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Prolonged wear soft contact lenses
prolonged wear soft contact lenses James]. Salz, M.D. ] ay L. Schlanger, O.D. Beverly Hills, California
Prolonged wear soft contact lenses are a possible alternative to intraocular lens implants and aphakic spectacles for visual rehabilitation of the cataract patient. Reported herein are the results of our study on 63 eyes receiving prolonged wear soft lenses and followed for up to four years. Fitting technique, success rate, complications and the economic implications of the prolonged wear soft lens compared to the intraocular lens are discussed.
SUBJECTS AND METHODS Patient selection criteria included adequate tear flow and absence of infection in the aphakic eye. Also considered was the patient's degree of motivation, intelligence and personal hygiene. Patients were initially fitted with a trial lens, preferably in the morning. This lens was selected for the flattest base curve and the smallest lens diameter that would remain stable in the eye. The lens was left on the eye for about 30 minutes and then the correctness of fit was judged: a properly fitted lens moved about 1 mm with a blink and stayed centered in the eye with minimum lag during gaze up, down, left or right. The patient wore the trial lens for several hours and returned for examination in the afternoon. If the lens had tightened there was decreased movement with the blink, little movement with changes in fixation and often limbal conjunctival injection. Very tight lenses sometimes were associated with early microcystic corneal edema. If the lens had tightened, it was removed and the patient was refitted on another day. If the fit was satisfactory, the patient was instructed to wear the lens overnight and return in the morning. The next day, an over-refraction was performed and the initial contact lens prescription was ordered from the manufacturer. RESULTS Ten patients wore a trial lens overnight without apparent difficulty but elected not to go further. Because contact lenses were not ordered for these patients, they were not included in the investigational study. Eighteen other patients were unable to continue prolonged lens wear after fitting had been com-
menced. Most of these patients were seen frequently and often several lenses were ordered in an attempt to fit them. In six cases, the lens was not stable or comfortable. Seven patients were unhappy with their vision, even with spectacle over-refraction. Four patients experienced lens-induced corneal edema or conjunctival injection and one patient had recurrent peripheral corneal ulcers. Although these patients could not wear a soft contact lens on a prolonged basis, nine were successfully fitted with either hard or soft contact lenses on a daily basis. Fifty unilaterally or bilaterally aphakic patients were successfully fitted with prolonged wear lenses. Forty-eight eyes received Sauflon PW lenses (HeyerSchulte), 13 received Permalenses (Cooper Labs) and two received Hydrocurve lenses (Continuous Curve). Both Sauflon and Permalens styles are high water content soft lenses, developed in England. Sauflon lenses have a water content of approximately 80% and excellent oxygen permeability. Permalenses have a water content of approximately 70% and also have excellent oxygen permeability. Of these 63 eyes, 42 (67%) obtained visual acuities in the range of 20/20 to 20/40, over a follow-up period ranging from four months to four years (Table 1). Many patients required a cylinder over-correction to achieve this level of visual acuity. Vision less than 20/40 was attributable to retinal or optic nerve
pathology.
Table 1. Follow-up periods for 63 eyes of 50 aphakic patients. Follow-up Period 2 to 4 years
20
1 to 2 years
26
4 months to 1 year
17
Many of these patients had initial minor complications of corneal edema, discomfort and variable vision; these problems were resolved by improving lens fit. More serious complications included four cases of conjunctivitis, two of which also developed peripheral corneal ulcerations. After lens removal and antibiotic treatment, all four cases resumed prolonged lens wear
Presented at the Third u.s. Intraocular Lens Symposium, Los Angeles, CA, March 28,1980. Reprint requests to Dr. Salz, 8631 W. Third Street, Suite 800-E, Los Angeles, CA 90048. 246
Number of Eyes
AM INTRA-OCULAR IMPLANT SOC J-VOL. 6, JULY 1980
and have continued successfully for three years. There were no cases of central corneal ulceration with hypopyon. Five patients developed peripheral corneal ulcers; three ulcers were sterile and two were caused by staph infections. All five eyes cleared without incident and three of these patients are still wearing their lenses. A fourth patient underwent secondary implantation of an intraocular lens following significant neovascularization into the area of the previous ulceration. The fifth patient was a bilaterally aphakic infant who developed ulcerations in both eyes at different times. Because of a problem with adequate follow-up, the lenses were discontinued and the patient unfortunately had to be given cataract glasses. Five patients developed significant corneal neovascularization beyond the limbal arcades, occasionally extending to the optical portion of the contact lens (approximately 2.5 mm anterior to the limbus). In each case, neovascularization was confined to small areas and did not indicate lens removal.
