Novel use of 3T MRI in assessment of optic nerve volume in glaucoma

Purpose

To measure optic nerve (ON) volume using 3 T magnetic resonance imaging (MRI), to correlate ON volume with retinal nerve fiber layer (RNFL) thickness, and to determine the viability of MRI as an objective tool in distinguishing glaucoma severity.

Methods

In this cross-sectional study, 30 severe glaucoma patients, 30 mild glaucoma patients and 30 age-matched controls were recruited. All subjects underwent standard automated perimetry, RNFL analysis and 3 T MRI examinations. Glaucoma patients were classified according to the Hodapp–Anderson–Parish classification. Pearson’s correlation coefficient was used to correlate ON volume with RNFL, and receiver operating curve (ROC) analysis was performed to determine the sensitivity and specificity of ON volume in detecting glaucoma severity.

Results

Optic nerve volume was significantly lower in both the left and right eyes of the severe glaucoma group (168.70?±?46.28 mm³; 167.40?±?45.36 mm³) than in the mild glaucoma group (264.03?±?78.53 mm³; 264.76?±?78.88 mm³) and the control group (297.80?±?71.45 mm³; 296.56?±?71.02 mm³). Moderate correlation was observed between: RNFL thickness and ON volume (r?=?0.51, p <0.001), and in mean deviation of visual field and optic nerve volume (r?=?0.60, p?<?0.001). ON volume below 236 mm³ was 96 % sensitive and 80 % specific for the detection of severe glaucoma.

Conclusions

MRI measured optic nerve volume is a reliable method of assessing glaucomatous damage beyond the optic nerve head. A value of 236 mm³ and below can be used to define severe glaucoma.     

Results of excimer laser penetrating keratoplasty in aphakic eyes

Background

Corneal grafting in aphakic eyes is often challenging. We report about the outcome of excimer laser trephination in aphakic eyes.

Methods

We examined 17 eyes of 17 patients. Diagnosis in 11 eyes was endothelial decompensation and in six, corneal scars. We performed an excimer laser keratoplasty with intraoperative “Flieringa ring” suturing. Follow-up ranged between 3 and 41 (17.6?±?11.7) months. Main outcome measures included: best-corrected visual acuity (BCVA), intraocular pressure (IOP), topographic astigmatism, corneal refractive power (CRP), central corneal thickness (CCT) and endothelial cell density (ECD).

Results

Preoperative BCVA was light perception in two eyes, hand motion in seven, finger counting in one eye, under 20/400 in six eyes and 20/200 in one eye. IOP ranged between 4 and 28 (13.6?±?5.1) mmHg. Topographic astigmatism ranged from 0.5 to 18.5 (7.0?±?6.9) dioptres. CRP was between 38 and 59 (46?±?9) dioptres. CCT was between 404 and 1069 (748?±?181) μm. Postoperative BCVA was hand motion in five eyes, under 20/400 in two and ranged between 20/200 and 20/20 in ten eyes. IOP ranged between 10 and 40 (18.3?±?8.5) mmHg. Topographic astigmatism ranged from 0.9 to 13 (5.5?±?3.2) dioptres. CRP was between 31.9 and 46.7 (42?±?4.1) dioptres. CCT was between 349 and 820 (552?±?115.57) μm. ECD was between 592 and 2319 (1674?±?553) cells/mm².

Conclusions

Excimer laser trephination can deliver beneficial visual outcomes in most of the aphakic eyes.     

Retinal and optic nerve evaluation by optical coherence tomography in adults with obstructive sleep apnea–hypopnea syndrome (OSAHS)

Objective

To assess the peripapillary retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) morphologic parameters, and macular thickness and volume in patients affected by obstructive sleep apnea–hypopnea syndrome (OSAHS).

Methods

This prospective, observational case-control study consisted of 96 eyes of 50 OSAHS patients (mean age of 50.9?±?12.4 years, best-corrected visual acuity ≥20/20, refractive error less than 3 spherocylindrical diopters, and intraocular pressure <21 mmHg) who were enrolled and compared with 64 eyes of 33 age-matched controls. Peripapillary RNFL thickness, ONH parameters, macular thickness and volume were measured by optical coherence tomography (OCT).

