Is routine pupil dilation safe among asian patients with diabetes?

Management of diabetic ocular complications: from cellular insights to community strategies

The editorial outlines an integrated approach to managing diabetic ocular complications, combining advanced scientific research with practical public health strategies to improve the prevention, diagnosis, and treatment of diabetic retinopathy and macular edema globally.

Risk of acute angle-closure and changes in intraocular pressure after pupillary dilation in patients with diabetes

BACKGROUND

To evaluate the risk of AAC and intraocular pressure (IOP) changes in diabetic patients after pupil dilation.

METHODS

This cross-sectional study enrolled 2,287 diabetic patients among community residents in Guangzhou, China. All participants underwent routine pupil dilation unless they had a history of glaucoma. IOP was measured using a non-contact tonometer before and one hour after pupil dilation with tropicamide 0.5% and phenylephrine 0.5% eye drop. The proportion of AAC and changes in IOP after pupil dilation were evaluated.

RESULTS

Only one of the 2,287 participants (0.04%) with diabetes developed post-dilation AAC. The mean pre and post-dilation IOP in the right was 16.1 ± 2.7 and 16.5 ± 2.8 mmHg (P < 0.001); mean pre and post-dilation IOP in the left was 16.5 ± 2.7 and 16.8 ± 2.8 mmHg (P < 0.001). Sixty-one participants (2.7%) showed an increase in IOP ≥ 5 mmHg and 25 participants (1.1%) showed a post-dilation IOP > 25 mmHg, including 11 participants (0.5%) who had both an increase in IOP ≥ 5 mmHg and post-dilation IOP > 25 mmHg. Lower pre-dilation IOP (OR = 0.827; 95% CI, 0.742-0.922; P = 0.001) and shallower anterior chamber depth (ACD) (OR = 0.226; 95% CI, 0.088-0.585; P = 0.002) were significant risk factors for an increase in IOP ≥ 5 mmHg in multivariate logistic regression analysis.

CONCLUSIONS

The risk of developing AAC after pupil dilation in diabetic patients was very low. Lower pre-dilation IOP and shallower ACD are risk factors for increased post-dilation IOP.

Comparison of Handheld Retinal Imaging with ETDRS 7-Standard Field Photography for Diabetic Retinopathy and Diabetic Macular Edema

PURPOSE

To compare nonmydriatic (NM) and mydriatic (MD) handheld retinal imaging with standard ETDRS 7-field color fundus photography (ETDRS photographs) for the assessment of diabetic retinopathy (DR) and diabetic macular edema (DME).

DESIGN

Prospective, comparative, instrument validation study.

SUBJECTS

A total of 225 eyes from 116 patients with diabetes mellitus.

METHODS

Following a standardized protocol, NM and MD images were acquired using handheld retinal cameras (NM images: Aurora, Smartscope, and RetinaVue-700; MD images: Aurora, Smartscope, RetinaVue-700, and iNview) and dilated ETDRS photographs. Grading was performed at a centralized reading center using the International Clinical Classification for DR and DME. Kappa statistics (simple [K], weighted [Kw]) assessed the level of agreement for DR and DME. Sensitivity and specificity were calculated for any DR, referable DR (refDR), and vision-threatening DR (vtDR).

MAIN OUTCOME MEASURES

Agreement for DR and DME; sensitivity and specificity for any DR, refDR, and vtDR; ungradable rates.

RESULTS

Severity by ETDRS photographs: no DR, 33.3%; mild nonproliferative DR, 20.4%; moderate DR, 14.2%; severe DR, 11.6%; proliferative DR, 20.4%; no DME, 68.0%; DME, 9.3%; non-center involving clinically significant DME, 4.9%; center-involving clinically significant DME, 12.4%; and ungradable, 5.3%. For NM handheld retinal imaging, Kw was 0.70 to 0.73 for DR and 0.76 to 0.83 for DME. For MD handheld retinal imaging, Kw was 0.68 to 0.75 for DR and 0.77 to 0.91 for DME. Thresholds for sensitivity (0.80) and specificity (0.95) were met by NM images acquired using Smartscope and MD images acquired using Aurora and RetinaVue-700 cameras for any DR and by MD images acquired using Aurora and RetinaVue-700 cameras for refDR. Thresholds for sensitivity and specificity were met by MD images acquired using Aurora and RetinaVue-700 for DME. Nonmydriatic and MD ungradable rates for DR were 15.1% to 38.3% and 0% to 33.8%, respectively.

CONCLUSIONS

Following standardized protocols, NM and MD handheld retinal imaging devices have substantial agreement levels for DR and DME. With mydriasis, not all handheld retinal imaging devices meet standards for sensitivity and specificity in identifying any DR and refDR. None of the handheld devices met the established 95% specificity for vtDR, suggesting that lower referral thresholds should be used if handheld devices must be utilized. When using handheld devices, the ungradable rate is significantly reduced with mydriasis and DME sensitivity thresholds are only achieved following dilation.

