Do optic nerve head and visual field parameters in patients with obstructive sleep apnea syndrome differ from those in control individuals?

BACKGROUND: It has been suggested that sleep apnea syndrome may play a role in normal-tension glaucoma contributing to optic nerve damage. The purpose of this study was to evaluate if optic nerve and visual field parameters in individuals with sleep apnea syndrome differ from those in controls. PATIENTS AND METHODS: From the records of the sleep laboratory at the University Hospital in Bern, Switzerland, we recruited consecutive patients with severe sleep apnea syndrome proven by polysomnography, apnea-hypopnea index >20, as well as no sleep apnea controls with apnea-hypopnea index <10. Participants had to be unknown to the ophtalmology department and had to have no recent eye examination in the medical history. All participants underwent a comprehensive eye examination, scanning laser polarimetry (GDx VCC, Carl Zeiss Meditec, Dublin, California), scanning laser ophthalmoscopy (Heidelberg Retina Tomograph II, HRT II), and automated perimetry (Octopus 101 Programm G2, Haag-Streit Diagnostics, Koeniz, Switzerland). Mean values of the parameters of the two groups were compared by t-test. RESULTS: The sleep apnea group consisted of 69 eyes of 35 patients; age 52.7 ± 9.7 years, apnea-hypopnea index 46.1 ± 24.8. As controls served 38 eyes of 19 patients; age 45.8 ± 11.2 years, apnea-hypopnea index 4.8 ± 1.9. A difference was found in mean intraocular pressure, although in a fully overlapping range, sleep apnea group: 15.2 ± 3.1, range 8-22 mmHg, controls: 13.6 ± 2.3, range 9-18 mmHg; p<0.01. None of the extended visual field, optic nerve head (HRT) and retinal nerve fiber layer (GDx VCC) parameters showed a significant difference between the groups. CONCLUSION: Visual field, optic nerve head, and retinal nerve fiber layer parameters in patients with sleep apnea did not differ from those in the control group. Our results do not support a pathogenic relationship between sleep apnea syndrome and glaucoma.

Assessment of a new Goldmann applanation tonometer.

BACKGROUND/AIMS: The classic Goldmann applanation tonometer (GAT) has been further developed by Haag-Streit International. The applanation principle has been retained, while the internal force transmission and the pressure gauging have been optimised, the display of results digitised. The authors compared the GAT standard with the new GAT digital. METHODS: Four fixed tonometer pairs were used. The protocol included: non-contact pachymetry, slit-lamp examination, three consecutive measurements with each tonometer with a 5 min interval in between, check for side effects in 15 min. Three groups (intraocular pressure (IOP) levels) were defined: (1) IOP ≤ 16; (2) IOP>16 and <23; (3) IOP ≥ 23 mm Hg. RESULTS: 125 Patients (250 eyes) were evaluated. IOP (mm Hg), GAT standard versus GAT digital, for the rights eyes was: Group 1: 12.94 ± 0.55 versus 13.11 ± 0.53, p=0.71. Group 2: 18.26 ± 0.59 versus 18.03 ± 0.52, p=0.53; Group 3: 30.28 ± 0.48 versus 30.42 ± 0.41, p=0.97; all right eyes: 17.48 ± 7.48 versus 17.73 ± 7.4, p=0.99. For the left eyes, there was no significant difference, either. The correlation was very good and was not influenced by the IOP level. The Pearson coefficient for the right eye was 0.985, and for the left eye 0.994. In the Bland-Altman analysis, although there were two single readings that differed by as much as 5 mm Hg, GAT digital measures showed almost no skew, and the mean difference was 0.03 ± 1.23 mm Hg (n=250). A multiple regression analysis showed no influence of order of measurement, eyeside or pachymetry. CONCLUSIONS: The new GAT digital is as reliable and safe as GAT standard. IOP values correlate well. It offers a digitised display and a wireless transfer of data. The display of values up to the first decimal digit is not necessarily associated with a more precise measurement, but may offer an additional comfort compared with the 2 mm Hg scale of the classic GAT.

[Orbital fat atrophy in glaucoma patients treated with topical bimatoprost--can bimatoprost cause enophthalmos?]. / Orbitale Fettgewebsatrophie bei lokaler Bimatoprost-Therapie - Kann Bimatoprost einen Enophthalmus verursachen?

