To maintain clear vision, the tear film needs to be stable between blinks. The tear film stability depends on a delicate balance between the production, spread, and clearance of tear fluids. However, little is known about whether abnormal spread of tear fluids over the cornea is sufficient to cause visual disturbance. Herein we report a case of a large, cystic glaucoma bleb in which the patient complained not only of dysesthesia,1,2 but also of fluctuating blurry vision.
A 75-year-old woman with a history of primary open glaucoma received trabeculectomy and cataract surgeries in both eyes in 2000. After the surgeries, she complained of dry eye, sharp pain, and fluctuating blurry vision in both eyes.
In May 2004, both eyes received surgical correction of conjunctivochalasis. After the surgeries, the pain and dryness were relieved in both eyes. Nevertheless, she still complained of fluctuating blurry vision in the left eye.
Further examination revealed that a cystic bleb present on the superior bulbar conjunctiva was bulging and hanging over the cornea more in the left eye than in the right eye (Figure 1A and B). We used a dental mirror to determine the elevation of the eyelid by the oversize bleb and to reveal that the upper eyelid was overriding the lower eyelid to a greater extent in the left eye (Figure 1C and D). After a complete blink, air bubbles were released from the upper eyelid margin of the left eye. The blurry vision fluctuated and could not be improved with refraction. The tear film was analyzed with sequential images taken by a Tearscope Plus (Keeler, Windsor, England), which showed an air bubble (Figure 2) that subsequently burst to create a gigantic water wave or tsunami that traveled from the upper eyelid margin across the cornea, including the visual axis (Figure 2). When artificial tears were instilled, the formation of bubbles was eliminated, and vision improved.
External photographs showing the height (marked by a yellow star) of a cystic bleb in the right eye (A). Such a bleb height was greater in the left eye, where the bleb was also hanging further over the cornea (B, marked by a white star). The photograph taken via a dental mirror revealed a normal distance between the last eyelash and the contact of the lower eyelid skin, ie, the overriding distance (white star) in a normal subject (C). This overriding distance was greater in the patient's left eye (D).
Representative sequential interference images taken of the left eye by a Tearscope Plus (Keeler, Windsor, England). Immediately after the eye opened (* and 0), a bubble formed near the bleb close to the upper eyelid (marked by white arrowheads). This bubble burst (the next frame) to generate a gigantic countercurrent wave (tsunami) traveling from the epicenter (white arrowhead) toward the visual axis. This wave could be detected by the distorted interference images (marked by black arrowheads) that traveled across the central black viewing hole. These consecutive frames were taken at speed of 30 frames per second.
Grajeswki et al1 first described “bubble dysesthesia” to denote “pain” or “ocular discomfort” associated with large glaucoma blebs. Budenz et al2 further demonstrated a strong correlation between the position of the glaucoma bleb covered by the upper eyelid and the bleb dysesthesia score. We confirmed this finding by using a dental mirror to visualize more precisely the position of the upper eyelid margin relative to the lower eyelid margin (Figure 1). We speculate that such a large overriding facilitated the entrapment of air under the upper eyelid. Topical application of artificial tears was beneficial in reducing the formation of bubbles presumably by filling the small gaps created by the uneven upper eyelid margin apposition against the cystic bleb.
For first time, we demonstrated that a large glaucoma bleb could create episodic distortion of the tear film by generating bubbles that create gigantic waves or tsunami on bursting. Such waves traveled downward against the physiological upward movement of the tear film, leading to distortion of the tear film over the visual axis.
Correspondence: Dr Tseng, Ocular Surface Center, 7000 SW 97 Ave, Suite 213, Miami, FL 33173 (firstname.lastname@example.org).
Financial Disclosure: None reported.
Funding/Support: This study was supported in part by an unrestricted grant from the Ocular Surface Research and Education Foundation, Miami, Fla.
Previous Presentation: This case was accepted as a video presentation for the Annual Meeting of the American Academy of Ophthalmology; October 18-21, 2005; Chicago, Ill.
Di Pascuale MA, Elizondo A, Gao YY, Raju VK, Tseng SCG. Gigantic Waves in the Tear Film Generated by Bubbles From a Large Glaucoma Bleb. Arch Ophthalmol. 2007;125(4):573-574. doi:10.1001/archopht.125.4.573