• A Glaucoma Surgery: 'So Safe, So Easy and So Certain …'

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    “We have now in our hands a method so safe, so easy and so certain that I feel sure that this dread [of surgical intervention] will ere long pass away, and that the diagnosis of glaucoma will then be followed by a very early operation.”

    The author was not an enthusiastic innovator describing a 2019 minimally-invasive glaucoma procedure, but Lt. Col. Robert Elliot describing his full-thickness Elliott trephine procedure in 1913. This inventing surgeon had not seen a secondary infection in 1,200 cases of his new procedure. He went on to advocate the procedure bilaterally, “despite the fact that the second eye was then to all appearances non-glaucomatous."

    Book coverThose of us who have had the occasion to perform full-thickness glaucoma surgeries would agree with “easy,” but less so with “safe” or “certain.”

    Figure 1: "Glaucoma: A Symposium",  published presentations of the 1913 Chicago Ophthalmological Society meeting. 

    My colleague and bibliophile, H. Stanley Thompson, MD, owned a bookstore that focused on historic ophthalmology books. He occasionally passed interesting books on to friends. I was the recipient of a bound volume titled, “Glaucoma: A Symposium” – the published presentations of the 1913 Chicago Ophthalmological Society meeting (see Figure 1).

    Reading these proceedings was like eavesdropping on a Subspecialty Day meeting 100 years ago. This volume provided a glimpse into the thinking and practices of that era’s ophthalmology giants.

    Elliott’s trephine procedure was one in a cornucopia of glaucoma surgeries being performed at that time. Dr. Casey Wood reviewed the other 31 operations – some with intriguing names like the Sterns-Semmereole sclerotomia antero-posterior.

    The Lagrange procedure seemed to be the most popular surgery at the time. In this procedure, an unsutured subconjunctival flap of sclera was created in a single pass with a von Graefe knife and an iridectomy performed. The aqueous drained into the subconjunctival space. Wood’s own horrifying modification of the Lagrange procedure removed the conjunctiva and let the aqueous flow into the tear film, leaving the iris and ciliary body exposed: “It is necessary to clear the neighborhood of the operation wound entirely of conjunctiva.”

    Although there were many glaucoma surgeries to choose from in 1913, there were very few other therapies. Dr. George Edmund De Schweinitz reviewed the nonsurgical options, which he suggested be used when surgery was not possible or advisable. The only medicines routinely used were the cholinergic agonists or “myotics” (sic), physostigmine (Eserine) and pilocarpine.

    Dr. De Schweinitz deemed that the most important doses were upon retiring for the night and again between 2 and 4 a.m. Patients using these drugs not only suffered from severe miosis and accommodation, but also with recurrent severe conjunctivitis. Osmotic agents were employed acutely. Sodium chloride was administered orally. Dr. De Schweinitz preferred the “introduction by bowel of fairly large doses of physiologic salt solutions.” Various hypertonic salts were administered subconjunctivally.

    The opioid ethylmorphine (Dionin) was used acutely and was felt to be especially effective if used with the topical anesthetic Holocaine. Topical epinephrine was sometimes mixed with “myotics” but frequently caused a profound increase in intraocular pressure (IOP). Part of the confusion about the varied reaction to epinephrine was because ophthalmologists at the time did not differentiate open angle and closed angle glaucoma.

    Maximilian Salzmann wouldn’t describe gonioscopy for another year. It was recognized that the iridectomy, as described by Dr. Albrecht von Graefe, was only truly effective in cases of acute glaucoma. Once anterior synechiae had formed it tended to be unsuccessful unless an inadvertent filtering bleb developed.

    Edward JacksonMechanical measures for lowering the IOP included massage, vibration massage and suction massage. The Piesbergen instrument was placed over closed lids and vibrated at 3,000 vibrations per second. Manual massage with the thumb through the lid was used with as many as one thousand pulses. Another therapy was low voltage electrical current passed through the eye with the negative pole on the eye and the positive pole on the neck. This was employed for 10 to 15 minutes at a time twice a week. It was also felt that lowering systemic blood pressure might lower the IOP, and some authors even recommended periodic phlebotomy, removing 3 grams of blood per kilogram of body weight.

    Examination techniques received little discussion. Although IOP could be measured with Schiøtz tonometry, it was usually estimated by palpation and expressed, for example, as “T+2.” Bjerrum’s nasal visual field loss was recognized as a consequence of glaucoma but there was no mention that the visual field was measured routinely.

