Secondary Angle-closure Glaucoma Research Articles

Targeted Overexpression of TGF-α in the Corneal Epithelium of Adult Transgenic Mice Induces Changes in Anterior Segment Morphology and Activates Noncanonical Wnt Signaling

Transforming growth factor-alpha (TGF-α) transduces its signal through the epidermal growth factor receptor and is essential for corneal epithelial homeostasis. Previous studies have demonstrated that overexpression of TGF-α in the developing eye leads to anterior segment dysgenesis. However, the underlying mechanisms remain unclear. Here we examined the effects of TGF-α overexpression on adult ocular surface homeostasis. Binary Tet-On transgenic Krt12(rtTA)/tet-O-TGF-α mice were subjected to doxycycline (Dox) induction to overexpress TGF-α in the corneal epithelium. Intraocular pressure (IOP) was measured by noninvasive tonometry. The enucleated eyes of the experimental mice were subjected to histopathology, immunohistochemistry, and biochemistry examination. Histologic and immunofluorescent examination showed that double-transgenic mice overexpressing TGF-α manifested peripheral anterior synechiae. Elevation of IOP, activation of glial cells, and loss of retinal ganglion cells were also observed. Quantitative real-time PCR revealed that the expressions of genes (RXRα, PITX2, and FOXC1) related to anterior segment dysgenesis were downregulated. Canonical Wnt signaling was suppressed, whereas noncanonical Wnt ligands (Wnt4 and Wnt5a) were upregulated. Increased myosin light chain phosphorylation suggested that noncanonical Wnt signaling is activated in affected eyes. Overexpression of TGF-α in the corneal epithelium induces changes in anterior segment morphology. Corneal endothelial abnormalities are associated with the activation of the noncanonical Wnt and RhoA/ROCK signaling axis, indicating a potential application of RhoA/ROCK inhibitors as a therapeutic strategy for certain types of secondary angle-closure glaucoma.

Angle-closure glaucoma secondary to inflammatory capsular block syndrome following routine cataract surgery

A 78-year-old man had uneventful cataract surgery with implantation of a 1-piece plate-haptic intraocular lens in the capsular bag. Seven weeks later, he presented as an emergency with intense fibrinous uveitis and increased intraocular pressure (IOP). Examination revealed an inflammatory capsular block syndrome (CBS) causing fibrinous anterior uveitis and secondary angle-closure glaucoma. The glaucoma resolved and the patient's vision improved following neodymium:YAG laser posterior capsulotomy. Inflammatory CBS should be considered in pseudophakic patients presenting with fibrinous anterior uveitis, increased IOP, and secondary angle closure.

Acetazolamide-induced cilio-choroidal effusion after cataract surgery: unusual posterior involvement

Idiosyncratic reactions to a large number of drugs have been reported to cause choroidal detachment and secondary angle-closure glaucoma (ACG). We report a case of bilateral acute ACG and peculiar choroidal effusion following administration of oral acetazolamide immediately after cataract surgery. Few cases of acute secondary ACG with choroidal effusion and anterior shift of the lens-iris diaphragm have been associated with acetazolamide compared with other sulfonamides. As far as we are aware, posterior involvement with retinal folds and papillary edema due to acetazolamide has not been described before.

Acute bilateral angle closure glaucoma induced by methazolamide

PurposeTo report a case of bilateral acute myopia and angle closure glaucoma after ingestion of methazolamide.MethodsAn interventional case report of a 70-year-old male who developed bilateral, acute myopia and angle closure glaucoma after ingesting methazolamide tablets for the treatment of normal tension glaucoma.ResultsBilateral anterior chamber shallowing associated with ciliary body edema, supraciliary effusions, and shallow posterior choroidal effusions were documented with slit-lamp photography and high-frequency ultrasonography. Near complete resolution of these signs after discontinuation of methazolamide were also documented.ConclusionMethazolamide may be associated with secondary myopia and angle closure glaucoma. Discontinuation of methazolamide leads to resolution of this process, as documented by slit-lamp photography and high-frequency ultrasonography.

