A mathematical description of nerve fiber bundle trajectories and their variability in the human retina.

We developed a mathematical model wherein retinal nerve fiber trajectories can be described and the corresponding inter-subject variability analyzed. The model was based on traced nerve fiber bundle trajectories extracted from 55 fundus photographs of 55 human subjects. The model resembled the typical retinal nerve fiber layer course within 20 degrees eccentricity. Depending on the location of the visual field test point, the standard deviation of the calculated corresponding angular location at the optic nerve head circumference ranged from less than 1 degrees to 18 degrees , with an average of 8.8 degrees .

Diurnal intraocular pressure profiles and progression of chronic open-angle glaucoma.

PURPOSE: To evaluate whether the amplitude of day-and-night intraocular pressure (IOP) profiles influences the rate of progression of chronic open-angle glaucoma. METHODS: The hospital-based clinical observational study included day-and-night profiles of IOP measurements performed on 458 patients (855 eyes) with chronic open-angle glaucoma or ocular hypertension. The 24-h pressure profiles obtained by Goldmann applanation tonometry contained measurements at 0700, noon, 1700, 2100, and midnight. RESULTS: In the whole study population, IOP amplitude was significantly (P<0.001) and positively associated with the mean (r=0.26), minimal (r=-0.23) and maximal (r=0.59) IOP values. Taking the whole study population, glaucoma progression was not associated with the IOP amplitude (P=0.09). After adjustment for age, neuroretinal rim area and the other IOP measurements, age (P<0.001) and neuroretinal rim area (P=0.05) remained as significant predictive factors in the selected Cox model. In the normal-pressure glaucoma group (n=174 eyes), progression was significantly positive associated with the minimal IOP value (P<0.001), the mean of the IOP values (P=0.024), and, less significantly (P=0.037) and negatively, with the pressure profile amplitudes. In the high-pressure glaucoma group (n=681 eyes), rate of glaucoma progression was not associated with the IOP amplitude (P=0.734) or the other IOP parameters. CONCLUSIONS: Taking into account the highly significant associations between the IOP amplitude and the mean, minimal and maximal IOP values suggests that it is the IOP itself, and less the pressure amplitude, which has the main influence on the rate of the glaucoma progression.

Cataract surgery combined with intravitreal injection of triamcinolone acetonide.

PURPOSE: To evaluate whether the addition of cataract surgery to an intravitreal injection of triamcinolone acetonide markedly increases frequency and spectrum of complications. METHODS: The comparative nonrandomized clinical interventional investigation included a study group of 60 eyes (56 patients) undergoing cataract surgery and additionally receiving an intravitreal injection of about 20 mg of triamcinolone acetonide and a triamcinolone control group of 290 eyes (262 patients) that consecutively received an intravitreal injection of about 20 mg triamcinolone acetonide without cataract surgery. Reasons for intravitreal injection of triamcinolone acetonide were exudative age-related macular degeneration (n=228; 65%), diffuse diabetic macular edema (n=94; 27%), central retinal vein occlusion (n=17; 5%), and branch retinal vein occlusion (n=11; 3%). Mean follow-up was 8.6+/-6.8 months. A second control group included 1068 patients (1068 eyes) who consecutively underwent routine cataract surgery without intravitreal injection. RESULTS: Study group and triamcinolone control group did not vary significantly in best visual acuity during follow-up (p=0.08), final visual acuity at the end of follow-up (p=0.30), maximal intraocular pressure during follow-up (p=0.99), frequency of an intraocular pressure higher than 21 mmHg (p=0.66), and intraocular pressure at the end of follow-up (p=0.06). Postoperative infectious endophthalmitis, wound leakage or other corneal wound healing problems, persisting corneal endothelial decompensation, rhegmatogenous retinal detachment, marked postoperative pain, or a clinically significant decentration of the intraocular lens were not observed. Study group and the non-triamcinolone control group did not vary significantly in the rate of posterior lens capsule rupture (p=0.11), postoperative infectious endophthalmitis, and persisting postoperative corneal endothelial decompensation. CONCLUSIONS: The addition of cataract surgery to an intravitreal injection of triamcinolone acetonide may not markedly increase amount and frequency of side effects and complications of intravitreal triamcinolone acetonide. No safe conclusions can be reached regarding differences in frequency of postoperative infectious endophthalmitis.