DISCUSSION The results of our study compare well with those of Phillips 1 who reported a similar success rate in his United Kingdom study of Sauflon, Permalens and Duragellenses. In the United States, Stark et al 2 reported a 91 % success rate for eyes receiving Permalenses for prolonged wear (defined as continuous wear for 60 hours or longer). Kersley3 in Great Britain reported on a series of 50 aphakic patients receiving Sauflon prolonged wear soft lenses, noting three corneal ulcers and two cases of conjunctivitis; of the 50 patients in this series, five developed potentially serious corneal ulcerations while wearing prolonged wear soft lenses. In general we have found that if a patient does well in the overnight test, he has a good chance of wearing the lens for a prolonged period. Economic implications of prolonged wear lenses To evaluate the economic implications of prolonged wear lenses, we preselected ten patients who we felt had been very easy to fit and had adapted to prolonged wear with a minimum of difficulty. The FDA protocol requires 12 office visits during the first year of prolonged lens wear: these ten "easy" patients averaged 15 visits during the first year and two lenses per eye. They required an average of two office visits for their fitting. During the second year, they averaged five office visits (four are required by the FDA protocol) and required an average of one lens per eye. In summary, a patient doing very well with prolonged wear lenses averaged 20 office visits and three lenses
per eye during the first two years. Now that the lenses are approved, many uncomplicated cases can probably be fitted during the first two office visits and then examined five or six additional times during the first year, thus reducing the number of office visits from 12 to about seven or eight - for an "easy" uncomplicated case. To provide a comparison for this group of "easy" patients, we reviewed the records of our two most difficult cases. Although both patients were highly motivated to the idea of prolonged lens wear and were ultimately successful, one patient required 24 office visits and a total of 20 lenses for both eyes and the other patient was seen 31 times during the first year and required a total of 15 lenses for both eyes. In general, patients fall somewhere between the "easy" and the "difficult" groups. Often the initial prescription will remain unchanged, but it is not unusual to change prescriptions one or more times. Even when a patient does extremely well, he will probably require a minimum of one pair of lenses and four office visits per year for the rest of his life (Table 2). In our experience, most patients require more than four visits per year and more than one pair of replacement lenses per year, even after the first year. We also reviewed the records of ten patients who had undergone uncomplicated implantation of an intraocular lens. These patients averaged seven office visits in the immediate postoperative period and three additional visits during the first year. After the first year, these patients were usually seen once a year and required no lens replacement (Table 2).
CONCLUSION We advocate prolonged soft lens fitting in those patients who have a contraindication to lens implantation. For example, patients with diabetic retinopathy, poorly controlled glaucoma or a history of retinal detachment are ideal candidates for prolonged wear lenses. Children and young adults facing cataract surgery can have a trial of prolonged wear lenses, especially if they find it difficult to handle conventional contact lenses. A unilaterally aphakic patient who has not adjusted to cataract glasses and is facing cataract surgery and lens implantation in the other eye is an excellent candidate for a prolonged wear lens in the already aphakic eye. A trial of prolonged lens wear is indicated in any patient being considered for secondary lens implantation. Finally, a trial of a prolonged wear lens for two to three days is often helpful for patients with borderline contraindications for lens implantation, e.g. mild glaucoma, mild background diabetic retinopathy, or a 59-year-old patient with monocular cataract.
AM INTRA-OCULAR IMPLANT SOC J-VOL. 6, JULY 1980
247
Table 2. Average annual fees for monocular uncomplicated intraocular lens patients and prolonged wear soft lens patients. It is assumed that the surgical fees for an average, uncomplicated monocular intraocular lens patient include office visits during the first three postoperative months. The patient is then seen six months and twelve months postoperatively, and yearly thereafter. The fitting fee for the prolonged wear soft lens patient includes the final lens and all office visits for the first three months. On the average, soft lens patients require one replacement lens and three additional visits during the first year, and one lens and four office visits yearly thereafter. Although the cost to the intraocular lens patient is higher during the first year, costs are about equal by the end of the second year. After the second year, the cost to the intraocular lens patient is $55 a year and the cost to the prolonged wear soft lens patient is $240 a year.
