Poor intraoperative visibility and postoperative astigmatism associated with trabecular micro-bypass stent for corneal dystrophy: A case report.

RATIONALE: There are reports of safe cataract surgery in eyes with posterior polymorphous corneal dystrophy (PPCD); however, to our knowledge, there are no reports of minimally invasive glaucoma surgery (MIGS) in eyes with PPCD. Herein, we report a case of poor intraoperative visibility with gonioscopy, postoperative corneal edema, and corneal astigmatism in eyes with PPCD treated with trabecular micro-bypass stent combined with cataract surgery. PATIENT CONCERNS/DIAGNOSIS: A 78-year-old man was referred to our hospital for MIGS. He presented with bilateral corneal endothelial vesicular changes and band lesions. Endothelial cell density was 2983/2871 cells/mm2 (right/left eye), central corneal thickness was 581 µm/572 µm, best-corrected visual acuity values (Snellen equivalent) were 20/32 (right) and 20/100 (left), and corneal astigmatism was -2.7D in the right eye and -2.5D in the left eye. INTERVENSIONS/ OUTCOMS: After phacoemulsification and aspiration with intraocular lens implantation with a 2.4-mm corneal incision in both eyes, trabecular micro-bypass stents were inserted successfully despite the poor intraoperative visibility with gonioscopy. One week after surgery, the central corneal thickness was 614 µm/609 µm, and Descemet's membrane folds and mild corneal edema were observed. Best-corrected decimal visual acuity was 20/40 for the right eye and 20/50 for the left eye. In the left eye, total corneal astigmatism increased from -2.5D to -5.5D. Corneal astigmatism and edema showed gradual improvement. LESSONS: Although reports have shown that cataract surgery can be safely performed in eyes with PPCD, MIGS in eyes with PPCD may require caution regarding intraoperative visibility with gonioscopy and visual function in the early postoperative period.

Background factors determining the time to intraocular lens dislocation.

PURPOSE: To clarify the characteristics of intraocular lens (IOL) dislocation requiring IOL suture or intraocular scleral fixation. METHODS: This retrospective consecutive case series included 21 eyes (21 patients) who required sutured or sutureless intrascleral IOL fixation following IOL extraction owing to IOL dislocation at the outpatient clinic in the Department of Ophthalmology, Saitama Red Cross Hospital, Japan, between January and December 2019. Medical records were retrospectively reviewed for background diseases, location of the dislocated IOL (intracapsular/extracapsular), insertion of a capsular tension ring (CTR), and the period from IOL insertion to dislocation. RESULTS: We included 21 eyes of 21 patients who required IOL suture or intrascleral fixation for IOL dislocation at our clinic from January to December 2019 were included. The most common background disease was pseudoexfoliation syndrome (four cases), followed by atopic dermatitis, dysplasia/dehiscence of the zonule, post-retinal detachment surgery, high myopia, and uveitis (three cases each). At the time of dislocation, the IOLs were either intracapsular (16 cases, including 3 cases with CTR insertion) or extracapsular (5 cases). The time from IOL insertion to IOL dislocation was 13.7 ± 8.1 years (maximum: 31.3 years, minimum: 1.7 years). CONCLUSIONS: In this study, all 21 cases represented late IOL dislocations occurring after 3 months postoperatively. Among these late IOL dislocation cases, IOL dislocation occurred in a short-medium period of time, especially in those with CTR insertion and weakness/dehiscence of the zonule, with an average of 3 to 5 years postoperatively. We propose referring to these cases as intermediate-term IOL dislocation.

Effects of reduction in intraocular pressure after trabeculotomy on axial length and intraocular lens selection.