Results

OSAHS patients showed a significant reduction of the nasal quadrant RNFL thickness (74.7?±?15.8 μm) compared with those values observed in control patients (81.1?±?16.6 μm, p?=?0.047, Student's t-test). No differences in peripapillary RNFL thickness were observed when dividing the OSAHS group in accordance with disease severity. Vertical integrated rim area (VIRA) (0.67?±?0.41 mm³ in OSAHS vs 0.55?±?0.29 mm³ in controls; p?=?0.043, Student's t-test), horizontal integrated rim width (HIRW) (1.87?±?0.31 mm² in OSAHS vs 1.8?±?0.25 mm² in controls; p?=?0.039, Student's t-test) and disc area (2.74?±?0.62 mm² in OSAHS vs 2.48?±?0.42 mm² in controls; p?=?0.002, Student's t-test) showed significant differences, all of them being higher in the OSAHS group. Severe OSAHS had significant higher disc area (2.8?±?0.7 mm²) than controls (2.5?±?0.4 mm²; p?=?0.016, ANOVA test). Temporal inner macular thickness was significantly higher in mild–moderate OSAHS patients (270?±?12 μm) than in severe OSAHS patients (260?±?19 μm; p?=?0.021, ANOVA test).

Conclusions

OSAHS patients showed decreased peripapillary nasal RNFL thickness, and increased ONH area and volume parameters when they were evaluated by OCT. These findings suggest that neuronal degeneration might be present in the retina of OSAHS patients, as previously observed in some neurodegenerative disorders     

Pars plana vitrectomy for the repair of primary, inferior rhegmatogenous retinal detachment associated to inferior breaks. A comparison of a 25-gauge versus a 20-gauge system

Background

To compare anatomical, functional outcomes and complications of high-speed 25-gauge (G) pars plana vitrectomy (PPV) versus 20-G PPV for the management of primary inferior rhegmatogenous retinal detachment (RRD) associated to inferior breaks/holes.

Methods

Eighty-five eyes from 85 patients with a minimum follow-up of 3 months were retrospectively evaluated. Forty-one patients underwent 25-G and 44 patients underwent 20-G PPV. All patients underwent PPV with fluid-air exchange, sulfur hexafluoride (SF6) 20 % gas tamponade and laser or cryo retinopexy.

Results

The mean follow-up interval was 6.51(±2.32) and 6.63 (±2.58) months in the 25-G and 20-G groups respectively. Single-operation success rate was 92.7 % for the 25-G group and 81.8 % for the 20-G group (P?=?0.24). Post-operative hypotony was observed in no case. Redetachment occurred in 3 eyes operated on with 25-G and in 8 eyes operated on with 20-G system. All retinas were attached at final follow-up. Logarithm of the minimum angle of resolution visual acuity significantly improved from 0.69?±?0.76 to 0.33?±?0.37 in the 25-G and from 0.47?±?0.59 to 0.21?±?0.28 in the 20-G group (P?=?0.0007 and P?<?0.0001 respectively).

Conclusions

High-speed PPV and SF6 gas tamponade using either 25-G or 20-G PPV system, yields similar single operation anatomical success rates for the repair of uncomplicated, primary inferior RRDs associated to inferior breaks.     

Subbasal nerve morphology, corneal sensation, and tear film evaluation after refractive femtosecond laser lenticule extraction

Background

The purpose of this study was to compare corneal subbasal nerve morphology, corneal sensation, and tear film parameters after femtosecond lenticule extraction (FLEX) and small-incision lenticule extraction (SMILE).

Methods

A prospective, randomized, single-masked, paired-eye design clinical trial of 35 patients treated for moderate to high myopia with FLEX in one eye and SMILE in the other. In both techniques, an intrastromal lenticule was cut by a femtosecond laser and manually extracted. In FLEX, a LASIK-like flap allowed removal of the lenticule, whereas in SMILE, it was removed through a small incision. In-vivo confocal microscopy was used to acquire images of the central corneal subbasal nerve plexus, from which nerve density, total nerve number, and nerve tortuosity were analyzed. Corneal sensation was measured using Cochet–Bonnet esthesiometry. A visual analog scale, tear osmolarity, non-invasive tear film break-up time (keratograph) tear meniscus height (anterior segment OCT), Schirmer's test, and fluorescein tear film break-up time were used to evaluate tear film and ocular surface symptoms. Patients were examined before and 6 months after surgery.

