Caffeine increases tear volume depending on polymorphisms within the adenosine A2a receptor gene and cytochrome P450 1A2.

PURPOSE: The primary aim of the present study was to examine the effect of caffeine on tear volume. The secondary aim was to investigate the relation between caffeine-induced changes in tear volume and polymorphisms in ADORA2A and CYP1A2. DESIGN: Double-masked, placebo-controlled, crossover study. PARTICIPANTS: Seventy-eight healthy volunteers were recruited for the study. METHODS: Subjects participated in 2 sessions in which they received capsules containing either placebo or caffeine. The caffeine capsules were given to the subjects to keep the caffeine volume per body weight within 5 to 7 mg/kg. After caffeine intake, tear meniscus height (TMH) was measured. Subjects provided a blood sample for genotyping. MAIN OUTCOME MEASURES: Tear meniscus height, single nucleotide polymorphism. RESULTS: The tear volume increased after caffeine consumption. The net increase in TMH was 0.08 mm (95% confidence interval, 0.05-0.10) greater when participants were given caffeine than when given placebo (P<0.0001). In ADORA2A, the difference in the net increase in TMH for participants who were heterozygous at rs5751876 and rs2298383 was 0.07 mm (P = 0.001) and who were minor homozygous was 0.08 mm (P = 0.007). In CYP1A2, the net increase in TMH for participants who were minor homozygous at rs2472304 was lower than for those who were major homozygous; the difference was 0.06 mm (P = 0.039). CONCLUSIONS: Caffeine intake increases tear volume and polymorphisms within ADORA2A, and CYP1A2 is associated with the tear increase after caffeine intake. Genetic polymorphisms had a significant effect on tear meniscus that was of limited clinical significance.

Laser treatment of giant iris cyst with nanophthalmos.

We report a case of a giant iris cyst treated with neodymium-doped yttrium aluminum garnet laser cystotomy. A 33-year-old woman presented with nanophthalmos and ocular hypertension secondary to a giant iris cyst after congenital cataract surgery in the left eye. Examination with a rotating Scheimpflug camera and anterior-segment optical coherence tomography revealed a large iris cyst surrounding the pupillary region. She underwent laser iridocystotomy and irrigation of the anterior chamber. No recurrence of the iris cyst has been noted after 18 months and the IOP is normal. The cyst was treated successfully by laser cystotomy without other ocular tissue damage. Examination with a rotating Scheimpflug camera and anterior-segment optical coherence tomography proved to be simple and quick methods for assessing the iris cyst.

Recent causes of subconjunctival hemorrhage.

PURPOSE: To assess the relationship between the incidence of subconjunctival hemorrhage (SCH) and age during each season of the year, and to examine recent risk factors for SCH. METHODS: A total of 161 patients with SCH aged 1-94 years were involved in the study. The age, gender, medical history and ocular history were determined for all subjects. RESULTS: The peak age of onset of SCH was between 61 and 70 years. Fourteen patients (77.7%) had trauma or contact-lens-induced injury, and 4 patients (22.3%) among the younger patients aged 0-40 years had an unknown etiology. Among the older patients aged 61-94 years, the chief risk factor for SCH was hypertension (47.5%), followed by unknown etiology (39.4%) and then diabetes (13.1%). CONCLUSION: These results suggest that the major current risk factors for SCH are trauma and contact-lens-induced injury in younger patients, while hypertension is the main factor in older patients. The incidence of acute hemorrhagic conjunctivitis was decreased.

Location and extent of subconjunctival hemorrhage.

PURPOSE: Subconjunctival hemorrhage (SCH) is a relatively frequent disease; however, there have been no reports about its location and extent. We examined its location and extent. METHODS: A total of 151 patients with SCH aged 2-94 years were studied. The conjunctiva was divided into 8 equal areas. The age, gender, medical history, ocular history and site of hemorrhage were determined for all subjects. RESULTS: The number of areas involved by SCH showed an age-related increase. Traumatic SCH had a smaller extent compared with SCH related to hypertension, diabetes and hyperlipidemia, or idiopathic SCH. Overall, SCH was significantly more common in the inferior areas than the superior areas (55.3% vs. 25.0%, p < 0.000001). In patients with SCH secondary to trauma or diabetes, however, the temporal areas were affected more often than the nasal areas (61.5% vs. 30.8% and 73.3% vs. 20.0%, respectively). CONCLUSION: SCH showed an age-related increase in extent and was predominant in the inferior areas. However, traumatic SCH was usually detected as localized hemorrhage in the temporal areas.

