = 0.131). Total corneal thickness was 549.1 ± 32.7 μm before surgery and increased to 582.7 ± 46.3 μm on day 1 (P = 0.001), but recovered to 566.4 ± 29.7 μm on day 3 (P = 0.097). Densitometry reading correlated positively with corneal thickness (correlation coefficient = 0.13, P = 0.003). Densitometry is useful to detect corneal edema that is not detectable by slit-lamp examination.

Introduction Maintaining the correct orientation of the donor graft is important during Descemet's membrane endothelial keratoplasty (DMEK). We describe a new method of marking the donor graft prior to DMEK. Methods Twelve eyes of 10 patients with bullous keratopathy who underwent DMEK were retrospectively analysed. Donor discs were created by stripping the endothelium–Descemet's membrane layer from corneoscleral buttons. Four semicircular marks, two 1.0 mm and two 1.5 mm in diameter, were created at the edge of the donor disc. The small and large marks were paired. Each donor graft was inserted into the anterior chamber, unfolded and attached to the posterior corneal stroma with an air bubble. Results The inserted grafts were all appropriately orientated when attached to the back surfaces of the corneas. The two pairs of asymmetric marks afforded valuable guidance. Even when the graft was partially folded or decentred, and one pair of marks was obscured, the other pair was always visible to indicate graft orientation. Best spectacle-corrected visual acuity improved significantly in all patients (p<0.001). Compared with the preoperative endothelial cell density of the donor graft, that of the corneal endothelium had decreased 44.0%±10.0% by 6 months after surgery. Conclusions Two pairs of asymmetrical semicircular marks placed on the edge of the donor graft allowed appropriate graft orientation during DMEK.