Rod Photoreceptor Ribbon Synapses in DBA/2J Mice Show Progressive Age-Related Structural Changes

The DBA/2J mouse is a commonly used animal model in glaucoma research. The eyes of DBA/2J mice show severe age-related changes that finally lead to the degeneration of retinal ganglion cells and the optic nerve. Recent electroretinogram studies identified functional deficits, which suggest that also photoreceptor cells are involved in the pathological processes occurring in the DBA/2J mouse retina. In a comparative study, we examined anatomical and molecular changes in the retinae of DBA/2J and C57BL/6 control mice with light and electron microscopy and with PCR analyses. In the retina of the DBA/2J mouse, we found a thinning of the outer plexiform layer, the first synaptic layer in the transfer of visual signals, and age-dependent and progressive degenerative structural changes at rod photoreceptor ribbon synapses. The structural ribbon changes represent a photoreceptor synaptic phenotype that has not yet been described in this animal model of secondary angle-closure glaucoma. Furthermore, genes of the classical complement cascade were upregulated in the photoreceptor cells of aging DBA/2J mice, suggesting a putative link between ribbon synapse degradation and the innate immune system.

Glaucoma surgery in uveitis

AbstractGlaucoma surgery and uveitis (course) Management of uveitis glaucoma requires careful diagnosis and managment of both uveitis and glaucoma. Before deciding surgery it is essential to identify the mechanisms of IOP elevation and to differentiate secondary open angle glaucoma, secondary angle closure glaucoma with or without pupillary block. In case of secondary glaucoma with pupil block in phakic patients lens extraction might be considered if the uveitis is well controlled. Uveitis can negatively affect the outcome of glaucoma surgery. Filtration surgery with the use of adjunctive mitomycin C is the standard of care because of the risk of fibosis of the filtration bleb. Non penetrating surgery is an attractive option if the angle is open avoiding anterior chamber entry and hypotony. Aqueous shunt implantations is another option and could be proposed as a primary surgical procedure. Cyclophotocoagulation is best avoided in uveitics because the ciliary body is compromised by cyclitis. This procedure should be used cautiously because patients with uveitis already have atrophic ciliary epithelium, and the risk of permanent hypotony is increased with a cyclodestructive procedure

Ocular hypertension and glaucoma incidence in patients with scleritis

Scleritis belongs to the group of chronic inflammatory eye diseases that may cause ocular hypertension (OHT) and secondary glaucoma (SG). Aim of this study was to identify the incidence and risk factors for OHT and SG with regard to the scleritis form. Single-center retrospective analysis of all consecutive patients with scleritis. A total of 271 scleritis patients (161 women, mean age 51.0 ± 16.9 years) were enrolled. The median follow-up was 17.0 ± 21.4 months (range 6-116). Of these patients, 56 (21 %) showed an intraocular pressure (IOP) increase with an open chamber angle at any time during follow-up. Another four patients (7 %) had secondary angle-closure glaucoma. An increase in IOP was found more frequently in patients with necrotizing (42 %) than in those with posterior (30 %), nodular (18 %) or diffuse anterior scleritis (18 %, p = 0.022). Most patients (82 %) developed the pressure increase during acute scleritis episodes. Initially, 72 % of patients with increased IOP were classified as OHT; this figure had decreased to 56 % at the end of follow-up. In the course of disease, the IOP normalized in 13 %. The univariate analysis of risk factors showed an increased risk in the presence of anterior uveitis, peripheral ulcerative keratitis, posterior synechiae, and previous cataract surgery. An increase in IOP occurs in about one-fifth of patients with scleritis. The initial pressure elevation occurs mostly in the acute phase of disease. An increase in pressure is found most often in patients with necrotizing scleritis.

Bilateral transient myopia, angle-closure glaucoma, and choroidal detachment induced by methazolamide

We report the case of a patient with acute bilateral transient myopia, secondary angle-closure glaucoma, and choroidal detachment associated with oral administration of methazolamide. A 51-year-old man developed bilateral transient myopia and secondary angle-closure glaucoma with choroidal detachment after oral administration of methazolamide. Both eyes presented a shallow anterior chamber and elevated intraocular pressure. Ultrasound biomicroscopy revealed annular ciliochoroidal effusion and diffuse thickening of the ciliary body. Angiography showed many scattered islands of hypofluorescence in both eyes. Methazolamide was stopped and prednisolone given orally. Eight days after treatment initiation, clinical symptoms and signs had resolved. The abnormal findings on ultrasound biomicroscopy and angiography disappeared by 2 months. Methazolamide can induce bilateral transient myopia, angle-closure glaucoma, and choroidal detachment. Prompt identification of the causative medications and subsequent discontinuation can induce rapid resolution of angle closure.

