Comparing acromegalic patients to healthy controls with respect to intraocular pressure,central corneal thickness,and optic disc topography findings

Aims:

The aim was to compare the intraocular pressure (IOP), central corneal thickness (CCT), and optic disc topography findings of biochemically controlled acromegalic patients and the control group and to evaluate the effect of the duration of acromegaly and serum growth hormone and insulin-like growth factor-1 (IGF-1) levels on these ocular parameters.

Materials and Methods:

IOP measurement with Goldmann applanation tonometry, CCT measurement with ultrasonic pachymetry, and topographic analysis with Heidelberg retinal tomograph III were performed on 35 biochemically controlled acromegalic patients and 36 age- and gender-matched controls.

Results:

Mean IOP and CCT were 14.7 ± 2.9 mmHg and 559.5 ± 44.9 μm in the acromegaly patients and 13.0 ± 1.6 mmHg and 547.1 ± 26.7 μm in controls (P = 0.006 and P = 0.15, respectively). A significant moderate correlation was found between the duration of acromegaly and CCT (r = 0.391) and IOP (r = 0.367). Mean retinal nerve fiber layer (RNFL) thickness was significantly lower in the acromegalic patients (0.25 ± 0.05 mm) as compared to controls (0.31 ± 0.09 mm) (P = 0.01). A significant moderate correlation was detected between IGF-1 level and disc area (r = 0.362), cup area (r = 0.389) and cup volume (r = 0.491).

Conclusion:

Biochemically controlled acromegalic patients showed significantly higher CCT and IOP levels and lower RNFL thickness compared to healthy controls and the duration of disease was correlated with CCT and IOP levels.     

The applicability of correction factor for corneal thickness on non-contact tonometer measured intraocular pressure in LASIK treated eyes

Purpose

To determine the applicability of central corneal thickness (CCT) based correction factor for non-contact tonometer (NCT) measured intraocular pressure (IOP) readings.

Method

A prospective, non-randomized study involved 346 eyes of 173 consecutive patients with age ⩾21 years undergoing laser-assisted in situ keratomileusis (LASIK) for myopia and/or myopic astigmatism. The CCT and IOP were measured before and after the LASIK procedure. The IOP pre and post-LASIK was compared after applying the correction factor for CCT. Patients not completing the 3 month postoperative follow-up were excluded.

Results

The median spherical equivalent before undergoing LASIK was −4.25D (inter-quartile range, −3.25D). The mean preoperative CCT was 536.82 ± 33.71 μm which reduced to 477.55 ± 39.3 μm (p < 0.01) post-LASIK. The mean IOP reduced from a preoperative value of 14.6 ± 2.32 mmHg to 10.64 ± 2.45 mmHg postoperatively (p < 0.01). On applying correction for the corneal thickness, the pre and postoperative IOP was 15.14 ± 2.8 mmHg and 15.37 ± 2.65 mmHg (p = 0.06) respectively with a strong positive correlation (r = 0.7, p < 0.01). Three hundred eyes (86.7%) had an absolute difference in IOP of less than 3.0 mmHg post-CCT correction which is within the retest variability of NCT. Only 46 eyes (13.3%) had an absolute difference of more than 3.0 mmHg.

Conclusion

The modified Ehler’s correction algorithm used in this study can be effectively applied in the normal IOP range in a majority of patients.     

Evaluating the change in central corneal thickness in neonates (term and preterm) in Indian population and the factors affecting it

Background and Aim:

Central corneal thickness (CCT) of term and preterm infants in Indian population is not known. We did a prospective noninterventional study to measure the CCT in term and preterm infants.

Materials and Methods:

An ultrasonic pachymeter was used. The data regarding the date of birth, expected date of delivery, birth weight were recorded. The preterm and the term infants were followed up at 8 weeks, 20 weeks and at 1-year.

Results:

A total of 85 (170 eyes) children were included in the study. The mean age was 264.6 ± 21.8 days postconception. The mean birth weight and CCT were 1834.4 ± 512.1 g and 595.8 ± 72.4 μ respectively. A comparison of CCT on the basis postgestational age showed a mean thickness of 620.7 ± 88.8 and 574.4 ± 78.3 μ in the <260 days and >260 days age groups respectively. The difference was statistically significant (Student''s test, P = 0.002). The CCT of preterm infants (<260 days) decreased from a mean value of 620.7 ± 88.8 μ to 534.1 ± 57.6 μ at the end of 1-year.