Subconjunctival hemorrhage and conjunctivochalasis.

OBJECTIVE: Subconjunctival hemorrhage (SCH) is a relatively common disease, but there have been no reports concerning the relationship between SCH and conjunctivochalasis (CCh). We compared the grade of CCh between patients with SCH and control patients. DESIGN: Prospective, nonrandomized study. PARTICIPANTS: A total of 104 patients with SCH aged 41 to 94 years and 120 age- and gender-matched controls aged 41 to 94 years were enrolled. METHODS: The conjunctiva was divided into the following 8 equal areas: superior, superior/nasal, nasal, inferior/nasal, inferior, inferior/temporal, temporal, and superior/temporal. The age, gender, medical history, ocular history, site of hemorrhage, grade of CCh at 3 locations (nasal, middle, and temporal), and other parameters of CCh were determined in all subjects. MAIN OUTCOME MEASURES: Grade of each CCh parameter and location of SCH. RESULTS: The mean grade of CCh was higher in patients with SCH than in control patients at the nasal (P<0.00001), middle (P<0.00001), and temporal areas (P<0.00001). The downward gaze- or digital pressure-dependent changes of CCh and the frequency of superficial punctate keratitis were all increased in SCH patients compared with control patients (P<0.00001, P<0.00001, and P = 0.00106, respectively). The number of areas involved by SCH and the presence of SCH in each area were positively correlated with the grade of each CCh-related parameter (P<0.05). CONCLUSIONS: This was the first assessment of the grade of CCh in a large series of consecutive patients with SCH. Our results strongly suggest that CCh may have an important role in the pathogenesis of SCH.

Relationship between myopia and allergen-specific serum IgE levels in patients with allergic conjunctivitis.

PURPOSE: Various exogenous allergens can cause allergic conjunctivitis, whereas refractive errors are also related (as an endogenous factor) to the pathogenesis of allergic conjunctivitis. However, little is known about the interaction between exogenous and endogenous factors in patients with allergic conjunctivitis. We investigated the relationship between refractive errors and exogenous allergens in patients with allergic conjunctivitis. METHODS: Sixty patients with allergic conjunctivitis and 60 healthy subjects (non-allergy patients) were enrolled. Refraction was carried out in all subjects. In addition, total immunoglobulin E (IgE) and specific IgE levels for 12 inhaled allergens were measured by the capsulated hydrolic carrier polymer system. RESULTS: The patients who were positive for-specific IgE to indoor allergens had higher myopia than those who were negative, including those positive for house dust IgE (-3.66 +/- 2.95 vs. -1.05 +/- 3.39, P = 0.0015), Dermatophagoides pteronyssinus (D. pteronyssinus) IgE (-3.50 +/- 2.91 vs. -1.01 +/- 3.46, P = 0.0021), and acarus IgE (-3.45 +/- 2.21 vs. -1.51 +/- 3.73, P = 0.0087), whereas antibody-positive and antibody-negative patients for outdoor allergens showed no significant differences of refraction. Refractions in indoor group (-3.58 +/- 3.42) and indoor/outdoor (-3.70 +/- 2.64) group were higher than those in outdoor group (-0.84 +/- 2.30, P = 0.0047 and P = 0.0032) and the non-allergy group (-1.30 +/- 1.48, P = 0.0082 and P = 0.0054) [-refraction] was significantly correlated with total IgE (r = 0.333, P = 0.0093), house dust (r = 0.355, P = 0.0054) and D. pteronyssinus (r = 0.379, P = 0.0028), while no correlation between refractive error and outdoor allergens was proven. CONCLUSION: These results suggest that specific IgE levels for indoor allergens, such as house dust, might be associated with refractive errors.

