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Intraocular lens implantation in microphthalmic patients
Intraocular lens implantation in microphthalmic patients Robert M. Sinskey, M.D., Pranav Amin, M.S., Juan Stoppel, M.D.
Microphthalmos is a developmental disorder of the eye consisting of a smaller than normal eye. l This disorder can present as an isolated condition or related to hereditary transmission following an autosomal dominant or autosomal recessive pattern,2 but it can also be associated with other systemic abnormalities such as in trisomy 13,3 Hallermann-Streiff syndrome,4 Meyer-Schwickenath syndrome, 5 Sjogren-Larsson, 6 Galtz,6 Cornelia de Lange,6 Mickel's 7 syndromes, and congenital rubella syndrome,8 among others. It is not uncommon for patients with microphthalmos to have congenital cataracts and nystagmus. These cases are a challenge to the ophthalmologist because there is not much in the modern literature that can guide us in managing cataracts in these patients. The most conservative approach would be extraction of the cataract followed by visual rehabilitation using spectacles or contact lenses, but the optical correction of aphakia in these patients is difficult since contact lens fitting is complicated by
the anatomy of the eye. The contact lens is often poorly tolerated. For patients unable to use a contact lens, nystagmus exacerbates the optical aberrations produced by aphakic spectacles. All this makes the implantation of an intraocular lens (IOL) a reasonable rehabilitation alternative in these patients. SUBJECTS AND METHODS Between 1985 and 1991, 11 IOLs were implanted in seven microphthalmic patients. The patients' ages ranged from 21/2 years to 47 years. Four had primary implantation following cataract extraction and seven had secondary implantation with sulcus-fixated posterior chamber IOLs. None of the secondary implantation patients were able to wear contact lenses because of problems with fitting or tolerance. All 11 eyes were less than 9.5 mm in diameter measured from white to white. Seven eyes had nystagmus. All patients 18 years of age or
Reprint requests to Robert M. Sinskey, M.D., 2232 Santa Monica Boulevard, P.O. Box 4031, Santa Monica, California 90404-0031.
480
J CATARACT REFRACT SURG-VOL 18,
SEPTEMBER 1992
less were approved by the Institutional Review Committee for IOL implantation. Intraocular lens measurements were performed under general anesthesia when patients were too young to cooperate. The IOL powers were selected to achieve emmetropia.
Surgical Technique The surgical technique in microphthalmic cases is basically the same as in other pediatric or adult cases without microphthalmos. One must be careful to measure the incision size required since the smaller cornea changes the spatial relationship. The incision appears larger and the lenses seem bigger. In primary cases a modified capsulorhexis (combination of can opener and capsulorhexis) was performed with a viscoelastic-filled anterior chamber. We were unable to remove the cataracts by irrigation and aspiration alone because they were too firm; an ultrasound needle was used for removal. In secondary implantation cases the anterior and posterior synechias were broken with the Sinskey hook or Vannas scissors before IOL placement. The IOL used in ten cases was a 6.0 mm planoconvex poly(methyl methacrylate) (PMMA) optic (Sinskey-style lens model UI02E, GI07E, 3260S IOLAB) with polypropylene loops. In the remaining case a 6.5 mm biconvex, three-piece, all-PMMA lens was used (3161B IOLAB). The overall diameter of all the lenses was 13.5 mm or 14.0 mm. The lenses selected for emmetropia were between 13.5 and 30.0 diopters. The lenses with the Sins keytype (modified J) loops were placed in the posterior chamber, either in the sulcus or in the bag, without experiencing difficulties with insertion. In five cases the posterior capsule was left intact and in one of these cases there was a thick plaque which was peeled off with a bent 30-gauge needle after the lens was inserted. In performing this technique the capsule opened without vitreous loss. At the end of the procedure the IOL was tested for stability and rotated with the Sinskey hook so the loops lay at the 3 o'clock and 9 o'clock positions. The anterior chamber was irrigated with balanced salt solution and the wound was sutured. We did not use intracameral miotics at the end of the procedure because they cause a reaction. Betamethasone sodium phosphate and betamethasone acetate (Celestone® Soluspan®) and Cephalosporin were injected subconjunctivally and an eye shield without an eye pad was taped over the eye. Postoperative Care Dilating drops were not used in children over 22 months of age. A mobile pupil is preferred over a
fixed dilated pupil to prevent synechial formation. Tobradex eyedrops were prescribed four times a day for three days and then prednisolone acetate (Pred Forte®) was given four times a day for one month. In younger patients it is extremely important to watch the parents actually put the drops into the eye to make sure that the medication is being administered properly. RESULTS The results in 11 eyes of seven patients are reported in this paper. They include six males and one female, with a mean age of 15 years (range 2112 to 47 years). The mean follow-up was 22 months (range three to 60 months). The mean interval between cataract extraction and secondary lens implantation was 23 years (range 2 to 46 years). The mean lens power implanted was 20 diopters (range 12.5 to 30.0 diopters). The clinical findings and postoperative results in 11 cases of microphthalmos are summarized in Table 1. Four of the 11 cases had primary implantation following cataract extraction and seven had secondary implantation. Many of these cases did not have marked improvement in the objective visual acuity but all of them reported better subjective visual acuity.