Conclusion:

We present the data of CCT in term and preterm infants in Indian population. We believe that the premature babies have slightly thicker corneas than mature term babies.     

Differences in central corneal thickness between the paired eyes and the severity of the glaucomatous damage

Purpose

To evaluate whether a difference in central corneal thickness (CCT) between the paired eyes could be associated to worse glaucoma in the thinner cornea eye.

Methods

From 16 different glaucoma centres, at least 50 glaucomatous patients were saved on the Italian Glaucoma Register. Eight hundred and sixteen glaucomatous patients were found in the register. CCT, ophthalmoscopic cup/disc ratio, mean deviation (MD), pattern SD (PSD), and intraocular pressure (IOP). The difference (Δ) between the paired eyes was calculated for all the considered parameters and two subgroups were created on the basis of ΔCCT. Because the difference between the two eyes could be positive or negative, the absolute value of Δ was considered for all the measurements. Three different ΔCCT cutoffs were selected: 10, 15, and 20 μm. Student''s t-test was used to compare the subgroups.

Results

When the entire group was divided in two subgroups using 20 μm as ΔCCT cutoff, no significant difference was found for ΔIOP (−0.38±2.53 (mean±SD) mm Hg and −0.07±2.35 mm Hg, respectively) between the two subgroups. Significant (P<0.001) difference was found for ΔMD (6.58±7.30 and 3.14±4.22 dB, respectively), ΔPSD (3.92±4.01 and 2.16±2.57, respectively), and ΔC/D (0.11±0.14 and 0.08±0.11, respectively) between the two subgroups. No significant correlation was found between ΔCCT and the other parameters.

Conclusion

The ΔCCT between the two eyes could be associated to a worse glaucoma in the thinner cornea eye.     

Risk factors for intraocular pressure rise following phacoemulsification

Purpose:

This study was designed to analyze the risk factors resulting in high intraocular pressure (IOP), which was accepted as IOP higher than 22 mmHg, following uncomplicated phacoemulsification.

Materials and Methods:

The records of 812 eyes of 584 patients who underwent uncomplicated phacoemulsification were evaluated. There were 330 men and 254 women ranging between the age of 26 and 89 years (65.4 ± 9.8 years). The preoperative, postoperative first day (day 1), first week (day 7), and first month (day 30) IOP values were analyzed. Data on history of diabetes, glaucoma, pseudoexfoliation (PXF), incision site, capsular staining with trypan blue, and surgeon were recorded. A multinomial regression analysis was performed to analyse the relationship of the factors with postoperative high IOP.

Results:

The mean IOP was 15.6 ± 4.3 mmHg preoperatively. Postoperatively that were changed to 19.7 ± 9.0 mmHg at day 1, 12.7 ± 4.5 mmHg at day 7, and 12.8 ± 3.7 mmHg at day 30. The factors such as surgeon, presence of PXF, diabetes, surgical incision site, and trypan blue were not related to the postoperative high IOP (P > 0.05, in all). The only factor that related to high IOP at all visits was glaucoma (P < 0.005).

Conclusion:

According to our results, preoperative diagnosis of glaucoma seems to be the only factor to affect the postoperative IOP higher than 22 mmHg.     

Assessment of intraocular pressure measured by Reichert Ocular Response Analyzer, Goldmann Applanation Tonometry, and Dynamic Contour Tonometry in healthy individuals