Is there an association of socioeconomic deprivation with acute primary angle closure?

BACKGROUND

Socioeconomic deprivation is known to increase the risk of late presentation of many diseases. This is the largest study in United Kingdom investigating the relationship between socioeconomic deprivation and acute primary angle closure (APAC).

METHODS

A retrospective review of case notes was conducted of 718 consecutive patients who underwent laser peripheral iridotomy (LPI) in Edinburgh (Princess Alexandra Eye Pavilion) and Fife (Queen Margaret Hospital) between 2015 and 2019. Baseline demographics including sex, age, ethnicity, pre-existing diabetes, use of anti-depressants, and family history of glaucoma were collected. Deprivation was scored using the Scottish Index of Multiple Deprivation (SIMD) Index 2020v2. A lower rank and decile indicate higher degrees of deprivation. We investigated differences in characteristics between patients who were referred routinely versus patients who referred as APAC.

RESULTS

The SIMD rank and deciles were consistently lower in patients who were referred urgently with APAC in both centres (P = <0.05) when compared to those referred routinely for LPI. On univariate and multivariate logistic regression, the presentation of APAC is negatively associated with SIMD Decile (OR = -0.101, 95% CI -0.178 to -0.026, P = 0.008) and family history of glaucoma (OR = -1.010, 95% CI -1.670 to -0.426, P = 0.001), and positively associated with age (OR = 0.029, 95% CI 0.009-0.049, P = 0.004).

CONCLUSIONS

Socioeconomic deprivation is an important risk factors for patients presenting with APAC. Socioeconomic deprivation should be incorporated into the design of glaucoma services and considered when triaging patients for prophylactic and therapeutic LPI and cataract surgery.

The Impact of Pharmacological Dilation on Intraocular Pressure in Primary Angle Closure Suspects

PURPOSE

To assess changes in intraocular pressure (IOP) 1 hour after pharmacological dilation in eyes treated with laser peripheral iridotomy (LPI) and untreated fellow eyes of primary angle closure suspects (PACS).

DESIGN

A prospective randomized, fellow-eye controlled trial.

METHODS

A total of 889 participants with PACS aged 50 to 70 years with LPI in 1 randomly selected eye and a fellow untreated eye were included. All participants underwent comprehensive examinations before and at 2 weeks, 6 months, 18 months, 36 months, 54 months, and 72 months after LPI. The IOP was measured using Goldmann applanation tonometry before and 1 hour after pharmacological dilation.

RESULTS

The mean predilation IOP in the untreated eyes was 14.8 ± 2.7 mm Hg, which increased to 16.4 ± 2.7 mm Hg after pharmacological dilation (P < .001). The treated and untreated eyes had similar predilation and postdilation IOP (all P > 0.05). The average postdilation IOP elevation was 1.5 mm Hg in the treated eyes and 1.6 mm Hg in the untreated eye, without significant differences (P = .802). Lower predilation IOP (P < .001), smaller AOD500 (P = 0.001), smaller ARA500 (P = .030), smaller TISA500 (P = .043), and larger Iarea (P < 0.001) were associated with postdilation IOP elevation of 5 mm Hg and greater. Three untreated eyes (1.04 per 1000 pupil dilation) and 1 treated eye (0.34 per 1000 pupil dilation) developed acute angle closure (AAC) after dilation during the 72-month follow-up.

CONCLUSIONS

Postdilation IOP elevation was similar among treated and untreated eyes, and the risk of developing AAC was very low, even among patients with PACS. Routine LPI before pupil dilation for people with PACS is not recommended.

Analysis of Iris volume using swept-source optical coherence tomography in patients with type 2 diabetes mellitus

PURPOSE

To evaluate iris volume before and after pupil dilation using swept-source anterior segment optical coherence tomography (SS-ASOCT) and investigate the associated factors of iris volume and iris volume change after pupil dilation in patients with type 2 diabetes mellitus (T2DM).

METHODS

A cross-sectional study was conducted in Zhongshan Ophthalmic Center among T2DM registered patients in the community of Guangzhou, China. Anterior chamber volume (ACV), iris volume, anterior chamber depth (ACD), angle opening distance at 500 μm (AOD 500) and pupil diameter were estimated using SS-ASOCT (CASIA; Tomey, Nagoya, Japan). Venous blood was taken for the measurement of glycosylated haemoglobin A1c (HbAlc). All biometric measurements were performed before and after pharmacologic pupil dilation.