PURPOSE: To investigate the relationship between intraocular pressure (IOP) and axial length (AL) and to compare the refractive predicted error in patients who have undergone cataract surgery alone or in combination with trabeculotomy. SETTING: Hospital. DESIGN: Single-center, retrospective, case-control. METHODS: The medical records of patients who had undergone cataract surgery alone or in combination with trabeculotomy using the Tanito microhook were retrospectively reviewed. Patients were grouped into cataract surgery alone (CAT) or cataract surgery combined with trabeculotomy (LOT) groups. Demographic data, preoperative and postoperative IOP and AL, and surgically induced astigmatism (SIA) were analyzed before and 1 month postoperatively to evaluate the interplay between IOP, AL, and refractive outcomes. RESULTS: 52 eyes (52 patients) underwent LOT, and 67 eyes (67 patients) underwent CAT. The mean IOP at baseline did not differ between the groups; the change in IOP (dIOP) was significantly higher in the LOT group than in the CAT group. The mean AL at baseline and the change in AL (dAL) were 24.0 ± 1.2 mm and 0.16 ± 0.11 mm, respectively, in the LOT group, and 23.8 ± 1.1 mm and 0.11 ± 0.070 mm, respectively, in the CAT group. The difference in dAL was also significant. In the LOT group, dIOP and dAL were significantly correlated. The mean SIA vectors did not significantly differ between the groups. CONCLUSIONS: AL decreased because of the reduction in IOP after cataract surgery combined with trabeculotomy. Consequently, the refractive target error was greater, and the postoperative refractive outcome showed a tendency toward hyperopia.

Clinical Outcomes of Phacoemulsification in Japanese Patients Receiving First and Revised Second-Generation Trabecular Microbypass Stents.

PURPOSE: This study evaluated the effectiveness and safety of first and revised second-generation trabecular microbypass stent insertion [iStent (IS) and iStent inject W (IW)] in cataract surgery. DESIGN: Single-center, retrospective, cohort study. METHODS: The study included 176 eyes that received trabecular microbypass stents combined with cataract surgery at the Saitama Red Cross Hospital between September 2017 and September 2021. Patients were divided into IS and IW groups depending on the implant type. Demographic characteristics, intraocular pressure (IOP), and the number of antiglaucoma medications (Med) were analyzed preoperatively and 12 months postoperatively. In addition, postoperative complications were compared between the groups. RESULTS: IS and IW were implanted in 86 eyes and 90 eyes, respectively. IOP and Med at 1, 3, 6, 9, and 12 months decreased significantly from baseline in both groups ( P = 0.04, P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively, for IOP in the IS group; P = 0.02, P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively, for IOP in the IW group; P = 0.03, P = 0.002, P < 0.001, P < 0.001, and P < 0.001, respectively, for Med in the IS group; and P < 0.001 for all time points for Med in the IW group). IOP did not vary significantly between the groups at 1, 3, 6, 9, and 12 months postoperatively. Med was significantly lower in IW than IS at 1, 3, 6, 9, and 12 months postoperatively ( P < 0.001, P < 0.001, P = 0.002, P = 0.002, and P = 0.002, respectively). Hyphema and IOP >30 mm Hg (spike) occurred in 1.2% and 4.4%, and 1.2% and 3.3% of patients in the IS and IW groups, respectively. The probability of successful discontinuation of medications at 12 months postoperatively was 10.5% and 41.1%, respectively ( P < 0.001). CONCLUSIONS: Postoperative Med was significantly lower in the IW group. Simultaneous insertion of IW in patients with glaucoma requiring cataract surgery may be preferred to IS because it reduces the burden of Med.

Anterior Chamber Shallowing from the Early Stage of Surgery and Suprachoroidal Effusion during Clear Corneal Small-Incision Cataract Surgery: A Case Report.