Severe hyperopic shift and irregular astigmatism after radial keratotomy.

OBJECTIVES: To report a case of acute high hyperopia occurring after radial keratotomy and evaluate the extent of corneal wavefront aberration with a Hartmann-Shack aberrometer. METHODS: A 45-year-old man had undergone bilateral radial keratotomy with four incisions for myopia 15 years earlier. The patient developed significant hyperopia and irregular corneal astigmatism in the left eye after the operation, reducing his best-corrected visual acuity. RESULTS: The best-corrected visual acuity was 20/20 (with refraction of +0.25-1.50 diopters [D] x 169) in the right eye and 10/20 (with refraction of +9.5D-3.00D x 50) in the left eye. Topography showed marked flattening of the left cornea, and simulated retinal images of Landolt C circles were distorted in the left eye. CONCLUSIONS: This is a rare case in which radial keratotomy induced severe hyperopic shift. Wavefront analysis with a Hartmann-Shack aberrometer revealed severe irregular astigmatism with small clear zones.

Nontraumatic keratomycosis caused by Alternaria in a glaucoma patient.

A case of keratomycosis caused by Alternaria species in a patient with glaucoma is reported. A 55-year-old Japanese man who had been followed for developmental glaucoma presented with corneal ulcer in his right eye, which did not respond to antibacterial agents. There was no history of traumatic episode. Culture on potato dextrose agar from corneal scraping yielded Alternaria species. Topical amphotericin B treatment achieved recovery from ulceration although the corneal opacity remained.

Transplantation of a sheet of human corneal endothelial cell in a rabbit model.

PURPOSE: To develop a novel method for constructing a sheet of human corneal endothelial cells (HCECs) and examine the properties of the HCEC sheet. METHODS: HCECs were cultured on a cell culture insert for a week; ethylenediamine tetraacetic acid was applied from the bottom of the cell culture insert to attenuate the attachment of HCECs. The sheet of HCECs was constructed by bluntly detaching the cell sheet with a spatula. HCEC cell sheets were placed on the posterior surface of excised rabbit corneal buttons and transplanted onto the corneal beds of donor rabbits. In two eyes from the HCEC sheet group, cultured HCECs were labeled with PKH26 to observe the localization of HCECs after transplantation. RESULTS: Cultured HCECs could be bluntly detached en bloc from the bottom of a culture insert. Immunostaining for ZO-1, Na+, K+-ATPase, laminin, fibronectin, and type IV collagen was positive in the cell sheet. The average cell density in a HCEC sheet was 2,425 cells/mm(2). After HCEC sheet transplantation, corneal edema decreased much earlier in the HCEC group than in the control group. In the HCEC sheet group, the monolayer of continuous cells attached to the posterior surface of the transplanted rabbit cornea and the posterior surface of transplanted cornea was covered with PKH26-labeled cells. The average endothelial cell density in the HCEC sheet group seven days postoperatively was 2,244 cells/mm(2). CONCLUSIONS: This technique for producing an HCEC sheet might be useful in regenerative medicine for the cornea and reconstruction of the corneal endothelium.

Necessary prone position time for human corneal endothelial precursor transplantation in a rabbit endothelial deficiency model.

