Published papers

AIM: To evaluate the signs and symptoms of dry eye disease (DED) in adolescents. METHODS: This was a cross-sectional, case-control study and outpatients aged 10 to 19y were recruited from six eye clinics of various practices and locations in Japan, and 253 non-DED subjects and 70 DED patients were enrolled. Participants were examined for DED-related signs. Patients were also interviewed to ascertain the presence or absence of six common DED-related symptoms: dryness, irritation, pain, eye fatigue, blurring, and photophobia. Main outcome measures were differences in signs and symptoms of dry eye disease between boys and girls. RESULTS: Of the 323 adolescents recruited, 70 (21.7%) were diagnosed with DED. Significant differences between the non-DED and DED groups were found for short tear break-up time (BUT; /=3; P=0.000). Late adolescent girls reported fewer symptoms than late adolescent boys, although their DED-related signs were worse compared to other groups. The prevalence and severity of DED were similar in the Tokyo area compared with suburban and local areas but myopic errors were worse. CONCLUSION: We find that adolescents reported symptoms of DED similar to those found in adults, and the majority have short BUT-type DED. The prevalence and severity of DED in late adolescent girls is comparable with adults. Adolescents with DED are underserved and we believe that DED is a hidden but potentially serious health problem for this age group.

PURPOSE: We retrospectively investigated the efficacy of corneal crosslinking (CXL) on progressive keratoconus in a Japanese population and compared the outcomes of conventional and accelerated CXL. STUDY DESIGN: A retrospective cohort study METHODS: A total of 108 consecutive eyes in 95 patients (75 men; 21.9 +/- 6.2 years) with progressive keratoconus were enrolled. The epithelium was ablated in all eyes. After presoaking the corneal stroma in riboflavin, UV-A was irradiated at 3.0 mW/cm(2) (conventional CXL) for 30 min on 23 eyes and 18.0 mW/cm(2) for 5 min (accelerated CXL) on 85 eyes. Best spectacle-corrected visual acuity (BSCVA), manifest refraction, keratometric value, corneal thickness, corneal endothelial cell density (ECD), intraocular pressure, and complications were evaluated at 1, 3, 6, and 12 months after the procedure. RESULTS: BSCVA, manifest refraction, ECD, and corneal thickness did not change significantly after both procedures. The keratometric value was significantly decreased from the preoperative value at 12 months (p < 0.001). Progression to more than 1.0 D after CXL was observed in 10 eyes (9.3%). The DeltaKmax was negatively associated with preoperative Kmax (p < 0.001) and positively associated with preoperative thinnest corneal thickness (p < 0.001). Both treatment modules showed no significant difference in all parameters. CONCLUSION: CXL was as effective in treating keratoconus in Japanese patients as in individuals of other ethnicities. Overall, CXL could be performed using either the conventional or accelerated approach to halt the progression of keratoconus in Japanese populations.

PURPOSE: To evaluate the results of intraocular lens (IOL) power calculation using different corneal power measurements provided by an optical biometer combined with a dual Scheimpflug analyzer and a Placido disk topographer (Galilei G6). SETTING: G.B. Bietti Foundation, Rome, Italy, and Keio University Hospital, Tokyo, Japan. DESIGN: Evaluation of diagnostic technology. METHODS: Consecutive patients having cataract surgery were enrolled. The IOL power was calculated with the Barrett Universal II, Haigis, Hoffer Q, Holladay 1, and SRK/T formulas. Different options were used to calculate the corneal power: simulated keratometry (K) based on anterior corneal surface measurements only and total corneal power (TCP) based on ray tracing through both corneal surfaces. Three TCP measurements (TCP1, TCP2, and TCP-IOL) were evaluated. RESULTS: The study analyzed 118 eyes. The mean values of simulated K (43.74 diopters [D] +/- 1.40 [SD]), TCP1 (43.13 +/- 1.35 D), TCP2 (41.87 +/- 1.30 D), and TCP-IOL (42.62 +/- 1.35 D) were significantly different (P < .0001). The best results were obtained using simulated K: the median absolute error ranged between 0.22 D and 0.29 D and the percentage of eyes with a prediction error of +/-0.50 D or less, between 76.2% and 84.7%, depending on the formula. After constant optimization, the results using any TCP value and simulated K were similar with no statistically significant differences. CONCLUSIONS: Biometric measurements provided by the Scheimpflug-Placido optical biometer can be used to accurately calculate the IOL power. Simulated K and TCP led to similar outcomes after constant optimization.