Results

There were no statistically significant differences in baseline parameters between FLEX and SMILE (p?>?0.050). With regard to changes from before to 6 months after surgery, mean reduction in subbasal nerve density was 14.22?±?6.24 mm/mm² in FLEX eyes, and 9.21?±?7.80 mm/mm² in SMILE eyes (p?<?0.05). The total number of nerves decreased more in FLEX eyes than in SMILE eyes (p?<?0.05). No change was found when comparing tortuosity (p?>?0.05). Corneal sensation was reduced with 0.38?±?0.49 cm in FLEX eyes, and 0.10?±?0.34 cm in SMILE eyes (p?<?0.01). No differences were found between FLEX and SMILE in tear film evaluation tests (p?>?0.05). Significantly more patients felt postoperative foreign body sensation in the FLEX eye within the first days after surgery, as compared to the SMILE eye.

Conclusions

Six months after surgery, the less invasive SMILE technique seemed better at sparing the central corneal nerves as compared to FLEX. Corneal sensation was only significantly reduced in FLEX eyes. There were no differences between FLEX and SMILE when comparing tear film evaluation tests 6 months after surgery.     

Comparison of observation, intravitreal bevacizumab, or pars plana vitrectomy for non-proliferative type 2 idiopathic macular telangiectasia

Purpose

To compare visual and anatomic outcomes in eyes with type 2 idiopathic macular telangiectasia (Mactel) treated with either intravitreal bevacizumab (IVB), observation, or pars plana vitrectomy (PPV) with internal limiting membrane removal.

Methods

Retrospective, consecutive, interventional case series of phakic patients with Mactel. Best-corrected Snellen visual acuity (BCVA) and complete ophthalmic exam was obtained prior to treatment and at subsequent 3-month intervals for a minimum of 6 months. Fluorescein angiographic and spectral-domain optical coherence tomography features were examined, and compared to BCVA at treatment initiation and follow-up.

Results

Fifty-six eyes of 28 patients were evaluated. Mean age was 65?±?12 years, and mean follow-up was 24?±?13 months. Patients were treated with either observation (n?=?33), IVB (n?=?15), or PPV (n?=?8). Mean number of treatments for the IVB group was 2.5?±?3.5 intravitreal injections. No significant differences in BCVA change were observed between treatment groups via one-way ANOVA (p?=?0.49). Presence of inner retinal cysts was not correlated to BCVA (p?>?0.05). Discontinuous outer nuclear layer was significantly related to worse initial and final vision, but not to BCVA change.

Conclusion

IVB and PPV with ILM removal appear ineffective in improving visual outcome in eyes with non-proliferative Mactel. SD-OCT evidence of disrupted foveal outer nuclear layer is related to decreased BCVA, but not related to BCVA change following treatment.     

Trans-conjunctival aqueous humor outflow in glaucomatous patients treated with prostaglandin analogues: an in vivo confocal microscopy study

Purpose

To analyze, using in vivo laser scanning confocal microscopy (LSCM), the conjunctival features in glaucomatous patients receiving prostaglandin analogues (PGA).

Methods

Eighty eyes of 80 consecutive glaucomatous patients naive for therapy were enrolled; 30 eyes of 30 healthy subjects served as a control. Patients were randomized to: preservative-free (PF) and preserved latanoprost (groups 1 and 2, respectively), PF and preserved timolol (groups 3 and 4), and controls to vehicle of latanoprost or physiological buffered saline solution (groups 5 and 6). All subjects underwent LSCM of bulbar conjunctiva at baseline and 3 months after initiating therapy. The main outcomes were: mean density (MMD: cysts/mm²) and mean area (MMA: cysts/mm²) of epithelial microcysts. The relations between MMA and MMD with intraocular pressure (IOP), age, and mean defect (MD), were analyzed.

Results

At baseline, microcysts were found in all subjects. At month three, MMD did not change in all groups (p?>?0.05). MMA significantly increased only in group 1 from 2,158.81?±?524.09 to 3,877.77?±?867.31, and in group 2 from 2,019.71?±?541.03 to 5,560.39?±?1,176.14, with values significantly higher in group 2 (p?p?>?0.05).

