Relationship between raised intraocular pressure and ischemia-modified albumin in serum and humor aqueous: a pilot study in rabbits

AIM:To evaluate the relationship between increased intraocular pressure(IOP),is chemia-modified albumin levels in serum(IMA-s)and in humor aqueous(IMA-HA)in rabbits.METHODS:Twenty-five albino New Zealand rabbits weighing between 2.0 and 2.8 kg were used in this pilot study.With permission from Canakkale Onsekiz Mart University Animal Ethics Committee,the IOP of both eyes of each rabbit were recorded with a Tonopen(Tono-Pen XL,Reichart Inc.,Depew,NY,USA)after the application of topical proparacaine 0.5%HCl anesthesia.Blood(4 mL)was collected from the marginal ear vein and an intracameral injection of 2.3 mg/mL sodium hyaluronate and subconjunctival dexamethasone was given in the right eye.Anterior chamber aqueous fluid was obtained using a limbal approach with a 27 gauge needle from both eyes.The left eyes were used as controls.IOP was measured on the 1st,3rdand 10thday after the initial injection,with Tonopen,IMA-s levels and IMA-HA examined simultaneously.RESULTS:Beforetheinjections,IOPwas11.4±3.0mmHg in the right eye and 11.3±3.1 mm Hg in the left eye(P】0.05).There was a statistically significant difference between IMA-s levels before the IOP increase(IMA-s0)and IMA-s levels on the 1stand 3rddays after the increase in IOP(P=0.012 and P=0.01,respectively).No difference was observed between IMA-s0and serum IMA levels on the 10thday(IMA-s10)after IOP increase(P=0.989).IMA-HA in the right eye in the first day after the injection was positively correlated with IOP(r=0.748;P=0.02).No othercorrelation is found between any other parameter with IMA-HAlevels at any test time.A statistically significant positive correlation was observed between IMA-s values and IOP on the 1stand 3rddays(r=0.398,P=0.04 and r=0.382,P=0.04,respectively).There was no correlation between IMA-s levels and increased IOP on the 10thday after IOP increase(r=0.026,P=0.902).CONCLUSION:IMA may be an important indicator of acute damage caused by diseases involving ischemic damage to the eye,especially in case of increased intraocular pressure.

Optic Nerve Head Drusen, Myopia and Ocular Hypertension: A Case Report

A 20-year-old male patient presented at our clinic complaining of strange visual experiences (neither decreased nor blurred) and a mild headache while reading. His best corrected visual acuity revealed 20/20 with a fort myopic correction. Intraocular pressures measured with Dynamic Contour Tonometer (DCT) (Swiss Microtechnology AG, Port, Switzerland) were 23.3 mmHg in the right eye (OD) and 27.4 mmHg in the left eye (OS) with cenral corneal thicknesses (CCTs) of 588 (OD) and 591 (OS) microns, respectively. Optic discs were bilateral pale with indistinct and scalloped margins without cupping. Red free photos showed autofluorescence of both optic discs, representative of optic disc drusen. Visual field analysis (VFA) of both eyes revealed sensitivity depression with localized defects consistent with the Optical Coherence Tomography (OCT) findings. Optic nerve head drusen (ONHD), myopia and high intraocular pressures (IOPs), may cause ganglion cell damage resulting in RNFL thinning and visual field loss. Because of the difficulty in detecting the exact cause and the extent of the damage, patients with ONHD associated with high IOPs and myopia should be examined closely with serial monitoring using OCT and VFA. In case of RNFL thinning and visual field defects, topical antiglaucomatous therapy should also be determined.