Optic nerve damage in highly myopic eyes with chronic open-angle glaucoma.

PURPOSE: To compare the amount of optic nerve damage in relation to intraocular pressure in highly myopic eyes with chronic open-angle glaucoma versus non-highly myopic eyes with chronic open-angle glaucoma. METHODS: The comparative clinical observational study included 1841 eyes of 1100 patients with chronic open-angle glaucoma. The highly myopic study group consisted of 25 eyes with a myopic refractive error equal to or higher than -8 diopters. It was subdivided into eyes with an optic disc size larger than 2.7 mm2 and eyes with an optic disc smaller than 2.7 mm2. The control group included the remaining, non-highly myopic eyes (n=1816). For all patients, a morphometric analysis of color stereo optic disc photographs was performed. Main outcome measures were morphometric optic disc measurements and intraocular pressure. RESULTS: In the highly myopic, large-optic-disc study group compared with the control group, maximal and minimal intraocular pressure readings were significantly (p<0.05) lower and neuroretinal rim area corrected for optic disc size was slightly (p=0.16) smaller. Comparing the total highly myopic study group with a control group adjusted for optic disc area, neuroretinal rim area was significantly (p=0.039) smaller in the study group with no significant difference in intraocular pressure measurements between the groups. CONCLUSIONS: At a given intraocular pressure in chronic open-angle glaucoma, optic nerve damage may be more pronounced in highly myopic eyes with large optic discs than in non-highly myopic eyes. This may suggest a higher susceptibility for glaucomatous optic nerve fiber loss in highly myopic eyes than in non-highly myopic eyes.

[Follow-up examination of eyes with chronic open-angle glaucoma and optic disc hemorrhages]. / Nachfolgeuntersuchung von Augen mit chronischem Offenwinkelglaukom und streifenförmigen Papillenblutungen.

PURPOSE: To evaluate the frequency of neuroretinal rim loss in glaucomatous eyes with ophthalmoscopically detected optic disc hemorrhages. METHODS: The prospective comparative clinical observational study included 78 eyes from 69 Caucasian patients with chronic open-angle glaucoma and a flame-shaped optic disc hemorrhage at the time of presentation, and 386 eyes from 252 patients with chronic open-angle glaucoma without disc hemorrhages. All patients underwent repeated qualitative and morphometric evaluation of color stereo optic disc photographs. RESULTS: Patients with disc hemorrhages were older than patients without hemorrhages and showed an initially smaller neuroretinal rim area. Of the 78 eyes with disc hemorrhages 39 showed loss of neuroretinal rim during the follow-up period. For the remaining 39 eyes, no changes of the neuroretinal rim could be detected on optic disc photographs. Of the 386 eyes without disc hemorrhages 71 showed loss of neuroretinal rim during the follow-up period. A survival analysis confirmed a hazard ratio of three between eyes with and without disc hemorrhages and a hazard ratio of 1.85 per decade of patient's age (multivariate analysis). CONCLUSIONS: Disc hemorrhages lead to a 3-fold increase of risk for further retinal rim loss in eyes with chronic open-angle glaucoma.

Factors influencing visual outcome after penetrating keratoplasty combined with intraocular lens implantation.

PURPOSE: To establish which factors influence visual outcome after penetrating keratoplasty combined with intraocular lens implantation. METHODS: This retrospective noncomparative clinical interventional case series study included 135 consecutive patients (mean age 70.2 +/- 13.6 years) who underwent central penetrating allogenic keratoplasty combined with intraocular lens (IOL) implantation, all operated by the same surgeon. There were 79 triple procedures, 33 keratoplasties combined t with an exchange of OL, and 23 penetrating keratoplasties combined with a secondary implantation of posterior chamber lens. Mean follow-up was 28.3 +/- 18.7 months (range 3.3-112 months). Reasons for keratoplasty were herpetic or traumatic corneal scars or defects (46), Fuchs corneal endothelial dystrophy (22), pseudophakic or aphakic bullous keratopathy (49), corneal endothelial decompensation due to other reasons (15), and keratoconus (3). Main outcome measures were postoperative visual acuity and agin in visual acuitvy RESULTS: Mean postoperative visual acuity and mean gain in visual acuity were 0.33 +/- 0.21 (median 0.30) and 0.25 +/- 0.20 (median 0.20), respectively. Compared with the preoperative measurements, mean visual acuity increased in 129 patients (129 /135, 95.6%). Factors influencing postoperative visual outcome and gain in visual acuity were preoperative visual acuity (p < 0.005), reason for keratoplasty (p < 0.005), and diameter of the graft (p = 0.046). ostoperative visual outcome was independent of age, sex, right or left eye, presence of diabetes mellitus, preoperative refractive error, length of follow-up, duration of surgery, and preoperative intraocular pressure. CONCLUSIONS: The most important factors influencing visual outcome after central penetrating allogenic keratoplasty combined with IOL surgery are preoperative visual acuity, graft size, and reason for keratoplasty. Other factors such as age, sex, diabetes mellitus, and preoperative refractive error do not substantially influence postoperative visual outcome.