AIM: To investigate the accuracy of intraocular pressure (IOP) as measured by a Reichert Ocular Response Analyzer (ORA), as well as the relationship between central corneal thickness (CCT) and IOP as measured by ORA, Goldmann applanation tonometry (GAT), and dynamic contour tonometry (DCT). METHODS: A total of 158 healthy individuals (296 eyes) were chosen randomly for measurement of IOP. After CCT was measured using A-ultrasound (A-US), IOP was measured by ORA, GAT, and DCT devices in a randomized order. The IOP values acquired using each of the three tonometries were compared, and the relationship between CCT and IOP values were analyzed separately. Two IOP values, Goldmann-correlated IOP value (IOPg) and corneal-compensated intraocular pressure (IOPcc), were got using ORA. Three groups were defined according to CCT: 1) thin cornea (CCT<520μm); 2) normal-thickness cornea (CCT: 520–580μm); and 3) thick cornea (CCT>580μm) groups. RESULTS: In normal subjects, IOP measurements were 14.95±2.99mmHg with ORA (IOPg), 15.21±2.77mmHg with ORA (IOPcc), 15.22±2.77mmHg with GAT, and 15.49±2.56mmHg with DCT. Mean differences were 0.01±2.29mmHg between IOPcc and GAT (P>0.05) and 0.28±2.20mmHg between IOPcc and DCT (P>0.05). There was a greater correlation between IOPcc and DCT (r=0.946, P=0.000) than that between IOPcc and GAT (r=0.845, P=0.000). DCT had a significant correlation with GAT (r=0.854, P=0.000). GAT was moderately correlated with CCT (r=0.296, P<0.001), while IOPcc showed a weak but significant correlation with CCT (r=?0.155, P=0.007). There was a strong negative correlation between CCT and the difference between IOPcc and GAT(r=-0.803,P=0.000), with every 10μm increase in CCT resulting in an increase in this difference of 0.35mmHg. The thick cornea group (CCT>580μm) showed the least significant correlation between IOPcc and GAT (r=0.859, P=0.000); while the thin cornea group (CCT＜520μm) had the most significant correlation between IOPcc and GAT (r=0.926, P=0.000). The correlated differences between IOPcc and DCT were not significant in any of the three groups (P>0.05). CONCLUSION: Measurement of IOP by ORA has high repeatability and is largely consistent with GAT measurements. Moreover, the ORA measurements are affected only to a small extent by CCT, and are likely to be much closer to the real IOP value than GAT.     

Efficacy of combined intravitreal bevacizumab and triamcinolone for branch retinal vein occlusion

Purpose:

To evaluate the efficacy of combined treatment with intravitreal bevacizumab (IVB) and triamcinolone acetate (IVT) for patients with macular edema secondary to branch retinal vein occlusion (BRVO).

Materials and Methods:

Retrospective analysis of 20 eyes injected with 1.25 mg IVB and 2 mg IVT for clinically identified BRVO within 8 weeks of onset. All patients lacked concomitant ocular pathology and completed 6 months’ follow-up. Clinical examination including LogMAR visual acuity (VA) and central macular thickness (CMT) by spectralis optical coherence tomography (OCT) was performed preoperatively and at 1, 3 and 6 months post-operatively.

Results:

Mean patient age was 61.3 years with a mean BRVO diagnosis time of 3 weeks at presentation. VA improved from logMAR 1.08 preoperatively to Mean logMAR VA of 0.55 ± 0.17 at 1 month (P < 0.001), 0.56 ± 0.21 at 3 months (P < 0.001), and 0.38 ± 0.1 at 6 months (P < 0.001) Mean CMT improved from 482 ± 107 μm preoperatively to 319 ± 53 μm at 1 month (P < 0.001), 344 ± 89 μm at 3 months (P < 0.001), and 241 ± 29 μm at 6 months (P < 0.001). Mean IOP preoperatively was 16.5 mmHg, 21 mmHg at 1 month, and 15 mmHg at 6 months. Six out of 20 patients (30%) were re-injected with IVB and IVT at 3 months.

Conclusions:

Early combined treatment with IVB and IVT is effective in improving anatomic and functional outcomes in patients with macular edema secondary to BRVO.     

Changes of intraocular pressure and refractive status in children following cycloplegic refraction with 1% cyclopentolate and 1% tropicamide

Purpose:

To evaluate the effect of cycloplegic mydriasis with 1% cyclopentolate and 1% tropicamide on the intraocular pressure (IOP) and refractive status of children for cycloplegic refraction and compare the [OP and refractive changes between hyperopic and myopic groups.

Methods:

This study was designed as a retrospective cohort study. Ninety one children received cycloplegic mydriasis. The IOP was measured with a noncontact tonometer before cycloplegic administration. One drop of 1% cyclopentolate was administered, which was followed by two drops of 1% tropicamide at an interval of 10 minutes. The IOP was then measured 30 minutes after tropicamide instillation. Autorefraction was assessed with an autorefractometer before and after cycloplegic mydriasis.