RESULTS

A total of 117 subjects were included in the analysis. The mean age (±SD) was 64.96 ± 7.75 years, and 62.4% were females. After pupil dilation, iris volume decreased in all eyes. Shorter duration of diabetes (p = 0.035), longer axial length (p < 0.001) and smaller pupil diameter (p < 0.001) were associated with larger iris volume. The change in iris volume per millimetre change in pupil diameter was 1.35mm³ /mm. Smaller baseline iris volume (p = 0.002) and higher HbA1c level (p = 0.010) were associated with smaller change in iris volume per millimetre change in pupil diameter, after adjusting for other factors.

CONCLUSION

Iris volume can be estimated by SS-ASOCT. Diabetic duration was associated with static anatomy of iris volume, while HbA1c level indicated the dynamic response of iris volume. It is likely that diabetic duration and HbA1c level could affect the macroscopic and microscopic composition of the iris in the diabetic population.

Effect of Mydriasis-Caused Intraocular Pressure Changes on Corneal Biomechanical Metrics

Purpose: To evaluate the dependence of biomechanical metrics on intraocular pressure (IOP).

Methods: 233 refractive surgery patients were included in this study—all were examined 3 times with the Corvis ST before and after dilation, and the differences (∆) in the main device parameters were assessed. The data collected included the biomechanically corrected IOP (bIOP), the central corneal thickness (CCT), and six dynamic corneal response (DCR) parameters, namely DA, DARatio2mm, IIR, SP-A1, CBI, and SSI. Participants were divided into three groups according to the changes in patients’ bIOP after mydriasis.

Results: Intra-operator repeatability was generally high in most of the DCR parameters obtained before and after dilation. The mean changes in bIOP and CCT after dilation were −0.12 ± 1.36 mmHg and 1.95 ± 5.23 μm, respectively. Only ∆DARatio2mm, ∆IIR, and ∆CBI exhibited a statistically significant correlation with ∆CCT (p < 0.05). The changes in all DCR parameters, especially ∆DA and ∆SP-A1 were also correlated with ∆bIOP (p < 0.01)—a 1-mmHg change in bIOP was associated, on average, with 5.612 and −0.037 units of change in SP-A1 and DA, respectively. In contrast, the weakest correlation with ∆bIOP was exhibited by ∆SSI.

Conclusion: Most corneal DCR parameters, provided by the Corvis ST, were correlated with IOP, and more weakly with CCT. Changes experienced in CCT and IOP should therefore be considered in studies on corneal biomechanics and how it is affected by disease progression and surgical or medical procedures.

Various models for diabetic retinopathy screening that can be applied to India

The increased burden of diabetes in India has resulted in an increase in the complications of diabetes including sight-threatening diabetic retinopathy (DR). Visual impairment and blindness due to DR can be prevented by early detection and management of sight-threatening DR. Life-long evaluation by repetitive retinal screening of people with diabetes is an essential strategy as DR has an asymptomatic presentation. Fundus examination by trained ophthalmologists and fundus photography are established modes of screening. Various modes of opportunistic screening have been followed in India. Hospital-based screening (diabetes care/eye care) and community-based screening are the common modes. Tele-ophthalmology programs based on retinal imaging, remote interpretation, and grading of DR by trained graders/ophthalmologists have facilitated greater coverage of DR screening and enabled timely referral of those with sight-threatening DR. DR screening programs use nonmydriatic or mydriatic fundus cameras for retinal photography. Hand-held/smartphone-based fundus cameras that are portable, less expensive, and easy to use in remote places are gaining popularity. Good retinal image quality and accurate diagnosis play an important role in reducing unnecessary referrals. Recent advances like nonmydriatic ultrawide field fundus photography can be used for DR screening, though likely to be more expensive. The advent of artificial intelligence and deep learning has raised the possibility of automated detection of DR. Efforts to increase the awareness regarding DR is essential to ensure compliance to regular follow-up. Cost-effective sustainable models will ensure systematic nation-wide DR screening in the country.

Diabetic retinopathy screening guidelines in India: All India Ophthalmological Society diabetic retinopathy task force and Vitreoretinal Society of India Consensus Statement

Diabetic retinopathy (DR) is an emerging preventable cause of blindness in India. All India Ophthalmology Society (AIOS) and Vitreo-Retinal Society of India (VRSI) have initiated several measures to improve of DR screening in India. This article is a consensus statement of the AIOS DR task force and VRSI on practical guidelines of DR screening in India. Although there are regional variations in the prevalence of diabetes in India at present, all the States in India should screen their population for diabetes and its complications. The purpose of DR screening is to identify people with sight-threatening DR (STDR) so that they are treated promptly to prevent blindness. This statement provides strategies for the identification of people with diabetes for DR screening, recommends screening intervals in people with diabetes with and without DR, and describes screening models that are feasible in India. The logistics of DR screening emphasizes the need for dynamic referral pathways with feedback mechanisms. It provides the clinical standards required for DR screening and treatment of STDR and addresses the governance and quality assurance (QA) standards for DR screening in Indian settings. Other aspects incorporate education and training, recommendations on Information technology (IT) infrastructure, potential use of artificial intelligence for grading, data capture, and requirements for maintenance of a DR registry. Finally, the recommendations include public awareness and the need to work with diabetologists to control the risk factors so as to have a long-term impact on prevention of diabetes blindness in India.

