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Complications Associated with Aphakic Contact Lenses
Symposium: Contact Lenses .,.
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COMPLICATIONS ASSOCIATED WITH APHAKIC CONTACT LENSES R. LINSY FARRIS, MD NEW YORK, NEW YORK Complications associated with rigid contact lenses are more frequent in aphakia. The limited dexterity of older patients not only may prove an insurmountable barrier to the mastery of daily contact lens insertion and removal, but also may produce significant direct eye trauma, its seriousness determined by the integrity of the cataract wound. Since prolonged wear of aphakic contact lenses is the rule rather than the exception, the risk of irreversible corneal changes such as vascularization and erosions is greater. A poorly fitted aphakic contact lens that does not permit adequate oxygenation of all corneal areas makes such complications even more likely to occur. Decreased corneal sensitivity associated with cataract surgery permits continued wear of a poorly fitted lens, which does not allow the cornea to recover between wearing periods. Detection of keratoconjunctivitis sicca, more prevalent in the older age group, may prevent the associated complications of corneal erosion, iritis, and infection. Complications of aphakic contact lenses can be controlled by patient instruction, appropriate contact lens adjustments, and regularly scheduled follow-up examinations.
Submitted for publication Nov 9, 1978. From the Edward S. Harkness Eye Institute, College of Physicians and Surgeons, Columbia University, New York, and the Department of Ophthalmology, Harlem Hospital Medical Center, New York. Presented in combination with the Contact Lens Association of Ophthalmologists at the 1978 Annual Meeting of the American Academy of Ophthalmology, Kansas City, Mo, Oct 22-26. Reprint requests to 635 W 165th St, New York, NY 10032.
NOT infrequently, the aphakic patient has complications with contact lens wear.l The ophthalmologist must detect and differentiate complications of cataract surgery aggravated by a contact lens from complications more directly associated with contact lens wear.
A 65-year-old man was seen by the author seven months after cataract surgery for redness and irritation associated with soft contact lens wear. The initial evaluation revealed no apparent cause. However, examination after four hours of soft contact lens wear revealed an extremely red, irritated eye with red blood cells deposited on the anterior vitreous face and the posterior cornea inferiorly. Careful gonioscopic examination at this point revealed a fine net of dilated blood vessels at the periphery of an iridotomy extending onto the posterior surface of the cornea. A fine stream of red blood cells appeared when pressure was exerted with the gonioprism. These vessels were trea ted through the gonioprism with the argon laser. A follow-up visit three months later revealed no further difficulties with an irritated eye. Late hyphema caused by wound vascularization has been reported by Swan,2 Watzke,3 and most recently, by Benson and co-workers.4 Argon laser photocoagulation has
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SYMPOSIUM ON CONTACT LENSES
given varying results in the management of this condition. 5 Rocking the Goldmann lens was suggested by Watzke as the best way to provoke a small hemorrhage. This was found to be true using the pressure gonioscopy technique described by Forbes. 6 This aphakic contact lens wearer found no difficulty in producing hemorrhage by merely inserting and removing his soft contact lens. Vascularization of the iridotomy site and the posterior surface of the cataract incision was the cause of this late hyphema seven months after cataract surgery. Corneal indentation occuring with contact lens insertion and removal was sufficient to rupture the fine vessels and produce a late hyphema. Internal wound separation and iris prolapse has also been known to occur in association with the intiation of contact lens wear as late as 12 weeks after cataract surgery (R.C. Welsh, MD, oral communication, August 1978). The strength of the human cataract wound and its ability to tolerate contact lens insertion and removal has not been rigorously studied. Tensile strength of the cataract wound is acquired slowly over a period of years and probably never reaches that of unaltered tissue. 7 Many factors influence this healing process. 8 Human studies of wound healing after cataract surgery have placed varying emphasis on the length of time required for wound remoulding 9 and elimination of posterior gapinglO following cataract surgery. Wound remoulding in human postmortem material requires up to 21/2 years to complete, whereas posterior wound gaping is eliminated usually in six months if there is no adherent iris. Evaluation of wound integrity is clearly indicated
1121