PURPOSE: We previously performed human corneal endothelial precursor cell transplantation into the anterior chamber and maintenance of the prone position for 24 hours in a bullous keratopathy model. This time, we investigated the necessary postoperative time in the prone position for clinical application of precursor cell transplantation. METHODS: The sphere-forming assay was used to obtain precursors from cultured human corneal endothelial cells. Chloromethyl benzamidodialkylcarbocyanine (CM-DiI)-labeled precursor cells were injected into the anterior chamber of the eye in rabbits with corneal endothelial defects, and the prone position was maintained for 0, 1, 6, or 24 hours to allow attachment to Descemet's membrane. Rabbits maintained in the prone position for 24 hours without precursor cell transplantation were the controls. Each group was observed for 28 days after surgery, followed by histological examination and fluorescence microscopy. RESULTS: The mean corneal thickness of the rabbits kept in the prone position for 1, 6, or 24 hours after precursor cell transplantation was significantly less than that of the rabbits without adoption of the prone position after transplantation or the untransplanted rabbits at 14 days (p<0.005), 21 days (p<0.0001), and 28 days (p<0.0001) after surgery. And there was no significant differences in corneal thickness between the two groups kept in the prone position for 6 hours and 24 hours throughout the observation DiI-positive human corneal endothelial-like hexagonal cells were detected on Descemet's membrane in the rabbits kept in the prone position for 1, 6, or 24 hours, but not in the control groups. Three of the six corneas in the 1-hour group showed focal edema and incomplete coverage of the endothelial defects. CONCLUSIONS: Our findings demonstrated that transplantation of human corneal endothelial precursors into the anterior chamber with adoption of the prone position for 6 hours treated bullous keratopathy in rabbits with similar efficacy to maintenance of the prone position for 24 hours after surgery.

Preoperative evaluation of cultured human corneal limbal epithelium on amniotic membrane by confocal microscopy.

PURPOSE: Although sheet transplantation with cultured corneal limbal epithelium has been widely performed as a strategy for ocular surface reconstruction, there has been no optimal method for evaluating the morphology of these sheets prior to transplantation. We propose the use of in vivo confocal microscopy as a novel method for the evaluation of limbal corneal epithelium cultured on amniotic membrane. METHODS: Human limbal epithelial sheets were grown on amniotic membranes by following a standard protocol and were stained with hematoxylin and eosin. Morphology was studied using in vivo confocal microscopy for cultured corneal epithelium on amniotic membrane, human intact amniotic membranes, and epithelium-denuded human amniotic membranes. RESULTS: Histologic examination showed a stratified corneal epithelium sheet by the fourth week of culture. The surface and basal layers of the cultured limbal epithelium and amniotic membrane were clearly distinguished by in vivo confocal microscopy. A monolayer of amniotic epithelial cells was observed on the intact amniotic membrane, but not on the epithelium-denuded human amniotic membrane. CONCLUSIONS: Our findings support the use of in vivo confocal microscopy as a valid technique for the preoperative evaluation of cultured corneal limbal epithelial cell sheets on amniotic membrane.

Longitudinal changes in corneal irregular astigmatism and visual acuity in eyes with keratoconus.

PURPOSE: To quantitatively investigate the time course of changes in corneal irregular astigmatism and their relation to best spectacle-corrected visual acuity (BSCVA) in eyes with keratoconus. METHODS: Subjects were 47 patients (57 eyes) with keratoconus who had undergone videokeratography examinations at least twice, with an interval of 1 year or longer between each examination. By means of Fourier series harmonic analysis, topography data were separated into spherical component, regular astigmatism, asymmetry, and higher order irregularity. RESULTS: In eyes that showed apparent progression on color-coded maps, the yearly rate of change was significantly positive for spherical component (P = 0.03) and higher order irregularity (P = 0.006). In eyes with apparent progression, the yearly change rate of BSCVA was significantly positive (P = 0.001), but not in the eyes without apparent progression (P = 0.1655). In eyes with progression on maps, the yearly change rate of BSCVA was significantly correlated with the change rate of higher order irregularity per year (r = 0.770, P = 0.0004). CONCLUSIONS: The results indicated that progression of keratoconus is associated with deterioration of BSCVA, which is in turn significantly correlated with increases in corneal higher order irregularity.

Comparison of central corneal thickness measurements by rotating Scheimpflug camera, ultrasonic pachymetry, and scanning-slit corneal topography.