Ocular findings in cerebro-oculo-facial-skeletal syndrome (Pena-Shokeir-II syndrome).

PURPOSE: To report the ocular findings in cerebro-oculo-facial-skeletal syndrome or Pena-Shokeir-II syndrome. METHODS: Case report. RESULTS: A five-month-old male infant presented with bilateral posterior polar cataract, microphthalmos, nystagmus, and marked non-glaucomatous optic nerve atrophy. Systemic abnormalities such as microcephaly, micrognathia, flexion contractures of the elbows and knees, hypotonic musculature, and failure to thrive, with pronounced statomotor retardation, led to the diagnosis of cerebro-oculo-facial-skeletal syndrome or Pena-Shokeir-II syndrome. Cataract surgery did not improve the poor visual performance. CONCLUSIONS: Cerebro-oculo-facial-skeletal syndrome (Pena-Shokeir-II syndrome) should be included in the differential diagnosis of bilateral microphthalmos, congenital cataract, nystagmus, and pronounced optic nerve atrophy, and cataract surgery does not markedly improve vision.

Determination of optic cup depth by confocal scanning laser tomography.

PURPOSE: To assess whether confocal scanning laser tomography of the optic disc and clinical ophthalmoscopy using stereoscopic optic disc photographs, agree in the evaluation of the deepest part of the optic cup. PATIENTS AND METHODS: The study included 33 eyes of patients with focal normal-pressure glaucoma. Using 15 degrees color stereoscopic optic disc photographs and dividing the optic disc into an upper and a lower half, two trained observers independently established the location of the deepest part of the cup. By selection, the two observers had made congruent judgements for all eyes in the study. All patients also underwent confocal scanning laser tomography of the optic disc using the Heidelberg Retina Tomograph (HRT). The location of the deepest "mean cup depth" was noted. RESULTS: The deepest optic cup region based on stereoscopic evaluation of photographs and on scanning laser tomography did not correlate significantly with each other (p=0.18; chi-square test, linear-by-linear association). According to the scanning laser tomography data, the maximal optic cup depths were not correlated with the corresponding locations of maximal visual field defect (p=0.80). Using the stereo photographic data, the locations of maximal optic cup depth and maximal visual field defect were correlated (p=0.006). CONCLUSIONS: In some glaucomatous eyes, confocal scanning laser tomographic assessment of the location of the deepest optic cup region does not agree with clinical judgement and, in contrast to clinical examination, does not correlate with the location of the maximal visual field defect.

[Influence of ciliary-retinal arteries on functional damage in open-angle glaucoma]. / Einfluss zilioretinaler Gefässe auf funktionelle Schädigungen beim Offenwinkelglaukom.

PURPOSE: The pattern of functional perimetric loss and morphologic neuroretinal rim loss in glaucoma depends on the localization of the central retinal vessel trunk in the lamina cribrosa. The purpose of the present study was to determine if the pattern of perimetric loss and rim loss are influenced by the presence and position of cilioretinal arteries. PATIENTS AND METHODS: Using automated perimetry and 15 degrees color stereo optic disc photographs of the optic disc, we compared 20 open-angle glaucoma patients exhibiting cilioretinal arteries in the temporal horizontal disc region with 70 open-angle glaucoma patients without cilioretinal arteries. RESULTS: Eyes with cilioretinal arteries and eyes without cilioretinal arteries did not differ significantly in global visual field indices nor in the mean defect for the central 10 degrees. No differences were detected for the areas of optic disc, neuroretinal rim, ratios of the temporal horizontal area-to-total area of rim and ratio of temporal horizontal rim area-to-nasal rim area. CONCLUSIONS: In contrast to the position of the central retinal vessel trunk, the presence and position of cilioretinal arteries do not markedly influence the pattern of glaucomatous damage.