before initiating daily contact lens insertion and removal. External inspection as well as internal inspection by gonioscopy are easily and quickly performed at the slit lamp, using a Zeiss four-mirror gonioprism on a metal fork handle. Careful instruction concerning insertion and removal techniques and the patient's acceptance of assistance when necessary from a spouse, offspring, or neighbor will diminish the likelihood of excessive stress and wound complication.H Observation of a patient's ability to insert and remove a contact lens will have a significant effect on the choice of various cataract surgical techniques and also on the decision to initiate daily contact lens wear. The aphakic eye is not only a wounded eye; it is also less sensitive as a result of imperfect regeneration of the sectioned corneal nerve fibers.l2 The decreased sensation resulting from cataract surgery and the decreased corneal sensation associated with contact lens wear l3 produce a greater opportunity for the aphakic patient to wear contact lenses for prolonged periods and, as a result, to have complications of contact lens overwear. Oxygen debt in the corneal epithelium may develop to an extent that both epithelial and stromal edema occur. l4 This hypoxic state and the edematous state of the corneal tissues for prolonged periods leads to blood vessel growth into the cornea. l5 Contact lens parameters may be changed in order to obtain more adequate oxygenation. Contact lenses for the aphakic patient are now available in new plastics 16 and silicone l7 that permit additional oxygen supply through the lens. In order to prevent corneal damage, adequate oxygenation of the cornea, rather
1122
R. LINSY FARRIS
than perfect centering and minimal lens movement, must be the prime goal. A deficient tear state often occurs in older adults, and keratitis sicca has been reported to exacerbate after cataract surgery, resulting in severe corneal ulceration. 1s Aphakic contact lens wearers may have chronic irritation, red eyes, recurrent infections, and corneal ulcers as a result of contact lens wear in the presence of an inadequate tear film. Liberal use of artificial tear solutions and contact lens wetting solutions assists in improving the condition of the eye and, in combination with limited schedules of contact lens wear, protects against corneal injury. The dry eye is frequently overlooked and difficult to diagnose owing to the production of reflex tearing during the commonly used Schirmer test. Reflex tearing during the examination will frequently mask a dry eye condition that is present as a result of inadequate basal secretions. The patient may actually complain of excessive tearing because he only notices discomfort when the eyes become dry enough to stimulate another flood of reflex tears. The tear film in keratoconjunctivitis sicca has been demonstrated to be hypertonic, and this offers a mechanism for cellular changes more susceptible to damage by contact lens wear. Frequent use of a new diagnostic test for keratoconjunctivitis sicca 19 that determines tear osmolarity will alert contact lens fitters to the possibility of this complication with contact lens wear. In summary, the aphakic eye is a wounded eye, a desensitized eye, and frequently, a dry eye. These factors, kept in mind throughout the fitting, initial wear, and
OPHTH AAO
follow-up of aphakic contact lens wearers, should be helpful in avoiding complications. REFERENCES 1. Dixon M, Young CA, Baldone J A, et al: Complications associated with the wearing of contact lenses. JAMA 195:901-903, 1966. 2. Swan KC: Hyphema due to wound vascularization after cataract extraction. Arch Ophthalmol 89:87-90, 1973. 3. Watzke RC: Intraocular hemorrhage from wound vascularization following cataract surgery. Trans Am Ophthalmol Soc 72:242-252, 1974. 4. Benson WE, Karp LA, Nichols CW et al: Late hyphema due to vascularization of the cataract wound. Ann Ophthalmol 10:1109-1112, 1978. 5. Swan KC: Late hyphema due to wound vascularization. Trans Am Ophthalmol Soc 81:138-144, 1976. 6. ForbelS M: Gonioscopy with corneal indentation: A method for distinguishing between appositional closure and synechial closure. Arch Ophthalmol 76:488-492, 1966. 7. Gloedman ML, Karlson KE: Wound healing and wound strength of sutured limbal wounds. Am J Ophthalmol 39:859866, 1955. 8. Dunnington JH: Ocular wound healing with particular reference to the cataract incision. Arch Ophthalmol 56:639-659, 1956. 9. Flaxel JT, Swan KC: Limbal wound healing after cataract extraction. A histologic study. Arch Ophthalmol 81:653-659, 1969. 10. Heller MD, Irvine SR, Straatsma BR, et al: Wound healing after cataract extraction and position of the vitreous in aphakic eyes as studied postmortem. Trans Am Ophthalmol Soc 69:245-260, 1971. 11. Hoefle FB, Koverman JJ: Contact lens insertion and removal for aphakes. Contact Lens Med Bull 6:19-22, 1973. 12. Zander E, Weddell G: Reaction of corneal nerves to injury. Br J Ophthalmol 35:61-88, 1951. 13. Millodot M: Effect of long-term wear of hard contact lenses on corneal sensitivity. Arch Ophthalmol 96:1225-1227, 1978.