PURPOSE: To compare central corneal thickness measurements and their reproducibility when taken by a rotating Scheimpflug camera, ultrasonic pachymetry, and scanning-slit corneal topography/pachymetry. DESIGN: Experimental study. PARTICIPANTS: Seventy-four eyes of 64 subjects without ocular abnormalities other than cataract. METHODS: Corneal thickness measurements were compared among the 3 methods in 54 eyes of 54 subjects. Two sets of measurements were repeated by a single examiner for each pachymetry in another 10 eyes of 5 subjects, and the intraexaminer repeatability was assessed as the absolute difference of the first and second measurements. Two experienced examiners took one measurement for each pachymetry in another 10 eyes of 5 subjects, and the interexaminer reproducibility was assessed as the absolute difference of the 2 measurements of the first and second examiners. MAIN OUTCOME MEASURES: Central corneal thickness measurements by the 3 methods, absolute difference of the first and second measurements by a single examiner, absolute difference of the 2 measurements by 2 examiners, and relative amount of variation. RESULTS: The average measurements of central corneal thickness by a rotating Scheimpflug camera, scanning-slit topography, and ultrasonic pachymetry were 538+/-31.3 microm, 541+/-40.7 microm, and 545+/-31.3 microm, respectively. There were no statistically significant differences in the measurement results among the 3 methods (P = 0.569, repeated-measures analysis of variance). There was a significant linear correlation between the rotating Scheimpflug camera and ultrasonic pachymetry (r = 0.908, P<0.0001), rotating Scheimpflug camera and scanning-slit topography (r = 0.930, P<0.0001), and ultrasonic pachymetry and scanning-slit topography (r = 0.887, P<0.0001). Ultrasonic pachymetry had the smallest intraexaminer variability, and scanning-slit topography had the largest intraexaminer variability among the 3 methods. There were similar variations in interexaminer reproducibility among the 3 methods. CONCLUSIONS: Mean corneal thicknesses were comparable among rotating Scheimpflug camera, ultrasonic pachymetry, and scanning-slit topography with the acoustic equivalent correction factor. The measurements of the 3 instruments had significant linear correlations with one another, and all methods had highly satisfactory measurement repeatability.

Ocular manifestations of congenital insensitivity to pain with anhidrosis.

PURPOSE: To describe ocular manifestations in Japanese patients with congenital insensitivity to pain with anhidrosis (CIPA), focusing particularly on the status of the ocular surface. DESIGN: Observational case series. METHODS: Eighteen patients with CIPA underwent applicable ophthalmologic examinations, including visual acuity, refraction, slit-lamp examination, fundus examination, tear breakup time, Schirmer 1 test, corneal sensitivity, and corneal topography. RESULTS: Superficial punctate keratopathy (SPK) was observed at the interpalpebral area in 23 (64%) of 36 eyes. Corneal opacity was observed in three eyes (8.3%). Tear breakup time was below the lower limit of the normal range in all examined eyes, and the value of Schirmer 1 test was above the lower limit of the normal range in most of the examined eyes. CONCLUSIONS: Superficial punctate keratopathy is observed in most cases of CIPA, which might predispose patients to corneal infection. Investigation of dry eye in patients with CIPA will provide unique opportunities to explore the critical roles of the autonomic sympathetic nervous system as well as the sensory nervous system in the physiology of tear production.

Effects of Switching from Timolol to Brimonidine in Prostaglandin Analog and Timolol Combination Therapy.

PURPOSE: To assess the efficacy and safety of switching from timolol 0.5% to brimonidine 0.1% in patients with glaucoma treated with a prostaglandin analog (PGA) and timolol combination. METHODS: This prospective, open-label multicenter study enrolled patients with open-angle glaucoma or ocular hypertension who were being treated with a PGA and timolol. After baseline measurements, timolol was switched to brimonidine 0.1%, and patients were followed for 12 weeks. Patients visited at 4 and 12 weeks after switching. The main outcome measure was the change in intraocular pressure (IOP). For safety evaluations, hyperemia, formation of conjunctival follicles, superficial punctate keratopathy as a local side effect, blood pressure (BP), and heart rate (HR) were evaluated. RESULTS: One hundred seven patients participated in this study. Among them, 103 patients completed the study. The IOP values at baseline, 4 weeks, and 12 weeks after the transition were 15.7 ± 2.7, 14.3 ± 2.8, and 14.0 ± 2.8 mmHg, respectively. IOP was significantly reduced at 4 and 12 weeks compared with baseline (p<0.001). There were no significant changes in hyperemia or follicle formation. The superficial punctate keratopathy score was significantly reduced at 12 weeks compared with baseline (p<0.05). Systolic and diastolic BP values were significantly reduced and HR significantly increased after switching (p<0.05). CONCLUSION: Switching from timolol 0.5% to brimonidine 0.1% may not change IOP in the combination use of timolol 0.5% and a PGA and was well tolerated by patients without severe ocular or systemic side effects.