Is the nasal optic disc sector important for morphometric glaucoma diagnosis?

BACKGROUND/AIM: Since the central retinal vessel trunk usually located in the nasal optic disc sector can render difficult the delineation of the neuroretinal rim and optic disc, the aim of this study was to evaluate whether the nasal region of the optic nerve head is important, or can be left out, for the morphometric glaucoma diagnosis. METHODS: The clinical observational study included 1337 patients with primary or secondary open angle glaucoma and 649 normal subjects. The glaucoma group was divided into 1187 patients with glaucomatous visual field defects ("perimetric glaucoma"), and into 150 patients with optic nerve head changes and normal visual fields ("preperimetric glaucoma"). Colour stereo optic disc photographs were morphometrically evaluated. RESULTS: Highest diagnostic power for the separation between the normal group and the perimetric glaucoma group, and for the differentiation between the normal group and the preperimetric glaucoma group, had the sum of inferotemporal rim area plus superotemporal rim area, the sum of inferotemporal rim area plus superotemporal rim area plus temporal rim area, and the inferotemporal rim area as single parameter. The lowest diagnostic precision had the nasal rim area as single parameter or in combination with rim measurements in other disc sectors. CONCLUSION: Excluding the nasal optic disc sector does not markedly decrease the diagnostic power of morphometric optic disc analysis in glaucoma diagnosis. It may have importance for an automated computerised morphometric detection of glaucomatous optic nerve damage.

Retinal redetachment after removal of intraocular silicone oil tamponade.

AIM: To evaluate frequency and risk factors of retinal redetachment after removal of intraocular silicone oil tamponade. METHODS: The study included 225 patients who consecutively underwent intraocular silicone oil removal at a mean interval of 10 months after pars plana vitrectomy had been performed by one of two surgeons. Mean follow up time was 17.37 (SD 14.40) months (range 3.02-67.42 months). RESULTS: In 57 of 225 (25.3%) patients, the retina detached after removal of silicone oil. Risk factors for retinal redetachment were the following: number of previously unsuccessful retinal detachment surgeries (p=0.0008); surgeon (p=0.007); visual acuity before silicone oil removal (p=0.009); incomplete removal of vitreous base (p=0.01); absence of an encircling band in eyes with proliferate vitreoretinopathy in which an inferior retinotomy had not been performed (p=0.01); and indication for pars plana vitrectomy. Rate of retinal redetachment was statistically (p>0.05) independent of the technique of silicone oil removal and duration of silicone oil endotamponade. CONCLUSION: Retinal redetachment after removal of silicone oil endotamponade can occur in approximately a fourth of patients, depending on the criteria to use and to remove silicone oil. Risk factors for recurrent detachment included the following: number of previously unsuccessful retinal detachment surgeries, surgeon, preoperative visual acuity, incomplete removal of the vitreous base, absence of an encircling band, and reason for pars plana vitrectomy. The rate of retinal redetachment is independent of the technique of silicone oil removal and duration of silicone oil endotamponade, with a minimal duration of silicone oil tamponade of about 3 months in the present study.

Tectonic sclerokeratoplasty and tectonic penetrating keratoplasty as treatment for perforated or predescemetal corneal ulcers.