Results:

The mean age of the 44 girls and 47 boys was 7.3 ± 2.4 years. The mean precycloplegic IOP was 14.45 ± 2.47 mmHg and the mean postcycloplegic IOP was 15.06 ± 3.08 mmHg in all eyes. A significant difference was noted in the IOP change (p = 0.033). In the 39 hyperopic eyes, the mean precycloplegic IOP and postcycloplegic IOP were 14.54 ± 2.53 mmHg and 15.69 ± 3.35 mmHg, respectively. There was a significant difference in the IOP change (p = 0.008). In the 52 myopic eyes, the mean precycloplegic IOP and postcycloplegic IOP were 14.38 ± 2.44 mmHg and 14.61 ± 2.80 mmHg, respectively (p = 0.72). There was no significant IOP change in the myopic group. The postcycloplegic IOP was significantly different between the hyperopic and the myopic groups (p = 0.021). Three eyes (3.3%) had an IOP elevation more than 5.0 mmHg after cycloplegic mydriasis. Postcycloplegic refraction showed significant hyperopic shifts in all eyes (p < 0.0001).

Conclusion:

Cycloplegic mydriasis with 1% cyclopentolate and 1% tropicamide caused IOP changes in preschool and school-aged children with hyperopia. Ophthalmologists should be very cautious in monitoring IOP changes for children with cycloplegic medication use.     

Comparison of surgical outcomes after phacotrabeculectomy in primary angle-closure glaucoma versus primary open-angle glaucoma

Purpose:

To compare postoperative outcomes and assess factors associated with intraocular pressure (IOP) reduction after phacotrabeculectomy in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).

Methods:

This is a retrospective study of patients who underwent phacotrabeculectomy between 2010 and 2013. Factors including age, gender, visual field (VF), the number of glaucoma medications used, biometric changes, IOP, and surgical success rates were compared between groups.

Results:

There were 27 PACG and 34 POAG patients. The PACG group had a greater mean IOP reduction after phacotrabeculectomy compared to the POAG group (5.5 ± 7.9 mmHg versus 2.0 ± 4.2 mmHg; p = 0.03). However, the final mean IOP was similar between the two groups (PACG: 12.2 ± 4.8 mmHg, POAG: 12.3 ± 3.1 mmHg; p = 0.92). Phacotrabeculectomy resulted in a mean decrease in axial length (AL) of 0.16 ± 0.15 mm in PACG and 0.16 ± 0.11 mm in POAG (p = 0.96), and an increase in anterior chamber depth (ACD) of 1.41 ± 0.91 mm in PACG, and 0.87 ± 0.86 mm in POAG (p = 0.04). At 2 years follow-up, the cumulative success rate of phacotrabeculectomy was 74% in PACG and 62% in POAG. Multivariate analysis found that early glaucoma stage, greater postoperative increase in ACD, and high preoperative IOP were factors associated with greater IOP reduction.

Conclusion:

Postoperative success rates and mean IOP on the final visit after phacotrabeculectomy were similar between the PACG and POAG groups. Factors associated with IOP reduction were greater postoperative increase in ACD, and high preoperative IOP.     

Comparison of the Thickness of the Lamina Cribrosa and Vascular Factors in Early Normal-tension Glaucoma with Low and High Intraocular Pressures

Purpose

To compare the thickness of the lamina cribrosa (LC) and vascular factors of early normal-tension glaucoma (NTG) patients with high and low intraocular pressure (IOP) that are expected to be associated with the development of glaucoma.

Methods

Seventy-one Korean NTG patients with low IOP (the highest IOP <15 mmHg, 40 patients) and high IOP (the lowest IOP >15 mmHg, 31 patients) were included in this study. The thickness of LC and vascular factors were compared. The thickness of the LC was measured using the enhanced depth imaging method with spectral domain optical coherence tomography (Heidelberg Spectralis).

Results

The mean thickness of the central LC was 190.0 ± 19.2 µm in the low IOP group and 197.8 ± 23.6 µm in the high IOP group, but there was no statistical significant difference between the two groups (p > 0.05). The prevalence of self-reported Raynaud phenomenon was significantly higher in the low IOP group (33.0%) than the high IOP group (10.3%, p = 0.04).

