Assessment of intraocular pressure measurement between Goldman applanation tonometer, rebound tonometer, non-contact tonometer, and its correlation with central corneal thickness

Purpose

To compare readings of intraocular pressure (IOP) taken with the Goldmann applanation tonometer (GAT), the non-contact tonometer (NCT), and the rebound tonometer (RBT), and to compare their correlation with central corneal thickness (CCT).

Methods

This was a prospective, cross-sectional, observational study to which patients above 18 years of age were enrolled. A total of 400 eyes of 200 non-glaucomatous patients underwent IOP recordings using the GAT, NCT, and RBT, and CCT was also noted. Informed consent of the patients was taken. The IOP readings taken via the three methods were compared and correlated with CCT. Paired t test was used to compare the two devices. Simple and multivariate linear regression analyses were used to study the relationship between factors. A P value less than 0.05 was considered significant. Correlation was determined using the Pearson correlation coefficient, and a Bland-Altman graph was plotted.

Results

Mean IOP measured by the NCT was 15.65 ± 2.80 mmHg, by the RBT was 14.23 ± 3.05 mmHg, and by the GAT was 14.69 ± 2.97 mmHg. The mean CCT was 510.61 ± 33.83 microns. The difference between mean IOP recorded by the NCT and that by the RBT was 1.41 ± 2.39 mmHg, between the NCT and GAT was 0.95 ± 2.03 mmHg, and between the GAT and RBT was 0.45 ± 2.22 mmHg. The difference between the IOP values was statistically significant (P < 0.005). All tonometers showed a statistically significant correlation with CCT, but it was observed that the NCT had a stronger correlation (0.4037).

Conclusion

The IOP readings taken by all the three methods were comparable; however, RBT values were closer to GAT values. CCT did influence the IOP values, and this should be kept in mind while evaluating.

Utility of a smartphone assisted direct ophthalmoscope camera for a general practitioner in screening of diabetic retinopathy at a primary health care center

Purpose:

To assess the use of smartphone-based direct ophthalmoscope photography for screening of diabetic retinopathy (DR) in known diabetic patients walking into a general practitioner's clinic and referring them to a vitreoretinal specialist for further evaluation and management if required.

Methodos:

The study included 94 eyes of 47 walk-in patients in a general practitioner's OPD who were known to have type 2 diabetes mellitus and were already on treatment for the same.

Results:

The study included 47 patients with diabetes with a mean age of 56.2 ± 9.4 years. The Cohen's kappa values revealed that the diagnosis related to the DR status made using a camera was in substantial agreement with the clinical diagnosis (Kappa value: 0.770). The Cohen's kappa values revealed that the diagnosis related to the DME made using a camera was in moderate agreement with the clinical diagnosis (Kappa value: 0.410). The agreement between the findings of the camera and clinical diagnosis was statistically significant (P < 0.05).

Conclusion:

Direct ophthalmoscope-based smartphone imaging can be a useful tool in the OPD of a general practitioner. These images can be assessed for retinopathy, and patients can be referred to a vitreoretinal specialist for further evaluation and management if needed. Hence, the burden of vision loss due to complications of DR in the rural sector can be abridged.

Role of Preoperative Nd:YAG Laser Anterior Capsulotomy in Mature Intumescent Cataracts

PURPOSE

The aim of this study was to examine the role of preoperative Nd:YAG laser anterior capsulotomy in preventing intraoperative complications in mature intumescent cataracts.

DESIGN

A prospective, interventional, observational study.

METHODS

A total of 52 eyes of 52 patients were selected in this prospective study. Preoperative Nd:YAG laser anterior capsulotomy was performed in all eyes with 1 shot of 1.2 mJ and a gush of the liquified cortex was noted. Anterior chamber depth was measured using anterior segment optical coherence tomography and intraocular pressure using Goldmann applanation tonometer were measured pre- and post-laser. Intraoperative complications and surgeon's operative comfort were noted.

RESULTS

There was a mean increase in anterior chamber depth by 0.24 mm and a mean decrease in intraocular pressure by 1.61 mm Hg postlaser. No intraoperative complications were noted except for capsulorhexis extension in 1 eye (1.92%). The surgeon experienced a good control while performing the capsulorhexis and overall an uneventful surgery.

CONCLUSIONS

Preoperative Nd:YAG laser anterior capsulotomy is a safe and effective technique in reducing intralenticular pressure and avoiding intraoperative complications in mature intumescent cataracts.

Delayed presentation of cataracts in children: are they worth operating upon?

PURPOSE

Childhood cataract is an important cause of avoidable blindness in children. The study aimed to investigate the outcome of surgery in cataracts with delayed presentation which had been operated upon as new pediatric ophthalmology centers were set up in India.

METHODS

This was a retrospective interventional case series from a community eye care center in Western India. Demographic, surgical, pre-operative and post-operative details were obtained from the patients records and entered into Microsoft excel and statistical analysis conducted using SPSS-11 software (SPSS, Chicago, IL). Vision was tested 6 weeks after surgery. The predictors of good vision (> or =6/18) were identified by regression analysis. If the interval between detection of cataract in children and their presentation for surgery was more than 18 months for developmental and 6 months for congenital the cataract was defined having a delayed presentation.

RESULTS

Five hundred and twenty nine eyes of 437 children aged 2 months to 16 years were operated upon in 2004-2006. Preoperative vision was <3/60 in 405 (76.6%) eyes with cataract. Of these 529, 242 eyes were with delayed presentation of cataract (83 congenital and 149 other). 102 had up to 5 years, 91 had 6-10 years and 49 had >11 yrs delay in presentation. At 6 weeks following surgery, vision was > or = 6/18 in 36/93 (38.7%) of eyes with delayed presenting cataracts, as compared to 94/244 (38.5%) > or =6/18 in those without.

CONCLUSION

Surgery for cataracts with delayed presentation helps to regain functional vision, which can be used for navigation and low vision aids.