PURPOSE: The aim of this communication is to report enophthalmos as a possible new adverse effect of topical bimatoprost treatment. PATIENTS AND METHODS: A retrospective case series of five glaucoma patients under long-term topical bimatoprost treatment was evaluated. Documentation with photo and Hertel exophthalmometry was reviewed. RESULTS: In all five patients a deep lid sulcus, reduced infraocular fat pads and enophthalmos-suspicious Hertel values were found (mean 11.9 mm; SD 2.4). Other aetiologies for enophthalmos were excluded anamnestically and by clinical examination. CONCLUSION: Bimatoprost may lead to an alteration of the eyelid with deepening of the lid sulcus and may also be responsible for an iatrogenic orbital fat atrophy. A possible mechanism of action might be the induction of apoptosis of orbital fibroblasts with a remodelling of the extracellular matrix. Prospective studies are necessary to confirm this cross-sectional observation.

Simultaneous, bilateral anterior ischemic optic neuropathy (AION) in polycythemia vera: a case report.

BACKGROUND: Polycythemia vera (PV) is a hemopoetic disorder. Apparently, although thrombosis accounts for the majority of morbidity, AION has not been associated with PV so far. PATIENT AND FINDINGS: A 63 y-old woman with PV was hospitalized because of acute liver failure. She also experienced bilateral painless loss of vision. Bilateral, pale optic disc swelling with flame-like hemorrhages, more pronounced in the right eye, constricted visual fields, and relative afferent papillary defect (RAPD) on the right side were present. Computer tomography scan revealed no signs of intraorbital pathology, elevated intracranial pressure or hemorrhages. CLINICAL COURSE: We interpreted the findings as AION associated with the hyperviscosity syndrome. Liver transplantation had to be carried out in the next days. Three weeks later, vision improved slightly, but RAPD persisted, and disc pallor developed in both eyes. The patient died two months later. DISCUSSION: Central retinal artery and vein occlusions have been described as complications of Essential thrombocythemia, but not of PV. We observed a rare case of bilateral neuropathy suggestive of AION. This condition has so far not been associated with PV.

Glaucoma phenotype in a large Swiss pedigree with the myocilin Gly367Arg mutation.

AIMS: To characterize genotype, phenotype, and age-related penetrance in a Swiss pedigree with juvenile open-angle glaucoma (JOAG). METHODS: In a large Swiss family with history of glaucoma and 82 living members of four generations, we conducted molecular analysis and a detailed phenotype characterization in 52 family members. Mutation analysis was carried out using single-strand conformation polymorphism and DNA sequence analyses of the suspected candidate gene, myocilin (MYOC). RESULTS: We detected a Gly367Arg mutation in the MYOC gene of 13 family members. Nine of them (69.2%) had glaucoma: mean IOP 35.3 mm Hg, range 24-50 mm Hg; mean age at diagnosis 34.9 years, range 28-51 years. Two mutation carriers were glaucoma suspects, one (age 15) was unaffected, and one (age 16) not available for clinical examinations. Age-related glaucoma penetrance was 50% at 30 and 78% at 40. Untreated IOP resulted in rapid disease progression, whereas good IOP control, usually only by means of filtration surgery, could stabilize the disease. None of the wild-type members had glaucoma. CONCLUSIONS: This Swiss family is the largest reported Gly367Arg pedigree to date. The exact genotype and phenotype characterization allowed a reliable risk and prognosis assessment and targeted eye-care planning for the family. The study demonstrates the importance of genetic investigations in glaucoma families, carrying the potential of long-term socio-economic benefits.

Long-term outcome of trans-scleral diode laser cyclophotocoagulation in refractory glaucoma.

BACKGROUND: Long-term outcome and complications of diode laser cyclophotocoagulation (DCPC) may be important, since eyes, once treated with DCPC, are less likely to be subjected to other types of interventions in the further follow-up. METHODS: Retrospective review of 131 eyes of 127 patients treated from 2000 through 2004. Success was defined as intraocular pressure (IOP) at last visit 6-21 mm Hg; hypotony: IOP

[Treatment of uveitis-associated refractory ocular hypotony with topical ibopamine]. / Therapie einer refraktären okulären Hypotonie bei Uveitis mit topischem Ibopamin.

BACKGROUND: Ibopamine is a non-selective dopamine- and adrenalin-receptor agonist that has been shown to cause pupillary dilation and an increase in aqueous humour secretion. This novel drug can be used as a mydriatic agent, as a provocative test in open-angle glaucoma, and for the treatment of persisting ocular hypotony. HISTORY AND SIGNS: This 47-year-old man had a history of uveitis associated with Crohn's disease. Six years after deep sclerectomy for uveitic secondary glaucoma, he developed severe hypotony in his left eye with drop of visual acuity (VA). The hypotony did not respond to topical steroid treatment. 2 % Ibopamine solution was ordered t. i. d. concomitant to 1 % prednisolone acetate. THERAPY AND OUTCOME: Intraocular pressure (IOP) began to rise after 3 weeks of Ibopamine treatment and returned to normal (12 mmHg) with continuous recovery of VA after 8 weeks. Ibopamine was discontinued at an IOP of 16 mmHg after a course of 12 weeks. IOP and VA remained stable during the 12-month follow-up period. CONCLUSIONS: Ibopamine 2 % eye drops in combination with topical steroids are a therapeutic option in uveitis-associated ocular hypotony.

