Tatsuro Tanabe

Corneal epithelial barrier function in diabetic patients

Purpose To evaluate the corneal epithelial barrier function in diabetic patients. Methods In 29 eyes of 29 diabetic patients and 55 eyes of 55 nondiabetic controls, corneal epithelial permeability to fluorescein was measured using an anterior fluorophotometer. The average fluorescein concentration in the central cornea was compared between diabetic patients and controls. Multiple regression analysis was used to assess the factors that affect corneal epithelial barrier function in diabetic patients. Results The average fluorescein concentrations in diabetic patients and nondiabetic controls were 44.1 ± 25.3 ng/mL and 29.9 ± 19.8 ng/mL (mean ± SD), respectively (P = 0.0057, unpaired t test). An explanatory variable relevant to the impaired corneal epithelial barrier function was the serum hemoglobin A1c (HbA1c) concentration (standardized partial regression coefficient = 0.466, P = 0.0163). Conclusions The corneal epithelial barrier function is impaired in diabetic patients. Diabetic patients with higher serum HbA1c levels are more predisposed to impaired barrier function in the corneal epithelium.

Progression of keratoconus assessed by fourier analysis of videokeratography data

OBJECTIVE To quantitatively document changes in corneal refractive parameters in relation to the progression of keratoconus over years. DESIGN Retrospective observational case series. PARTICIPANTS Eighty-five eyes of 64 patients with keratoconus who had undergone videokeratography examinations at least twice with an interval of 1 year or longer between each examination. METHODS By means of Fourier series harmonic analysis, topography data were decomposed into spherical component, regular astigmatism, decentration component, and higher order irregularity. MAIN OUTCOME MEASURES Change rate of each parameter per year was calculated by use of the least squares method. RESULTS All four refractive parameters were significantly larger in the keratoconic eyes than in the age-matched normal controls (P < 0.001, Students t test). The yearly rate of change was significantly positive for spherical component (P = 0.008) and higher order irregular astigmatism (P = 0.015) but not for the regular astigmatism and decentration component. In eyes that showed apparent progression on color-coded maps, spherical component showed a significantly positive change rate per year (P = 0.002), but other parameters did not. In eyes without apparent progression, the yearly change rate of higher order irregular astigmatism was significantly larger than zero (P = 0.049). CONCLUSIONS Keratoconus progression over years was quantitatively described. It was indicated that spherical equivalent is a manifest indicator for the apparent progression of keratoconus, and irregular astigmatism increases along with the natural course of the disease.

Intracameral air injection for acute hydrops in keratoconus

PURPOSE To evaluate the efficacy and safety of intracameral air injection in treating acute hydrops in keratoconus. DESIGN Retrospective, nonrandomized, comparative trial. METHODS PATIENTS Thirty eyes (30 patients) with acute hydrops secondary to keratoconus. INTERVENTION Nine eyes (nine patients) with acute hydrops in keratoconus were treated with intracameral injection of 0.1 ml filtered air. Additional 0.1 ml filtered air was injected if corneal edema persisted when air disappeared from the anterior chamber. Twenty-one eyes (21 patients) with acute hydrops that received no therapy or conventional therapy not likely to shorten the duration of hydrops served as controls. MAIN OUTCOME MEASURES The period of persistence of corneal edema, the interval between the onset of acute hydrops, and the time when the eye could begin to wear a hard-contact lens, and best spectacle-corrected and hard-contact lens-corrected visual acuity after corneal edema subsided were used as criteria to evaluate any differences between the two groups. RESULTS The average period of persistence of corneal edema was 20.1 +/- 9.0 days (+/- SD) in the intracameral air injection group and 64.7 +/- 34.6 days in the control (P =.0008). The average interval between the onset of acute hydrops and the time when the eye could begin to wear a hard-contact lens, was 33.4 +/- 5.6 days in the air injection group and 128.9 +/- 85.8 days in the control group (P =.0058). The best-corrected visual acuity after corneal edema subsided was similar between the two groups. Intracameral air injection induced no complications. CONCLUSIONS The results suggest that the intracameral air injection is a safe and useful therapy to shorten the period of corneal edema in acute hydrops secondary to keratoconus.

Regular and irregular astigmatism after superior versus temporal scleral incision cataract surgery.

OBJECTIVE To evaluate the effect of superior and temporal scleral incisions on regular and irregular astigmatism in small incision cataract surgery. DESIGN Prospective, randomized, comparative clinical trial. PARTICIPANTS One hundred seventy-four eyes of 87 patients with bilateral cataracts scheduled to undergo routine cataract surgery. METHODS One eye of each patient was randomly assigned to the superior incision group, and the contralateral eye was allocated to the temporal incision group. Phacoemulsification and intraocular lens implantation were performed through an unsutured 4.1-mm scleral incision. Patients were examined 1 day and 1, 3, and 6 months after surgery. MAIN OUTCOME MEASURES Surgically-induced regular astigmatism calculated with vector analysis method, irregular astigmatism obtained by Fourier analysis of videokeratography data, and uncorrected and corrected visual acuity. RESULTS Postoperatively, the superior incision group showed slight against-the-rule astigmatic changes, whereas slight with-the-rule astigmatism was seen in the temporal incision group. The amount of against-the-wound astigmatism and absolute value of length of the induced vector did not differ significantly between groups (P > 0.05, paired t test). In both groups, irregular astigmatism 1 day after surgery was significantly greater than the preoperative levels (P < 0.001), but not thereafter. No significant intergroup difference was observed in the amount of irregular astigmatism at any postoperative visits (P > 0.05). There was no significant difference in uncorrected and corrected visual acuity between groups postoperatively (P > 0.05, chi-square test). CONCLUSIONS In small scleral incision cataract surgery, superior and temporal approaches are comparable in terms of visual rehabilitation and induction of regular and irregular astigmatism.