Suprachoroidal effusion (SCE) is a rarely observed complication due to the recent generalization of clear corneal small-incision cataract surgery. We report a case of anterior chamber shallowing (ACS) from the early stage of surgery and SCE during clear corneal small-incision cataract surgery. A 69-year-old man was referred to our department for primary open-angle glaucoma and grade 2 nuclear cataract. The intraocular pressure (IOP) was 18 and 12 mm Hg in the right and left eyes with the instillation of three antiglaucoma eye drops in both eyes, respectively, and deep anterior chamber and normal axial length were observed. At the age of 70 years, which was 4 months after the initial visit to our department, the IOP of the right eye increased to 30 mm Hg. Hence, cataract surgery and microhook ab interno trabeculotomy (µLOT) of the right eye were scheduled. Mild ACS was observed during continuous curvilinear capsulorhexis (CCC), and ACS worsened as the surgery progressed, making the surgery progressively challenging. SCE was observed by fundus examination after phacoemulsification and cortex removal, and the wound was immediately closed with a suture. The IOP was 28 mm Hg on postoperative day (POD) 1 and decreased to 14 mm Hg on POD 5. SCE disappeared on POD 12. On POD 18, intraocular lens implantation into the bag and µLOT were performed under general anesthesia. Subsequently, the IOP decreased to 15 mm Hg 3 months after the surgery. Mild ACS was already present at the time of CCC, so it is possible that SCE occurred in the early stage of surgery. If ACS is observed intraoperatively, especially if there are SCE risk factors, such as hypertension, glaucoma, and lung cancer, as in this case, and even if the eye has deep anterior chamber and normal axial length preoperatively, fundoscopic examination should be performed even at an early stage of clear corneal small-incision cataract surgery to rule out SCE.

Massive intraocular hemorrhage, presumably from the central retinal artery after cataract surgery, and difficult hemostasis during vitrectomy: a case report.

BACKGROUND: Severe intraocular hemorrhage is a rare complication of cataract surgery due to the recent generalization of minimal-incision cataract surgery. We report a case of a massive intraocular hemorrhage that probably originated from the central retinal artery after cataract surgery, in which hemostasis was difficult to achieve during vitrectomy. CASE PRESENTATION: An 86-year-old woman was referred to our department for intraocular lens (IOL) dislocation after undergoing cataract surgery. Massive intraocular hemorrhage was observed during the initial visit to our department. She underwent pars plana vitrectomy (PPV) and IOL repositioning under local anesthesia. However, the hemorrhage could not be removed completely because of continued massive intraoperative bleeding from the posterior fundus, and it was extremely difficult to achieve hemostasis during the initial surgery. At 7 days after the initial surgery, PPVs were performed under general anesthesia. Bleeding significantly decreased in the second surgery compared to the first. The bleeding probably originated from the central retinal artery on the optic disc; hemostasis was obtained by coagulation of the bleeding site with intraocular diathermy. After the second surgery, there was no exacerbation of bleeding and the patient's condition was stable. However, the patient's visual acuity showed no light perception after the second surgery. CONCLUSIONS: Massive intraocular hemorrhage may occur from the central retinal artery after undergoing cataract surgery. In such cases, surgery with general anesthesia with a lower maintained blood pressure (instead of surgery under local anesthesia) should be recommended, considering the possibility of difficult hemostasis in the event of bleeding from the retinal artery.

The effects of antithrombotic therapy in ab interno trabeculotomy with a spatula-shaped microhook.