Conclusions

The laminar thickness did not significantly differ between the high and low IOP groups. However, the prevalence of Raynaud phenomenon was higher in the low IOP groups. These results suggest that the development of glaucoma with low IOP patients may be more influenced by peripheral vasospasm, such as Raynaud phenomenon, rather than laminar thickness in NTG.     

Comparison of trabeculectomy with Ex-PRESS shunt implantation in primary-open-angle-glaucoma patients: A retrospective study

Purpose:

To investigate the efficacy of intraocular pressure (IOP) control and medication use over time after trabeculectomy (TRBC) and Ex-PRESS shunt implantation in primary-open-angle-glaucoma (POAG) patients.

Design:

Retrospective case series.

Patients and methods:

A total of 33 unilateral POAG patients were enrolled, and 17 patients received traditional TRBC and 16 patients received Ex-PRESS device implantation. Data on IOP, reduction of antiglaucoma medication, and major complications were collected and analyzed after 12 months of follow up.

Results:

After 12 months of follow up, both groups showed good IOP control. The mean preoperative IOP decreased from 38.5 (±6.9) to 18.2 (±11) mmHg after TRBC, and from 38.5 (±9.1) to 19.53 (±12.36) mmHg after Ex-PRESS implantation (both p < 0.05). The mean number of antiglaucoma medications prescribed at the last follow up decreased from 3.2 (±0.5) preoperatively to 1.2 (±1.4) after TRBC versus 3.3 (±0.7) preoperatively to 1 (±0.9) after Ex-PRESS implantation (both p < 0.05). Complete success rate (defined as no medication after surgery with IOP >5 and <18 mmHg) and qualified success rate (defined as with or without medication after surgery with IOP >5 and <18 mmHg) were similar (47% vs. 43% and 76.47% vs. 75%) between the two groups without statistical difference (p > 0.05). However, postoperative hypotony rate was more frequent after Ex-PRESS (37.5%) than after TRBC (17.64%).

Discussion:

TRBC and Ex-PRESS implantation provided similar IOP control and reduction of postoperative medication with low incidence of postoperative complications at intermediate-term follow up. However, the Ex-PRESS implantation device may last longer but with extra costs. It is up to the surgeon to decide which procedure to use according to the patient''s situation and economic circumstances.     

Safety and efficacy of Ahmed glaucoma valve implantation in refractory glaucomas in Northern Indian eyes

Purpose

To evaluate the safety and efficacy of Ahmed glaucoma valve (AGV) implantation in refractory glaucoma in Northern Indian eyes.

Background

The success rate of trabeculectomy remains low in cases of refractory glaucoma even with the use of antifibrotics. Glaucoma drainage devices have proven to be more efficacious in reducing intraocular pressure (IOP) in these glaucomas.

Methods

Retrospective records of 55 consecutive patients who underwent AGV implantation at Dr. Shroff’s Charity Eye Hospital, New Delhi, India from January 2003 to December 2012 were reviewed. Pre-operative data included age, gender, eye laterality, specific diagnosis, number of anti-glaucoma medications, number of prior incisional surgeries, visual acuity and IOP on medical treatment. Postoperative data included visual acuity and IOP on day one, 1 week, 1 month, 3 months, 6 months, 1 year and yearly thereafter, number of anti-glaucoma medications, any complication or additional surgical intervention required. Success was defined as IOP >5 and <22 mmHg with or without treatment.

Results

Mean IOP decreased from 39.71 ± 8.99 pre-operatively to 17.52 ± 5.72 mmHg at last follow-up (p < 0.001) and number of medications reduced from 3.27 ± 0.84 to 1.25 ± 0.88 (p < 0.001). Visual acuity remained within one Snellen line or improved at last follow-up in 47 cases (85.4%). The cumulative probability of success was 85.45% at 1 year and 79.63% at 3 years. The incidence of post-operative complications was 25.45%.

Conclusion

AGV implantation has proven to be safe and is effective in controlling IOP in refractory glaucoma in Northern Indian eyes.     