VOLUME 86 JUNE 1979
SYMPOSIUM ON CONTACT LENSES
1123
14. Farris RL, Kubota Z, Mishima S: Epithelial decompensation with corneal contact lens wear. Arch Ophthalmol 85: 651-660, 1971.
17. Dahl AA, Brocks ER: The use of continuous-wear silicone contact lenses in the optical correction of aphakia. Am J Ophthalmol 85:454-461, 1978.
15. Dixon JM: Ocular changes due to contact lenses. Am J Ophthalmol 58:424443, 1964.
18. Radtke N, Meyers S, Kaufman HE: Sterile corneal ulcers after cataract surgery in keratoconjunctivitis sicca. Arch Oph· thalmol 96:51-52, 1978.
16. Hales RH: Gas-permeable cellulose acetate butyrate (CAB) contact lenses. Ann Ophthalmol 9:1085-1090, 1977.
19. Gilbard JP, Farris RL, Santamaria J II: Osmolarity of tear microvolumes in keratoconjunctivitis sicca. Arch Ophthalmol 96:677-681, 1978.
.,.
f
COMPLICATIONS ASSOCIATED WITH APHAKIC CONTACT LENSES R. LINSY FARRIS, MD NEW YORK, NEW YORK Complications associated with rigid contact lenses are more frequent in aphakia. The limited dexterity of older patients not only may prove an insurmountable barrier to the mastery of daily contact lens insertion and removal, but also may produce significant direct eye trauma, its seriousness determined by the integrity of the cataract wound. Since prolonged wear of aphakic contact lenses is the rule rather than the exception, the risk of irreversible corneal changes such as vascularization and erosions is greater. A poorly fitted aphakic contact lens that does not permit adequate oxygenation of all corneal areas makes such complications even more likely to occur. Decreased corneal sensitivity associated with cataract surgery permits continued wear of a poorly fitted lens, which does not allow the cornea to recover between wearing periods. Detection of keratoconjunctivitis sicca, more prevalent in the older age group, may prevent the associated complications of corneal erosion, iritis, and infection. Complications of aphakic contact lenses can be controlled by patient instruction, appropriate contact lens adjustments, and regularly scheduled follow-up examinations.
Submitted for publication Nov 9, 1978. From the Edward S. Harkness Eye Institute, College of Physicians and Surgeons, Columbia University, New York, and the Department of Ophthalmology, Harlem Hospital Medical Center, New York. Presented in combination with the Contact Lens Association of Ophthalmologists at the 1978 Annual Meeting of the American Academy of Ophthalmology, Kansas City, Mo, Oct 22-26. Reprint requests to 635 W 165th St, New York, NY 10032.
NOT infrequently, the aphakic patient has complications with contact lens wear.l The ophthalmologist must detect and differentiate complications of cataract surgery aggravated by a contact lens from complications more directly associated with contact lens wear.
