Kenji Konomi

Improved functional visual acuity after punctal occlusion in dry eye patients.

PURPOSE To report an increased functional visual acuity, which was recently reported as a simulation of visual function of daily acts of gazing, in dry eye patients after punctal occlusion. DESIGN Prospective comparative interventional study. METHODS We measured ordinary best-corrected visual acuity and functional visual acuity in eight eyes of eight dry eye patients after punctal occlusion, and compared the results with those of 22 eyes of 22 dry eye patients without punctal occlusion. RESULTS Functional visual acuity in dry eye patients after punctal occlusion was 0.962 in decimal notation, which was significantly higher than that of patients without punctal occlusion, 0.283 (P <.0001). CONCLUSIONS This study shows that punctal occlusion can improve the impaired functional visual acuity of dry eye patients.

The Contribution of the Posterior Surface to the Corneal Aberrations in Eyes after Keratoplasty

PURPOSE To investigate the contribution of posterior corneal surfaces to higher-order aberrations (HOAs) of the cornea, optical quality, and visual acuity after keratoplasty. METHODS Corneal topography of anterior and posterior surfaces and pachymetry were conducted using anterior segment optical coherence tomography (AS-OCT) in 40 eyes (10 eyes after penetrating keratoplasty [PK], 10 eyes after deep anterior lamellar keratoplasty [DALK], 10 eyes after Descemets stripping automated endothelial keratoplasty [DSAEK], and 10 normal eyes). Anterior, posterior, and total corneal HOAs were calculated using ray-tracing and decomposition into Zernike polynomials and were evaluated as root mean square values. Modulation transfer functions (MTFs) were also evaluated. RESULTS Topography maps of the anterior and posterior surfaces showed reverse patterns in the normal, PK, and DALK eyes, but not in DSAEK eyes. In the normal, PK, and DALK eyes, the total corneal HOAs were significantly smaller (~10%) than were the HOAs of the anterior surface (P < 0.01), whereas there was no significant difference between total and anterior HOAs in the DSAEK eyes (P = 0.483). In the normal, PK, and DALK eyes, the MTFs of the total cornea were slightly better than those of the anterior surface. In the DSAEK eyes, the MTFs of the total cornea were lower than those of the anterior surface. Visual acuity was significantly correlated with total and anterior surface HOAs (P < 0.05). CONCLUSIONS Posterior surfaces compensate for anterior aberrations in normal, PK, and DALK eyes. In DSAEK eyes, the posterior surface increased total corneal HOAs and had a negative influence on MTFs.

Transplantation of corneal endothelium with Descemet’s membrane using a hyroxyethyl methacrylate polymer as a carrier

Aims: To evaluate the histology and function of Descemet’s membrane transplanted with intact endothelium. Methods: Japanese white rabbits and human eyebank eyes were used as donors and recipients of Descemet’s membrane transplantation. Donor endothelium was hydrodissected by injecting indocyanine green from a limbal incision, and then processed as a corneal scleral button. A 6 mm diameter donor sheet was trephined, and folded in half using a 6 mm diameter polymer as a carrier. Recipient endothelium was also hydrodissected from the limbus using trypan blue to stain the Descemet’s membrane. Continuous curvilinear descemetorhexis (CCD) was performed to remove a circular section of the Descemet’s membrane using a 27 gauge cystotome. Donor tissue was inserted into the anterior chamber through a 5 mm limbal incision and apposed to the host stroma. Polymers were removed following transplantation. Similar surgical procedures were performed in both rabbits and eyebank eyes. Haematoxylin eosin stains were performed after 28 days in rabbits, and eyebank eyes were fixed immediately following surgery for endothelial cell counts. Results: Rabbit control eyes demonstrated stromal oedema caused by loss of Descemet’s membrane, whereas transplanted eyes had clear corneas. The mean (standard deviation) pachymetry of operated eyes was 376.6 (SD 32.5) μm compared with 389.6 (SD 25.1) μm in the unoperated eye. Mean endothelial density immediately following surgery in eyebank eyes was 2749 (SD 288) cells/mm2. Conclusions: Transplantation of Descemet’s membrane by CCD produces a functional graft with an optically clear interface similar to control cornea.