Conclusions

PGA increased MMA in therapy-naive glaucomatous patients, indicating a possible enhancement of the trans-conjunctival aqueous humor outflow. Therefore, conjunctiva seems an additional target tissue to evaluate the hydrodynamic pathways in glaucoma and modifications induced by medical therapy.     

Clinical results of selective laser trabeculoplasty in silicone oil-induced secondary glaucoma

Background

To analyze the efficacy of selective laser trabeculoplasty (SLT) on silicone oil-induced secondary glaucoma in terms of intraocular pressure (IOP).

Patients and Methods

42 patients (42 eyes) with silicone oil-induced secondary glaucoma were selected, and SLT was performed with 360° of the trabecular meshwork. During the 12-month follow-up, the complications, IOP, and antiglaucoma medication usage were observed.

Results

The mean IOP decreased from 23.1?±?1.9 mmHg before treatment to 18.4?±?3.7 mmHg after treatment (p?<?0.05). Mean number of antiglaucoma medications used for IOP control also decreased from 2.17?±?1.21 to 1.25?±?0.89 (p?<?0.05). The 12-month success rate in the total sample was 59.5 %. The success rate was 60.7 % (17 eyes) and 57.1 % (eight eyes) for phakic and aphakic eyes, respectively (p?>?0.05)

Conclusions

SLT is a safe and effective option for the treatment of patients with silicone oil-induced secondary glaucoma.     

Changes in fundus autofluorescence in polypoidal choroidal vasculopathy during 3 years of follow-up

Purpose

To investigate changes in fundus autofluorescence (FAF) during 3 years of follow-up in patients with polypoidal choroidal vasculopathy (PCV).

Design

Retrospective study.

Methods

We retrospectively reviewed the charts of 48 eyes of 47 patients (35 men, 12 women; mean age, 69.9?±?7.1 years) with treatment-naïve PCV for whom FAF and indocyanine green angiography (ICGA) images were available at baseline and at 3 years?±?3 months follow-up examination. The main outcome measures were the FAF changes during 3 years of follow-up, and the correlation between them and polypoidal lesions and branching vascular networks on ICGA.

Results

The FAF of the polypoidal lesions showed three patterns at baseline and changes during 3 years of follow-up: confluent hypoautofluorescence surrounded by a hyperautofluorescent ring (86.1 %?→?51.4 %), confluent hypoautofluorescence without a ring (8.3 %?→?43.0 %), and no marked changes (5.6 %?→?5.6 %). The FAF in 96.2 % of resolved polypoidal lesions persisted on images with abnormal FAF during the 3 years of follow-up. The granular hypoautofluorescence at the branching vascular networks at baseline became partially confluent hypoautofluorescence in 41 eyes (85.4 %). The mean area with confluent hypoautofluorescence that corresponded to the branching vascular network lesions increased significantly (P?<?0.001) from 1.75 mm² to 5.10 mm² after 3 years of follow-up.

Conclusion

The FAF changes in PCV during the 3 years of follow-up can indicate that FAF imaging is a useful and clinically beneficial tool for noninvasively evaluating the PCV lesions and disorders of the upper retinal pigment epithelium.     

Toric implantable collamer lens for moderate to high myopic astigmatism: 3-year follow-up

Background

To evaluate the 3-year clinical outcomes after toric implantable collamer lens (ICL) implantation for the management of moderate to high myopic astigmatism.

Methods

Thirty-four eyes of 20 patients who underwent toric ICL implantation were reviewed. All eyes completed 3-year follow-up. Uncorrected (UDVA) and corrected (CDVA) distance LogMAR visual acuities, refraction, endothelial cell density (ECD), and surgical complications were evaluated. Vectorial analysis of astigmatic correction was also done.

Results

A significant improvement in UDVA, CDVA, manifest spherical and cylindrical refraction was observed at 1 week and remained stable after 3 years. Twenty-six eyes (76.5 %) gained lines of CDVA, and two eyes (5.9 %) showed a loss of 1 line of CDVA. The spherical equivalent (SE) was within ±0.50 D of emmetropia in 18 eyes (52.9 %) and within ±1.00 D in 28 eyes (82.4 %). Differences between target-induced astigmatism (TIA) and surgically-induced astigmatism (SIA) were statistically significant (p?<?0.01), and a trend to undercorrection of the refractive astigmatism was present after 3 years. The magnitude of flattening effect (FE) was found to be significantly lower than the magnitude of TIA (p?<?0.01). The magnitude of the torque vector was always positive, with a value below 0.50 D in all cases. No vision-threatening complications were observed during the follow-up.