Intraocular Lens Patient First Year
Prolonged Wear Soft Lens Patient
Future Years
First Year
Future Years
$1500.00
0
Lens implantation surgery
400.00
0
0
0
Assistant surgeon
380.00
0
300.00
0
Intraocular lens
300.00
0
0
0
0
0
400.00
0
Cataract surgery
Prolonged wear soft lens fitting
0
Replacement lenses
0
$2640.00
Total Total for first two years
$55.00
Of 78 patients eligible for prolonged wear contact lenses, 50 (65%) were successfully fitted and followed for four months to four years. The most serious complication was peripheral corneal ulceration, occurring in 5 (10%) patients. None of these patients suffered permanent visual loss. The fitting of prolonged wear lenses required six or seven office visits during the first year and at least one lens per eye during the first year, for uncomplicated cases. In difficult cases the number of office visits and the number of replacement lenses increased significantly. In terms of the number of office visits and replacement lenses,
90.00 (3)
120.00 (4)
120.00 (1)
120.00 (ll $240.00
$2410.00
$2695.00
SUMMARY
248
5,5.00 (1)
60.00 (2)
Office visits
0
$1500.00
$2650.00
the soft contact lens compares unfavorably with the intraocular lens. It is our feeling that the prolonged wear soft contact lens should be used when a lens implant is contraindicated or as an alternative to secondary lens implantation. REFERENCES 1. Phillips AJ: Extended wear hydrogen lenses in the United
Kingdom. International Contact Lens Clinic Jan/Feb:54, 1979 2. Stark WJ, Kracher GP, Cowan CL et al: Extended wear contact lenses and intraocular lenses for aphakic correction. Am] Ophthalmol 88:535, 1979 3. Kersley JR, Kerr C, Pierse D: Rydrophillic lenses for continuous wear in aphakia. BrJ OphthalmoI61:38, 1977
AM INTRA-OCULAR IMPLANT SOC J-VOL. 6, JULY 1980
Prolonged wear soft contact lenses are a possible alternative to intraocular lens implants and aphakic spectacles for visual rehabilitation of the cataract patient. Reported herein are the results of our study on 63 eyes receiving prolonged wear soft lenses and followed for up to four years. Fitting technique, success rate, complications and the economic implications of the prolonged wear soft lens compared to the intraocular lens are discussed.
SUBJECTS AND METHODS Patient selection criteria included adequate tear flow and absence of infection in the aphakic eye. Also considered was the patient's degree of motivation, intelligence and personal hygiene. Patients were initially fitted with a trial lens, preferably in the morning. This lens was selected for the flattest base curve and the smallest lens diameter that would remain stable in the eye. The lens was left on the eye for about 30 minutes and then the correctness of fit was judged: a properly fitted lens moved about 1 mm with a blink and stayed centered in the eye with minimum lag during gaze up, down, left or right. The patient wore the trial lens for several hours and returned for examination in the afternoon. If the lens had tightened there was decreased movement with the blink, little movement with changes in fixation and often limbal conjunctival injection. Very tight lenses sometimes were associated with early microcystic corneal edema. If the lens had tightened, it was removed and the patient was refitted on another day. If the fit was satisfactory, the patient was instructed to wear the lens overnight and return in the morning. The next day, an over-refraction was performed and the initial contact lens prescription was ordered from the manufacturer. RESULTS Ten patients wore a trial lens overnight without apparent difficulty but elected not to go further. Because contact lenses were not ordered for these patients, they were not included in the investigational study. Eighteen other patients were unable to continue prolonged lens wear after fitting had been com-
menced. Most of these patients were seen frequently and often several lenses were ordered in an attempt to fit them. In six cases, the lens was not stable or comfortable. Seven patients were unhappy with their vision, even with spectacle over-refraction. Four patients experienced lens-induced corneal edema or conjunctival injection and one patient had recurrent peripheral corneal ulcers. Although these patients could not wear a soft contact lens on a prolonged basis, nine were successfully fitted with either hard or soft contact lenses on a daily basis. Fifty unilaterally or bilaterally aphakic patients were successfully fitted with prolonged wear lenses. Forty-eight eyes received Sauflon PW lenses (HeyerSchulte), 13 received Permalenses (Cooper Labs) and two received Hydrocurve lenses (Continuous Curve). Both Sauflon and Permalens styles are high water content soft lenses, developed in England. Sauflon lenses have a water content of approximately 80% and excellent oxygen permeability. Permalenses have a water content of approximately 70% and also have excellent oxygen permeability. Of these 63 eyes, 42 (67%) obtained visual acuities in the range of 20/20 to 20/40, over a follow-up period ranging from four months to four years (Table 1). Many patients required a cylinder over-correction to achieve this level of visual acuity. Vision less than 20/40 was attributable to retinal or optic nerve
pathology.
