Correlation between Central Corneal Thickness and Intraocular Pressure Measured by Goldmann Applanation Tonometry or Pascal Dynamic Contour Tonometry.

PURPOSE: The aim of this study was to investigate the relationship between central corneal thickness and intraocular pressure measured by Goldmann applanation tonometry and Pascal dynamic contour tonometry. PATIENTS AND METHODS: The study included 45 persons (90 eyes), divided into 4 groups: a) 10 normal volunteers (20 eyes); b) 16 patients (32 eyes) with primary open-angle glaucoma; c) 8 patients (16 eyes) with normal-tension glaucoma; and d) 11 patients (22 eyes) with ocular hypertension. Intraocular pressure was measured by Goldmann applanation tonometry and Pascal dynamic contour tonometry, and central corneal thickness was measured by ultrasound pachymetry. The relationship between intraocular pressure and central corneal thickness was evaluated. RESULTS: Intraocular pressure was correlated positively but not strongly enough with central corneal thickness when it was measured by Goldmann applanation tonometry. On the contrary, there was no correlation between intraocular pressure and central corneal thickness when intraocular pressure was measured by Pascal dynamic contour tonometry. CONCLUSION: Central corneal thickness is an important variable in the evaluation of intraocular pressure by Goldmann applanation tonometry. This factor does not interfere with the intraocular pressure measurements taken by Pascal dynamic contour tonometry.

Ocular pulse amplitude measurement using pascal dynamic contour tonometer in glaucoma patients.

AIM: This study aims to measure and compare the ocular pulse amplitude using Pascal dynamic contour tonometry in normal persons and in glaucoma patients. PATIENTS AND METHODS: 20 patients (40 eyes) with primary open angle glaucoma (Group A), 8 patients (16 eyes) with normal tension glaucoma (Group B), and 12 patients (24 eyes) with ocular hypertension (Group C) were included in the study. Control group (Group D) comprised 25 normal volunteers (50 eyes). Intraocular pressure was measured using both Goldmann applanation tonometry in the slit-lamp and Pascal dynamic contour tonometry. Ocular pulse amplitude was evaluated with Pascal dynamic contour tonometry. Statistical evaluation of the differences in ocular pulse amplitude and intraocular pressure among the different groups was performed using Student's t-test. RESULTS: Mean ocular pulse amplitude values expressed in mmHg were 3.66 ± 1.00, 2.46 ± 0.60, 4.04 ± 1.47, and 2.52 ± 0.52, for Groups A, B, C, and D, respectively. The ocular pulse amplitude was significantly higher in Group A (primary open angle glaucoma) and Group C (ocular hypertension) when compared with Group D (control group) and Group B (normal tension glaucoma). No statistically significant difference was detected between Group D (control group) and Group B (normal tension glaucoma). CONCLUSIONS: Although we can measure the intraocular pressure with Goldmann applanation tonometry, no information can be derived regarding the ocular pulse amplitude. The use of Pascal dynamic contour tonometry in intraocular pressure estimation provides useful clinical information also about the magnitude of the ocular pulse amplitude in different types of glaucoma. Pascal dynamic contour tonometry discloses an elevation of ocular pulse amplitude in primary open angle glaucoma and ocular hypertension patients. On the contrary, the ocular pulse amplitude is within normal limits in normal tension glaucoma patients.

Impact of preoperative and intraoperative factors in cataract surgery.

