Descemet Membrane Endothelial Keratoplasty in Corneal Endothelial Decompensation After a Forceps-Induced Corneal Birth Injury: Case Series and Technique.

PURPOSE: The aim of this study was to describe the efficacy of Descemet membrane endothelial keratoplasty (DMEK) in patients with corneal endothelial decompensation secondary to a forceps-induced corneal birth injury. METHODS: This was a retrospective, noncomparative, interventional case series. Four eyes of 4 patients (1 female and 3 males; mean age, 64.0 ± 4.7 years) with corneal endothelial decompensation due to forceps-induced corneal birth injury were included. DMEK was performed in all cases, using a combined technique, including the use of intraoperative optical coherence tomography, vital staining of Descemet membrane of both host and donor, removal of scarred Descemet membrane with side-port forceps and vitreous cutter to smoothen the posterior corneal surface, epithelial peeling, and illumination for visualization. The examination included preoperative and postoperative ophthalmologic examinations: best-corrected visual acuity (converted to logarithm of the minimum angle of resolution [logMAR]), intraocular pressure, endothelial cell density (ECD), and central corneal thickness. RESULTS: No postoperative complications were noted, and corneal transparency was maintained during follow-up (mean follow-up period, 32.0 ± 27.0 months; range, 3-71 months). The mean best-corrected visual acuity was 0.52 ± 0.35 logMAR preoperatively and 0.15 ± 0.09 logMAR at the last visit. The mean postoperative ECD was 1632 ± 631 cells/mm2 (mean ECD at baseline, 3167 cells/mm2). Central corneal thickness decreased from 640 ± 67 µm preoperatively to 576 ± 58 µm postoperatively. CONCLUSIONS: This study suggests that DMEK can be performed uneventfully in eyes with a forceps-induced corneal birth injury. The combination of surgical techniques may be an effective approach for DMEK.

Incidence of Graft Rejection in Descemet Membrane Endothelial Keratoplasty After COVID-19 mRNA Vaccination.

PURPOSE: The aim of this study was to investigate the Descemet membrane endothelial keratoplasty (DMEK) rejection rate after COVID-19 vaccination with an mRNA vaccine. METHODS: This was a multicenter, retrospective cohort study. A total of 198 patients who underwent DMEK between January 2006 and December 2020 were divided into 2 cohorts: consecutive patients who received at least 1 COVID-19 vaccination in 2021 (vaccination started from February 2021 in Japan) and nonvaccinated patients (control cohort). Patients who had a postoperative observation period of less than 90 days were excluded. The main outcome measurement was the incidence of graft rejection. A Cox proportional hazards regression model was used for comparisons with the nonvaccinated group. RESULTS: Six rejection episodes were observed in 198 patients (124 nonvaccinated and 74 vaccinated patients), with 1 occurring in the nonvaccinated group and 5 in the vaccinated group. In the univariate model, vaccination had a significant effect on rejection episodes ( P = 0.003). The effect of vaccination was also significant ( P = 0.004) after adjusting for covariates. CONCLUSIONS: This study suggests that there may be a higher rejection rate after COVID-19 vaccination in patients who underwent DMEK. Patients should be warned of the rejection risk and its typical symptoms before receiving an mRNA COVID-19 vaccine, although further larger studies are needed to confirm the involvement of vaccination.

Evaluation of corneal nerves and dendritic cells by in vivo confocal microscopy after Descemet's membrane keratoplasty for bullous keratopathy.

This study evaluated changes in corneal nerves and the number of dendritic cells (DCs) in corneal basal epithelium following Descemet membrane endothelial keratoplasty (DMEK) surgery for bullous keratopathy (BK). Twenty-three eyes from 16 consecutive patients that underwent DMEK for BK were included. Eyes of age-matched patients that underwent pre-cataract surgery (12 eyes) were used as controls. In vivo confocal microscopy was performed pre- and postoperatively at 6, 12, and 24 months. Corneal nerve length, corneal nerve trunks, number of branches, and the number of DCs were determined. The total corneal nerve length of 1634.7 ± 1389.1 µm/mm2 before surgery was significantly increased in a time-dependent manner to 4485.8 ± 1403.7 µm/mm2, 6949.5 ± 1477.1 µm/mm2, and 9389.2 ± 2302.2 µm/mm2 at 6, 12, and 24 months after DMEK surgery, respectively. The DC density in BK cornea pre- and postoperatively at 6 months was significantly higher than in the controls, and decreased postoperatively at 12 and 24 months and was significantly lower than that at 6 months postoperatively. Thus, our results suggest that DMEK can repair and normalize the corneal environment.

Superior Oblique Myokymia: A Case Report of Surgical Treatment, Review of the Literature, and Consideration of Surgical Approach.