Standardized color-coded scales for anterior and posterior elevation maps of scanning slit corneal topography

PURPOSE To find the most appropriate color-coded scales for the anterior and posterior elevation maps of scanning slit topography in the screening of abnormal corneas such as keratoconus. DESIGN Retrospective case-control study. PARTICIPANTS Eighty eyes of 40 normal subjects and 175 eyes of 95 patients with keratoconus. INTERVENTION Anterior and posterior corneal elevations were assessed using Orbscan 2. Best-fit sphere maps were drawn with several color-coded scales: 2-, 5-, 10-, and 20-microm height per each color interval. MAIN OUTCOME MEASURES The maps were judged to be abnormal when more than three colors (discriminant number) were found within the central 3-mm area. For each color-coded scale, sensitivity, specificity, positive predictive value, negative predictive value, and sensitivity + specificity were calculated. After determining the most appropriate color-coded scales for the anterior and posterior elevation maps, validity of the discriminant number was assessed. By varying the discriminant number from two to eight, receiver operator characteristic (ROC) curves were created using the sensitivity and specificity for each threshold number. RESULTS The highest sensitivity + specificity values and highly balanced predictive values were obtained with the 10- and 20-microm scales for the anterior and posterior elevation maps, respectively. The ROC curve analyses showed that the best discriminant color number is three, indicating that maps with four or more colors within the central 3-mm area are judged abnormal in screening. CONCLUSIONS The 10- and 20-microm interval color scales are most appropriate for the anterior and posterior elevation maps of the scanning slit topography, respectively.

Difference map or single elevation map in the evaluation of corneal forward shift after LASIK

PURPOSE Forward shift of the cornea after excimer laser refractive surgery has been assessed on a difference map generated from two elevation maps of the scanning-slit corneal topography. The current study was conducted to test whether similar evaluation is possible on a postoperative color-coded elevation map alone. DESIGN Prospective, noncomparative case series. PARTICIPANTS One hundred sixty-three eyes of 86 patients with myopic refractive errors of -1 to -13.50 diopters. INTERVENTION LASIK was performed. Corneal topography of the posterior corneal surface was obtained with the scanning-slit topography system before and 1 month after surgery. MAIN OUTCOME MEASURES The amount of forward shift of the posterior corneal surface was determined at the center of the difference map generated from preoperative and postoperative elevation maps. For surface alignment in the difference map, the 3-mm wide peripheral annular fit-zone was used. The eyes were classified into two groups depending on the amount of forward shift, using 50 micro m as the threshold. Next, on the single postoperative color-coded elevation map, which is drawn relative to the individual best-fit sphere, the eye was judged to be abnormal (with significant forward shift) when more than three colors (discriminant number) were found within the central 3-mm area, and sensitivity and specificity were calculated. By varying the discriminant number from 3 to 9, receiver operator characteristic (ROC) curves were created. RESULTS The ROC curve analyses demonstrated that sufficient true positive ratio (sensitivity) and false-positive ratio (100-specificity [%]) could not be obtained with any discriminant color number when judgments were made on a single color-coded map. There was a weak, but significant, correlation between the amount of corneal forward shift and the radius of curvature of the posterior best-fit sphere (Pearson r = -0.170; P = 0.030), indicating that a cornea with greater forward shift tended to be drawn on a steeper best-fit sphere, and thus the forward protrusion of the posterior surface failed to be depicted. CONCLUSIONS Forward shift of the cornea after excimer laser surgery should be evaluated on the difference map generated from two elevation maps, such as preoperative and postoperative maps.

Case of metastatic pulmonary carcinoma in optic disc diagnosed from results of biopsy performed during vitrectomy surgery.

BackgroundMost intraocular metastatic tumors occur in the uveal tract, while isolated metastasis to the optic nerve is rarely found. We report a case of metastasis to the optic disc from primary lung cancer, diagnosed from biopsy findings obtained during a vitrectomy.Patient and methodsA 69-year-old male presented with gradual visual impairment due to a milky white tumour that extended from the optic disc into the vitreous cavity. A systemic examination revealed primary squamous cell lung cancer.ResultsA biopsy specimen was obtained from the optic disc tumor during a vitrectomy, which led to a diagnosis of metastasis from lung cancer. Despite courses of chemotherapy and radiotherapy, the patient died of brain metastasis.DiscussionThere are few reports of secondary optic disc tumors and pathological biopsy findings are rare. When a milky white tumor is observed extending from the optic disc, a possible differential diagnosis is metastatic neoplasm.