PURPOSE: To validate a paper-based visual acuity (PBVA) questionnaire. METHODS: In 2015, a cross-sectional survey was conducted among 301 young and middle-aged, mostly male, Japanese subjects. The participants were asked to self-rate their visual acuity (VA) on a scale from 1 to 5. Self-ratings of VA were categorized into three groups: good (1 and 2), normal (3), and poor (4 and 5). For objective validation, we performed a functional VA (FVA) assessment in the same subjects. RESULTS: A total of 301 subjects answered the PBVA and completed the FVA test including initial VA. We found out that the result of PBVA was significantly correlated with FVA test and initial VA (r=0.33, P<0.0001, r=0.273, P<0.0001). The trend test analysis between PBVA and FVA also showed statistically significant (P<0.0001). CONCLUSION: There was a significant statistical correlation between the PBVA and the FVA, as well as the initial VA. This short questionnaire on VA might be a sensitive tool that is easy to implement and utilized in large epidemiological and clinical researches.

PURPOSE: Prior studies suggested that glaucoma patients suffer worse dry eye and mood and sleep disorders than non-glaucoma subjects. Prostaglandin analogues are first-line therapy for glaucoma, inducing few instillation problems and sufficient pressure-reduction effects. This study compared dry eye, sleep quality, and mood status between glaucoma patients receiving prostaglandin monotherapy and non-glaucoma subjects. METHODS: This cross-sectional study evaluated 1520 patients (579 males and 941 females) for glaucoma status and dry eye-related symptoms (dryness, eye fatigue, photophobia, pain, blurring) and signs (Schirmer test, tear break-up time, corneal staining scores). Of the total cohort, 93 patients were also evaluated by Pittsburgh sleep quality index (PSQI) and hospital anxiety and depression score (HADS). Inclusion criteria were consecutive patients >/= 51 years of age and best-corrected visual acuity >/= 20/25. Glaucoma patients included those treated with prostaglandin or a fixed combination including prostaglandin. Exclusion criteria were history of ocular surgery within one month. Data were analyzed using the chi-square or Mann-Whitney U tests, at 5% significance. RESULTS: There were no significant differences in dry eye-related signs and symptoms between the control (n = 1431, mean age of 66.9 years) and glaucoma groups (n = 89, 67.9 years). The psychiatric sub-analysis of the control (n = 61, 66.2 years) and glaucoma groups (n = 32, 67.3 years) revealed mean scores of 5.02 +/- 3.10 and 5.16 +/- 3.46 for PSQI (normal range = 5), 9.47 +/- 5.61 and 9.42 +/- 7.36 for HADS (normal range </= 10), 4.84 +/- 3.22 and 4.71 +/- 3.45 for anxiety (normal range </= 5), and 4.63 +/- 3.05 and 4.71 +/- 4.40 for depression (normal range </= 5), respectively, without statistical significance. CONCLUSIONS: Our results were comparable between glaucoma patients on prostaglandin monotherapy and non-glaucoma subjects for dry eye-related clinical manifestations, sleep quality, and mood status.

