Retinal phakomatosis and Von Hippel-Lindau peripheral capillary hemangioblastoma: proposal for staged surgery.

PURPOSE: Retinal capillary hemangioblastoma (RCH) is present in about half of the carriers of the VHL (von Hippel-Lindau) gene mutation and can lead to the evolution of blindness. Herewith is a proposal for surgical intraretinal feeder vessel ligature to induce ischemia the phakoma and to resolve the exudative secondary retinal detachment, with satisfying results at the 6 months follow-up end point. METHODS: The patient underwent a chandelier-assisted 23 G pars plana vitrectomy with valved trocars. A bimanual transretinal ligature of the hemangioblastoma's feeder vessel was performed, followed by localized endolaser to ablate the surrounding retina and capillaries, and a Polydimethylsiloxane 1000 (PDMS 1000) final tamponade. After 3 months, exchange PDMS/air/balanced salt solution (BSS), phacoemulsification, and in-the-bag intraocular lens (IOL) implantation were performed. RESULTS: At sixth month, fundus fluorescein angiography (FFA) showed a significant reduction of blood flow in the phakoma. Final best-corrected visual acuity (BCVA) was 6/6 (9 lines gain obtained compared to the baseline time). CONCLUSIONS: This surgical technique seems to be effective and promising for the treatment of VHL retinal capillary hemangioblastomas and their related retinal complications.

Intraocular Lens Power Calculation Without Corneal Parameters: A New Option.

OBJECTIVES: To compare different methods in calculating the corneal radius (R) to be used in case of intraocular lens power calculations when it is immeasurable. METHODS: The right eyes of 1,960 patients were randomly divided into 2 equal groups. The first group of right eyes (group A) was divided in three groups according to the axial length (AL) (≤21.99 mm, between 22 and 24.99 mm, and ≥25 mm). In these groups, the correlation between the AL and the corneal radius (R) provided three different regression formulas. The second group of right eyes (group B) was used to test the following methods of estimating the R: the regression formulas determined from group A, formula from Logan et al., formula from Stenström, the mean R calculated from group A, and the fellow eye group B. A Student paired T test was used for the statistical evaluation. RESULTS: In case of AL≤21.99, the best results have been obtained with the fellow eye R, followed by either the regression formula or the mean R from group A (mean=0.00±0.09 mm, P=0.94, mean=0.05±0.21 mm, P=0.05, mean=0.05±0.22 mm, P=0.08, respectively). In case of AL between 22 and 24.99 mm, the best results have been obtained with the fellow eye R, followed by either the regression formula or the mean R from group A (mean=-0.01±0.09 mm, P=0.38, mean=0.01±0.21 mm, P=0.12, mean=0.01±0.24 mm, P=0.18, respectively). In case of AL≥25 mm, the best results have been obtained with the fellow eye R, followed by either the regression formula or the mean R from group A (mean=-0.003±0.08 mm, P=0.94 mean=-0.004±0.25 mm, P=0.85, mean=-0.004±0.25 mm, P=0.85, respectively). CONCLUSIONS: The new calculated regression formulas seem to represent a reliable method to calculate the R when it is undetectable, as in case of corneal dystrophies.

Biometric Parameters and Corneal Astigmatism: Differences Between Male and Female Eyes.

PURPOSE: To evaluate the gender-related differences in demographic and ocular biometric trends in a defined population presenting for consultation within the Italian public health system and to collect data of several ocular parameters at different stages of life, highlighting the differences between females and males. PATIENTS AND METHODS: In this retrospective study, keratometry, corneal astigmatism, and axial eye length of 729 patients (729 eyes; mean age: 58±21 years; range: 18-96 years) were evaluated using partial coherence interferometry. Statistical evaluation was performed utilizing a paired t-test and R2 analysis. RESULTS: In females (396 eyes of 396 patients), mean keratometry ranged between 40.59-47.78 D (44.27±1.36 D), corneal astigmatism ranged between 0-3.82 D (1.13±0.74 D), and axial length ranged between 20.5-31.32 mm (24.07±1.74 mm). In males (333 eyes of 333 patients), mean keratometry ranged between 38.5-46.95 D (43.54±1.35 D; p<0.001), corneal astigmatism ranged between 0.1-3.97 D (1.15±0.79; p=0.75), and axial length ranged between 20.41-31.21 mm (24.57±1.78 mm; p<0.001). Both genders presented a shorter axial length in advanced age. Elderly males presented a higher percentage of against-the-rule astigmatism. CONCLUSION: Females may have steeper corneas and shorter eyes. A trend toward axial length reduction with age was observed in both genders. This finding is probably due to the difference in growth between generations, as the new ones have an higher size than the old ones.

Can We Use the Fellow Eye Biometric Data to Predict IOL Power?