BACKGROUND: Cataract surgery is the most common procedure in ophthalmology. However the surgical outcome depends on various factors. The impact of preoperative and intraoperative factors on the surgical procedure were investigated. PATIENTS AND METHODS: Prospective consecutive study of eyes that underwent cataract surgery. The studied parameters included: age, body mass index (BMI), medical history, type of anaesthesia, preoperative patient's anxiety level (scale from 0 to 10), spherical equivalent (SE), keratometry, axial length (AL), time and percentage of ultrasounds (US), intraoperative complications, duration of surgery. The eyes were separated into two groups: the "no complication group" and the "complication group". RESULTS: 529 eyes were included. Age averaged 75.5 years old (44; 100), mean BMI (kg/m2) was 26.3 (13.7; 45.2), patients had cardiovascular history in 61.05% of cases, the type of anaesthesia used was topical in 93.4%, subtenon in 4.7% and general in 1.9% of cases. Mean preoperative anxiety was 4.04 (0; 10), mean preoperative SE was -0.12 (-10; 7.5), mean keratometry (diopters) was 43.88 (39.5; 49), mean AL (mm) was 23.29 (20.91; 29.78), mean time of US (minutes) was 1.89 (0.08; 9.2), mean percentage of US was 10.5 (2; 30) and mean surgical duration (minutes) was 17.15 (5; 50). There was a statistically significant difference (p < 0.0001 in all cases) between both groups in the preoperative anxiety, the time of US and the duration of surgery. The "complication group" had higher scores in all cases as well as more proportion of patients with cardiovascular history. There was no statistically significant difference between both groups for the BMI, SE, AL, keratometry and percentage of US. CONCLUSIONS: The preoperative anxiety level and a cardiovascular medical history together with a prolonged time of US and a longer surgical duration seem to provide more complications during the surgery. The BMI, SE, AL and keratometry did not influence the surgical procedure.

Central foveal thickness before and after cataract surgery in normal and in diabetic patients without retinopathy.

BACKGROUND: This study aims to evaluate and compare central foveal thickness (CFT) changes after cataract surgery between normal and diabetic patients without retinopathy, using optical coherence tomography (OCT). PATIENTS AND METHODS: Ninety-eight patients (49 patients with type 2 diabetes and 49 healthy controls, sex- and age-matched) undergoing phacoemulsification in one eye were included. The presence of retinopathy was an exclusion criterion. The OCT examination was performed preoperatively as well as one, three, six and twelve months postoperatively. CFT was evaluated and compared between groups. RESULTS: Preoperative CFT showed no significant difference between the two groups (normals: 205 ± 18 µm vs. diabetics: 202 ± 23 µm, p > 0.1). Postoperative CFT in diabetics at all time-points of the follow-up period was significantly increased when compared to controls (first month, normals: 215 ± 28 µm vs. diabetics: 262 ± 33 µm, p < 0.05; third month, normals: 211 ± 19 µm vs. diabetics: 250 ± 27 µm, p < 0.05; sixth month, normals: 208 ± 12 µm vs. diabetics: 266 ± 13 µm, p < 0.05; and twelfth month, normals: 209 ± 13 µm vs. diabetics: 280 ± 11 µm, p < 0.05). The incidence of cystoid macular edema (CME) was 4.0 % and 28.6 % for the control group and the diabetic group, respectively, at the end of the follow-up period (p < 0.05). CONCLUSION: Eyes of diabetic patients without retinopathy present higher CFT and a higher incidence of CME after cataract surgery on OCT examination compared to eyes of healthy controls. This may explain the unsatisfactory visual acuity following cataract surgery in these patients.

Should central serous chorioretinopathy be added to the list of ocular side effects of phosphodiesterase 5 inhibitors?

INTRODUCTION: Rare cases of central serous chorioretinopathy (CSC) associated with the intake of sildenafil citrate have been reported, although CSC is not included in the list of phosphodiesterase 5 (PDE5) inhibitor side effects. MATERIALS AND METHODS: We present a review of the literature and 2 cases of CSC in 2 men taking PDE5 inhibitors (vardenafil and tadalafil) for erectile dysfunction. In both cases chorioretinopathy appeared after intake of the inhibitor, resolved once the latter was discontinued, reappeared when the inhibitor was restarted and resolved once again after the inhibitor had been discontinued for the second time. DISCUSSION: PDE5 inhibitors used for male erectile dysfunction have been associated with ocular side effects including lid edema, hyposphagma, photophobia, mydriasis, dyschromatopsia, and nonarteritic anterior ischemic optic neuropathy. CSC was previously described in patients taking sildenafil citrate. Very recently, a case of CSC after tadalafil intake was reported. The relevant literature is reviewed and possible pathophysiologic mechanisms are discussed. CONCLUSION: The 2 presented cases of CSC after intake of vardenafil or tadalafil with positive dechallenge, rechallenge and second dechallenge reactions provide important arguments for considering CSC as a rare PDE5 inhibitor class-specific side effect.