Five-year follow-up of photorefractive keratectomy for myopia.

PURPOSE: To analyze long-term results of photorefractive keratectomy (PRK) for myopia and myopic astigmatism. METHODS: This retrospective study included 15 eyes of 8 patients who were examined annually for 5 years after PRK. The Nidek EC-5000 laser with an ablation zone of 5.0 mm was used. Evaluations included spherical equivalent manifest refraction, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal haze, and corneal astigmatism calculated by Fourier analysis of videokeratography data. RESULTS: A tendency toward myopic regression was most evident within the first postoperative year, with manifest refraction changing from +0.80 +/- 1.62 D at 1 week to -0.45 +/- 0.70 D at 1 year postoperatively (P = .007). Regression continued after the second postoperative year. There was a statistically significant difference between manifest refraction at 2 years (-0.36 +/- 0.75 D) and 5 years (-1.11 +/- 1.12 D) (P = .002). Postoperative UCVA stabilized from 3 months up to 3 years, but slightly deteriorated at 4 years and thereafter due to the myopic refractive shift. BSCVA remained stable throughout the 5-year follow-up period. Several eyes developed mild corneal haze after surgery, but haze was minimal in the majority of patients by 1 year and continued to fade over time. The asymmetry component of the cornea significantly increased after surgery, with all postoperative values significantly higher than before PRK (P < .05). Higher order irregularity increased after surgery, with a statistically significant difference between preoperative and 1 year postoperative (P < .05), but values after 2 years were not different from preoperative baseline. CONCLUSION: Fifteen eyes with a baseline refraction of -3.00 to -9.00 D had PRK with the Nidek EC-5000 laser and a 5-mm-diameter ablation zone. Myopic regression occurred in the first year, with continued mild regression of approximately -0.75 D between 2 and 5 years. Nevertheless, the results show the procedure was relatively safe and effective in this group.

New graft inserter for descemet stripping automated endothelial keratoplasty.

PURPOSE: The aim of this study was to introduce a newly developed graft inserter for Descemet stripping automated endothelial keratoplasty, which can be readily used with 1 hand, and to examine endothelial cell loss (ECL) after graft insertion using this new inserter in an ex vivo rabbit model. METHODS: Rabbit corneal grafts (∼150 µm) were prepared by using a femtosecond laser. The grafts were inserted into an artificial anterior chamber by the pull-through technique using a Busin glide or the push-out technique using our new inserter. ECL was evaluated by means of trypan blue and alizarin red S staining. Grafts that were not injected served as a control group. RESULTS: The mean percentages of ECL area in the control, Busin glide, and new inserter groups were 18.7 ± 1.79%, 25.4 ± 2.32%, and 24.7 ± 1.56%, respectively. The mean percentages of the ECL area in both the Busin glide group and new inserter groups were significantly greater than that in the control group (P = 0.001). There was no statistically significant difference between the Busin glide group and the new inserter group. CONCLUSIONS: Our new inserter may provide a favorable option for donor tissue insertion in Descemet stripping automated endothelial keratoplasty procedures.

Effect of trabeculectomy on ocular and corneal higher order aberrations.