Conclusion

Toric ICL implantation is an effective and safe surgical option that provides a relatively predictable and stable refractive correction of myopic astigmatism. Further improvements are needed to minimize the degree of undercorrection.     

Long-term intraocular pressure changes after vitrectomy for epiretinal membrane and macular hole

Background

To investigate long-term intraocular pressure (IOP) changes after vitrectomy for epiretinal membrane (ERM) or macular hole (MH).

Methods

We retrospectively reviewed the medical records of 57 eyes with ERM and 61 eyes with MH that underwent vitrectomy. IOP levels and changes at 1, 3, 6, 12 months, and the final visit from baseline were evaluated in vitrectomized eyes and non-vitrectomized fellow eyes.

Results

In the ERM group, the mean follow-up period was 29.3 months; the mean preoperative IOP in the operated eyes was 12.9?±?2.5 mmHg and the final IOP was 13.2?±?2.9 mmHg. In the MH group, the mean follow-up period was 25.6 months; the mean preoperative IOP in the operated eyes was 13.3?±?2.5 mmHg and the final IOP was 14.0?±?3.2 mmHg. The mean final IOP of the fellow unoperated eyes was 13.0?±?2.5 mmHg in the ERM group and it was 12.9?±?3.2 mmHg in the MH group. A significant difference was found between the operated eyes and fellow eyes at the final visit in the MH group (P?<?0.01) but not in the ERM group (P?=?0.40). MH group was significantly at high risk of IOP increase after vitrectomy (P?<?0.01).

Conclusions

IOP increase after vitrectomy was found in some eyes with MH during long-term follow-up but it was unlikely in eyes with ERM.     

The effect of photodynamic therapy on macular sensitivity in eyes with acute central serous chorioretinopathy

Background

To evaluate the effect of half-fluence rate indocyanine green angiography (ICGA)-guided verteporfin photodynamic therapy (PDT) on macular sensitivity (MS) in eyes with acute symptomatic central serous chorioretinopathy (CSC).

Methods

Single-center consecutive case series by retrospective chart review. Sixteen eyes of 16 patients with acute CSC of 3 months duration or less, treated with half-fluence (25 mJ/cm²) ICGA-guided verteporfin PDT were reviewed. At baseline and after 1, 3, and 6 months, all patients underwent MS testing of the central 20 °, MS testing of the retinal area covered by the PDT laser spot (MSLS), and evaluation of fixation stability (FS) for the central two degrees with the MP-1 microperimeter (Nidek, Vigonza, Italy).

Results

Macular sensitivity improved from 16.4?±?3.0 dB at baseline (n?=?16) to 18.2?±?2.4 dB (p?<?0.001) at 1 month (n?=?16). At the 3-month (n?=?13) and 6-month (n?=?12) follow-up, MS stabilized at 19.5?±?0.9 dB (p?=?0.21) and 19.0?±?1.3 dB (p?=?0.74), without changes when compared to respective precedent follow-up. Mean MSLS improved from 12.9?±?5.4 dB at baseline to 16.4?±?4.9 dB (p?<?0.001) after 1 month. At the 3- and 6-month follow-up, MSLS was 19.1?±?1.2 dB (p?=?0.1) and 18.9?±?1.9 dB (p?=?0.8) respectively. Mean FS at the central 2 ° was 78.8?±?30.4 % before treatment and 81.8?±?29.5 % (p?=?0.7), 81.9?±?27.5 % (p?=?0.7) and 83.6?±?17.1 % (p?=?0.5) respectively 1, 3 and 6 months after treatment.

Conclusion

Half-fluence (25 mJ/cm²) PDT significantly increased mean MS of central 20 ° and mean MSLS, in eyes with acute symptomatic CSC. Fixation stability was stable at baseline and throughout 6 months of follow-up.     