Scleral- fixated intraocular lens implantation in microspherophakia

Background:

In microspherophakia, abnormal laxity of the lenticular zonules leads to development of a spherical lens and possible subluxation. We evaluated long-term results of lens removal with scleral-fixated intraocular lens (SFIOL) implantation in microspherophakia.

Materials and Methods:

Case series. SF IOLs were implanted in four consecutive patients with bilateral microspherophakia (eight eyes [three with pupillary block and secondary glaucoma who underwent immediate surgery and five with only subluxation who underwent elective surgery]). Post-operative best-corrected visual acuity (BCVA), intraocular pressure (IOP) and lens position were evaluated periodically from day 1 to 18 months.

Results:

All patients were females (mean age 28 ± 7.03 years). In group 1 eyes (three eyes that presented with pupillary block), the mean BCVA improved from 0.008 decimals (preoperative) to 0.50 decimals (final post-operative visit); in group 2 eyes (the other five eyes), the mean BCVA improved from 0.12 ± 0.21 decimals to 0.73 ± 0.14 decimals. The preoperative mean IOP (54.53 ± 7.33 mmHg) in group 1 eyes was significantly (P = 0.03) higher than that (16 ± 4.30 mm Hg) in group 2 eyes. At final post-operative visit, the mean IOP (11.67 ± 2.88 mmHg) in group 1 eyes was not significantly different from that in group 2 eyes (13.0 ± 3.08 mmHg). All SFIOLs were well- centred at the final visit. None of the patients encountered any peroperative or postoperative complications.

Conclusions:

SFIOLs may be an option for surgical management of microspherophakia.     

Not only pregnancy but also the number of fetuses in the uterus affects intraocular pressure

Aim:

To investigate whether, intraocular pressure (IOP) is affected when there is a second fetus in the uterus during pregnancy.

Materials and Methods:

Eighty eyes of 40 twin pregnancies (TwPs), 80 eyes of 40 singleton pregnancies (SiPs) and 80 eyes of 40 non-pregnant females (NoPs) were included in the study.

Statistical Analysis:

Repeated measurements analysis of variance with two factors, one-way analysis of variance (ANOVA) and theTukey''s multiple comparison test were used.

Results:

The mean IOP (MIOP) values in TwPs were 14.29 ± 1.28, 11.48 ± 1.20, and 9.81 ± 1.36 mmHg and the MIOP values in SiPs were 14.42 ± 0.95, 13.12 ± 0.75, and 10.97 ± 0.89 mmHg in subsequent trimesters. The MIOP values in NoPs were 14.77 ± 1.18, 14.92 ± 1.33, and 15.08 ± 0.89 mmHg in subsequent 3-month measurements. The results show that the MIOP values for the TwPs group were significantly lower than the SiPs in all trimesters.

Conclusions:

During pregnancy, the number of fetuses in the uterus is an indirectly important factor that influences the decrease in IOP. We hypothesize that the increased ocular hypotensive effect of TwPs is most likely related to the presence of higher levels of hormones, particularly estrogen, progesterone and relaxin compared with SiPs.     

Diurnal variation in central corneal thickness and intraocular pressure in eyes with pseudoexfoliation syndrome without glaucoma

Aim:

The aim was to ascertain if any differences exist in diurnal central corneal thickness (CCT) and intra-ocular pressure (IOP) between eyes with pseudoexfoliation (PXF) syndrome without glaucoma and eyes with no ocular pathology. A secondary aim was to determine whether there was a significant relationship between CCT and IOP.

Settings and Design:

This study was a prospective design conducted within a hospital setting.

Materials and Methods:

The experimental group consisted of seven participants with bilateral PXF (14 eyes) and the control group comprised of 15 participants (30 eyes). Testing included CCT and IOP measured at four different times on one given day (8.00 a.m.; 11 a.m.; 2 p.m. and 5 p.m.).

Statistical Analysis:

The data were analyzed with the generalized linear latent mixed model.

Results:

PXF eyes displayed a significantly thinner overall mean CCT (520 μm) compared to controls (530 μm). Furthermore, a significant reduction in CCT and IOP occurred in the PXF group from 8 a.m. to 5 p.m. The mean overall IOP in PXF eyes was significantly lower than the control group. A significant association between IOP and CCT was also found in PXF eyes.