Scleral Thickness in Human Eyes

PurposeTo obtain information about scleral thickness in different ocular regions and its associations.MethodsThe histomorphometric study included 238 human globes which had been enucleated because of choroidal melanomas or due to secondary angle-closure glaucoma. Using light microscopy, anterior-posterior pupil-optic nerve sections were measured.ResultsIn the non-axially elongated group (axial length ≤26 mm), scleral thickness decreased from the limbus (0.50±0.11 mm) to the ora serrata (0.43±0.14 mm) and the equator (0.42±0.15 mm), and then increased to the midpoint between posterior pole and equator (0.65±0.15 mm) and to the posterior pole (0.94±0.18 mm), from where it decreased to the peri-optic nerve region (0.86±0.21 mm) and finally the peripapillary scleral flange (0.39±0.09 mm). Scleral thickness was significantly lower in the axially elongated group (axial length >26 mm) than in the non-axially elongated group for measurements taken at and posterior to the equator. Scleral thickness measurements of the posterior pole and of the peripapillary scleral flange were correlated with lamina cribrosa thickness measurements. Scleral thickness measurements at any location of examination were not significantly (all P>0.10) correlated with corneal thickness measurements. Scleral thickness was statistically independent of age, gender and presence of glaucoma.ConclusionsIn non-axially elongated eyes, the sclera was thickest at the posterior pole, followed by the peri-optic nerve region, the midpoint between posterior pole and equator, the limbus, the ora serrata, the equator and finally the peripapillary scleral flange. In axially elongated eyes, scleral thinning occurred at and posterior to the equator, being more marked closer to the posterior pole and the longer the axial length was. Within the anterior and posterior segment respectively, scleral thickness measurements were correlated with each other. Posterior scleral thickness was correlated with lamina cribrosa thickness. Scleral thickness measurements at any location of examination were not significantly correlated with corneal thickness or with age, gender and presence of absolute secondary angler-closure glaucoma.

Clinical forms of glaucoma in a tertiary hospital in Nigeria

Background : Glaucoma is responsible for 16% of blindness in Nigerian adults and the foremost cause of irreversible blindness among Nigerian adults. Clinical care of glaucoma must therefore be individualized to the specific forms of the disease. Aim : To evaluate the relative frequencies of the different clinical types of glaucoma among newly diagnosed glaucoma patients in University of Port Harcourt Teaching Hospital (UPTH). Methods : A retrospective study of all new patients referred to the Glaucoma Clinic of UPTH from December 2009 to December 2010. All patients had measurement of intraocular pressure, gonioscopy, slit lamp examination with +78D super field lens and central visual field analysis. Diagnosis of glaucoma was based on cupping and atrophy of the optic disc, visual field loss, with or without raised intraocular pressure. Patients so diagnosed were classified according to the European Glaucoma guidelines as Primary Open Angle Glaucoma (POAG) including Normal Tension Glaucoma (NTG), Secondary Open Angle Glaucoma (SOAG), Primary Angle Closure Glaucoma (PACG), and Secondary Angle Closure Glaucoma (SACG). Results : Ninety-eight patients were studied. Of this, 52% were males and 48% females; their mean age was 49.70±14.06 years. The distribution of the clinical forms of glaucoma were as follows: Congenital Glaucoma (CG) 1 %( n=1), JOAG 3.1 %( n=3), PACG 3.1% (n=3), SOAG 5.1% (n=5), SACG 11.2% (n=11), NTG 14.3%(n=14) and POAG 62.2%(n=61). More than 75% of the patients were over 40 years with a peak presentation in the sixth decade. Conclusion : Primary Open Angle Glaucoma was the most prevalent subtype of the disease in this study. Peak presentation was in the sixth decade of life.

Retinal Vein Occlusions.