Outcomes of cataract surgery in eyes with a low corneal endothelial cell density

PURPOSE: To evaluate the surgical outcomes of cataract surgery in eyes with a low preoperative corneal endothelial cell density (ECD) and analyze factors affecting the prognosis. SETTING: Tokyo Dental College, Ichikawa General Hospital, Chiba, Japan. DESIGN: Noncomparative case series. METHODS: Eyes with a preoperative ECD of less than 1000 cells/mm2 that had cataract surgery between 2006 and 2010 were identified. Standard phacoemulsification with intraocular lenses was performed using the soft‐shell technique. The rate of endothelial cell loss, incidence of bullous keratopathy, and risk factors were retrospectively assessed. RESULTS: Sixty‐one eyes (53 patients) with a low preoperative ECD were identified. Preoperative diagnoses or factors regarded as causing endothelial cell loss included Fuchs dystrophy (20 eyes), laser iridotomy (16 eyes), keratoplasty (10 eyes), traumatic injury (3 eyes), trabeculectomy (3 eyes), corneal endotheliitis (2 eyes), and other (7 eyes). The corrected distance visual acuity improved from 0.59 ± 0.49 logMAR preoperatively to 0.32 ± 0.48 logMAR postoperatively (P<.001). The mean ECD was 693 ± 172 cells/mm2 and 611 ± 203 cells/mm2, respectively (P=.001). The mean rate of endothelial cell loss was 11.5% ± 23.4%. Greater ECD loss was associated with a shorter axial length (AL) (<23.0 mm) and diabetes mellitus. Bullous keratopathy developed in 9 eyes (14.8%) and was associated with posterior capsule rupture. CONCLUSIONS: The results suggest that modern techniques for cataract surgery provide excellent visual rehabilitation in many patients with a low preoperative ECD. Shorter AL, diabetes mellitus, and posterior capsule rupture were risk factors for greater ECD loss and bullous keratopathy. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Long-term results of amniotic membrane transplantation for partial limbal deficiency

Purpose: To evaluate the long-term efficacy of amniotic membrane transplantation as a treatment option in cases with partial limbal deficiency. Methods: Sixteen eyes of 14 patients with partial limbal deficiency underwent amniotic membrane patch (AMP) or amniotic membrane graft with patch (AMGP) following keratectomy for conjunctivalization of the cornea. The average follow-up period was 52 months. We evaluated the mean corneal epithelialization time, visual acuity improvement, complications, and recurrence rate after the surgery. Results: Eleven eyes underwent AMP, and the remaining 5 eyes received AMGP. All eyes eventually attained corneal reepithelialization. The mean time to reepithelialization was not significantly different between the AMP group (9 days) and the AMGP group (27 days). At the final follow-up visit, improved Landolt visual acuity was observed in 6 of the 11 eyes in the AMP group and in 2 of the 5 eyes in the AMGP group. No intraoperative complications were observed. However, 6 eyes in the AMP group and 3 eyes in the AMGP group had a recurrence or developed a persistent epithelial defect after mean durations of 21.2 and 17.7 months, respectively. Conclusion: Both AMP and AMGP appear to be effective in attaining corneal reepithelialization, but neither could provide stable, clear corneal epithelialization in the long term.

Ocular surface reconstruction for thermal burns caused by fireworks

Purpose: To describe 6 eyes with severe firework-related ocular surface injuries that were treated by limbal stem cell transplantation combined with amniotic membrane transplantation (AMT). Methods: Six eyes of 6 patients with firework-related ocular injuries were retrospectively studied. All subjects were men, with age ranging from 9 to 26 years. All patients were in chronic stage of thermal injury, and all had total limbal stem cell dysfunction and subsequent conjunctival fibrosis. They had limbal stem cell transplantation (1 had an allograft and 5 had autograft transplantation) combined with AMT to restore vision. Mitomycin C was used in 1 eye intraoperatively. Results: After ocular surface reconstruction using limbal stem cell transplantation combined with AMT, corneal epithelialization was achieved in 4 eyes after a mean duration of 20.8 ± 12.2 days (range, 4-33 days). After a mean follow-up period of 36 months (range, 5-87 months), marked reduction of fibrosis was noted in all eyes. At last examination, the corneal surface was covered by corneal-phenotype epithelium in 4 eyes, and the remaining 2 eyes had conjunctivalization. The cornea was optically clear in 3 eyes, with corrected visual acuity of 20/100 in these 3 eyes. Both eyes that developed conjunctivalization had massive fibrosis preoperatively and severe eyelid deformities. Conclusion: Although severe firework-related ocular surface injuries were difficult to treat, limbal stem cell transplantation combined with AMT enable some success in cosmetic and visual outcome. Management of eyelid abnormalities and ocular surface fibrosis seemed to be a key to success in visual rehabilitation.

Efficacy of core vitrectomy preceding triple corneal procedure

Aims: To evaluate the effectiveness of core vitrectomy preceding triple corneal procedure (penetrating keratoplasty, extracapsular cataract extraction, and intraocular lens (IOL) implantation). Methods: Thirty one consecutive eyes of 31 patients with indication for triple corneal procedure were randomly assigned to either triple procedure with core vitrectomy (vitrectomy group) or without vitrectomy (control group). The success rate of IOL implantation, IOL positioning, intraoperative and postoperative complications, endothelial cell loss, and best corrected visual acuity (BCVA) were compared. Follow up period was six months. Factors that may contribute to vitreous pressure elevation were also investigated in each case. Results: There was no statistically significant difference in each clinical parameter examined except a tendency of facilitating IOL implantation (p = 0.11). There were two cases of vitreous loss in the control group. Retinal detachment was not seen in any of the cases. The body mass index and age were related to higher vitreous pressure (p<0.05). Conclusion: Core vitrectomy preceding triple corneal procedure is not necessary for all cases.

