Intraocular Pressure Fluctuation: Is It Important?

Elevated intraocular pressure (IOP) is a major risk factor for the development and progression of glaucoma. Previous prospective, randomized, long-term studies have demonstrated the strength of IOP reduction in slowing the progression of disease. It is well known that IOP is not a fixed value but fluctuates considerably over time. Although there have been some studies on IOP fluctuation and the progression of glaucoma, whether IOP fluctuation is an independent risk factor for glaucomatous damage and disease progression remains controversial. In this article, we reviewed the definition of IOP fluctuation, and both the evidence and the speculation for and against the effect of IOP fluctuation on glaucoma progression. Although conclusions seem to vary from study to study, we considered that different studies examined different groups of patients, at different stages of disease, and at different IOP levels. Our conclusion is that these apparently disparate results are not conflicting, but rather can be viewed as complementary. In clinical care, we recommend the consideration of IOP "modulation" rather than just IOP "reduction" when glaucoma patients are treated. Quality-based IOP control may be more effective than quantity-based IOP reduction to prevent or retard disease progression

First-order and multi-order diffractive lens using a device with 8P phase modulation range

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Cataract surgery in eyes with filtered primary angle closure glaucoma.

PurposeTo evaluate the effect of cataract surgery on intraocular pressure (IOP) in filtered eyes with primary angle closure glaucoma (PACG).MethodsIn this prospective interventional case series, 37 previously filtered eyes from 37 PACG patients with mean age of 62.1±10.4 years were consecutively enrolled. All patients had visually significant cataracts and phacoemulsification was performed at least 12 months after trabeculectomy. Visual acuity, IOP and the number of glaucoma medications were recorded preoperatively, and 1, 3, 6 and 12 months after surgery. Anterior chamber (AC) depth was measured preoperatively and 3 months after cataract surgery with A-scan ultrasonography. The main outcome measure was IOP at 12 months.ResultsIOP was decreased significantly from 18.16±5.91 mmHg at baseline to 15.37±2.90 mmHg at final follow-up (P<0.01). The mean number of glaucoma medications was significantly decreased from 1.81±0.24 to 0.86±1.00 (P=0.001) at 1 year postoperatively. At final follow up, 36 (97.2%) eyes and 32 (86.4%) eyes had IOP≤21 and IOP≤18 mmHg, respectively; 14 (37.8%) eyes and 9 (24.3%) eyes had IOP≤21 and IOP≤18 mmHg without medications, respectively. The magnitude of IOP reduction was correlated with higher preoperative IOP (r=0.85, P<0.001), shallower preoperative AC depth (r=-0.38, P=0.01) and greater changes in AC depth (r=-0.39, P=0.01).ConclusionCataract surgery reduces IOP and the number of glaucoma medications in previously filtered PACG eyes. This reduction seems to be greater in patients with higher preoperative IOP and shallower anterior chambers

Refractive change following pseudophakic vitrectomy: a retrospective review

Background To assess the occurrence and magnitude of refractive change in pseudophakic eyes undergoing 20 gauge pars plana vitrectomy without scleral buckling and to investigate possible aetiological factors. Methods Retrospective case note review of 87 pseudophakic eyes undergoing 20 gauge pars plana vitrectomy for a variety of vitreo-retinal conditions over a three-year period. Anterior chamber depth (ACD) was measured before and after vitrectomy surgery in 32 eyes. Forty-three pseudophakic fellow eyes were used as controls. Results Eighty-seven eyes (84 patients) were included in the study. Mean spherical equivalent refraction prior to vitrectomy was -0.20 dioptres, which changed to a mean of -0.65 dioptres postoperatively (standard deviation of refractive change 0.59, range-2.13 to 0.75 dioptres) (p < 0.001). Sixty-one of the 87(70%) eyes experienced a myopic shift and 45(52%) eyes had a myopic shift of -0.5 dioptres or more. Mean fellow eye refraction was -0.19 dioptres preoperatively and -0.17 dioptres postoperatively (p = 0.14)(n = 37) Mean ACD preoperatively was 3.29 mm and postoperatively 3.27 mm (p = 0.53) (n = 32) and there was no significant change in ACD with tamponade use. Regression analysis revealed no statistically significant association between changes in anterior chamber depth, as well as a wide variety of other pre-, intra and postoperative factors examined, and the refractive change observed. Conclusion Significant refractive changes occur in some pseudophakic patients undergoing 20 g pars plana vitrectomy. The mean change observed was a small myopic shift but the range was large. The aetiology of the refractive change is uncertain

Outcomes of ab interno trabeculectomy with the trabectome by degree of angle opening.

AimTo analyse ab interno trabeculectomy (AIT) with the trabectome and combined phacoemulsification with AIT (phaco-AIT) by Shaffer angle grade (SG).MethodsProspective study of AIT and phaco-AIT with narrow angles of SG≤2 versus open angles ≥3. Outcomes included intraocular pressure (IOP), medications, complications, secondary surgery and success (IOP &lt;21 mm Hg and &gt;20% reduction without further surgery). Exclusion criteria were missing preoperative data and &lt;1 year follow-up.ResultsOf 671 included cases, at 1 year AIT SG≤2 (n=43) had an IOP reduction of 42% from 27.3±7.4 to 15.7±3.0 mm Hg (p&lt;0.01) versus AIT SG≥3 (n=271) with an IOP reduction of 37% from 26.1±7.8 to 16.4±3.9 mm Hg (p&lt;0.01). In phaco-AIT with SG≤2 (n=48), IOP was reduced 24% from 20.7±7.0 to 15.7±3.6 mm Hg (p&lt;0.01) versus phaco-AIT with SG≥3 (n=309) with an IOP reduction of 25% from 22.6±6.4 to 17.0±3.4 mm Hg (p&lt;0.01). There was no difference between SG≤2 and SG≥3 in reduction of IOP or medications, complications, secondary surgery and success rates (p&gt;0.05).ConclusionsSG≤2 is not associated with worse outcomes in AIT or phaco-AIT

The Association of Central corneal thickness with Intra-ocular Pressure and Refractive Error in a Nigerian Population

The purpose of this study was to determine the variation of central corneal thickness (CCT) with intraocular pressure (IOP) and spherical equivalent refractive error. A total of thirty-nine (N=39) subjects within 20-75 years with mean age 45.2 ± 15.4 years were used for this study. The central corneal thickness was assessed with the Corneo-Gage plus ultrasonic Pachymeter, the IOP with slit-lamp mounted Goldmann applanation tonometer and refractive status by Protec 2000 autorefractor, phoropter and trial lens set. Results obtained showed that there was no linear correlation between CCT and spherical equivalent errors, although the association between them was significant (p<0.05). The linear correlation between CCT and IOP was not statistically significant. The central corneal thickness was weakly correlated with age; with increasing age the central corneal thickness decreases. Neither the central corneal thickness nor the intraocular pressure was affected by gender