Retinal vein occlusions (RVOs) are second to diabetic retinopathy in the prevalence as retinal vascular disorder and are characterized by dilatation of the retinal veins with retinal and subretinal hemorrhages, macular edema, hard retinal exudates, retinal ischemia, and consequent atrophy of the retina and optic nerve. They are differentiated into central RVOs and branch RVOs (BRVO), into ischemic versus nonischemic RVOs, and in the case of BRVOs, into intrapapillary BRVOs and extrapapillary BRVOs. Diagnosis is based on ophthalmoscopy, fluorescein angiography, and spectral-domain optical coherence tomography. The latter can display the presence and integrity of the retinal outer limiting membrane and of the inner and outer segments of the photoreceptors as useful information for prognosis and a guide for treatment. Risk factors for RVOs are glaucoma and arterial hypertension. Ischemic RVOs can develop iris neovascularization and secondary angle-closure glaucoma. Formerly, therapy consisted of laser photocoagulation in a "grid" pattern over the leaking area, leading to a reduction of macular edema and, as adverse effect, to focal retinal destruction. Intravitreal medical therapy including steroids and vascular endothelial growth factor inhibitors shows a marked antiedematous effect leading to an at least temporary reduction in foveal edema and correspondingly improves visual function. Intravitreal medical therapy is associated with the disadvantage of a limited duration of its effect and the advantage of not damaging the retina. A preventive therapy to avoid a recurrence of RVO or the development of an RVO in the contralateral eye has not been proven yet.

Uveal Effusion Associated With Campylobacter jejuni Infection Presenting as Bilateral Angle Closure Glaucoma

We present a case in which a gastrointestinal infection with Campylobacter jejuni presented as acute angle closure glaucoma secondary to the uveal effusion syndrome. A 58-year-old white man presented with acute angle closure and raised pressure in both the eyes along with diarrhea. Ultrasound B-scans showed choroidal effusion. Stool culture grew C. jejuni. A 3-week treatment with topical steroids and antiglaucoma medication resolved the condition. He was also treated with oral antibiotics. C. jejuni has not been isolated earlier in a case of uveal effusion presenting as secondary angle closure glaucoma. In this respect our case is unique.

Secondary angle-closure glaucoma due to posterior synechiae formation following phacovitrectomy

Iris posterior synechiae formation after phacovitrectomy is usually regarded as a trivial problem. We report a case of secondary angle-closure glaucoma due to 360°PS 5years after a phacovitrectomy for recurrent vitreous haemorrhage secondary to diabetic retinopathy. To our knowledge this is the first such reported case of this potentially sight-threatening complication of phacovitrectomy. We discuss our successful management of our patient, as well as potential risk factors and preventative measures.

The evaluation of lens extraction combined with goniosynechialysis for secondary angle closure glaucoma

Objecive To observe the change of anterior chamber angle of secondary angle closure glaucoma after lens extraction and goniosynechialysis surgery and evaluate the curative efficacy.Methods 36 patients (36 eyes) suffered with secondary angle closure glaucoma and cataract were treated with lens extraction and goniosynechialysis.The visual acuity,intraocular pressure,central anterior chamber depth and morphology of anterior chamber angle were obsrved and compared before and after the surgery.Results Patients were followed up for 6 months to 3 years after the surgery.The best corrected visual acuity was improved in all of 36 eyes.Anterior chamber was deepened in all of 36 eyes from ( 1.612 ± 0.354) mm preoperatively to (3.214 ±0.277) mm postoperatively.The intraocular pressures of 36 eyes were obviously reduced from preoperative mean of (28.69 +4.12) mmHg to postoperative mean of (14.07 ±3.48) mmHg.The postoperative gonioscopy showed that anterior chamber angle was open at 1 month in 36 eyes,but 5 eyes remained synechia.The morphology of chamber angle did not changed followed at least 6 months after the surgery.Conclusion Lens extraction combined with goniosynechialysis are safe and effective to treat secondary angle closure glaucoma. Key words: Lens extraction; Goniosynechialysis; Secondary angle closure glaucoma

Histology of the Parapapillary Region in High Myopia

To examine histomorphometrically the parapapillary region in highly myopic eyes. Retrospective laboratory investigation. We examined a highly myopic glaucomatous group (36 human globes; axial length >26.5 mm) and a non-highly myopic group (28 globes with secondary angle-closure glaucoma; 17 eyes with malignant choroidal melanoma). Using light microscopy, pupil-optic nerve sections were assessed. The length of the scleral flange (sclera between optic nerve border and optic nerve dura mater) increased with axial length (P < .001; correlation coefficient r = 0.70) and decreased with its thickness (P < .001; r = 0.75). In all highly myopic eyes (n = 15) with a distance of >0.5 mm between optic nerve border and beginning of Bruch membrane, the parapapillary region consisted of an elongated parapapillary scleral flange associated with a scleral flange thinning and a retrobulbar cerebrospinal fluid space extended into the retroparapapillary region. The parapapillary retina was composed of retinal nerve fiber layer (or its remnants) only, without elements of any other retinal layer, without underlying Bruch membrane or choroid. These histologic features were not detected in any of the non-highly myopic eyes. Since parapapillary scleral thickness influences the lamina cribrosa biomechanics, the findings may partially explain the increased glaucoma susceptibility in highly myopic eyes. The implications of an absence of Bruch membrane and choroid in the highly myopic parapapillary region, and the implications of the retrobulbar parapapillary extension of the cerebrospinal spinal fluid space for the pathophysiology of the optic nerve head, have to be elucidated.