To evaluate the effects of the discontinuation of antithrombotic drugs on intraocular pressure (IOP) reduction and complications from ab interno trabeculotomy for patients with glaucoma. We performed a retrospective chart review on the data of patients treated with antithrombotic agents who have undergone ab interno trabeculotomy through Tanito microhook combined with cataract surgery at the Asahi General Hospital and the Tokyo University Hospital, with 6 months of follow-up. The patients were classified into two groups depending on whether they discontinued (AT-) or continued (AT+) antithrombotic therapy during the perioperative phase. The demographics, pre- and postoperative IOP, medication score, best-corrected visual acuity (BCVA), and postoperative complications were analyzed preoperatively and postoperatively at 1 week and 1-6 months. The series included 44 eyes from 44 Japanese patients. The AT- and AT+ groups included 21 eyes from 21 patients and 23 eyes from 23 patients, respectively. The decrease in IOP from the baseline at 1 week postoperative was significantly different between the two groups (p = 0.009), but there were no significant differences observed in the other visits. Hyphema and IOP spikes exceeding 30 mmHg occurred in 10% and 10% of AT- participants, and in 43% and 26% of AT+ participants, respectively. Hyphema and spikes with hyphema occurred more frequently in the AT+ than in the AT- group (p = 0.02 and p = 0.05). The number of patients who had spikes was not significantly different (p = 0.27). In trabeculotomy using the Tanito microhook®, discontinuing antithrombotic therapy had better IOP-lowering effects and less postoperative complications.

Diagnosis of cytomegalovirus corneal endotheliitis using surgically removed Descemet's membrane and endothelium despite negative results with aqueous humor PCR: a case report.

BACKGROUND: Cytomegalovirus (CMV) has been known to cause unilateral corneal endotheliitis with keratic precipitates and localized corneal edema, iridocyclitis, and secondary glaucoma. CMV endotheliitis is diagnosed based on clinical manifestations and viral examination using qualitative polymerase chain reaction (PCR) of the aqueous humor. CASE PRESENTATION: An 80-year-old woman was referred to our department for bullous keratopathy. Pigmented keratic precipitates were found in the right eye without significant anterior chamber inflammation. After 8 months there was inflammation relapse with mutton fat keratic precipitates and PCR on aqueous humor was performed, with negative results for CMV, herpes simplex virus, and varicella zoster virus. Keratic precipitates disappeared with steroid instillation, and Descemet-stripping automated endothelial keratoplasty (DSAEK) was performed for the right eye. CMV-DNA was positive at 6.0 × 102 copies/ GAPDH 105 copies in real time PCR of corneal endothelial specimen removed during DSAEK with negative results for all the other human herpes viruses. After diagnosis of CMV corneal endotheliitis, treatment with systemic and topical ganciclovir was initiated and there was resolution of symptoms. No recurrence of iridocyclitis or corneal endotheliitis was observed at 6 months follow up. CONCLUSIONS: This case report suggests that PCR should be performed using the endothelium removed during DSAEK for bullous keratopathy of an unknown cause, even if PCR for aqueous humor yields negative results.

Traumatic midline subarachnoid hemorrhage on initial computed tomography as a marker of severe diffuse axonal injury.

OBJECTIVEThe objective of this study was to test the hypothesis that midline (interhemispheric or perimesencephalic) traumatic subarachnoid hemorrhage (tSAH) on initial CT may implicate the same shearing mechanism that underlies severe diffuse axonal injury (DAI).METHODSThe authors enrolled 270 consecutive patients (mean age [± SD] 43 ± 23.3 years) with a history of head trauma who had undergone initial CT within 24 hours and brain MRI within 30 days. Six initial CT findings, including intraventricular hemorrhage (IVH) and tSAH, were used as candidate predictors of DAI. The presence of tSAH was determined at the cerebral convexities, sylvian fissures, sylvian vallecula, cerebellar folia, interhemispheric fissure, and perimesencephalic cisterns. Following MRI, patients were divided into negative and positive DAI groups, and were assigned to a DAI stage: 1) stage 0, negative DAI; 2) stage 1, DAI in lobar white matter or cerebellum; 3) stage 2, DAI involving the corpus callosum; and 4) stage 3, DAI involving the brainstem. Glasgow Outcome Scale-Extended (GOSE) scores were obtained in 232 patients.RESULTSOf 270 patients, 77 (28.5%) had DAI; tSAH and IVH were independently associated with DAI (p < 0.05). Of tSAH locations, midline tSAH was independently associated with both overall DAI and DAI stage 2 or 3 (severe DAI; p < 0.05). The midline tSAH on initial CT had sensitivity of 60.8%, specificity of 81.7%, and positive and negative predictive values of 43.7% and 89.9%, respectively, for severe DAI. When adjusted for admission Glasgow Coma Score, the midline tSAH independently predicted poor GOSE score at both hospital discharge and after 6 months.CONCLUSIONSMidline tSAH could implicate the same shearing mechanism that underlies severe DAI, for which midline tSAH on initial CT is a probable surrogate.

