As many of you know, for the last few years, I have been living in Phoenix and shuttling back and forth to New York to see patients. At first I returned every other week, then every third week. Eventually, it became once a month and then the visits became even less frequent. The problem was that I loved my practice and my patients, but the commute and being away from home, in addition to my other travels, became increasingly difficult.

After a while, an odd thing happened. The less frequent my visits became, the more uncomfortable I became. It was almost like a part of me was missing and it just didn't feel right. After a lot if introspection, I came to realize that like many of you, what makes me who I am is seeing patients. I love research and writing, speaking and educating and speaking my mind, but first and foremost, I am a clinician. That's what makes me tick and that is, for better or worse, who I am.

I have been thinking about opening a practice in Phoenix for quite some time, but the economy and the uncertain healthcare landscape has been a major concern. Finally, I couldn't take it any longer, and I started working with a colleague close to home on a clinical study.

You would think that a clinical trial would be sterile and the momentary contact with patients unsatisfying. However, I've rediscovered that patient contact is intrinsically satisfying. I am not sure that this is true of all people, but my experience with colleagues like you tells me that it is true of most ODs. Maybe it's in my blood—but after more than 30 years, being an OD still turns me on.

Arthur B. Epstein, OD, FAAO Chief Medical Editor [email protected]

 

 

Researchers sought to assess the utility of digital color sensing to quantify iris color using digital photographs and to determine whether gender or iris color affects the dark-adapted pupil diameter (DAPD). They found that contrary to long-held beliefs, female patients and blue-eyed patients do not have larger DAPD.

They measured the right DAPD of subjects aged 18–80 years (n=263) with no eye disease after 2 minutes of dark adaptation at 1 lux using the NeurOptics pupillometer. They also took a high-resolution digital slip lamp photograph of the iris and subjectively classified iris color as blue, blue-green, green-brown, light brown or dark brown. The researchers also objectively measured the digital photographs on-screen with the Minolta TV Color Analyzer II using the Commission Internationale de l'Eclairage system of color description and performed regression analyses to identify correlations between subjective iris color, Commission Internationale de l'Eclairage measurements and DAPD.

According to the researchers, gender and iris color had no effect on the DAPD. They observed that the Minolta TV Color Analyzer could discriminate all blue eyes (blue and blue-green) from all brown eyes (light and dark), but could not distinguish between shades of blue or shades of brown. They also noted that green-brown irises had no unique chromatic properties and could not be distinguished from other colors using their technique of digital color analysis.

The study researchers concluded that digital color sensing is a useful technique for objectively describing iris color.

To evaluate a novel contact lens-embedded pressure sensor for continuous measurement of intraocular pressure (IOP), repeated measurements of IOP and ocular pulse amplitude (OPA) were recroded in 12 eyes of 12 subjects in sitting and supine positions using three configurations of the dynamic contour tonometer: slit-lamp mounted (DCT), hand-held (HH) and contact lens-embedded sensor (CL). The IOP and OPA for each condition were compared using repeated measures ANOVA and the 95% limits of agreement were calculated.

It was reported that the sitting IOP (mean and 95% CI) for each configuration was DCT: 16.3 mmHg (15.6 to 17.1 mmHg), HH: 16.6 mmHg (15.6 to 17.6 mmHg) and CL: 15.7 mmHg (15 to 16.3 mmHg). The sitting OPA for each configuration was noted as DCT: 2.4 mmHg (2.1 to 2.6 mmHg), HH: 2.4 mmHg (2.1 to 2.7 mmHg) and CL: 2.1 mmHg (1.8 to 2.3 mmHg). Supine IOP and OPA measurements with the CL and HH sensors were both noted to be greater than their corresponding sitting measurements, but were significantly less with the CL sensor than the HH sensor. The mean difference and 95% Limits of Agreement were smallest for the DCT and CL sensor comparisons (0.7 ± 3.9 mmHg) and widest for the CL and HH sensors (–1.9 ± 7.25 mmHg); these wider limits were attributed to greater HH measurement variability.

It was concluded that the CL sensor was comparable to HH and DCT sensors with sitting subjects and is a viable method for measuring IOP and OPA. Moreover, supine measurements of IOP and OPA were greater than sitting conditions and were comparatively lower with the CL sensor. Additionally, HH measurements were more variable than CL measurements and this influenced the Limits of Agreement for both sitting and supine conditions.

The authors of the following study sought to examine dark adaptation in subjects with type 2 diabetes during transient hyperglycemia. They randomized 24 subjects with type 2 diabetes and minimal diabetic retinopathy to undergo an oral glucose tolerance test (OGTT) or to remain fasting.

The study authors measured dark adaptometry in one eye, chosen at random, using a computer-controlled dark adaptometer and dark adaptation as well as capillary blood glucose at baseline and 80 minutes into the OGTT/fasting test. They reported that blood glucose remained stable throughout the examination in the 12 fasting subjects, whereas glycemia increased in the 12 OGTT subjects, from 8.6 ± 2.1 at baseline to 21.1 ± 3.6 mM after 80 min. In the OGTT group, four out of seven subjects with delayed dark adaptation at baseline reached normal values during hyperglycemia.

According to the authors, all examined aspects of rod adaptation were accelerated by hyperglycemia (time to rod-cone break –26%; time to rod intercept –16%, rod sensitivity recovery slope (log units/min) +35%), whereas no measurable change in cone adaptation was seen. The results are consistent with rod adaptation being limited by glycemia and with rod adaptation being delayed in subjects with diabetes compared to healthy subjects, the delay being reversible in response to hyperglycemia.