Typical migraine or ophthalmologic emergency?

We describe the case of a 47-year-old woman who came to the emergency department (ED) complaining of worse than typical migraine headache and blurry vision after recently doubling the dose of topiramate earlier that day. After complete neurologic and ophthalmologic evaluation, she was found to have elevated intraocular pressures and was diagnosed with topiramate-induced bilateral acute angleclosure glaucoma, which is a rare side effect of this commonly prescribed medication. She was treated with timolol, brimonide, and prednisolone drops to reduce intraocular pressure as well as cessation of topiramate and was discharged home. This report briefly discusses the clinical history, appropriate evaluation, differential diagnosis, and approach to secondary acute angle-closure glaucoma in the ED.

Secondary Bilateral Angle Closure Glaucoma due to Topiramate

We examined a 39-year-old female with severe headache and blurred vision. She was on topiramate, 50 mg once a day for one week because of migraine. Periorbital edema, chemosis, myopia, high intraocular pressures, and shallow anterior chambers were present at the initial examination. Iridocorneal angles were closed, ultrasound showed choroidal effusions. We stopped topiramate and started antiglaucoma treatment. After one week the intraocular pressure was 10 mm Hg in both eyes without treatment. A new ultrasound showed no choroidal effusions. Topiramate has been associated with acute secondary angle closure glaucoma as an idiosyncratic reaction to the drug. Physicians prescribing topiramate need to alert patients of this potential sight-threatening idiosyncratic reaction.

Anterior Segment Optical Coherence Tomography in Glaucoma Diagnostics: is Fourier- or Time-domain more useful?

Several new methods based on evolving technologies were introduced in the last decades to enhance and facilitate anterior segment diagnostics in glaucoma. Nowadays, in addition to conventional slit lamp biomicroscopy and gonioscopy, ultrasound biomicroscopy (UBM) and recently anterior segment optical coherence tomography (AS-OCT) are considered to be valuable and indispensable tools especially for patients with primary and secondary angle closure glaucomas. In the early 1990s the AS-OCT was introduced for cornea and glaucoma diagnosis [1]. In contrast to UBM, AS-OCT is a noncontact, high resolution imaging technique which is fast and optimal for noncompliant patients or even children [2] and has been used to image a variety of anatomic ocular structures in glaucoma patients such as filtering bleb, anterior chamber angle, episcleral and intracameral shunts, posterior chamber and iris. An optimal AS-OCT is not yet available, since each module has its own advantages and limitations, making it increasingly difficult to choose among them.

Topiramate Induced Acute Secondary Angle Closure Glaucoma And Myopic Shift : A Case Review

Introduction : Acute myopia and secondary acute angle-closure glaucoma are serious adverse effects of topiramate use, both of which are reversible with immediate discontinuation of the drug. Topiramate is an oral sulfamate medication used primarily for epilepsy and migraine1. Other uses of topiramate include use in management of peripheral neuropathies and radiculopathies, idiopathic intracranial hypertension, adjunctive therapy in alcohol dependence and nicotine cessation2• Case presentation: A 40 year old man, on oral topiramate for alcohol dependence, presented with complaints of severe pain, redness and sudden loss of vision in both eyes since two days. Best corrected visual acuity was 20/20 in both eyes with minus three diopters sphere. A diagnosis of secondary angle closure glaucoma with myopic shift was made.• Conclusion : Topiramate was discontinued immediately and anti glaucoma therapy initiated along with topical steroids. Unaided visual acuity returned to 20/20 in both eyes with normal anterior segment and intraocular pressure within one week of treatment.

