Estimation of the melatonin suppression index through clear and yellow-tinted intraocular lenses

A systematic literature review: building window's influence on indoor circadian health

Light has been shown to have a non-visual impact on the biological aspects of human health, particularly on circadian rhythms. Building windows are a potential means of regulating daylight conditions for circadian health and well-being. As a result of advancements in window and glazing technologies and variations in outdoor solar/sky conditions, understanding daylight's spectral characteristics, which pass through building window systems, is complex. Therefore, a systematic review and summary of the knowledge and evidence available regarding windows' impact on human circadian health is necessary. This study provides an overview of research in this domain, compares approaches and evaluation metrics, and underscores the importance of window parameters' influence on circadian health. Published studies available on various online databases since 2012 were evaluated. The findings of this study define a holistic approach to the melanopic performance of windows and provide an overview of current knowledge regarding the effect of windows on circadian health. Additionally, this work identifies future research directions based on the studies reviewed. This research contributes to the growing body of knowledge on the impact of windows on circadian health, which has implications for the design and construction of buildings in ways that support indoor human health and well-being from the circadian light adequacy perspective.

Preferred cataract surgery practices in Malaysia: a survey based study

BACKGROUND

To describe the preferred cataract surgery practices among Malaysian ophthalmologists and medical officers in comparison with the recommended practices.

METHODS

An online questionnaire was sent out in April 2021, to Malaysian Ophthalmologists and medical officers who perform cataract surgeries. The questions were focused on the preferred cataract surgery practices of the participants. All data obtained were collected, tabulated and analysed.

RESULTS

A total of 173 participants responded to the online questionnaire. 55% of the participants were within 31-40 years of age. 56.1% preferred peristaltic pump over venturi system. 91.3% of participants practised povidone iodine instillation to the conjunctival sac. With regards to the main wound incision, more than half of the surgeons (50.3%) preferred fixed superior incision and 72.3% of them preferred 2.75 mm microkeratome blade. Most of the participants (63%) were inclined towards C-Loop clear intraocular lens (IOL) with a single-handed push preloaded system. 78.6% of the surgeons routinely use carbachol in their cataract surgery.

CONCLUSIONS

This survey provides some insight into the current practices among Malaysian ophthalmologists. Most of the practices are in line with international guidelines for preventing postoperative endophthalmitis. This article could help trainees and ophthalmologists benchmark and observe the common cataract surgery practices among their seniors and peers in Malaysia.

Estimations of Retinal Blue-Light Irradiance Values and Melatonin Suppression Indices Through Clear and Yellow-Tinted Intraocular Lenses

Spectral transmittance values in the wavelength range of 300 to 800 nanometers were measured using a spectrophotometer for 18 intraocular lenses (IOLs) including clear (ZCB00) and yellow-tinted (ZCB00V, both from AMO Japan) IOLs with three different lens powers. Also measured were the blue-light irradiance (BLI) values, which might reflect retinal damage caused by sunlight, and the melatonin suppression indices (MSIs), which might reflect the nonvisual photoreception function, through these IOLs. The BLIs (in mWcm^-2) calculated were 7.62, 7.50, and 7.46 for the +10-diopter (D), +20-D, and +30-D ZCB00 IOLs, respectively; 4.10, 3.92, and 4.00 for the +10-D, +20-D, and +30-D ZCB00V IOLs, respectively; 5.76 for phakic eyes; and 15.00 for aphakic eyes. The MSIs (in mWcm-2sr-1) calculated were 1.18, 1.19, and 1.18 for the +10-D, +20-D, and +30-D ZCB00 IOLs, respectively; 0.98, 0.94, and 0.95 for the +10-D, +20-D, and +30-D ZCB00V IOLs, respectively; 1.03 for phakic eyes; and 1.21 for aphakic eyes. The data from the six clear IOLs (SA60AT, Alcon Japan; VA-60BBR, Hoya; AU6 K, Kowa, N4-18B, Nidek; X-60, Santen; KS-3Ai, Staar Japan) and seven yellow-tinted IOLs (SN60AT; YA-60BBR, Hoya; AU6N, Kowa; N4-18YG, Nidek; NX-60, Santen; KS-AiN, Staar Japan; XY-1, Hoya) reported previously also were discussed. Compared to aphakic eyes, ZCB00 and ZCB00V IOLs reduce the BLI values by 49-50% and 73-74%, respectively; and currently available ultraviolet-blocking clear and yellow-tinted IOLs reduce the BLI values by 43-82%, respectively. Yellow-tinted IOLs absorb more circadian rhythm-associated light than clear IOLs. Although the data presented in this study cannot be applied directly to IOL implanted in patients, the balance between photoprotection and photoreception must be considered when using IOLs in a clinical setting.