PURPOSE: To study the correlation between right (RE) and left eye (LE) keratometry readings (K) and axial lengths (AL) in a population-based sample of normal subjects. METHODS: In a cross-sectional retrospective study conducted at S. Giuseppe Moscati Hospital, Avellino, Italy, 4516 eyes of 2258 patients with a mean age of 67 ± 16.36 years (range 18-96 years) were included. Partial coherence interferometry data obtained in right (RE) and left (LE) eyes were analyzed and correlated. RESULTS: The average K was 44.01 ± 1.50 diopters (D) (range 39.09-49.89 D) in the RE and 44.04 ± 1.53 D (range 39.63-51.89 D) in the LE (p = 0.0075). 4.5% of the patients (101) presented with differences in the corneal power ≥ 1 D, corresponding to a difference of roughly 1 D in the IOL power. The average AL was 23.89 ± 1.77 mm (range 19.09-35.15 mm) in the RE and 23.84 ± 1.68 mm (range 19.23-35.04 mm) in the LE (p = 0.0018). 19.2% of the patients (433) presented with differences in the AL ≥ 0.4 mm, corresponding to a difference of roughly 1 D in the IOL power. CONCLUSIONS: In calculating the IOL power, we must be aware of these results when we measure the fellow eye to validate the measurements in the first eye. In the case of postcataract refractive error, the outcome could be used for the second eye only when symmetric biometric findings are present.

Prevalence of corneal astigmatism before cataract surgery in Caucasian patients.

PURPOSE: To analyze and quantify the pattern of corneal astigmatism in patients awaiting cataract surgery to provide information for cataract surgeons and intraocular lens (IOL) manufacturers and to establish the demand for toric IOLs in a hospital. METHODS: This cross-sectional retrospective study evaluated keratometric (K) values measured by partial coherence interferometry (IOLMaster) in cataract surgery candidates, who were then analyzed and correlated by age and axial length (AL) ranges. RESULTS: The study evaluated the K values in 757 eyes of 380 patients with a mean age of 71.9 ± 10.2 years (range 33-96 years). The mean corneal astigmatism was 1.02 ± 0.69 D (range 0.06-4.57 D). It was 1 D or higher in 316 (41.74%) eyes. The mean AL was 23.56 ± 1.35 mm (range 20.53-31.86 mm). CONCLUSIONS: Our study shows that roughly 50% of the eyes have more than 1 D of astigmatism. The results can help hospitals plan and analyze the amount and costs of using toric IOLs in patients with corneal astigmatism.

Pharmacotherapy of intraocular pressure - part II. Carbonic anhydrase inhibitors, prostaglandin analogues and prostamides.

The second part of this two part review (please see Expert Opinion on Pharmacotherapy 10(16)) reports the characteristics of other antiglaucoma medications: systemic (acetazomide) and topical (dorzolamide and brinzolamide) carbonic anhydrase inhibitors, which suppress aqueous humour formation; and prostaglandin analogues (latanoprost and travoprost) and prostamides (bimatoprost), which raise aqueous humour outflow. The pharmacologic properties of each compound and its efficacy in the medical treatment of glaucoma, mainly the primary open-angle form, are discussed briefly, focusing on the clinical evidence supporting their use.

Pharmacotherapy of intraocular pressure: part I. Parasympathomimetic, sympathomimetic and sympatholytics.

Elevated intraocular pressure (IOP) has been recognized as the major risk factor for the development of glaucoma and a wide range of options are now available to reduce it: medical treatment, laser, filtering, or cyclodestructive surgery (alone or in combination). All these modalities act by decreasing eye pressure and, thereby, protecting the optic nerve head from a mechanic direct and/or vascular indirect insult. Topical medical therapy represents the first-choice treatment and, in most cases, it effectively controls IOP, avoiding the occurrence of further optic nerve damage. All medications lower IOP in two main ways: decreasing the production of aqueous humour or by increasing its outflow from the eye. Consequently, antiglaucoma drugs either suppress aqueous humour formation (beta-adrenergic antagonists, carbonic anhydrase inhibitors, and alpha-2-adrenergic agonists) or raise aqueous humour outflow throughout the conventional (e.g., pilocarpine) or uveoscleral (prostaglandin FP receptor agonists, and prostamides) route. In addition, fixed and unfixed combinations of antiglaucoma compounds have also been available for patients requiring more than one type of medication. This review, which is part one of two (please see Expert Opinion on Pharmacotherapy 10 (17)) briefly considers the characteristics of sympathomimetic, sympatholytics and parasympathomimetic commonly employed in the medical treatment of glaucoma, mainly the primary open-angle form, focusing the discussion on the clinical evidence supporting the use of these three classes of compound.