الفهرس 
Anatomy of the vitreous body and angle of anterior chamberOnly 14 pages are availabe for public view
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Abstract
Intravitreal injection of any drug may induce intraocular volume increase and therefore IOP rise is a strong possibility after any intravitreal drug injection. Although acute IOP spike is mostly transient, it still may have a negative effect on ocular circulation as high IOP may compromise the optic nerve head and/or central retinal artery blood flow and hinder axonal transport.
We studied the changes in IOP immediately postinjection by studying 60 eyes in which IVI of anti-VEGFs was indicated. The preinjection IOP was measured then it was remeasured five, 15 and 30 minutes after IVI. The possible risk factors that may influence IOP elevation after IVI injection were studied. Axial length, lens status and number of previous IVI were our variables.
The study was in the duration from December 2013 to June 2014. Patients with prior ocular surgeries (except uneventful cataract extraction), preexisting ocular pathologies that cause elevation in IOP (e.g. glaucoma, uveitis or trauma), topical or systemic medications that cause elevation in IOP (e.g. corticosteroids), history of previous IVI of corticosteroids and any patient subjected to paracentesis during the procedure of IVI were excluded.
IVI was found to induce a significant rise in IOP immediately after injection. Spikes of more than 25 mmHg were recorded five minutes after injection in about two thirds of the cases. Prevention of these pressure spikes is not too necessary, as IOP was found to decline gradually to return to baseline nearly in all patients within 30 minutes after IVI.
AL was not found to be risk factor for IOP rise after IVI as we found that among the 60 studied eyes there were 41 eyes that experienced an elevation of IOP 5 minutes after IVI above 25mm Hg. Among those 41 eyes the majority of eyes (43.9%) with p value=0.2, which is statically not significant according to our statistical rules, were hypermetropes followed myopes (29%) and the least number was emmetropic eyes (26.8%).
Lens status did not have any effect on immediate IOP after the injection. As analysis of the 41 eyes which showed IOP rise to >25 mm Hg. 18 eyes of these 41 eyes (43.9%; p=0.4) were pkakic and 23 eyes (56%, p=0.5) were pseudophakic eyes.
IOP increases transiently after the intravitreal injection of 0.1 mL of anti-VEGFs, the increase in IOP after the injection seems to be irrelevant to AL and anterior chamber depth.
Therefore, we postulated that IVI can be used safely in patients with age-related macular degeneration who have shallow anterior chamber and/or short axial length simultaneously.
To the best of our knowledge, this is one of the largest prospective study performed evaluating the immediate effect of IVI on IOP and nearly the first study on this topic using the tonopen to measure intraocular pressures, which may limit any comparisons done with other published studies on the subject.