Intravitreal l-Arginine injection reverses the retinal arteriolar vasoconstriction that occurs after experimental acute branch retinal vein occlusion.

To investigate the effect of l-Arginine on the retinal arteriolar diameter following acute branch retinal vein occlusion (BRVO) in minipigs. Under general anesthesia, 10 eyes of 10 minipigs were evaluated. Two hours after BRVO, an intravitreal juxta-arteriolar micro-injection of 30 microl l-Arginine 1 mM (pH = 7.4) was performed in 7 eyes. Three eyes received a micro-injection of 30 microl of the solvent (pH = 7.4) that was used to prepare the solution of l-Arginine and served as controls. Retinal arteriolar diameter changes were measured using a Retinal Vessel Analyzer. Overall (n = 10), 2 h after BRVO there was a 10.5 +/- 1.9% decrease in the retinal arteriolar diameter in the affected territories compared to baseline (p < 0.001). An increase of 16.0 +/- 3.0% (p = 0.001) and 21.0 +/- 7.0% (p = 0.013) of the arteriolar diameter was evidenced 10 and 15 min respectively after l-Arginine injection (n = 7) compared to the diameter prior to l-Arginine injection. Thereafter, the vasodilatory effect of l-Arginine started to decrease but persisted and remained significant at the end of the study period (5.0 +/- 1.5% at 30 min, p = 0.007). Micro-injection of the solvent alone (n = 3) did not produce any significant effect on the retinal arterioles, which remained constricted at all time-points (p > 0.1). These findings demonstrate a significant arteriolar vasodilation after intravitreal juxta-arteriolar l-Arginine micro-injection in eyes with experimental BRVO in the affected territories. l-Arginine micro-injection can reverse the arteriolar vasoconstriction that occurs in acute experimental BRVO by stimulating nitric oxide production.

Effect of brimonidine/timolol fixed combination on preventing the short-term intraocular pressure increase after intravitreal injection of ranibizumab.

BACKGROUND: The aim of this study was to evaluate the safety and efficacy of brimonidine 0.2 % and timolol 0.5 % instillation as a fixed combination (Combigan, Allergan Inc.) to prevent acute intraocular pressure (IOP) increase occurring after intravitreal injection of ranibizumab (Lucentis, Novartis Pharma AG). PATIENTS AND METHODS: A prospective double-blind placebo-controlled study was carried out. One eye of 88 consecutive normotensive age-related macular degeneration patients receiving Lucentis was randomized into placebo drops (artificial tears, 44 patients) or Combigan drops (44 patients) given twice a day the day before and the day of injection. IOP was measured before and 5, 10, 15 minutes and 1 hour after the intravitreal injection. RESULTS: The placebo group had the higher mean IOP at all time points after injection. Maximum IOP increase for both groups occurred at the 5-minutes time point. Mean post-injection IOP in the placebo group was 34.1 +/- 2.7 mmHg at 5 minutes post-injection versus 28.4 +/- 1.1 mmHg in the Combigan group (P < 0.001). IOP decreased to 24.9 +/- 1.8 mmHg (placebo group) and 19.9 +/- 1.1 mmHg (Combigan group) at 10 minutes post-injection. At 15 minutes post-injection, IOP was below 20 mmHg in all eyes of the Combigan group (100 %), whereas at the same time point these IOP levels were reached only by 34 % of the eyes of the placebo group (15 eyes). All eyes of both groups had a normal IOP 1 hour post-injection. No systemic or ocular side effect was recorded in either group. CONCLUSIONS: The use of Combigan drops twice a day the day before and the day of injection in eyes scheduled for intravitreal injection of Lucentis is a safe and effective prophylaxis to reduce the acute IOP spikes of the post-injection period.

Cilioretinal artery occlusion combined with central retinal vein occlusion - a report of two cases and review of the literature.