Clinical Performance Evaluation of a High-Risk Human Papillomavirus Genotyping Test "Clinichip HPV" Using Cervical Scrape Specimens.

BACKGROUND: Persistent infection with high-risk human papillomavirus (HPV) is closely associated with cervical cancer development. In this study, the performance of the Clinichip HPV genotyping assay as a screening laboratory test for high-risk HPV infection was evaluated. METHODS: The genotypes of 74 cervical scrape specimens were tested using the Clinichip HPV assay and a conventionally employed HPV polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. PCR sequencing was performed in cases with discrepant results between the Clinichip HPV test and PCR-RFLP. RESULTS: Genotyping using the Clinichip HPV assay and PCR-RFLP method resulted in 27% disagreement. PCR sequence results exhibited 79% and 21% consistency with the Clinichip HPV assay and PCR-RFLP method, respectively. Multiple infections were detected in 24.3% and 12.2% of the tested cases using the Clinichip HPV assay and PCR-RFLP method, respectively. CONCLUSIONS: The genotyping performance of the Clinichip HPV showed strong concordance with PCR sequencing, although this rate was partially diminished in cases with multiple HPV infections. The Clinichip HPV represents a suitable laboratory test for the clinical screening of high-risk HPV infections.

Intraventricular hemorrhage on initial computed tomography as marker of diffuse axonal injury after traumatic brain injury.

Intraventricular hemorrhage (IVH) on initial computed tomography (CT) was reported to predict lesions of diffuse axonal injury (DAI) in the corpus callosum (CC) on subsequent magnetic resonance imaging (MRI). We aimed to examine the relationship between initial CT findings and DAI lesions detected on MRI as well as the relationship between the severity of IVH (IVH score) and severity of DAI (DAI staging). A consecutive 140 patients with traumatic brain injury (TBI) who underwent MRI within 30 days after onset were revisited. We reviewed their initial CT for the following six findings: Status of basal cistern, status of mid-line shift, epidural hematoma, IVH, subarachnoid hemorrhage, and volume of hemorrhagic mass and IVH score were assigned in each patient. Based on MRI findings, patients were divided into DAI and non-DAI groups and were assigned a DAI staging. Then, to confirm that the IVH on initial CT predicts DAI lesions on MRI, we used multi-variate analysis of the six CT findings, including IVH, and examined the relationship between IVH score and DAI staging. The IVH detected on CT was the only predictor of DAI (p=0.0139). The IVH score and DAI staging showed significant positive correlation (p<0.0003). IVH score in DAI stage 3 (with DAI involving the brain stem; p=0.0025) or stage 2 (with DAI involving CC; p=0.0042) was significantly higher than that of DAI stage 0 (no DAI lesions). In conclusion, IVH on initial CT is the only marker of DAI on subsequent MRI, specifically severe DAI (stage 2 or 3).

Early CT findings to predict early death in patients with traumatic brain injury: Marshall and Rotterdam CT scoring systems compared in the major academic tertiary care hospital in northeastern Japan.