PURPOSE: To report the clinical outcome of patients with perforated or predescemetal corneal ulcers treated by tectonic, centric or eccentric penetrating keratoplasty or by tectonic sclerokeratoplasty. DESIGN: Nonrandomized clinical trial. METHODS: The study included 60 patients (60 eyes) with perforated or predescemetal corneal ulcers who were consecutively operated on by the same surgeon. Fifty-two patients underwent tectonic penetrating centric or eccentric keratoplasty. Eight patients with paralimbal corneal ulcers underwent tectonic sclerokeratoplasty. A control group consisted of 76 patients (76 eyes) electively undergoing central penetrating keratoplasty for treatment of inactive central corneal scars. RESULTS: In the study group with perforated or predescemetal corneal ulcers, best-corrected postoperative visual acuity ranged from perception of light to 0.80 (median, 0.10), with 54 of 60 eyes (90%) attaining an improvement of best visual acuity. In 10 of 60 patients (16.7%), tectonic penetrating keratoplasty had to be re-performed because of a recurring corneal ulcer. Patients with sclerokeratoplasty and patients with eccentric keratoplasty did not differ in clinical outcome, despite larger trephine and corneal lesion size in the sclerokeratoplasty group. Among study patients compared with control patients, postoperative visual acuity was significantly lower (P =.01), postoperative refractive and keratometric astigmatism were significantly higher (P <.05), and immunologic graft reactions (P =.02) and suture loosening (P <.001) occurred significantly more often. CONCLUSIONS: Eyes with perforated corneal ulcers or predescemetal corneal ulcers can usually be saved by tectonic keratoplasty or sclerokeratoplasty, with a moderate to considerable amount of remaining useful vision. In case of doubt, one may prefer conservative treatment of corneal ulcers and to electively perform central keratoplasty when the ulcers have healed. For selected clinical situations, sclerokeratoplasty is an alternative to keratoplasty for surgical treatment of paralimbal corneal defects.

Central retinal vessel trunk exit and location of glaucomatous parapapillary atrophy in glaucoma.

OBJECTIVE: To evaluate whether the position of the central retinal vessel trunk exit on the lamina cribrosa spatially correlates with the location of parapapillary atrophy in glaucoma. DESIGN: Clinic-based, observational, cross-sectional study. PATIENTS: Color stereo optic disc photographs of 95 patients with primary or secondary open-angle glaucoma and 65 healthy persons were morphometrically evaluated. The intrapapillary and parapapillary region was divided into four quadrants. We determined the position of the central retinal vessel trunk exit on the lamina cribrosa surface and measured the area of parapapillary atrophy and neuroretinal rim in the four quadrants. MAIN OUTCOME MEASURES: The area of neuroretinal rim and parapapillary atrophy and the position of the central retinal vessel trunk exit. RESULTS: Comparing measurements between opposite disc quadrants showed that beta zone of parapapillary atrophy was significantly (P < 0.05) larger and that the neuroretinal rim was significantly smaller when beta zone and neuroretinal rim were measured in the disc quadrant most distant to the central retinal vessel trunk exit, than if the beta zone and neuroretinal rim were measured in the quadrant containing the vessel trunk exit. Comparing measurements in the disc quadrants between eyes with different positions of the central retinal vessel trunk exit revealed that, in the respective disc quadrant, the beta zone was significantly larger and the neuroretinal rim was smaller in eyes with the vessel trunk exiting in the opposite disc quadrant than in eyes with the vessel trunk exit located in the respective disc quadrant where the measurements were obtained. CONCLUSIONS: Position of the central retinal vessel trunk exit on the lamina cribrosa influences the location of parapapillary atrophy in glaucoma. The longer the distance to the central retinal vessel trunk exit, the more enlarged is parapapillary atrophy and the smaller is the neuroretinal rim. This relationship agrees with the spatial relationship between glaucomatous neuroretinal rim loss and enlarged parapapillary atrophy in glaucoma. Diagnostically, it may indicate that, in eyes with an abnormal configuration of parapapillary atrophy or with an abnormal position of the central retinal vessel trunk exit, early glaucomatous rim changes should be looked for in the disc sector that is most distant to the central retinal vessel trunk exit and where parapapillary atrophy may be relatively large.

Autologous ipsilateral rotating penetrating keratoplasty.