PURPOSE: The purpose of this study was to evaluate the influence of seasons on the signs and symptoms of dry eye disease (DED). METHODS: This is a cross-sectional, case-control study, and participants were non-DED subjects (n=1,916, mean age 54.4+/-14.4 years) and DED patients (n=684, 54.2+/-12.1 years) visiting six eye clinics at various practices and locations in Japan. We evaluated the signs and symptoms of DED and the seasons with the most severe results were compared to those with the least severe results in both groups. Main outcome measures were differences in the severity of the signs and symptoms of DED between the most and least severe seasons. RESULTS: The majority of DED symptoms were most severe during spring and least severe in summer. Significant differences between these two seasons were found for irritation (P=0.001), pain (P=0.007), blurring (P=0.000), and photophobia (P=0.007) in the DED group. Superficial punctate keratopathy (P=0.001) and tear break-up time (BUT; P=0.000) results also indicated that DED was most severe in spring. In contrast, fewer patients had low Schirmer test results in spring, although this was not statistically significant (P=0.061). CONCLUSION: Our results demonstrated that the severity of DED is seasonal, which may explain the increase of short BUT-type DED cases observed in spring when air pollen counts are highest.

Various methods can correct presbyopia, but all require devices or surgeries. Recently, supplements or warming devices to relieve presbyopic symptoms have been developed, but no eye drops have been developed. We screened certain compounds possibly related to lens degeneration and identified pirenoxine, which has been used for cataracts, as a possible new pharmacologic treatment for presbyopia. We first researched the anti-presbyopic activity of pirenoxine in rats. The lens elasticity significantly (p = 0.028) increased with exposure to tobacco smoke for 12 days, and pirenoxine eye drops significantly (p < 0.001) suppressed lens hardening, which causes presbyopia in humans. In a parallel randomized controlled clinical study of the subjects in their fifth decade of life, the objective accommodative amplitude (AA) decreased significantly (p < 0.01) by 0.16 diopter (D) in the control group, and there was no detectable change in the treatment group after a 6-month treatment period, suggesting that pirenoxine eye drops might prevent progression of presbyopia. Subjects in their sixth decade of life, in whom the AA was already nearly 0 D, did not show similar results. Pirenoxine eye drops might be a new and the first pharmacologic treatment for preventing progression of presbyopia.

PURPOSE: To compare the visual and refractive outcomes up to 1 year postoperatively following implantation of a refractive segmented or a refractive segmented toric multifocal intraocular lens (IOL). METHODS: This retrospective study included 108 eyes of 64 patients who underwent cataract surgery with implantation of a refractive segmented multifocal IOL (Lentis Mplus LS-313 MF30 IOL) (LM group) and 81 eyes of 49 patients with implantation of a refractive segmented toric multifocal IOL (Lentis Mplus LU-313 MF30T IOL) (LMT group). The visual and refractive postoperative outcomes and the rate of additional refractive procedures were evaluated up to 1 year postoperatively. RESULTS: The uncorrected distance visual acuity (VA) and uncorrected near VA exceeded 1.0 and 0.60 in decimal VA, respectively, and both were stable postoperative groups. The postoperative subjective refractive astigmatism was also stable and the postoperative refraction was near emmetropia in both groups. No significant differences were found in the need for additional surgical refractive procedures. CONCLUSION: The outcomes with a refractive segmented toric multifocal IOL were comparable to those with a non-toric model despite higher preoperative corneal astigmatism.

PURPOSE: To assess the clinical outcomes of currently used refractive surgery procedures performed in 2015. DESIGN: Prospective, multicenter cohort study. METHODS: This prospective study included 15 011 eyes of 7622 consecutive patients who underwent laser in situ keratomileusis (LASIK), surface ablation, refractive lenticule extraction (ReLEx), or phakic intraocular lens (IOL) implantation at 42 major institutions. We determined the safety, efficacy, predictability, stability, and adverse events of these surgeries preoperatively and at 1 week and 1 and 3 months postoperatively. RESULTS: Mean logMAR corrected distance visual acuity 3 months after LASIK, surface ablation, ReLEx, posterior chamber phakic IOL, or iris-supported phakic IOL implantation was -0.18 +/- 0.07, -0.16 +/- 0.08, -0.17 +/- 0.09, -0.21 +/- 0.08, and -0.10 +/- 0.12, respectively; the corresponding values for logMAR uncorrected distance visual acuity were -0.15 +/- 0.11, -0.12 +/- 0.12, -0.12 +/- 0.13, -0.15 +/- 0.12, and 0.01 +/- 0.21, respectively. The percentages within +/-1.0 diopter (D) of the attempted correction were 96%, 93%, 97%, 99%, and 84% after LASIK, surface ablation, ReLEx, posterior chamber phakic IOL, and iris-supported phakic IOL implantation, respectively. Refractive change from 1 week to 3 months was -0.08 +/- 0.07, 0.21 +/- 0.63, -0.04 +/- 0.41, 0.01 +/- 0.31, and 0.01 +/- 0.46 D, respectively. No vision-threatening complications occurred during the observation period. CONCLUSIONS: Although more prolonged follow-up is still necessary, currently used refractive surgery procedures have good safety and efficacy outcomes, yielding predictable and stable results. Contemporary LASIK, surface ablation, ReLEx, and phakic IOL implantation appear to be feasible options for the treatment of refractive errors.