Accommodative loss after retinal cryotherapy.

PURPOSE To investigate the effects of peripheral retinal cryotherapy on accommodative amplitude in patients with retinal lattice degeneration. DESIGN Prospective, observational case series. METHODS We studied 92 eyes in 69 patients (age range, 13 to 79 years) treated with cryotherapy for lattice degeneration between December 2001 and September 2004. Pretreatment and posttreatment accommodative amplitudes were measured. Acute accommodative loss was calculated from the difference between accommodative amplitudes before treatment and one week after treatment. We investigated the time course of accommodative amplitudes, acute accommodative loss in different age groups and in pretreatment accommodative amplitude groups, the influence of cryotherapy numbers on accommodative amplitude, and the influence of cryotherapy sites on accommodative amplitude. RESULTS No significant difference was noted between pretreatment and posttreatment accommodative amplitudes in the overall subject cohort. Dividing subjects by age revealed significant decreases in accommodative amplitude only among patients in their 10s and 20s at one and three weeks after treatment. Accommodative amplitude was lowest among those in their 10s, followed by that among those in their 20s (P < .01). Accommodative amplitudes recovered to pretreatment level by six weeks. Acute accommodative loss was greatest in those in their 10s compared with other age groups (P < .01). A significant correlation was observed between acute accommodative loss and cryotherapy numbers (P = .03; r = 0.41). CONCLUSIONS The decrease in accommodative amplitude was greatest at one week after treatment and recovered to pretreatment levels after six weeks. Accommodative amplitude showed the greatest decrease after cryotherapy among patients in their 10s and 20s. A decrease in accommodative amplitude was observed with increased numbers of cryotherapy spots administered.

Intravitreal aflibercept for exudative age-related macular degeneration with good visual acuity: 2-year results of a prospective study

Purpose We report the 2-year outcomes of intravitreal aflibercept (IVA) for exudative age-related macular degeneration (AMD) with good visual acuity (VA) and examine the baseline factors associated with good visual outcome. Materials and methods This multicenter, prospective study evaluated 39 eyes (39 AMD patients) enrolled from August 2013 to August 2014 at 12 and 24 months. Only patients with initial best-corrected VA (BCVA) >0.3 logarithm of the minimum angle of resolution (20/40 Snellen) were eligible. Three consecutive monthly IVA injections were followed by 2 monthly injections for 12 months. Thereafter, patients received injections on a treat- and-extend regimen for up to 24 months. Outcome measures included BCVA and central macular thickness (CMT) at 12 and 24 months. Post hoc analysis, BCVA, and CMT were evaluated by AMD types (typical AMD [tAMD], type 1, and type 2 polypoidal choroidal vasculopathy [PCV]). Baseline characteristics and BCVA associations were evaluated with linear regression analysis and Student’s t-test. Results Mean age was 69 years and 26 of 39 eyes were male. tAMD, type 1 and type 2 PCV occurred in 18, 12, and 9 eyes, respectively. Baseline mean BCVA was 0.097 logarithm of the minimum angle of resolution (20/25 Snellen) and showed significant improvement to 0.058 (20/22 Snellen, P=0.03) at 12 months and 0.066 (20/23) at 24 months. CMT improved significantly from 320 (99) µm (mean [SD]) to 250 (93) µm (P=0.002) at 12 months and 240 (93) µm (P=0.0005) at 24 months. BCVA and CMT were not significantly different among the three groups. Only subretinal hemorrhage (SRH) was significantly associated with improved BCVA. BCVA change from baseline was −0.12 with SRH and −0.011 without SRH (P=0.017) at 12 months. Conclusion IVA showed good efficacy for exudative AMD with good VA at 24 months. tAMD and type 1 and 2 PCV showed similar prognosis. Baseline SRH predicted favorable long-term vision in AMD with good VA.

Effective Intravitreal Injections of Bevacizumab in a Case of Serous Macular Detachment from the Superior Border of the Posterior Staphyloma

Purpose: We present an atypical case of submacular fluid leading to serous macular detachment. Method/Patient: A 69-year-old man was evaluated for metamorphopsia in the left eye. Results: Best-corrected visual acuity was 20/25 in both eyes. He had undergone cataract surgeries in both eyes 12 years ago. The axial length was 25.93 mm (OD) and 24.12 mm (OS). Optical coherence tomography showed posterior staphylomas and subretinal fluid on the superior border of the staphylomas in both eyes; in the left eye, submacular fluid was noted extending up to the macula. Fundus fluorescein angiography revealed leakage from the superior border of the staphylomas in both eyes. The fluid persisted for 4 months. Four consecutive, monthly injections of bevacizumab (1.25 mg/0.05 mL) were administered in the left eye; subsequently, the subretinal fluid gradually dissipated from the macula and became localized at the superior border of the staphyloma. This localization persisted for 12 months. Conclusions: We have detailed a case of submacular fluid that spread from the superior border of the posterior staphyloma in a patient with macular detachment, in whom intravitreal injections of bevacizumab were highly effective in eliminating the fluid.