Table 1. Follow-up periods for 63 eyes of 50 aphakic patients. Follow-up Period 2 to 4 years
20
1 to 2 years
26
4 months to 1 year
17
Many of these patients had initial minor complications of corneal edema, discomfort and variable vision; these problems were resolved by improving lens fit. More serious complications included four cases of conjunctivitis, two of which also developed peripheral corneal ulcerations. After lens removal and antibiotic treatment, all four cases resumed prolonged lens wear
Presented at the Third u.s. Intraocular Lens Symposium, Los Angeles, CA, March 28,1980. Reprint requests to Dr. Salz, 8631 W. Third Street, Suite 800-E, Los Angeles, CA 90048. 246
Number of Eyes
AM INTRA-OCULAR IMPLANT SOC J-VOL. 6, JULY 1980
and have continued successfully for three years. There were no cases of central corneal ulceration with hypopyon. Five patients developed peripheral corneal ulcers; three ulcers were sterile and two were caused by staph infections. All five eyes cleared without incident and three of these patients are still wearing their lenses. A fourth patient underwent secondary implantation of an intraocular lens following significant neovascularization into the area of the previous ulceration. The fifth patient was a bilaterally aphakic infant who developed ulcerations in both eyes at different times. Because of a problem with adequate follow-up, the lenses were discontinued and the patient unfortunately had to be given cataract glasses. Five patients developed significant corneal neovascularization beyond the limbal arcades, occasionally extending to the optical portion of the contact lens (approximately 2.5 mm anterior to the limbus). In each case, neovascularization was confined to small areas and did not indicate lens removal.
DISCUSSION The results of our study compare well with those of Phillips 1 who reported a similar success rate in his United Kingdom study of Sauflon, Permalens and Duragellenses. In the United States, Stark et al 2 reported a 91 % success rate for eyes receiving Permalenses for prolonged wear (defined as continuous wear for 60 hours or longer). Kersley3 in Great Britain reported on a series of 50 aphakic patients receiving Sauflon prolonged wear soft lenses, noting three corneal ulcers and two cases of conjunctivitis; of the 50 patients in this series, five developed potentially serious corneal ulcerations while wearing prolonged wear soft lenses. In general we have found that if a patient does well in the overnight test, he has a good chance of wearing the lens for a prolonged period. Economic implications of prolonged wear lenses To evaluate the economic implications of prolonged wear lenses, we preselected ten patients who we felt had been very easy to fit and had adapted to prolonged wear with a minimum of difficulty. The FDA protocol requires 12 office visits during the first year of prolonged lens wear: these ten "easy" patients averaged 15 visits during the first year and two lenses per eye. They required an average of two office visits for their fitting. During the second year, they averaged five office visits (four are required by the FDA protocol) and required an average of one lens per eye. In summary, a patient doing very well with prolonged wear lenses averaged 20 office visits and three lenses
per eye during the first two years. Now that the lenses are approved, many uncomplicated cases can probably be fitted during the first two office visits and then examined five or six additional times during the first year, thus reducing the number of office visits from 12 to about seven or eight - for an "easy" uncomplicated case. To provide a comparison for this group of "easy" patients, we reviewed the records of our two most difficult cases. Although both patients were highly motivated to the idea of prolonged lens wear and were ultimately successful, one patient required 24 office visits and a total of 20 lenses for both eyes and the other patient was seen 31 times during the first year and required a total of 15 lenses for both eyes. In general, patients fall somewhere between the "easy" and the "difficult" groups. Often the initial prescription will remain unchanged, but it is not unusual to change prescriptions one or more times. Even when a patient does extremely well, he will probably require a minimum of one pair of lenses and four office visits per year for the rest of his life (Table 2). In our experience, most patients require more than four visits per year and more than one pair of replacement lenses per year, even after the first year. We also reviewed the records of ten patients who had undergone uncomplicated implantation of an intraocular lens. These patients averaged seven office visits in the immediate postoperative period and three additional visits during the first year. After the first year, these patients were usually seen once a year and required no lens replacement (Table 2).