BACKGROUND: We describe the clinical findings and course of cilioretinal artery occlusion (CAO) combined with central retinal vein occlusion (CRVO) in two patients and present a review of the relevant literature. HISTORY AND SIGNS: Case 1: An otherwise healthy 24-year-old woman presented to the emergency unit with a painless visual decrease in her right eye. Fundus examination revealed retinal edema due to CAO in association with signs of venous stasis. Fluorescein angiography (FA) showed a patent cilioretinal artery. Case 2: A heavy smoker, hypertensive, 59-year-old man was referred for sudden visual loss in his left eye. Fundus examination and FA revealed CAO and CRVO. THERAPY AND OUTCOME: No treatment was applied for the first patient. Two weeks after diagnosis, retinal edema had subsided and only the signs of venous stasis were evident. The central scotoma remained unchanged. In the second patient, within the next three months, the development of retinal ischemia led to retinal neovascularization. Panretinal photocoagulation was applied. Visual acuity remained very low (light perception). CONCLUSIONS: The combination of CAO and CRVO comprises a discrete clinical entity. In both our cases, FA did not show full obstruction of the cilioretinal artery. Even though many hypotheses have been postulated about this entity, it seems that it ensues from the increased intraluminal pressure in the retinal capillaries (due to the CRVO), which exceeds the pressure in the cilioretinal artery. Thus, it is probably a functional obstruction of the cilioretinal artery, although its pathogenesis remains controversial.

The role of spectral-domain optical coherence tomography in the diagnosis of retinal angiomatous proliferation.

BACKGROUND: We present the findings of spectral-domain optical coherence tomography (OCT) in 8 patients with retinal angiomatous proliferation. HISTORY AND SIGNS: Eight patients with a known history of age-related macular degeneration presented with a recent decrease of visual acuity in one eye. On fundus examination, all patients showed an elevated macular lesion associated with intra- or subretinal hemorrhage and retinal hard exudates. Fluorescein and indocyanine-green (ICG) angiography, together with spectral-domain OCT (Optopol Copernicus SOCT), were performed. THERAPY AND OUTCOME: Fluorescein angiography showed early hyperfluorescence with late leakage in all cases. A serous pigment epithelium detachment was present in 6 cases. ICG angiography showed a hot spot in the macular area. The OCT showed a serous pigment epithelium detachment in 6 cases and intraretinal cysts in all cases. The line crossing the ICG visible hot spot showed a greatly hyperreflective intraretinal lesion located at various depths inside the retina. CONCLUSIONS: Spectral-domain OCT is a useful complementary tool to confirm the diagnosis of retinal angiomatous proliferation. Its high resolution and speed enables accurate localization of the angiomatous lesion.

Hydrogel intraocular lens exchange: five-year experience.

BACKGROUND: This study presents an evaluation of the preoperative and postoperative best corrected visual acuity (BCVA), as well as of the incidence of perioperative and postoperative complications after opacified hydrogel intraocular lens (IOL) exchange. PATIENTS AND METHODS: We exchanged opacified hydrogel IOLs (Hydroview H 60 M, Bausch & Lomb) in 55 patients (55 eyes). Preoperative and postoperative BCVA were compared. Intraoperative and postoperative complications were recorded. Follow-up period ranged from 3 months to 24 months. RESULTS: Mean BCVA improved significantly from 0.05 preoperatively to 0.4 at 3 months postoperatively and to 0.2 at the end of the follow-up period. Forty patients (72.7 %) reported visual improvement. The procedure was uneventful in 30 eyes (54.5 %) with complete removal of the opacified IOL optics and haptics. Intraoperative complications included partial zonular dehiscence in 10 eyes (18.2 %), en block capsular bag-IOL extraction in 2 eyes (3.6 %), posterior capsule rupture in 2 eyes (3.6 %), hyphema in 3 eyes (5.5 %), retained haptics in 8 eyes (14.5 %). Postoperative complications included corneal decompensation in 5 eyes (9.1 %), cystoid macular edema in 15 eyes (27.3 %), elevated intraocular pressure in 6 eyes (10.9 %), and retinal detachment in 1 eye (1.8 %). CONCLUSIONS: Visual acuity improved after opacified hydrogel IOL exchange, however, coexistent ocular morbidity as well as the appearance of serious postoperative complications may not yield the expected results. For these reasons extensive informed consent is mandatory.