Peripapillary sclera thickness in human eyes with glaucoma

Editor, The biomechanics of the optic nerve head is of particular importance in glaucomatous optic neuropathy. It depends on several parameters such the thickness of the lamina cribrosa and peripapillary sclera (Burgoyne et al. 2005). Previous studies have shown that glaucoma is associated with a thinning of the lamina cribrosa (Jonas et al. 2003). It was postulated that this lamina cribrosa thinning may be one of the reasons for an increased risk of further glaucoma progression in advanced stages of the disease (Gordon et al. 2002; Jonas et al. 2003). It was also demonstrated that the peripapillary sclera is thinner in highly myopic eyes compared to non-highly myopic eyes (Jonas et al. 2004). One inferred that this myopic thinning of the peripapillary sclera may be one of the reasons for increased glaucoma susceptibility in highly myopic eyes (Xu et al. 2007). It has remained unclear so far, whether besides high myopia, also glaucoma leads to a thinning of the peripapillary sclera. In that case, it will be an additional cause for the elevated risk of further glaucoma progression in eyes with advanced glaucoma (Gordon et al. 2002). We, therefore, performed the present study to address the question whether glaucomatous optic nerve atrophy is associated with a thinning of the peripapillary sclera, parallel to a thinning of the lamina cribrosa, in non-highly myopic eyes. The histomorphometrical study included eight eyes of eight patients who had been enucleated because of absolute secondary angle-closure glau-coma and 25 eyes of 25 patients who had been enucleated because of a malignant choroidal melanoma (control group). Using paraffin-imbedded histological sections running in anterior–posterior direction through the pupil and the optic nerve, we measured the thickness of the sclera just at the optic disc border inside of the optic nerve meninges, at the location just outside of the optic nerve meninges, and at distances of 0.2, 0.4 and 0.6 mm from the optic disc border (Fig. 1). The latter was defined by the end of Bruch’s membrane. Both groups did not vary significantly in age (p=0.98) and axial length [23.9 ± 1.9 mm (22.0–26.0 mm) versus 23.8 ± 0.9 mm (22–25 mm); p=0.89]. Eyes with an axial length of more than 26 mm were excluded. Histophotograph of an optic nerve head, showing the thickness measurement of the peripapillary sclera inside of the optic nerve meninges (yellow arrows) and just outside of the optic nerve meninges (black arrows). Between the glaucoma and the control group, the scleral thickness measurements did not vary significantly, neither inside of the optic nerve meninges (356 ± 56 versus 367 ± 64 μm; p =0.66) (Fig. 2), nor just outside of the optic nerve meninges (696 ± 93 versus 740 ± 117 μm; p=0.29), nor at distances of 0.2 mm (445 ± 65 versus 418 ± 100 μm; p=0.38), 0.4 mm (529 ± 62 versus 543 ± 142 μm; p = 0.71) and 0.6 mm from the optic disc border (601 ± 65 versus 598 ± 121 μm; p=0.92). Box plots showing the distribution of the thickness of the peripapillary sclera inside of the optic nerve meninges at the optic disc border in 10 eyes with absolute secondary angle-closure glaucoma and 26 non-glaucomatous eyes (control group). The results suggest that in adult non-highly myopic human eyes with far advanced glaucoma and presumably high intraocular pressure as typically found in absolute secondary angle-closure glaucoma, the peripapillary sclera did not get markedly thinner. This finding is in contrast to recent investigations in monkeys which developed a posterior scleral thinning in the course of experimental high-pressure glaucoma (Downs et al. 2001). Correspondingly, another study in adult monkeys with unilateral experimental glaucoma showed a lengthening of the glaucomatous eyes compared to the fellow control eyes (Hayreh et al. 1998). That is in contrast to non-highly myopic humans with glaucoma, in whom a lengthening or an enlargement of the optic disc was not described (Jonas et al. 1988). The latter finding correlates with the findings in the present study in which the scleral thickness in the peripapillary region of non-highly myopic eyes did not differ significantly between eyes with glaucoma and eyes without glaucoma. The finding of our study may have importance for the discussion of glaucomatous optic neuropathy in that in non-highly myopic human eyes, glaucoma-related thinning of the peripapillary sclera did not occur and thus may not contribute to the progression of the disease. The differences between humans and monkeys with respect to the peripapillary sclera in glaucoma may be taken into account if results of experimental glaucoma studies in monkeys are transferred to patients.