PURPOSE: To evaluate visual outcome after autologous ipsilateral rotating penetrating keratoplasty. METHODS: The study included nine patients who consecutively underwent autologous ipsilateral rotating penetrating keratoplasty for treatment of traumatic central corneal avascular scars. These patients were compared with 105 patients who consecutively underwent homologous central penetrating keratoplasty in the same study period for treatment of avascular corneal scars extending to the corneal periphery. All operations were performed by the same surgeon. Mean follow-up time for both study groups was 31.27 +/- 21.54 and 32.0 +/- 19.4 months, respectively. RESULTS: In the autologous rotating keratoplasty group, visual acuity increased significantly (P = 0.03; Wilcoxon test) from 0.13 +/- 0.11 preoperatively to 0.29 +/- 0.16 postoperatively. Refractive astigmatism and keratometric astigmatism, respectively, increased (P = 0.02) from 3.19 +/- 2.53 diopters and 3.20 +/- 2.24 diopters, respectively, preoperatively to 6.9 +/- 1.82 diopters and 9.55 +/- 4.32 diopters, respectively, postoperatively. Comparing the study groups, postoperative visual acuity was significantly lower (P = 0.01), and keratometric astigmatism (P = 0.003) and refractive astigmatism (P = 0.01) were significantly higher in the autologous rotating keratoplasty group than in the control group. CONCLUSIONS: Autologous ipsilateral rotating penetrating keratoplasty compared with homologous central penetrating keratoplasty is associated with a high postoperative refractive and keratometric astigmatism leading to a relatively low postoperative visual acuity. It suggests that, in normal clinical conditions when donor material is available and postoperative follow-up examinations can be performed, homologous central penetrating keratoplasty may be superior to autologous ipsilateral rotating keratoplasty.

Intraocular pressure and silicone oil endotamponade.

PURPOSE: To evaluate intraocular pressure after instillation and eventual removal of silicone oil in patients undergoing pars plana vitrectomy combined with silicone oil endotamponade. METHODS: The study included 198 patients who underwent pars plana vitrectomy with silicone oil endotamponade (5,000 centistoke viscosity), in whom silicone oil was removed and in whom follow-up after oil removal was at least 3 months. All patients were operated on by one of two surgeons. RESULTS: After silicone oil instillation, intraocular pressure increased significantly (P < 0.001) from 12.9 +/- 4.4 mm Hg preoperatively to 16.1 +/- 5.5 mm Hg postoperatively. Intraocular pressure was statistically (P > 0.20) independent of the duration of silicone oil tamponade. Twenty percent of the 198 patients had at least one postoperative intraocular pressure measurement that was higher than 21 mm Hg. Main reasons for increased intraocular pressure were closed inferior iridectomy, iris neovascularisation, silicomacrophagocytic open-angle glaucoma secondary to silicone oil emulsification, and preoperative history of glaucoma. Glaucomatous optic nerve damage was detected in 14 (14 of 198, 7.1%) eyes, including 8 eyes with preoperative antiglaucoma treatment. Silicone oil emulsification occurring in 40 (40 of 198, 20.2%) patients did not statistically influence intraocular pressure after oil removal. Ocular hypotony occurred in 10 (10 of 198, 5.1%) patients after oil release leading to intraocular hemorrhages and loss of vision in 3 patients. CONCLUSION: Clinically significant increased intraocular pressure after pars plana vitrectomy with silicone oil endotamponade occurs relatively rarely, can usually be well controlled by topical antiglaucoma medication, and is reversible in most patients after oil removal. In patients with increased intraocular pressure and silicone oil endotamponade, oil removal may be preferred to invasive antiglaucoma surgery to reduce intraocular pressure.

Intraocular pressure after homologous penetrating keratoplasty.

PURPOSE: To evaluate intraocular pressure (IOP) changes after homologous central penetrating keratoplasty in a noncomparative interventional case series. METHODS: The study included 245 patients undergoing homologous central penetrating keratoplasty for keratoconus (n = 77), herpetic corneal scars (n = 29), nonherpetic corneal scars (n = 46), Fuchs endothelial dystrophy (n = 24), and secondary corneal endothelial decompensation caused by preceding intraocular operations (n = 69). Mean follow-up time was 30.4 +/- 18.7 months (range, 12.1-111.6 months). The same surgeon operated on all patients, and a peripheral iridotomy was routinely performed. RESULTS: On the first postoperative day, IOP was significantly (P = 0.02) higher than that before keratoplasty. Taking the whole study group and taking the study groups separately, IOP measurements determined on the third postoperative day (P = 0.57), 1 week after surgery (P = 0.55), or later (P > 0.50) were not significantly different from the preoperative values. Eyes undergoing keratoplasty with cataract surgery and eyes undergoing keratoplasty without additional intraocular procedures did not vary significantly (P > 0.10) in IOP measurements. IOP did not differ significantly (P > 0.50) between eyes with an immunologic graft reaction (n = 29) and eyes without a reaction (n = 216). Acute angle-closure glaucoma was not detected in any of the patients. IOP measurements were statistically independent of suture type (P > 0.10), age (P > 0.05), preoperative and postoperative refractive error (P > 0.05), preoperative and postoperative corneal astigmatism (P > 0.10), preoperative and postoperative visual acuity (P > 0.10), diameter of graft and trephine (P > 0.15), and oversize of the graft (P > 0.50). Postoperative IOP measurements were significantly (P < 0.01) correlated with preoperative IOP values. CONCLUSIONS: In eyes with a peripheral iridotomy performed during surgery, homologous central penetrating keratoplasty usually does not markedly change IOP. The main risk factor for postoperatively increased IOP is increased IOP before surgery.