PURPOSE: To examine the effect of trabeculectomy on ocular and corneal higher order wavefront aberrations. METHODS: Trabeculectomy with a limbal-based conjunctival flap was performed in 13 patients (13 eyes). Ocular and corneal higher order aberrations were measured using a wavefront analyzer before and after surgery. The higher order aberrations for a 4-mm pupil diameter were expanded into Zernike's polynomials. Coma aberration, spherical aberration, and total higher order aberrations were evaluated as root mean square values. RESULTS: Mean intraocular pressure was significantly reduced from 15.5 ± 3.1 mmHg preoperatively to 7.5 ± 3.5 and 7.2 ± 4.4 mmHg at 1 and 3 months after surgery, respectively. The mean spherical equivalent refractive error was not changed by the surgery. Mean vector powers for surgically induced refractive changes at 1 and 3 months postoperatively were 1.29 ± 0.69 and 1.30 ± 0.89 diopters, respectively. Corneal coma-like, spherical-like, and total higher order aberrations were not significantly changed by surgery. Trabeculectomy significantly increased ocular coma-like (P = 0.0021) and total (P = 0.0019) higher-order aberrations at 1 month, but not at 3 months postoperatively. CONCLUSION: Ocular coma-like and total aberrations were significantly increased at 1 month after trabeculectomy with a limbal-based conjunctival flap, but they had returned to normal levels by 3 months.

Identification of Schlemm's canal and its surrounding tissues by anterior segment fourier domain optical coherence tomography.

PURPOSE: To identify Schlemm's canal (SC) and trabecular meshwork (TM) by anterior segment Fourier-domain optical coherence tomography (AS-FD-OCT) with histologic confirmation in enucleated human eyes and to quantitatively evaluate SC and TM in living human eyes. METHODS: In enucleated human eyes, the imaging of the anterior chamber angle by AS-FD-OCT was performed before and after surgical expansion of SC with an injection of a viscoelastic material, followed by histologic examination. In 60 living human eyes, the agreement of identification of SC between examiners was evaluated with the Cohen's κ values, and the lengths of SC and TM and the area of TM were measured on temporal and nasal sections of the AS-FD-OCT images. RESULTS: In enucleated human eyes, SC was observed to be a thin, linear, lucent space in the AS-FD-OCT image obtained with the high-definition raster scan protocol, but not in those obtained with the bi-angle radial scan protocol. This space was enlarged after the SC expansion. In the histologic study, the SC was confirmed to be in the same position as in the AS-FD-OCT images. The κ values of observable SC in living human subjects were 0.92 or higher. The axial length of the SC averaged 347.2 ± 42.3 µm, TM length 466.9 ± 60.7 µm, and TM area 0.0671 ± 0.0058 mm². These measurements showed sufficient repeatability and reproducibility. CONCLUSIONS: Using the high-definition images of the AS-FD-OCT, SC and its surrounding tissues were successfully observed in most of the living eyes and were quantitatively evaluated in a noninvasive manner.

Extended long-term results of penetrating keratoplasty for keratoconus.

PURPOSE: To investigate the extended long-term results of penetrating keratoplasty (PK) for keratoconus. METHODS: The subjects were all patients with clinical keratoconus who underwent initial PK at University of Tokyo from 1971 to 1990 and whose medical records were available. Data were retrieved from the medical records. Kaplan-Meier survival analysis was performed to estimate the cumulative probability of immune reaction-free grafts and graft survival. RESULTS: One hundred twenty-five eyes in 125 patients met the entry criteria. The average age at the time of PK was 25.0 +/- 8.9 years. With an average follow-up period of 15.3 +/- 9.7 years, 12 eyes (9.6%) experienced rejection and 5 eyes (4.0%) experienced graft failure. Average best-corrected visual acuity in logarithm of the minimum angle of resolution at preoperation, 10, 20, and 25 years after surgery was 1.54 +/- 0.68, 0.06 +/- 0.22, 0.03 +/- 0.17, and 0.14 +/- 0.42, respectively. The cumulative probability of graft survival at 10, 20, and 25 years after PK was 98.8%, 97.0%, and 93.2%, respectively. CONCLUSIONS: Recovery of visual acuity was good after PK for keratoconus in an extended follow-up. The graft survival rate, however, gradually decreased 20 years after PK.