Retinal vessel diameter in normal-tension glaucoma patients with asymmetric progression

Purpose

To investigate the longitudinal changes in the central retinal vessel diameter in asymmetric progressive normal-tension glaucoma (NTG) patients.

Methods

This study included 27 patients with bilateral NTG without any systemic vascular disease who showed glaucomatous progression in one eye at the mean follow-up of 24.3 months (range, 18–29 months). Progression was determined by the development of new retinal nerve fiber layer (RNFL) defects or widening of pre-existing defects on red-free RNFL photographs. The central retinal arteriolar equivalent (CRAE) and the central retinal venular equivalent (CRVE) were measured at baseline and at the mean follow-up of 24.3 months. We classified the eyes of each patient as either progressed or stable eyes, and compared the differences and changes in the CRAE and CRVE.

Results

No significant inter-eye difference was observed at baseline in the mean CRAE (167.5?±?22.2 μm vs. 168.2?±?15.5 μm, p?=?0.809) and in the mean CRVE (276.3?±?18.2 μm vs. 281.6?±?21.9 μm, p?=?0.267) between the progressed and stable eyes. There were significant changes in CRAE in the progressed eyes between baseline and 2 years after baseline (from 167.5?±?22.2 μm to 146.9?±?18.0 μm, p?p?=?0.084).

Conclusions

In our series of NTG patients with asymmetric progression, central retinal artery diameter decreased over time in the progressed eyes, whereas no significant decrease in the central retinal artery diameter was seen in the stable eyes.     

Photoreceptor inner and outer segment layer thickness in multiple evanescent white dot syndrome

Purpose

To evaluate the photoreceptor inner and outer segment layer thickness in eyes with MEWDS.

Design

Prospective, non-comparative, observational case series. The follow-up duration was 4 months.

Methods

Four women were diagnosed with unilateral MEWDS. The ages of the patients were 25, 24, 35, and 40 years. The retinal microstructure was assessed by spectral-domain optical coherence tomography (SD-OCT). The thickness of the photoreceptor inner (IS) and outer (OS) segments and sum of them (IS + OS) at the fovea were analyzed.

Results

The visual acuity was reduced in three of four eyes at the acute phase. SD-OCT showed that the border of IS and OS (IS/OS) line and the cone outer segment tips (COST) line in the macula area were not detected in all four eyes. The IS + OS thickness was 50.3?±?5.6 μm and that of the healthy fellow eyes was 73.5?±?7.0 μm (n?=?4 eyes). The thickness of the IS was 27.8?±?2.6 μm and that of the OS was 45.8?±?7.3 μm. In all eyes, there was a spontaneous improvement of the visual acuity. SD-OCT showed a recovery of only the IS/OS line in the macular area, but the COST line was not visible in three cases. The mean IS + OS thickness increased to 56.0?±?7.9 μm (n?=?4), IS?=?26.0?±?2.0 μm (n?=?3), and OS?=?30.1?±?8.7 μm (n?=?3) in the early recovery phase, and to 64.8?±?9.3 μm (n?=?4), IS?=?28.5?±?1.7 μm (n?=?4), and OS?=?36.3?±?7.9 μm (n?=?4) in the late recovery phase. The mean inner and outer segment thickness remained unchanged in the fellow eyes.

Conclusion

Eyes with MEWDS have changes in the photoreceptor microstructures. The change in the IS + OS thickness during the natural recovery course might be due to an increase in the OS length.     

Response to anti-VEGF therapy in patients with subretinal fluid and pigment epithelial detachment on spectral-domain optical coherence tomography

Purpose

To analyse the long-term functional and morphological response of a specific choroidal neovascular membrane (CNV) phenotype to anti-vascular endothelial growth factor (VEGF) therapy.

Methods

Data from 30 eyes of 30 consecutive patients with subretinal fluid (SRF) and fibrovascular pigment epithelial detachment (PED) due to CNV on spectral-domain optical coherence tomography (SDOCT) with a follow-up of at least 20 months were retrospectively collected. Main outcome measures included change in visual acuity, quantitative and qualitative parameters on SDOCT [photoreceptor layer, outer nuclear layer (ONL), choroid, PED, SRF] and on fluorescein angiography (CNV activity). Subjects were divided into responders and non-responders based on morphological and functional aspects.