    Optic nerve examination was described – not in cup-to-disc ratios – but in diopters of cup depth. Dr. E.V.L. Brown reported to having seen “a cup of 7D. reduced to 1 D. in the course of a year after the tension had been lowered from 62 to 12.” Weeks described the development of peripapillary atrophy in patients with glaucoma, called a glaucomatous ring. This is impressive given the equipment of the era and the lack of photography.

    Some authors speculated on the underlying causes of glaucoma. One speculated that under physiologic conditions "the hydrostatic pressure within the eye and the skull are identical; it rises and falls simultaneously.” Lane points out that Edward Jackson "virtually puts aside the volumetric theory with his statement that" the balance of intraocular pressure is not maintained by the slight distensibility of the sclera-corneal coat." Among the discussions of pathophysiology where descriptions of the lymph system of the eye and even of the cornea.

    Abandoned Procedures

    Most of the presentations described understandings and procedures that have long since been abandoned, much as many of our current understandings and procedures will be lost to history in another one-hundred years. However, one presentation was by an ophthalmologist whose ideas were very far ahead of his time; Edward Jackson.

    Described as the most important American ophthalmologist, Jackson was famous for his cross cylinder and other contributions to refraction. He was a founding father of much of organized American ophthalmology (founder of the American Board of Ophthalmology, first editor of the modern American Journal of Ophthalmology and first President of the American Academy of Ophthalmology and Otolaryngology).

    Dr. Jackson had interests in cataract, infectious diseases and teaching. But what did he know about glaucoma? There were no peer-reviewed papers on glaucoma among his impressive publications, however his presentation in Chicago demonstrated that he had remarkable insight. There were two aspects of his presentation that were especially impressive. One was his opening paragraph (see Figure 2):

    Figure 2: Opening paragraph written by Dr. Edward Jackson. 

    “It is convenient to start with the conception that glaucoma is increased tension of the eye-ball, plus the causes and effects of such increase; although a broad survey of the facts may reveal a clinical entity to be called glaucoma, without increased tension constantly or necessarily present, and cases of increased intra-ocular tension not to be classed as glaucoma.”

    This sounds very much like the definition of glaucoma that we use today. Jackson recognized that glaucoma damage could occur in the absence of elevated IOP and that not everyone with elevated IOP will develop glaucoma. In 1857, Dr. von Graefe had described glaucomatous optic nerve damage without an elevated IOP (digitally estimated), but later abandoned this opinion. There were intermittent reports of “low-tension glaucoma” or “pseudoglaucoma” in the literature over the next decades.

    But the original editions of some of the classic works on glaucoma (Duke-Elder (1941), Becker and Shaffer (1961), Chandler and Grant (1965), Redmond Smith (1965) all include elevated IOP in the definition of glaucoma. For example, Becker and Shaffer stated: "A definite diagnosis of glaucoma cannot be made unless the increased intra-ocular pressure has produced damage to the optic nerve."  Dr. Smith addressed those with glaucoma-like damage: “The tendency has been to apply the term pseudoglaucoma or ‘soft’ glaucoma to these cases, but some have regarded them as a special form of optic neuropathy due to unknown causes and not to glaucoma.”

    Dr. Jackson also recognized the importance of the balance between IOP and systemic blood pressure.

    “In the eye there is probably a normal equilibrium between blood pressure, tissue activity, and intra-ocular tension.  This may be destroyed either by increasing the intra-ocular tension, or by lowering the tissue activity, or the blood pressure. … Glaucoma is probably not so much an increase of tension as a loss of balance between intra-ocular tension and nutritional activity.”

    In 1974, Sohan Hayreh would postulate nocturnal hypotension as a cause of worsening glaucoma in the face of normal IOP and publish proof of this in 1994 – 81 years after Jackson’s musings. It is humbling to appreciate that this man, who contributed so much on so many fronts, had such a sophisticated understanding of a disease that was not a focus of his practice or writings.

    This trip into the distant past made me appreciate how much easier glaucoma is to manage today than it was for our predecessors. Hopefully those who follow along 100 years hence will feel the same about our current management.

    I am humbled by the tremendous insights of ophthalmologists like Dr. Jackson and grateful for the shoulders upon which our current practices stand – Dr. Elliot’s trephine turned out to be neither “safe” nor “certain,” but was a necessary step towards the much safer trabeculectomy and the procedures that followed and will continue to evolve.