A 65-year-old man was seen by the author seven months after cataract surgery for redness and irritation associated with soft contact lens wear. The initial evaluation revealed no apparent cause. However, examination after four hours of soft contact lens wear revealed an extremely red, irritated eye with red blood cells deposited on the anterior vitreous face and the posterior cornea inferiorly. Careful gonioscopic examination at this point revealed a fine net of dilated blood vessels at the periphery of an iridotomy extending onto the posterior surface of the cornea. A fine stream of red blood cells appeared when pressure was exerted with the gonioprism. These vessels were trea ted through the gonioprism with the argon laser. A follow-up visit three months later revealed no further difficulties with an irritated eye. Late hyphema caused by wound vascularization has been reported by Swan,2 Watzke,3 and most recently, by Benson and co-workers.4 Argon laser photocoagulation has
1120
VOLUME 86 JUNE 1979
SYMPOSIUM ON CONTACT LENSES
given varying results in the management of this condition. 5 Rocking the Goldmann lens was suggested by Watzke as the best way to provoke a small hemorrhage. This was found to be true using the pressure gonioscopy technique described by Forbes. 6 This aphakic contact lens wearer found no difficulty in producing hemorrhage by merely inserting and removing his soft contact lens. Vascularization of the iridotomy site and the posterior surface of the cataract incision was the cause of this late hyphema seven months after cataract surgery. Corneal indentation occuring with contact lens insertion and removal was sufficient to rupture the fine vessels and produce a late hyphema. Internal wound separation and iris prolapse has also been known to occur in association with the intiation of contact lens wear as late as 12 weeks after cataract surgery (R.C. Welsh, MD, oral communication, August 1978). The strength of the human cataract wound and its ability to tolerate contact lens insertion and removal has not been rigorously studied. Tensile strength of the cataract wound is acquired slowly over a period of years and probably never reaches that of unaltered tissue. 7 Many factors influence this healing process. 8 Human studies of wound healing after cataract surgery have placed varying emphasis on the length of time required for wound remoulding 9 and elimination of posterior gapinglO following cataract surgery. Wound remoulding in human postmortem material requires up to 21/2 years to complete, whereas posterior wound gaping is eliminated usually in six months if there is no adherent iris. Evaluation of wound integrity is clearly indicated
1121
before initiating daily contact lens insertion and removal. External inspection as well as internal inspection by gonioscopy are easily and quickly performed at the slit lamp, using a Zeiss four-mirror gonioprism on a metal fork handle. Careful instruction concerning insertion and removal techniques and the patient's acceptance of assistance when necessary from a spouse, offspring, or neighbor will diminish the likelihood of excessive stress and wound complication.H Observation of a patient's ability to insert and remove a contact lens will have a significant effect on the choice of various cataract surgical techniques and also on the decision to initiate daily contact lens wear. The aphakic eye is not only a wounded eye; it is also less sensitive as a result of imperfect regeneration of the sectioned corneal nerve fibers.l2 The decreased sensation resulting from cataract surgery and the decreased corneal sensation associated with contact lens wear l3 produce a greater opportunity for the aphakic patient to wear contact lenses for prolonged periods and, as a result, to have complications of contact lens overwear. Oxygen debt in the corneal epithelium may develop to an extent that both epithelial and stromal edema occur. l4 This hypoxic state and the edematous state of the corneal tissues for prolonged periods leads to blood vessel growth into the cornea. l5 Contact lens parameters may be changed in order to obtain more adequate oxygenation. Contact lenses for the aphakic patient are now available in new plastics 16 and silicone l7 that permit additional oxygen supply through the lens. In order to prevent corneal damage, adequate oxygenation of the cornea, rather
