Abhi Krishan

My experience during the first week of clinical immersion was an exciting return to the environment of an eye clinic, especially one that had far more scope than I had seen in my previous roles. I was surprised how often I was seeing patients who were living with the conditions we had learned about during our first year of med school. Most notably, the GVHD/DED and contact lens clinics demonstrated a lot of overlap with autoimmune conditions like systemic lupus erythmatosus and Sjögren’s syndrome. In the contact lens clinic, we observed a lot of patient living with keratoconus, a condition in which the cornea deforms, becoming increasingly sensitive to damage and degrading vision. These two clinics shared a lot of similar diagnostic testing, with machines in each clinic sharing purposes, such as the corneal topographer and tonometers for IOP measurement.

Good Design: Corneal Topographer

Activity: This device is used in both clinics mentioned above, with different goals achieved through the same method. The machine allows for measurement of corneal thickness to assess progression of deformity of both dry eye disease and keratoconus.

Environment: In each of the clinics, these diagnostic machines were placed in rooms outside of designated exam lanes, giving the space exclusively the purpose of acquiring scans.

Interactions: Technicians instruct patients to place their heads into the machine and guide their gaze through the acquisition process. The patient has the machine accommodate to their body through height and depth adjustments

Objects: Device itself

Users: Technicians interact with the device with patients, while the results are interpreted by the MD and uploaded into EMR.

Bad Design: MMP-9 Tear film analysis

Activity: Acquisition of tear fluid from eye during exam to determine the presence of a biomarker relevant to DED.

Environment: Extremely narrow exam room, no more than 5-6 feet wide at its largest. Becomes cramped very quickly

Interactions: Multiple interactions between MD and two technicians, handoffs of glass capillaries and other materials.

Objects: Glass capillaries, slit lamp, serological pipet, test strip, eppendorf tubes, storage boxes.

Users: Multiple technicians and patient in the room with MD.

Admittedly, the process itself seems efficiently done when considering the techs in the room without us observers, but the amount of handoffs seems like it could introduce risk into the procedure.

This week I got to return to both the contact lens and oGVHD clinics, as well as my first foray into the OR for retina surgery. Despite patients presenting with a myriad of conditions the subsequent ocular manifestations of those conditions, a good amount of the visits remain the same across services. One thing that comes to mind primarily is the measurement of intraocular pressure (IOP) to assess progression of glaucoma in patients with a history of it, but it also serves as an integral marker for physicians suspecting glaucoma in their patients. There are a few different ways of measuring IOP, ranging from the gold standard (Goldman applanation tonometry) to handheld devices that can repeatedly tap the surface of the cornea to assess the pressure. In the clinics I shadowed, the first line of measurement was through the use of these handheld devices, namely the Tonopen. In my experience as a tech, I know firsthand that some patients find the tonopen to be uncomfortable and as such numbing drops are used to make the process more bearable.

A brief literature search on these devices gave me some insight as to the accuracy of handhelds vs the gold standard, notably through the article “Comparison of intraocular pressure measurements with different contact tonometers in young healthy persons” (Galgauskas 2016). This article compared the results of the devices to Goldman applanation and determined that although the handheld devices tended to overestimate the IOP of young healthy individuals, there was no statistically significant difference between the methods of acquisition. In practice however, I’ve noticed that glaucoma patients and non-glaucoma patients alike who present with an elevated IOP that was acquired by a handheld also tend to receive GAT as a sort of “measure twice, cut once” confirmation.

The patent US6093147A – Apparatus for measuring intraocular pressure describes a proposal for one of these devices, specifically the iCare line of tonometers. These devices were patented with claims that state the measurement of IOP is done in a way that can go without anesthetic drops, allowing for quicker acquisition times, as well as decreased patient discomfort. Additionally, these devices address another shortcoming in the handheld tonometry space, shaky hands. Techs can often face issues with patients either moving due to fear of the device touching their eye or the device moving around from multiple rounds of acquisition. The iCare line addresses these concerns by offering a small pad which technicians can fixate the device with by placing the pad on the brow while taking the pressure, reducing shakiness.

This slide addresses the current SOP for Inflammadry test strips in Dr. Jain’s oGVHD/DED clinic.

The following script for a storyboard reflects common findings from the contact lens fitting process:

1: Clinic Lobby

Patient enters, squinting slightly and rubbing eyes.

FRONT DESK TECH: Hi, welcome! Are you here for your scleral lens fitting? PATIENT: Yeah, I’ve been having trouble seeing clearly for a while. Tech checks the schedule and nods.

FRONT DESK TECH: We’ve got you down. A technician will call you in.

2: Pre-Test Room

Patient sits in front of a corneal topographer. Technician adjusts the machine.

TECH: We’re going to take a topographic map of your cornea. Just keep looking straight ahead. Screen shows a distorted map consistent with keratoconus.

3: Doctor’s Office

OD reviews the topography on a screen with the patient beside them.

OD: This confirms keratoconus. That cone shape makes standard lenses tough to wear. Scleral lenses are larger and rest on the white part of your eye, vaulting over the cornea completely.

PATIENT: Will they help with the ghosting and blur?

OD: That’s the goal. Let’s try a diagnostic lens and see how it looks.

4: Fitting Room

OD places a large diagnostic lens filled with saline and fluorescein on the patient’s eye. Tech holds a blue light for slit lamp.

OD: Okay, blinking normally… perfect. Now we’re checking the tear reservoir underneath the lens. Blue glow reveals an even green ring under the lens.

OD: Good. We’ll adjust the landing zone for better edge alignment.

SCENE 5: Training

OD sits with the patient at a counter with mirror, DMV plungers, and saline vials.

OD: Here’s how you insert the lens: fill it to the brim with saline, lean forward, and look straight down into the mirror.

PATIENT: Like this?

OD: Exactly. Don’t blink

6: Waiting Room

Patient sits with lenses in, blinking and slowly adjusting their eyes. Looks across the room at a sign.

7: OD’s Office

OD types into a computer, tech reads parameters from the diagnostic fitting.

TECH: 16.5 mm diameter, medium sagittal depth, toric landing zone. OD: Got it. Let’s place the order. These should be ready in about a week.

8: Follow-Up Fitting

Patient returns, sits in chair. OD places custom lens in and examines under slit lamp.

OD: Fit looks excellent—alignment is even, no impingement. How’s it feel?

PATIENT: Feels perfect. Like I don’t even notice it!