Effectiveness of topical cycloplegics as anterior segment analgesics: systematic review and meta-analysis

OBJECTIVE

Topical cycloplegic agents often are used in ophthalmology in the context of management of ocular inflammation. Preliminary searches of the literature provided little evidence to support their use in relieving pain or reducing inflammation. The goal of this study was to evaluate the current literature for any evidence regarding the effectiveness of cycloplegics for treatment of pain or inflammation in patients with anterior segment injury or inflammation through a systematic review and meta-analysis.

METHODS

Using multiple keywords relating to cycloplegics and inflammatory and infectious eye conditions, a search was conducted on multiple scientific databases for relevant articles. A 2-level screening approach was used and articles that were relevant to the topic were included in the systematic review. Data from these articles, if applicable, were extracted for meta-analyses. Statistical assessments involved computation of I²statistics, Z-value, and χ² statistics.

RESULTS

We screened 5753 articles for relevance. Seven were included in the systematic review and 5 were included in the meta-analysis. There was considerable heterogeneity between the included studies. Statistical analysis revealed significant reductions in pain using homatropine and cyclopentolate after 2 days. Nonsignificant changes in the anterior chamber cells and flare were seen using cyclopentolate and atropine at different follow-up times.

CONCLUSIONS

Little published evidence exists in the literature to guide the use of cycloplegics on relieving pain and treating inflammation. Therefore, higher-quality randomized controlled trials with longer follow-up times are needed to fully understand the role that cycloplegics play in reducing pain in inflammatory conditions.

Determinants of post-mydriatic intraocular pressure in phakic eyes with prevalent angle closure diseases

PURPOSE

This study aimed to identify acute angle closure (AAC) risk following pharmacologic mydriasis and the factors affecting post-mydriatic intraocular pressure (IOP) in a population with a high prevalence of angle closure disease.

METHODS

In total, 460 individuals aged ≥ 72 years were enrolled in this cross-sectional community-based screening program. IOP was measured at baseline and 1 hour after mydriasis. Individuals with post-mydriatic IOP spike > 6 mmHg received indentation gonioscopy and IOP-lowering medication. Linear regression analysis was used to identify ocular parameters associated with post-mydriatic IOP elevation.

RESULTS

The mean age of participants was 77.8 ± 4.1 years, and 65.4% of them were men. In total, 21 eyes of 16 participants (3.48%) had post-mydriatic IOP spikes (range: 6-13.7 mmHg); among them, 15 eyes had an IOP of > 21 mmHg. None of the participants developed AAC. All eyes with IOP spikes were phakic, except for one with pseudophakic angle closure. Analysis of 381 participants with at least one phakic eye revealed that higher post-mydriatic IOP and IOP changes were associated with narrower angle grading, more extensive peripheral anterior synechiae, shallower central anterior chamber, and thicker lens. According to multiple linear regression analysis, post-mydriatic IOP was independently associated with baseline IOP and factors suggestive of crowded anterior chamber based on gonioscopic findings and central or peripheral anterior chamber depth evaluation in conjunction with lens thickness.

CONCLUSION

Post-mydriatic IOP should be measured in phakic eyes with a crowded anterior chamber. Post-mydriatic IOP spikes can be effectively blunted with intervention to prevent AAC.

Advances in Retinal Imaging and Applications in Diabetic Retinopathy Screening: A Review

Rising prevalence of diabetes worldwide has necessitated the implementation of population-based diabetic retinopathy (DR) screening programs that can perform retinal imaging and interpretation for extremely large patient cohorts in a rapid and sensitive manner while minimizing inappropriate referrals to retina specialists. While most current screening programs employ mydriatic or nonmydriatic color fundus photography and trained image graders to identify referable DR, new imaging modalities offer significant improvements in diagnostic accuracy, throughput, and affordability. Smartphone-based fundus photography, macular optical coherence tomography, ultrawide-field imaging, and artificial intelligence-based image reading address limitations of current approaches and will likely become necessary as DR becomes more prevalent. Here we review current trends in imaging for DR screening and emerging technologies that show potential for improving upon current screening approaches.

Eye drop neurology

Eye drops can help to diagnose and prevent complications of neurological disorders. Guttae ophthalmicae (eye drops) are generally safe because the drugs rarely achieve significant systemic concentrations, although there are rare exceptions. This article covers contemporary pharmacological pupil testing; how to dilate a pupil safely; common reasons why pupils do not respond to drops; and corneal lubrication to prevent complications of weak eye closure.