CONCLUSION We advocate prolonged soft lens fitting in those patients who have a contraindication to lens implantation. For example, patients with diabetic retinopathy, poorly controlled glaucoma or a history of retinal detachment are ideal candidates for prolonged wear lenses. Children and young adults facing cataract surgery can have a trial of prolonged wear lenses, especially if they find it difficult to handle conventional contact lenses. A unilaterally aphakic patient who has not adjusted to cataract glasses and is facing cataract surgery and lens implantation in the other eye is an excellent candidate for a prolonged wear lens in the already aphakic eye. A trial of prolonged lens wear is indicated in any patient being considered for secondary lens implantation. Finally, a trial of a prolonged wear lens for two to three days is often helpful for patients with borderline contraindications for lens implantation, e.g. mild glaucoma, mild background diabetic retinopathy, or a 59-year-old patient with monocular cataract.
AM INTRA-OCULAR IMPLANT SOC J-VOL. 6, JULY 1980
247
Table 2. Average annual fees for monocular uncomplicated intraocular lens patients and prolonged wear soft lens patients. It is assumed that the surgical fees for an average, uncomplicated monocular intraocular lens patient include office visits during the first three postoperative months. The patient is then seen six months and twelve months postoperatively, and yearly thereafter. The fitting fee for the prolonged wear soft lens patient includes the final lens and all office visits for the first three months. On the average, soft lens patients require one replacement lens and three additional visits during the first year, and one lens and four office visits yearly thereafter. Although the cost to the intraocular lens patient is higher during the first year, costs are about equal by the end of the second year. After the second year, the cost to the intraocular lens patient is $55 a year and the cost to the prolonged wear soft lens patient is $240 a year.
Intraocular Lens Patient First Year
Prolonged Wear Soft Lens Patient
Future Years
First Year
Future Years
$1500.00
0
Lens implantation surgery
400.00
0
0
0
Assistant surgeon
380.00
0
300.00
0
Intraocular lens
300.00
0
0
0
0
0
400.00
0
Cataract surgery
Prolonged wear soft lens fitting
0
Replacement lenses
0
$2640.00
Total Total for first two years
$55.00
Of 78 patients eligible for prolonged wear contact lenses, 50 (65%) were successfully fitted and followed for four months to four years. The most serious complication was peripheral corneal ulceration, occurring in 5 (10%) patients. None of these patients suffered permanent visual loss. The fitting of prolonged wear lenses required six or seven office visits during the first year and at least one lens per eye during the first year, for uncomplicated cases. In difficult cases the number of office visits and the number of replacement lenses increased significantly. In terms of the number of office visits and replacement lenses,
90.00 (3)
120.00 (4)
120.00 (1)
120.00 (ll $240.00
$2410.00
$2695.00
SUMMARY
248
5,5.00 (1)
60.00 (2)
Office visits
0
$1500.00
$2650.00
the soft contact lens compares unfavorably with the intraocular lens. It is our feeling that the prolonged wear soft contact lens should be used when a lens implant is contraindicated or as an alternative to secondary lens implantation. REFERENCES 1. Phillips AJ: Extended wear hydrogen lenses in the United
Kingdom. International Contact Lens Clinic Jan/Feb:54, 1979 2. Stark WJ, Kracher GP, Cowan CL et al: Extended wear contact lenses and intraocular lenses for aphakic correction. Am] Ophthalmol 88:535, 1979 3. Kersley JR, Kerr C, Pierse D: Rydrophillic lenses for continuous wear in aphakia. BrJ OphthalmoI61:38, 1977
AM INTRA-OCULAR IMPLANT SOC J-VOL. 6, JULY 1980