This study aimed to identify the type of cataract opacity associated with subjective sleep quality for cataract patients. A total of 180 consecutive patients (average age 74.2 years) underwent cataract surgery with implantation of an ultraviolet-blocking or blue light-blocking intraocular lens. The participants' subjective sleep quality was evaluated using the Pittsburgh sleep quality index (PSQI) before and at 2 months after surgery. Patients were divided into two groups for analysis: normal sleepers (preoperative PSQI /=6). The preoperative and postoperative PSQI scores were 2.8 +/- 1.5 and 3.2 +/- 2.0, respectively, for normal sleepers (n = 99), and 8.5 +/- 2.9 and 7.4 +/- 3.3, respectively, for poor sleepers (n = 81). The improvement in PSQI was significant in poor sleepers (p < 0.0001, Wilcoxon's test) with measured values of 0.22 +/- 0.96 hours extension in sleep duration and 0.16 +/- 0.62 hours shortening in sleep latency. Patients with posterior subcapsular cataract (PSC) and nuclear opacity showed the greatest improvement in PSQI score, with regression analysis identifying PSC as having a significant effect on improvement in PSQI. Significant correlations were found between the subjective sleep and cataract opacity in cataract patients. Ophthalmic personnel should therefore be aware that cataract patients with PSC have a greater potential for disability and predictable benefits from surgery in vision and subjective sleep.

An understanding of corneal optics is important to optimize the visual outcome after eye surgery. Recent advances in the surgical techniques of lamellar keratoplasty have changed the strategies used for corneal transplantation. Lamellar keratoplasty has the advantage of having a lower rate of graft rejection, superior biomechanical properties, and reduced higher-order aberrations (HOAs) compared with penetrating keratoplasty; thus, the use of lamellar keratoplasty has increased over the last 15 years. However, some patients have poor postoperative visual acuity despite a clear cornea, and the reasons for the poor visual outcome are poorly understood. By combining corneal imaging technologies and the latest optical software, we proposed the concept of "parallelism of anterior and posterior surfaces in lamellar keratoplasty." In physiologically normal eyes, in which the anterior and posterior surfaces are parallel to each other, the posterior surface of the cornea compensates the HOAs of the anterior surface, and this is also true in eyes after penetrating keratoplasty. However, after lamellar keratoplasty, in which the anterior and posterior surfaces are independent and not parallel, irregularities in the posterior surface increase the HOAs of the anterior surface. This article introduces this concept to enhance our understanding of visual optics in eyes after penetrating and lamellar keratoplasties and how to apply this concept to surgery to improve and optimize patient visual outcomes.

We describe a foldable acrylic intraocular lens (IOL) with distended haptics suitable for transscleral fixation and the insertion procedure. The IOL has an acrylic optic and poly(methyl methacrylate) haptics with a microscopic indentation 1.3 mm from the tip. Transscleral fixation of the IOL was performed through corneal incisions in 22 eyes, and surgical results were retrospectively assessed. The IOL was sutured firmly in position using the cow-hitch procedure, and there was no suture loosening to the distended haptic. The IOL design provided suitable fixation and may be indicated for bag fixation as well as transscleral fixation. © 2009 ASCRS and ESCRS.