Deep stromal opacity after corneal cross-linking.

Purpose: To describe 3 cases with deep corneal stromal opacity that occurred several months after corneal cross-linking. Methods: A 36-year-old man, a 19-year-old man, and a 14-year-old girl underwent corneal cross-linking for their progressive keratoconus. Corneal cross-linking was performed according to the Dresden protocol. The corneal epithelium was ablated using an excimer laser in 2 cases and manually in 1 case. After 30 minutes of riboflavin presoaking, hypotonic riboflavin solution was applied until the corneal stroma swelled, after which the eyes were exposed to ultraviolet irradiation. Slit-lamp microscopy findings, uncorrected visual acuity, best-corrected visual acuity, manifest refraction, intraocular pressure, and corneal endothelial cell counts were evaluated, and corneal topography with Scheimpflug imaging was performed. Results: In all cases, the epithelium healed without delay. All eyes showed mild stromal infiltration a few days after the procedure; however, the inflammation was resolved within 1 week. The corneal stroma revealed no opacity up to 1 month after the procedure. A deep stromal opacity that extended to the inferior paracentral area developed after a few months and remained for 6 months to 1 year. Because the opacity was not on the visual axis, the visual acuity was not involved. Conclusions: Deep stromal opacity developed several months after uneventful corneal cross-linking. Postoperative inflammation may play a crucial role in its pathogenesis.

Changes in corneal sensation, epithelial damage, and tear function after descemet stripping automated endothelial keratoplasty.

Purpose: To study the ocular surface changes in eyes after Descemet stripping automated endothelial keratoplasty (DSAEK) compared with those after penetrating keratoplasty (PKP). Methods: This prospective study compared the changes in 31 eyes of 28 patients who underwent DSAEK (DSAEK group) with those in 15 disease-matched eyes of 15 patients who underwent PKP (PKP group). Corneal epithelial integrity was evaluated using a fluorescein staining score. Corneal sensation was measured with a Cochet–Bonnet esthesiometer. Tear function was evaluated using the Schirmer test, tear clearance test, tear function index, and tear break-up time. Results: The postoperative fluorescein staining score was significantly higher in the PKP group than in the DSAEK group (P = 0.02). Postoperative corneal sensation was significantly better in the DSAEK group than in the PKP group (P < 0.01). Corneal sensation after DSAEK was significantly better than the preoperative value (P = 0.02). There were no statistically significant changes in the Schirmer test, tear clearance test, tear function index, or break-up time before and after the surgery in both the DSAEK and PKP groups. No significant differences were observed between the DSAEK and PKP groups after the surgery. Conclusions: Corneal sensation was preserved, and epithelial damage was less severe after DSAEK compared with PKP. Preservation of corneal sensation may contribute to the early recovery of visual function and long-term maintenance of ocular surface health after DSAEK.

Flattening effect of corneal cross-linking depends on the preoperative severity of keratoconus

Abstract A retrospective observational study was conducted to validate the effect of corneal cross-linking (CXL) on eyes with progressing keratoconus, depending on severity. In total, 45 eyes of 33 patients (age: 23.9 ± 6.8 years, range: 14–42 years) with progressive keratoconus who underwent CXL were enrolled. Examinations were performed at pre-, 1, 3, 6, and 12 months after surgery. In addition to a slit lamp microscopy, measurement of visual acuity, the steepest keratometric value (Kmax), the thinnest corneal thickness (TCT), and the corneal endothelial cell density (ECD) were assessed. Change in Kmax (&Dgr;Kmax) was calculated by subtracting the preoperative Kmax from the 12-month postoperative Kmax. CDVA, TCT, and ECD did not change significantly throughout the follow-up period. Kmax was 56.4 ± 7.2 D preoperatively and 54.3 ± 5.6 D at 12 months after CXL (P = .174). The average value of &Dgr;Kmax was −2.23 ± 4.31 D at 12 months after CXL. &Dgr;Kmax was negatively correlated with preoperative Kmax (&rgr; = −0.5517, P = .0001), and positively correlated with preoperative TCT (&rgr; = 0.4791, P = .0012). However, no correlation was observed between Kmax and patient age or the decrease ratio of ECD. The more flattening was obtained after CXL in cases with the more advanced keratoconus. No complication, including corneal endothelial damage, was observed even in advanced cases.