Nicola Rosa

Intraocular Pressure and Corneal Biomechanical Properties in Patients with Myotonic Dystrophy

PURPOSE To compare intraocular pressure (IOP) between patients with myotonic dystrophy (DM1) and normal subjects, taking into account corneal characteristics. To determine whether lower IOP measurements in patients with DM1 are due to thinner corneas. DESIGN Comparative case series. PARTICIPANTS Fifty-three eyes of patients with DM1 and 53 eyes of normal age- and sex-matched subjects. METHODS Corneal biomechanical properties and corneal compensated intraocular pressure (IOPcc) measured with the Ocular Response Analyzer (Reichert Inc., Depew, NY), central corneal thickness measured with the Oculus Pentacam (Oculus, Wetzlar, Germany), and IOP were evaluated in patients with DM1 and compared with age- and sex-matched healthy subjects. MAIN OUTCOME MEASUREMENTS Goldmann applanation tonometry, central corneal thickness, corneal hysteresis (CH), corneal resistance factor (CRF), and IOPcc. RESULTS Compared with the healthy subjects, patients with DM1 showed lower IOP (12.4+/-3.6 mm Hg vs. 14.9+/-3.4 mmHg) (P<0.01) and IOPcc (12.7+/-4.5 vs. 15.9+/-3.5) (P<0.01), and thicker cornea (575.9+/-35.02 mum vs. 556.3+/-33.2 microm) (P<0.01), but no significant changes in CH (P = 0.03) and CRF (P = 0.37). CONCLUSIONS Lower IOP in patients with DM1 is not related to differences in central corneal thickness or corneal biomechanical properties. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Reliability of the IOLMaster in measuring corneal power changes after photorefractive keratectomy

Purpose: To test the accuracy of the IOLMaster® (Carl Zeiss) in detecting corneal power changes after photorefractive keratectomy (PRK). Setting: Department of Ophthalmology, 2nd University of Naples, Naples, Italy. Methods: Two hundred twenty‐five consecutive eyes that had PRK (mean −5.13 diopters [D] ± 2.98 [SD] [range +0.25 to −16.25 D]) were analyzed. The data included preoperative and postoperative (1, 3, and 6 months) subjective refraction and computerized keratometry. Statistical analysis was performed to determine the correlation between the changes in the subjective refraction at the corneal plane and the changes in keratometry. Results: The mean difference between the changes in refraction and the measured corneal changes was 0.75 ± 1.13 D (range −3.84 to +7.68 D) at 1 month, 0.92 ± 1.10 D (range −0.87 to +7.93 D) at 3 months, and 0.75 ± 0.98 D (range −1.70 to +3.85 D) at 6 months. The difference was significant (P<.001). Conclusion: Automated keratometry provided by the IOLMaster did not accurately reflect the effective refractive changes after PRK, particularly in eyes that had a high dioptric treatment.

Expulsive hemorrhage before phacoemulsification.

A 65-year-old white man who was scheduled for cataract extraction experienced a sudden increase in intraocular pressure (IOP) with flattening of the anterior chamber immediately after the anterior capsule incision. The eye was sutured, and because no decrease in pressure was noted, surgery was postponed. The presence of the cataract prevented ophthalmoscopic examination. Echographic examination revealed a hemorrhagic choroidal detachment with involvement of the ciliary body. The patient was examined regularly until the choroidal detachment disappeared 4 weeks later. He then had uneventful phacoemulsification and intraocular lens implantation.

Biometry and characterization of the lens

We measured the lens thickness in a group of patients with normal lenses compared to a group of patients with different age and with various types of lens opacities.