Late postoperative opacification of hydrogel intraocular lenses: analysis of 13 explanted lenses.

PURPOSE: We report the clinical, morphological, and ultrastructural findings of 13 consecutively explanted opacified Hydroview(R) (hydrogel) intraocular lenses (IOLs). Our purpose was to provide a comprehensive account on the possible factors involved in late postoperative opacification of these IOLs. PATIENTS AND METHODS: Thirteen consecutive opacified hydrogel IOLs (Hydroview H 60 M, Bausch & Lomb) were explanted due to the significant visual impairment they caused. The IOLs underwent macroscopical examination, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and electrophoresis for protein detection. Three unused control Hydroview IOLs served for comparison. RESULTS: Macroscopical examination showed a diffuse or localized grey-whitish opacification within the IOL optic. TEM confirmed the presence of lesions inside the optic in all the explanted IOLs and revealed 3 patterns of deep deposits: a) diffuse, thick, granular, electron-dense ones; b) small, thin, lattice-like ones, with prominent electron-lucent areas; and c) elongated electron-dense formations surrounded by electron-lucent halos. SEM showed surface deposits on four IOLs. EDS revealed oxygen and carbon in all IOLs and documented calcium, phosphorus, silicon and/or iron in the deposits. Two of the patients with iron in their IOLs had eye surgery prior to their phacoemulsification. Iron correlated well with the second TEM pattern of deep lesions, whereas calcium with the third TEM pattern. No protein bands were detected on electrophoresis. Control lenses did not show any ultrastructural or chemical abnormality. CONCLUSIONS: The present study supports the presence of chemical alterations inside the polymer of the optic in late postoperative opacification of Hydroview IOLs. This opacification does not follow a unique pathway but may present under different ultrastructular patterns depending on the responsible factors. Mechanical stress during surgery may initiate a sequence of events where ions such as calcium, phosphorus, silicon, and/or iron, participate in a biochemical cascade that leads to gradual alteration of the polymer network. Intraocular inflammation due to previous operation may be a factor inducing opacification through increase of iron-binding capacity in the aqueous humour. Calcification accounts only partially for the opacification noted in this type of IOL.

Retinal angiomatous proliferations: when should we suspect them and how should we detect them?

BACKGROUND: The aim of this study was to identify the clinical and angiographic features of retinal angiomatous proliferations (RAPs) in patients with age-related macular degeneration. PATIENTS AND METHODS: 26 eyes of 24 patients with RAPs were retrospectively reviewed. All patients had colour and red-free photographs, and fluorescein (FA) and indocyanine-green angiography (ICGA). The biomicroscopic and angiographic characteristics were evaluated and video-angiograms were analysed for staging the RAPs. RESULTS: The total number of RAPs was 29. Stage 1 was present in 3/29, stage 2 in 3/29 and stage 3 in 23/29 with a chorio-retinal anastomosis identified in 21 of these 23 eyes. The total number of retinal vessels involved were 83, 35 were arteries and 48 were veins. RAPs were seen in ICGA as hot spots in all but one case where it appeared as a plaque. A retinal pigment epithelial detachment (PED) was observed in 22/26 eyes. Cystoid macular oedema was observed in 13/26 eyes in FA and intraretinal ICG leakage in 6/26 eyes. Hard exudates were present in 21/26 eyes. Retinal haemorrhages were present in 23/26 eyes; all but one were intraretinal and had a size of less than half of the optic disc diameter. The RAP was bilateral in 2/24 patients. CONCLUSIONS: Clinicians should suspect the diagnosis of RAP when hard exudates, small intraretinal haemorrhages, PED or a hot spot in ICGA are present. Both fluorescein and ICG video-angiography provide adequate temporal resolution and vascular flow examination leading to easier RAP staging and identification of the anastomosis.