Conclusions:

Displaying a significantly thinner mean CCT highlights the importance of measuring CCT in an ophthalmic clinical setting as to avoid falsely underestimated IOP measurements in such a high-risk glaucoma population. Furthermore, a statistically significant correlation between IOP and CCT in PXF eyes suggests that the reduction in CCT that occurred in PXF eyes between 8 a.m. and 5 p.m. may be partly responsible for the reduction in IOP measurements.     

Efficacy of Hyperbaric Oxygen Therapy on Central Corneal Thickness,Intraocular Pressure,and Nerve Fiber Layer in Patients with Type 2 Diabetes: A Prospective Cohort Study

PurposeTo evaluate the effect of hyperbaric oxygen therapy (HBOT) on central corneal thickness (CCT), intraocular pressure (IOP), and the retinal nerve fiber layer (RNFL) thickness in patients with type 2 diabetes mellitus.MethodsThis prospective non-randomized cohort study consisted of type 2 diabetes mellitus patients who received 30 sessions of HBOT for diabetic foot ulcer. The CCT, IOP, and RNFL measured at baseline, after the 10th session of HBOT, after the 20th session of HBOT, after the 30th session of HBOT, and after the 3 months of the last session of HBOT. We gained the superior-nasal, superior-temporal, inferior-nasal, inferior-temporal, nasal and temporal quadrant RNFL values with a spectral-domain optical coharence tomography.ResultsForty-six eyes of 46 patients included in the study. During the study period, a statistically significant increase in mean IOP values compared to baseline was observed (p < 0.001). We found no significant changes at CCT and all quadrants of RNFL values during HBOT and after 3 months of the treatment (p > 0.05). During the study period, the IOP levels increased over 21 mmHg (between 22 and 28 mmHg) in seven eyes (15.2%). The mean hemoglobin A1c values of these patients with IOP >21 mmHg were 8.2 ± 0.9 mg/dL, and there was significant differences compared with those of patients with IOP values ≤21 mmHg (7.4 ± 2.8 mg/dL) (p = 0.001).ConclusionsHBOT increase IOP in type 2 diabetic patients especially in ones with impaired blood glucose regulation. However, it does not cause any changes in CCT and RNFL. As diabetic retinopathy and diabetic foot ulcer are in common pathologies, thus this brief report concludes a need for further studies with longer follow-up periods to explore the potential interaction of HBOT on CCT, IOP, and RNFL.     

Comparison of ocular response analyzer parameters in primary open angle glaucoma and exfoliative glaucoma patients

Aim:

We sought to identify differences in the following measures of the ocular response analyser (ORA) between primary open angle glaucoma (POAG) and exfoliative glaucoma (EXG) patients: Corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc) and Goldmann-correlated intraocular pressure (IOPg). We also sought to relate these ORA measures with central corneal thickness (CCT).

Materials and Methods:

This cross-sectional study was conducted on a total of 162 individuals (46 EXG patients, 66 POAG patients and 50 healthy subjects without any ocular and systemic disease). ORA measurements were performed, and a minimum of three readings were obtained from each test subject. Groups were compared according to their ORA parameters.

Results:

The mean CH levels of the EXG, POAG and healthy subjects were 7.6 ± 2.1, 9.1 ± 1.9 and 9.6 ± 1.7 mmHg, respectively. CH was significantly lower in the EXG patients compared to the other groups (P < 0.001). The mean CRF levels of the EXG, POAG and healthy subjects were 9.0 ± 2.0, 10.1 ± 1.7 and 9.8 ± 1.8mmHg, respectively. CRF levels in the eyes of the EXG patients were significantly lower compared to those of either the POAG patients (P = 0.005) or the healthy subjects (P = 0.03), but there was no significant difference in CRF levels between the POAG patients and the healthy subjects (P = 0.59). There was a significant positive correlation between CH and CCT in the EXG patients and healthy subjects (P < 0.001), but this correlation was not present in the POAG patients (P = 0.70).

Conclusions:

In this study, CH and CRF were found to be significantly reduced in the eyes of EXG patients compared to both the POAG patients and healthy subjects. Reduced CH in EXG patients might result in decreased support of peripapillary scleral structure and increased damage to the optic nerve during IOP increase.     