Results

An average number of 20.23?±?9.9 anti-VEGF injections were administered during a mean follow-up of 40.25?±?13.5 months. Fourteen eyes were categorized as morphological non-responders, 12 as functional non-responders and eight as complete non-responders. Complete non-responders were significantly younger than complete responders (68.5?±?4.5 vs 74.3?±?6.8 years; p?<?0.05) and presented thinner baseline ONL values (68.43?±?15.2 vs103.5?±?32.8 μm; p?<?0.05). Intermediate or large drusen as typical features for age-related macular degeneration (AMD) were less frequently present in complete non-responders; however, this was not statistically significant (62.5 % vs 91.7 %; p?=?0.25).

Conclusions

Our preliminary findings indicate that eyes with the specific SDOCT phenotype with isolated fibrovascular PED and SRF frequently demonstrate non-response to anti-VEGF therapy, and the underlying disease mechanism may be different from AMD. Larger prospective trials are required to validate those results, and to develop strategies to improve the morphological as well as functional outcome.     

The influence of axial length on confocal scanning laser ophthalmoscopy and spectral-domain optical coherence tomography size measurements: a pilot study

Purpose

To investigate the influence of axial length on SD-OCT and cSLO size measurements from the Heidelberg Spectralis.

Methods

In this pilot study, eight emmetropic pseudophakic eyes with subretinal visual implant were selected. The axial length was measured in three short (<22.5 mm), three medium (22.51–25.50 mm) and two long (>25.52 mm) eyes. The known size of subretinal implant sensor field (2800?×?2800 μm) was measured on 15 images per eye with cSLO and SD-OCT.

Results

The mean axial length was 20.8?±?0.8 mm in short eyes, 23.3?±?0.4 mm in medium eyes, and 26.3?±?0.5 mm in long eyes respectively. We found in short eyes, in medium eyes and in long eyes a mean value of sensor field size measurements from cSLO of 3327?±?9 μm, 2800?±?9 μm and 2589?±?12 μm and from SD-OCT of 3328?±?9 μm, 2800?±?12 μm and 2585?±?19 μm respectively. The size measurements decreased in SD-OCT and cSLO measurements with longer axial lengths significantly (p?<?0.0001).

Conclusion

The present findings demonstrate accuracy of the scaling in cSLO and SD-OCT measurements of the Heidelberg Spectralis for emmetropic medium eyes. The size measurements from SD-OCT to those from cSLO were approximately equal. Caution is recommended when comparing the measured values of short and long eyes with the normative database of the instrument. Further studies with larger sample sizes are needed to confirm findings.     

Long-term changes in endothelial cell counts after early phacoemulsification versus laser peripheral iridotomy using sequential argon:YAG laser technique in acute primary angle closure

Objective

To compare the change in endothelial cell counts (ECC) after early phacoemulsification and laser peripheral iridotomy (LPI) using sequential argon:yttrium–aluminum–garnet (YAG) laser technique for the treatment of acute primary angle closure (APAC).

Methods

This was a retrospective chart review, case-control study; 86 APAC patients were enrolled. Sixteen patients who underwent early phacoemulsification with intraocular lens implantation and 32 patients who underwent LPI were matched by propensity score analysis. All subjects underwent a complete ophthalmic examination, including intraocular pressure (IOP) measurements, optic disc examinations, and gonioscopy. ECC were acquired at the center of the cornea with a noncontact specular microscope before treatment, and at 1, 6, 12, and 24?months following phacoemulsification or LPI.

Results

The mean follow-up was 26.1?±?4.7?months in the phacoemulsification group and 26.3?±?4.5?months in the LPI group. After intervention, the changes in anterior chamber depth and Shaffer grading by gonioscopy were significantly different between groups. ECC were not different before treatment; however, after phacoemulsification or LPI at 12?months (2280?±?320 vs 1993?±?380?cells/mm²) and 24?months (2113?±?333 vs 1880?±?422?cells/mm²), there was a significant difference between the two groups (P?=?0.040 and P?=?0.032 respectively). Regression analysis showed that anterior chamber depth at baseline (P?=?0.041) and intervention modality (phacoemulsification vs LPI; P?<?0.001) were significantly related to the change in ECC.