RATIONALE AND OBJECTIVES: Computed tomography (CT) plays a crucial role in early assessment of patients with traumatic brain injury (TBI). Marshall and Rotterdam are the mostly used scoring systems, in which CT findings are grouped differently. We sought to determine the scoring system and initial CT findings predicting the death at hospital discharge (early death) in patients with TBI. MATERIALS AND METHODS: We included 245 consecutive adult patients with mild-to-severe TBI. Their initial CT and status at hospital discharge (dead or alive) were reviewed, and both CT scores were calculated. We examined whether each score was related to early death; compared the two scoring systems' performance in predicting early death, and identified the CT findings that are independent predictors of early death. RESULTS: More deaths occurred among patients with higher Marshall and Rotterdam scores (both P < .05, Mann-Whitney U test). The areas under the receiver operating characteristic curve (AUCs) indicated that both scoring systems had similarly good discriminative power in predicting early death (Marshall, AUC = 0. 85 vs. Rotterdam, AUC = 0.85). Basal cistern absence (odds ratio [OR] = 771.5, P < .0001), positive midline shift (OR = 56.2, P = .0011), hemorrhagic mass volume ≥25 mL (OR = 12.9, P = .0065), and intraventricular or subarachnoid hemorrhage (OR = 3.8, P = .0395) were independent predictors of early death. CONCLUSIONS: Both Marshall and Rotterdam scoring systems can be used to predict early death in patients with TBI. The performance of the Marshall score is at least equal to that of the Rotterdam score. Thus, although older, the Marshall score remains useful in predicting patients' prognosis.

Effects of extended context discrimination training and context extinction on transfer of context dependency of conditioned flavor aversion.

We trained rats in a context discrimination paradigm by pairing a sucrose solution with lithium chloride in one context (conditioning context) and simple exposure to the same fluid in a second (neutral) context to establish a context-dependent aversion to the conditioned fluid. We then investigated whether transfer of the context dependency to a test fluid (a sodium chloride solution) was affected by two post-discrimination training treatments, an extended context discrimination training, and non-reinforced exposure to the conditioning context (context extinction). We found that the context-dependent flavor aversion that had been specific to sucrose transferred to the test fluid after the extensive training (Experiment 1). Context extinction eliminated the transfer effect that had been observed immediately after the context discrimination training (Experiment 2). In addition, an aversion acquired by sucrose through a simple conditioning of sucrose-LiCl pairings did not generalize to the test fluid (Experiment 3). These results emphasize the importance of a Pavlovian excitatory association between the conditioning context and nausea as a primary source of transfer of the context dependency, rather than a generalization of aversion acquired by the conditioned fluid to the test fluid.

An automated detection method for the MCA dot sign of acute stroke in unenhanced CT.

The hyperdense middle cerebral artery (MCA) dot sign representing a thromboembolus is one of the important computed tomography (CT) findings for acute stroke on unenhanced CT images. Our purpose in this study was to develop an automated method for detection of the MCA dot sign of acute stroke on unenhanced CT images. The algorithm of the method which we developed consisted of 5 major steps: extraction of the sylvian fissure region, initial identification of MCA dots based on the morphologic top-hat transformation, feature extraction of candidates, elimination of false positives (FPs) by use of a rule-based scheme, and classification of candidates using a support vector machine (SVM) classifier with four features. Our database comprised 297 CT images obtained from seven patients with the MCA dot sign. The performance of this scheme for classification of the MCA dot sign was evaluated by means of a leave-one-case out method. The performance of the classification by use of the SVM achieved a maximum sensitivity of 97.5% (39/40) at a FP rate of 1.28 per image. The sensitivity for detection of the MCA dot sign was 97.5% (39/40) with a FP rate of 0.5 per hemisphere. The method we developed has the potential to detect the MCA dot sign of acute stroke on unenhanced CT images.

Transsphenoidal meningocele: an anatomical study using human fetuses including report of a case.