[Monitoring of morphometric changes of optic discs with morphologic progression of glaucomatous optic atrophy by means of laser scanner tomography]. / Morphometrische Querschnittsverlaufsbeobachtung der Papille mit dem HRT in Augen mit morphologischer Progression der glaukomatösen Atrophie der Papille des Nervus opticus.

AIM: Aim of this study was to measure morphometric changes in optic discs with laser-scanning tomography (HRT, Heidelberg-Retina-Tomograph, Heidelberg) in eyes with early glaucomatous morphologic progression. PATIENTS AND METHODS: 61 eyes of 36 patients with marked neuroretinal rim loss or its early morphologic signs (1. optic disc hemorrhages, 2. reduced visibility of the retinal nerve fiber layer (RNF), 3. appearance of narrowing of retinal vessels, 4. enlargement of the choroidal, parapapillary atrophy) were compared to 74 normal eyes of 39 probands. 15 degrees stereographs of the optic discs were evaluated for morphologic changes. The morphometric variables of the neuroretinal rim and excavation measured by the HRT were examined in the course of the disease. RESULTS: In the group of normals no significant changes of the neuroretinal rim in the course of 2.0 +/- 1.2 years were found. In the group of glaucomatous eyes (3.0 +/- 1.5 years follow-up) 34 eyes showed marked neuroretinal rim loss, 17 disc hemorrhages, 4 vessel narrowing, 3 an increased chorioidal atrophy, 3 a decreased visibility of the retinal nerve fiber layer. In these eyes a significant loss of rim area (p = 0.01) and an increase of excavation area (p = 0.0001) and volume (p = 0.003) was measured by the HRT. Only three eyes showed a perimetric loss of sensitivity (0.8-3.4 db) in Octopus static perimetry. CONCLUSIONS: Laser-scanning tomography of the optic disc seems to be able to measure morphometric changes in eyes with morphologic progression of glaucomatous optic atrophy, even before perimetric changes occur.

Influence of optic disc size on neuroretinal rim shape in healthy eyes.

PURPOSE: To evaluate the influence of optic disc size on segmental neuroretinal rim area in healthy eyes. PATIENTS AND METHODS: The study included 193 eyes of 193 healthy patients with physiologic disc cupping. On 15 degrees color stereophotographic optic disc diapositives, optic disc area and neuroretinal rim area were morphometrically determined in 36 radial optic disc segments each measuring 10 degrees. RESULTS: The correlations of segmental rim area to disc area were significantly strongest (P < 0.01) and the regression lines were steepest in the inferior disc region, and the values were lowest in the temporal disc region. Complementary to the rim data, the correlations of segmental cup area to disc area were significantly strongest (P < 0.01) and the regression lines were steepest in the temporal disc region, and the values were lowest in the inferior disc region. In comparison with neuroretinal rim area, cup area was significantly (P < 0.01) more strongly correlated with disc area and the regression line was steeper in the whole optic disc and in each disc segment. The regional distribution of the widest rim part and smallest rim part was independent of disc size. CONCLUSIONS: The increase of rim area and cup area with increasing disc size differs between various disc regions. Because cup area increases more than rim area with increasing disc size, correction for disc size may be more important for segmental cup area than for segmental rim area. The rim shape with respect to the location of the smallest or broadest rim part is independent of disc size.