Conclusions

Early phacoemulsification showed lower endothelial cell loss than did LPI in the treatment of APAC after a 2-year follow-up. In terms of ECC, early phacoemulsification could be a better intervention modality for APAC.     

Konfokale In-vivo-Hornhautmikroskopie nach Keratoplastik

Background

Seven eyes with clear grafts after penetrating keratoplasty were examined with in vivo confocal corneal microscopy in 1999. Our aim was the confocal microscopic investigation of the subclinical changes in clear grafts after long-term follow-up.

Methods

The preoperative diagnoses were keratoconus (two), granular corneal dystrophy (two), pseudophakic bullous keratopathy due to ACL (two), and corneal ulcer (one). The epithelium, corneal nerves, keratocytes of the anterior and posterior stroma, and endothelium were evaluated with confocal microscopy.

Results

Mean density of basal epithelial cells was 3928±378 cells/mm² at 15 months and 3284±565 cells/mm² at 66 months postoperatively. At 15 months the keratocyte density was 750±113 cells/mm² in the anterior stroma and 601±98 cells/mm² in the posterior stroma, at 66 months 383±53 cells/mm² in the anterior stroma and 411±98 cells/mm² in the posterior stroma. Endothelial cell density decreased from 1719±576 cells/mm² (15 months) to 965±272 cells/mm² (66 months).

Conclusions

In the follow-up period a significant decrease of keratocyte and endothelial cell density was detectable with confocal microscopy. The clinical importance of our findings must be clarified with further examinations on more patients.     

Iatrogenic retinal breaks in 20-G versus 23-G pars plana vitrectomy

Background

The purpose of this study was to compare the incidence of iatrogenic anterior retinal breaks in 20-G vitrectomy (PPV) with transconjunctival 23-G PPV.

Methods

Retrospective, observational review study involving consecutive patients undergoing PPV in a single center in the UK during a 2-year period.

Results

Sclerotomy-related entry-site breaks (ESB) were found in 50/628 (7.9 %) 20-G PPV cases and 5/296 (1.7 %) 23-G PPV eyes (p?<?0.0001*). Anterior non-sclerotomy iatrogenic breaks (ANSB) were present in 55/628 (8.7 %) 20-G PPV cases and 18/296 (6.1 %) 23-G PPV eyes (p?=?0.19). The incidence of total anterior iatrogenic breaks (ANSB?+?ESB) was 105/628 (16.7 %) for 20-G PPV and 23/296 (7.8 %) for 23-G PPV (p?=?0.002*). Univariate analysis showed that posterior vitreous detachment induction was the only risk factor significantly associated with the development of anterior retinal breaks for both 20-G and 23-G PPV. Multivariate logistic model of risk factors for development of iatrogenic retinal breaks demonstrated that 23-G PPV was the most important factor reducing the risk of anterior breaks (p?<?0.0001*).

Conclusions

We report the largest series of patients undergoing 20-G and 23-G vitrectomy, where 23-G vitrectomy was associated with a significantly lower incidence of anterior iatrogenic retinal breaks.     

In diabetic eyes, multifocal ERG reflects differences in function between the nasal part and the temporal part of the macula

Purpose

The purpose of the present study was to compare retinal function between the perifoveal nasal and perifoveal temporal areas of diabetic eyes using multifocalERG (mfERG).

Methods

We included 36 eyes from 27 patients with diabetes (age 58?±?14?years; duration of diabetes 13?±?9?years; HbA_1c 7.1?±?1.8%) and a control group with 18 eyes from 18 healthy subjects (age 57?±?11?years). Retinal thickness was assessed with optical coherence tomography (OCT) in the perifoveal areas corresponding to the summed nasal and temporal inner and outer areas. MfERG amplitude and implicit time were recorded from corresponding areas.

Results

Diabetic eyes showed lower mfERG amplitude in the nasal area than in the temporal area (14?±?6 vs 17?±?7?nV/deg²; p?p?=?0.005). In the control group, there were no significant differences between the two areas.

Conclusion

Diabetic eyes showed lower amplitude and longer implicit time in the nasal area than in the temporal, which might indicate that the nasal area is more vulnerable. These findings may be of importance for evaluation of diabetic maculopathy and outcome after laser treatment.