Comparison of rebound tonometry with Goldmann applanation tonometry and correlation with central corneal thickness.

BACKGROUND/AIMS: Rebound tonometry (RT) is performed without anaesthesia with a hand held device. The primary aim was to compare RT with Goldmann applanation tonometry (GAT) and to correlate with central corneal thickness (CCT). The secondary aim was to prove tolerability and practicability of RT under "study conditions" and "routine practice conditions." METHODS: In group 1 (52 eyes/28 patients), all measurements were taken by the same physician, in the same room and order: non-contact optical pachymetry, RT, slit lamp inspection, GAT. Patients were questioned about discomfort or pain. In group 2 (49 eyes/27 patients), tonometry was performed by three other physicians during routine examinations. RESULTS: RT was well tolerated and safe. Intraocular pressure (IOP) ranged between 6 mm Hg and 48 mm Hg. No different trends were found between the groups. RT tended to give slightly higher readings: n = 101, mean difference 1.0 (SD 2.17) mm Hg; 84.1% of RT readings within plus or minus 3 mm Hg of GAT; 95% confidence interval in the Bland-Altman analysis -3.2 mm Hg to +5.2 mm Hg. Both RT and GAT showed a weak positive correlation with CCT (r2 0.028 and 0.025, respectively). CONCLUSIONS: RT can be considered a reliable alternative for clinical screening and in cases where positioning of the head at the slit lamp is impossible or topical preparations are to be avoided.

Morphometric assessment of normal, suspect and glaucomatous optic discs with Stratus OCT and HRT II.

AIMS: To compare morphometric parameters and diagnostic performance of the new Stratus Optical Coherence Tomograph (OCT) Disc mode and the Heidelberg Retina Tomograph (HRT); to evaluate OCT's accuracy in determining optic nerve head (ONH) borders. METHODS: Controls and patients with ocular hypertension, glaucoma-like discs, and glaucoma were imaged with OCT Disc mode, HRT II, and colour disc photography (DISC-PHOT). In a separate session, automatically depicted ONH shape and size in OCT were compared with DISC-PHOT, and disc borders adjusted manually where required. In a masked fashion, all print-outs and photographs were studied and discs classified as normal, borderline, and abnormal. The Cohen kappa method was then applied to test for agreement of classification. Bland-Altman analysis was used for comparison of disc measures. RESULTS: In all, 49 eyes were evaluated. Automated disc margin recognition failed in 53%. Misplaced margin points were more frequently found in myopic eyes, but only 31/187 were located in an area of peripapillary atrophy. Agreement of OCT with photography-based diagnosis was excellent in normally looking ONHs, but moderate in discs with large cups, where HRT performed better. OCT values were consistently larger than HRT values for disc and cup area. Compared with HRT, small rim areas and volumes tended to be minimized by OCT, and larger ones to be magnified. CONCLUSIONS: Stratus OCT Disc protocol performed overall well in differentiating between normal and glaucomatous ONHs. However, failure of disc border recognition was frequently observed, making manual correction necessary. ONH measures cannot be directly compared between HRT and OCT.

Transconjunctival application of mitomycin C in combination with laser sclerostomy ab interno: a long-term morphological study of the postoperative healing process.