Evaluation of ocular pulse amplitude and choroidal thickness in diabetic macular edema

Purpose

The aim of this study is to evaluate the ocular pulse amplitude (OPA) and choroidal thickness (CT) measurements in patients with diabetic macular edema (DME) and healthy subjects.

Methods

A total of 34 patients (12 male and 22 female) who had type 2 diabetes mellitus with DME and 34 sex-matched healthy subjects (13 male and 21 female) were included in this prospective study. The intraocular pressure (IOP) and OPA were measured with Dynamic contour tonometer (Pascal DCT, Switzerland). The subfoveal CT was measured using the Cirrus HD-OCT (Carl Zeiss Meditec). The CT at 1500 μm and 3000 μm nasal and temporal to the central fovea was also measured.

Results

The mean IOP values were 18.4±3.5 and 17.1±2.1 mm Hg in DME patients and healthy controls, respectively (P= 0.091). The mean OPA values in patients with DME (2.58±0.96) and controls (3.52±1.03) were statistically different (P<0.001). The mean subfoveal CT value was 273.5±30.2 μm in the eyes with DME and 321.4±36.5 μm in the control group (P< 0.001). In both groups, linear regression analysis showed no significant association between OPA and CT measurements. The IOP showed a significantly positive correlation with OPA in both DME (P=0.002, r=0.526) and controls (P=0.004, r=0.483).

Conclusions

The current study suggests that both pulsatile choroidal blood flow and CT are decreased in patients with DME.     

Decreased keratocyte density and central corneal thickness in primary open-angle glaucoma patients undergoing treatment with topical prostaglandin analogues

Purpose:

To evaluate whether prostaglandin (PG) analogue use is associated with alterations in keratocyte density and central corneal thickness (CCT) in subjects with primary open-angle glaucoma (POAG).

Materials and Methods:

Thirty-five POAG patients treated with PG analogues for >2 years and 35 control subjects without glaucoma were included in this cross-sectional study. All subjects were underwent CCT measurements using ultrasound pachymetry. Keratocyte densities of each stromal layer were determined by in vivo confocal microscopy. Student''s t-test and Chi-square test were used for statistical evaluations. Correlations between keratocyte densities and CCT were analyzed using Pearson''s correlation analysis.

Results:

Keratocyte densities in each stromal layer were significantly lower in glaucoma patients receiving PG analogues as compared to those of controls (P < 0.001). The mean CCT was also lower in glaucoma patients (515.2 ± 18.8 μ) than control subjects (549.6 ± 21.1 μ, P < 0.001). A positive correlation between keratocyte densities in each stromal layer and CCT was observed in POAG patients.

Conclusions:

Long-term administration of topical PG analogues may adversely influence keratocyte densities and CCT. Further prospective studies are required clarify the relationship between PG analogues and their effects on the cornea.     

Age,gender and refractive error association with intraocular pressure in healthy Saudi participants: A cross-sectional study

Purpose

To determine the distribution of intraocular pressure (IOP) and its association with age, gender and refractive error in non-glaucomatous Saudi participants.

Design

Hospital-based cross-sectional observational study during Vision Day Screening Program. Participants: 458 participants living in the Al-Khobar, Saudi Arabia.

Methods

Recruited participants (aged 20 years or over) underwent a comprehensive questionnaire and ocular examination, including measurement of IOP with Perkins hand-held applanation tonometry and autorefraction.

Main outcome measures

The distribution of IOP of either of the eyes (right or left eye by randomization) and associations with age, gender and refractive error.

Results

Median IOP was 15.0 (range: 6–28) mmHg in the total population. There is no significant difference between the overall IOP of male participants, median 15 (range: 6–28) mmHg and female participants, median 16 (range: 6–28) mmHg (p = 0.180). No statistically significant difference in IOP in relation to age comparing 20–45 years group to 46–69 years group was documented (p = 0.751). There was no statistically significant relationship between refractive error category and IOP (p = 0.405). Ocular hypertension with IOP > 21 mmHg was found in 8.7% of the participants.

Conclusion

Variation in IOP by gender, age group and type of refractive error was not statistically significant. The observations need confirmation by study with larger sample representing Saudi population.