BACKGROUND: Superior oblique myokymia (SOM) is a rare disorder characterized by episodic microtremor of the eyeball. in patients with SOM, intermittent contraction of the superior oblique muscle causes irregular and rotatory eye movement, causing oscillopsia and diplopia. Microvascular decompression (MVD) of the trochlear nerve is potentially a definitive treatment method for SOM; however, owing to its rarity, this disorder is not well-known to neurosurgeons, and thus the optimal surgical approach has not yet been determined. CASE DESCRIPTION: A 77-year-old woman with left SOM had experienced oscillopsia for 2 years. MVD was performed via a left lateral superior cerebellar approach with the patient in the park-bench position. Her symptom resolved immediately after the surgery. CONCLUSIONS: We believe that MVD via a left lateral superior cerebellar approach can be safely performed to SOM in elderly patients like our patient. Therefore, MVD should be considered as the definitive treatment method for more patients with SOM.

Effect of Graft Shift Direction on Graft Detachment and Endothelial Cell Survival After Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To investigate the effects of graft shift orientation on clinical outcomes after Descemet membrane endothelial keratoplasty (DMEK). METHODS: This study used intraoperative video images to retrospectively examine the effect of graft shift direction in 50 eyes of 50 patients. Correlations were assessed between graft shift direction and multiple parameters. RESULTS: The graft detachment rate was higher in eyes with an inferior graft shift than in those without (superior, 0% and 5.0%; nasal, 0% and 20.0%; inferior, 16.7% and 55.0%; temporal, 16.7% and 45.0%; and any segment, 23.3% and 65.0%; for graft shift-negative and graft shift-positive cases, respectively). Postoperative endothelial cell density reduction was higher in eyes with an inferior graft shift (1 month, 23.6% ± 13.7% and 37.5% ± 18.8%; 3 months, 31.6% ± 16.4% and 45.2% ± 15.2%; and 6 months, 39.8% ± 14.9% and 50.7% ± 16.6%; for graft shift-negative and graft shift-positive cases, respectively). Eyes with a superior graft shift had lower postoperative endothelial cell density reduction than those without (1 month, 36.9% ± 16.6% and 20.0% ± 13.1%; 3 months, 45.3% ± 13.3% and 27.4% ± 16.2%; and 6 months, 51.3% ± 14.6% and 35.9% ± 14.5%; for graft shift-negative and graft shift-positive cases, respectively). Graft shift direction did not affect postoperative best-corrected visual acuity or central corneal thickness. CONCLUSIONS: Graft shift direction in DMEK, especially inferior graft shift, affected the postoperative graft detachment rate. Superior graft shift had a beneficial effect on postoperative corneal endothelial values. These data suggest that inferior graft shift should be avoided in DMEK.

COMPARISON OF THE RETINAL BLOOD FLOW VELOCITY BETWEEN LASER SPECKLE FLOWGRAPHY AND THE RETINAL FUNCTION IMAGER.

PURPOSE: To compare the retinal blood flow velocity using laser speckle flowgraphy (LSFG) and a retinal function imager (RFI) in healthy Japanese subjects. METHODS: This study included a total of 15 eyes of 15 healthy Japanese subjects (mean age, 41.7 ± 17.0 years). The retinal blood flow velocities were separately measured in arteries and veins around the optic disc using LSFG and an RFI. Linear regression analyses were used to analyze possible correlations of retinal blood flow velocities between the devices. RESULTS: The average blood flow velocities using LSFG as the mean blur rate were 18.6 ± 4.8 in arteries and 18.3 ± 5.5 in veins. The average blood flow velocities using the RFI were 3.4 ± 1.1 mm/second in arteries and 2.9 ± 0.9 mm/second in veins. Although retinal blood flow velocities in arteries and veins using LSFG were nearly the same, there were statistical differences in retinal blood flow velocities between arteries and veins using the RFI (P = 0.701 using LSFG, P = 0.041 using the RFI). Significant correlations were found between LSFG and the RFI in arteries and veins (all, P < 0.001). CONCLUSION: There were strong positive correlations in retinal blood flow velocities between LSFG and the RFI in healthy subjects.

Training regimen involving cyclic induction of pupil constriction during far accommodation improves visual acuity in myopic children.

PURPOSE: Myopia in school-age children has become increasingly prevalent in industrialized countries, especially in Asia. A large population of school-age children still suffers from low visual acuity. We have developed a novel, safe and noninvasive training method to activate a pupillary constriction response during far accommodation that results in improved visual acuity. METHODS: Myopic children (n = 95) were treated for 3-minute sessions up to twice a week for 12-106 weeks. We stimulated quick cycles of near/far accommodation by displaying a visual object on a LCD screen and moving the screen in cycles from a near (25 cm) to a far (70 cm) point and back, while keeping the retinal projection size and brightness of the object constant. RESULTS: Mechanistically, we noted pupillary constriction upon far accommodation in trained myopic children, which was not seen in normal subjects or in untrained myopic children. Eighty five percent (52/61) of trained myopic right eyes with two sessions weekly experienced improved visual acuity (VA) by more than 0.1 logMAR units with an average improvement of 0.30 +/- 0.03 standard error of mean (SEM) logMAR units. With maintained training, most eyes' improved VA stayed almost constant, for more than 50 weeks in the case of 12 long trained subjects. CONCLUSIONS: This simple, short and safe accommodation training greatly improves the quality of vision in a large population suffering from refractive abnormalities.