An asymptomatic transsphenoidal meningoencephalocele was discovered incidentally by fiber laryngoscopic examination in a 62-year-old man suffering from hoarseness due to dysplasia of the vocal cord epithelium. To provide a better understanding of the pathogenesis of this anomaly, we performed histologic observations of paraffin-embedded specimens of 42 human fetal heads at 12-16 weeks of gestation. At these stages, ossification had started in the clivus but the sphenoid sinus was not developed. In contrast to the very low incidence of the intra- or trans-sphenoidal remnant of Rathke's pouch after birth, we found (1) the typical mid-line cleft of the sphenoid body in two specimens (2/42 or 4.8 %) and (2) a duct-like, sellar inferior protrusion ending in the sphenoid body in 12 specimens (12/42 or 28.6 %). The cyst-like structure in the protrusion (two specimens) seemed to be composed of obstructed veins. The intra- and trans-sphenoidal anomalies were observed more frequently in specimens without ossification of the sphenoid body than in those with ossification. However, irrespective of ossification, a cyst-like remnant of the most upper part of Rathke's pouch was always seen between the anterior and posterior lobes of the developing pituitary gland. In addition, the bursa pharyngea was seen in four specimens and we confirmed that the notochord was attached to the bursa in each case. The consistent remnant of the intrasellar Rathke's pouch appeared to explain the high incidence of Rathke's cleft cyst in adults. The relatively high incidence of intrasphenoidal anomalies in fetuses (14/42) suggested that the intra- or trans-sphenoidal remnant of Rathke's pouch was physiologically closed by ossification of the sphenoid body.

Performance evaluation of the automated morphological analysis of erythrocytes by CellaVision DM96.

BACKGROUND: Automated digital morphology systems are utilized for blood cell morphological examination. The aim of this study is to evaluate the accuracy and efficacy of RBC morphological anomaly screening using the CellaVision DM96 (DM96) automated image analysis system. METHODS: The automated analysis of RBC shape, size, and chromasia abnormalities was conducted on the DM96 using 478 blood samples. A manual microscopic review was independently performed. RESULTS: The DM96 preclassified samples as poikilocytosis-positive for 98% of cases with schistocytosis or echinocytosis, 97% of elliptocytosis, and 92% or 65% of cases that were positive for teardrop cells or for target cells, respectively. The accuracy of the DM96 in the detection of RBC size and chromasia abnormalities of iron deficiency anemia cases was higher than direct microscopic observation. CONCLUSIONS: Automated morphological analysis with the DM96 has potential utility in the morphological screening of RBC anomalies that are associated with disease.

Induction of amyloid-ß(1-42) in the retina and optic nerve head of chronic ocular hypertensive monkeys.

PURPOSE: Recent studies have indicated that accumulation of amyloid ß(1-42) (Aß(1-42)), which is associated with the progression of Alzheimer disease, may also be responsible for retinal ganglion cell death in glaucoma. The purpose of this study was to investigate the expression and localization of Aß(1-42) in the retina and the optic nerve head (ONH) of monkeys with experimental glaucoma. METHODS: Five cynomolgus monkeys with a glaucomatous left eye at 4, 9, 11, 15, and 24 weeks after laser photocoagulation treatment were studied by immunohistochemical methods. Another two cynomolgus monkeys with a glaucomatous left eye at 133 weeks after laser photocoagulation treatment were used to measure Aß(1-42) concentrations in the retina by enzyme-linked immunosorbent assay. RESULTS: At 11 to 24 weeks after the laser photocoagulation treatment, Aß(1-42) was upregulated in the nerve fiber layer (NFL) and the ganglion cell layer (GCL) of the retina and the ONH, but the expression of amyloid precursor protein decreased in the NFL and ONH from levels at 9 weeks. The localizations of Aß(1-42) were merged in glial fibrillary acidic protein-positive astroglial cells but not phosphorylated neurofilament heavy- or nonphosphorylated neurofilament heavy-positive axons in the retina and the ONH. Likewise, Aß(1-42) concentrations in the retina of monkeys increased in the chronic stage of glaucoma. CONCLUSIONS: These findings indicate that the upregulation of Aß(1-42) after an intraocular pressure elevation could apply to monkeys since the structure of the ONH is more similar to humans than that of rodents.