1122
R. LINSY FARRIS
than perfect centering and minimal lens movement, must be the prime goal. A deficient tear state often occurs in older adults, and keratitis sicca has been reported to exacerbate after cataract surgery, resulting in severe corneal ulceration. 1s Aphakic contact lens wearers may have chronic irritation, red eyes, recurrent infections, and corneal ulcers as a result of contact lens wear in the presence of an inadequate tear film. Liberal use of artificial tear solutions and contact lens wetting solutions assists in improving the condition of the eye and, in combination with limited schedules of contact lens wear, protects against corneal injury. The dry eye is frequently overlooked and difficult to diagnose owing to the production of reflex tearing during the commonly used Schirmer test. Reflex tearing during the examination will frequently mask a dry eye condition that is present as a result of inadequate basal secretions. The patient may actually complain of excessive tearing because he only notices discomfort when the eyes become dry enough to stimulate another flood of reflex tears. The tear film in keratoconjunctivitis sicca has been demonstrated to be hypertonic, and this offers a mechanism for cellular changes more susceptible to damage by contact lens wear. Frequent use of a new diagnostic test for keratoconjunctivitis sicca 19 that determines tear osmolarity will alert contact lens fitters to the possibility of this complication with contact lens wear. In summary, the aphakic eye is a wounded eye, a desensitized eye, and frequently, a dry eye. These factors, kept in mind throughout the fitting, initial wear, and
OPHTH AAO
follow-up of aphakic contact lens wearers, should be helpful in avoiding complications. REFERENCES 1. Dixon M, Young CA, Baldone J A, et al: Complications associated with the wearing of contact lenses. JAMA 195:901-903, 1966. 2. Swan KC: Hyphema due to wound vascularization after cataract extraction. Arch Ophthalmol 89:87-90, 1973. 3. Watzke RC: Intraocular hemorrhage from wound vascularization following cataract surgery. Trans Am Ophthalmol Soc 72:242-252, 1974. 4. Benson WE, Karp LA, Nichols CW et al: Late hyphema due to vascularization of the cataract wound. Ann Ophthalmol 10:1109-1112, 1978. 5. Swan KC: Late hyphema due to wound vascularization. Trans Am Ophthalmol Soc 81:138-144, 1976. 6. ForbelS M: Gonioscopy with corneal indentation: A method for distinguishing between appositional closure and synechial closure. Arch Ophthalmol 76:488-492, 1966. 7. Gloedman ML, Karlson KE: Wound healing and wound strength of sutured limbal wounds. Am J Ophthalmol 39:859866, 1955. 8. Dunnington JH: Ocular wound healing with particular reference to the cataract incision. Arch Ophthalmol 56:639-659, 1956. 9. Flaxel JT, Swan KC: Limbal wound healing after cataract extraction. A histologic study. Arch Ophthalmol 81:653-659, 1969. 10. Heller MD, Irvine SR, Straatsma BR, et al: Wound healing after cataract extraction and position of the vitreous in aphakic eyes as studied postmortem. Trans Am Ophthalmol Soc 69:245-260, 1971. 11. Hoefle FB, Koverman JJ: Contact lens insertion and removal for aphakes. Contact Lens Med Bull 6:19-22, 1973. 12. Zander E, Weddell G: Reaction of corneal nerves to injury. Br J Ophthalmol 35:61-88, 1951. 13. Millodot M: Effect of long-term wear of hard contact lenses on corneal sensitivity. Arch Ophthalmol 96:1225-1227, 1978.
VOLUME 86 JUNE 1979
SYMPOSIUM ON CONTACT LENSES
1123
14. Farris RL, Kubota Z, Mishima S: Epithelial decompensation with corneal contact lens wear. Arch Ophthalmol 85: 651-660, 1971.
17. Dahl AA, Brocks ER: The use of continuous-wear silicone contact lenses in the optical correction of aphakia. Am J Ophthalmol 85:454-461, 1978.
15. Dixon JM: Ocular changes due to contact lenses. Am J Ophthalmol 58:424443, 1964.
18. Radtke N, Meyers S, Kaufman HE: Sterile corneal ulcers after cataract surgery in keratoconjunctivitis sicca. Arch Oph· thalmol 96:51-52, 1978.
16. Hales RH: Gas-permeable cellulose acetate butyrate (CAB) contact lenses. Ann Ophthalmol 9:1085-1090, 1977.
19. Gilbard JP, Farris RL, Santamaria J II: Osmolarity of tear microvolumes in keratoconjunctivitis sicca. Arch Ophthalmol 96:677-681, 1978.