The precise mechanism whereby mitomycin C enhances IOP reduction in glaucoma filtering surgery still eludes us. Ten rabbits received full-thickness Nd:YAG laser sclerostomy ab interno and adjunctive intraoperative treatment with mitomycin C (MMC) applied topically over the intact conjunctiva (0.5 mg ml-1 for 5 min). A systematic ultrastructural analysis of the fistulas and surrounding tissue was then conducted in conjunction with clinical observations, over the ensuing 10 weeks. In order to investigate also the extent to which MMC impedes fistula occlusion in the absence of percolating aqueous humour, we created non-perforating ('half-thickness') sclerostomies ab interno in three additional rabbits, one with and two without MMC therapy. Transconjunctival MMC application resulted in no serious complications. Eight of the ten full-thickness fistulas remained patent throughout the study, maintaining significant IOP reduction; the other two sclerostomies were compromised by iris incarceration. The MMC-treated, half-thickness canal remained as a tissue-free cul de sac; the two non-treated ones became completely occluded within one week without having recourse to extraocular cell populations. MMC suppressed the migration and proliferation of fibroblasts, macrophages and clump cells from the episclera, sclera, ciliary body and iris root. Repolymerization of heat-damaged collagen was abortive; neosynthesis was not observed. Myofibroblasts were encountered in the vicinity of the sclerostomy canals, and, after the fifth week, these cells were also found to be deployed as a canal-lining layer, delimiting the lumen from the surrounding stroma along most of the fistula length. Towards the external ostium, this layer of myofibroblasts was incomplete or absent. Near the internal ostium, lining cells were derived from the corneal endothelium. The transconjunctival mode of applying MMC appears to be efficient. This antifibrotic drug exerts its inhibitory influence by suppressing not only cell migration and proliferation, but also phagocytic and synthetic activities. However, exposed tissues are not acellular, and amongst the populations present, myofibroblasts are found to dominate the scene. The canal-delimiting cellular lining may play a role in maintaining fistula patency in MMC-treated eyes.

Spontaneous and pharmacologically-modulated wound healing after Nd:YAG laser sclerostomy ab interno in rabbits.

UNLABELLED: The course of tissue repair evoked by Nd:YAG laser sclerostomy ab interno and the effect of mitomycin-C on same were investigated ultrastructurally in 15 rabbits. In ten of them, the dynamics of the spontaneous postoperative healing response (i.e. in the absence of medication) was analyzed at two-day intervals by light- and electron microscopy. In two, fibroblast activity was assessed autoradiographically. In the last three rabbits, the sclerostomy site was exposed transconjunctivally to mitomycin-C (0.5 mg/ml; 5 minutes) before surgery, and morphological analysis was done on postoperative days 6 and 12. RESULTS: In the spontaneously healing group, blebs disappeared within five days of surgery. This corresponded to a massive invasion of macrophages and fibroblasts from the episclera and iris root. The sheath of coagulated tissue around the fistula appeared to act as a barrier to cell migration from the sclera itself at this stage. By days 8 to 12, the canal had become occluded by a network of cells and capillaries, and collagen fibrils in the coagulation sheath had undergone repolymerization. In the mitomycin-C group, large filtering blebs and patent, cell-free fistulas were observed over the entire period. Although applied transconjunctivally, the drug penetrated the whole scleral depth, as the iris root and ciliary body cell reaction was inhibited. Repolymerization of heat-damaged collagen was also hindered. The overall findings provide information on the sequence of repair events following laser sclerostomy. Local, non-invasive application of mitomycin-C delays the onset of this process, not only by inhibition of cell proliferation but also by suppressing the collagen recovery.

The repair response following Nd:YAG laser sclerostomy ab interno in rabbits.

This study was undertaken to examine ultrastructurally the course of tissue regeneration after thermally-induced laser sclerostomy and compare it with the post-operative clinical events in a rabbit model. Applying a continuous wave neodymium:YAG (Nd:YAG) laser, two sclerostomies were created ab interno on one eye in each of ten pigmented rabbits using a 200-microns-diameter quartz optical fiber; the unoperated fellow-eyes served as controls. Intraocular pressure (IOP) was measured daily before and after surgery. Animals were observed post-operatively for up to 16 days. Well-defined filtering blebs and a low complication rate demonstrated the success of the procedure. IOP was significantly lowered during the entire course of the observation period but after the fifth day, the conjunctival blebs had disappeared. The morphology of the changes in the sclerostomy fistulas were analysed at 2-day intervals by light and electron microscopy. Immediately after surgery, the canal was ensheathed by an approximately 100-microns-thick layer of coagulated collagenous tissue in which two zones could be distinguished according to the intensity of damage. Within 5 days, the inner and outer canal openings were invaded by macrophages and fibroblasts originating from the iris root and episclera, respectively. The former cells were engaged in the phagocytosis of disintegrated collagen adjacent to the lumen. More distally located fibrils which had incurred less severe damage, had retained their fibrillar structure but had lost banding periodicity. After thermal stress had faded, they appeared to undergo a process of repolymerisation. By day 10, the lumen had become occluded by a loose meshwork of phagocytes, fibroblasts and proliferating capillaries. These new vessels and the loose nature of the canal-occluding framework and of the surrounding regenerating collagenous tissue could have further permitted percolation and transport of aqueous humor, since IOP remained low, despite the disappearance of filtering blebs. Although the time course of repair is more rapid in rabbits than in humans, the data gleaned nonetheless yield valid information respecting the sequence of events following thermally-induced scleral fistula.