Case Reports Patient 1 (cases 1, 2). A 23-year-old man who had a history of bilateral microphthalmos and congenital cataracts with no other systemic abnormalities nor family history. He had a total of seven ocular surgical procedures in both eyes in the previous 22 years. He could not wear contact Ie rises because of fitting problems so secondary IOL implantation was considered. During the surgical procedure we observed that he had tightly encapsulated cortical material which we left undisturbed. Four days after the surgery on his right eye he noted a sudden loss of vision but no inflammation. The cortical material had expanded, filling the pupillary area behind the IOL. After watching for about three weeks, the patient was taken back to surgery and the cortical material was removed easily with mechanical irrigation/aspiration without complications. We attempted to prevent the same problem from occurring by removing as much of the cortical material as possible without tearing the posterior capsule when the left eye was operated on eight months later. The postoperative course was the same as the first eye and cortical material filled up the pupillary area behind the IOL, necessitating another surgical intervention. Apparently in freeing up the posterior synechias the encapsulated
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER 1992
481
Table l. Data from 11 microphthalmic cases.
Corneal Diameter Associated (mm) Condition Case Sex /Age Eye Bilat. condo nys1 R 9.S M/23 tagmus, aphakia previous eye surg. 2 Bilat. condo nysL 9 .S M/23 tagmus, aphakia previous eye surg.
Interval Between Cataract Surgery and 2° ImplantaVisual Acuity tion (years) Preop Postop Procedure Complication 22 C2° IOL with synech. Cortex in visual CF 400 axis re-surg cortical clean up 3161B 12.S
FollowUp 9 mon
400
200
23
2° IOL with synech. GI07E 13.S
6 mon
2 yrs
3
M/47
L
9 .0
Bilat condo aphakia, nystagmus
200
200
46
2° IOL UI02E 22 .0
4
M/47
R
9.0
Bilat condo aphakia, nystagmus
100
100
46
Capsular opacity/YAG
S
M/IS
L
9.0
Bilat. condo aphakia, nystagmus
SO
70
13
2° IOL 3161B 21.0 2° IOL 3260A 23 .S
6
M/lS
R
9.0
Bilat. condo aphakia, nystagmus
80
100
13
2° IOL 3260A 23.0
Cortex visual axis/re-surg
3 mon
7
M/21f2
L
9.0
Aphakia/bilat. condo
40
30
2
2° IOL UI02E 30.0
Cortex visual axis/re-surg
6 mon
8
M/9
L
9.0
Congo cataract, nystagmus
CF
80
Phaco IOL GI07E 15 .0 PC
5 yrs
9
M/3
L
9.0
Congo cataract
HM
400
4 yrs
10
M /5
R
9.0
Congo cataract
HM
400
Phaco IOL GI07E 19.5 PC Phaco IOL GI07E 19.5 PC
11
F /4
R
9.0
Congo cataract
HM
CF
cortical material was exposed to aqueous, causing it to flocculate and migrate into the pupillary area. Patient 2 (cases 3, 4). A 46-year-old space engineer who had a history of bilateral microphthalmos, cataracts, and nystagmus. He had bilateral cataract surgery 46 years previously. He was unable to wear contacts and in spite of his impaired visual acuity had a strong desire to free himself from the thick aphakic spectacles. Although the objective visual acuity did not change postoperatively, subjectively he was improved. Patient 3 (cases 5, 6). A I5-year-old boy who had a family history of microphthalmos and congenital cataracts (father, grandfather, and brother). He had bilateral cataract surgery 13 years earlier. He could not wear contact lenses because of fitting problems and because of the nystagmus did not feel 482
Phaco IOL Ul02E 19.5
2 yrs 1 yr
4 yrs PC cloudy, YAG posterior capsulotomy 6 mos
9 mon
comfortable with the aphakic spectacles. After the experience of treating patient 1, we attempted to remove the large amount of encapsulated cortical material. It was necessary to use the cystotome to expose the cortical material and the ultrasonic needle to break up the very hard nuclear-like cortical material and remove it. Despite this attention the patient had cortical material in the visual axis of his right eye postoperatively, requiring a second aspiration. Patient 4 (case 7). A 21J2-year-old child with a family history of microphthalmos and congenital cataracts (grandfather, father, and brother) who had bilateral cataract surgery two years earlier. He could not wear contact lenses because of allergy problems. A secondary implantation was done without complications. During the postoperative
J CATARACT REFRACT SURG-VOL 18,
SEPTEMBER 1992
period cortical material was found to occupy the visual axis, requiring a second aspiration. Patient 5 (case 8). A 9-year-old boy who had a history of familial microphthalmos, congenital cataracts, and nystagmus. He had surgery on his right eye eight years before in his native country, which resulted in phthisis bulbi . The examination of his left eye showed microphthalmos with a corneal diameter of 9 mm, nystagmus, and cataract (no red reflex), and a visual acuity of counting fingers at 11 inches. We decided to perform a cataract extraction with a primary IOL implantation because his socioeconomic condition would not enable him to buy contact lenses on a continuing basis. The surgery was uneventful. He did not have any postoperative problems. The visual acuity was objectively unchanged but subjectively improved. Patient 6 (cases 9,10). A 3-year-old boy who had a family history of microphthalmos, congenital cataracts, and nystagmus. His corneal diameter was 9 mm and his visual acuity in each eye was hand motion. He had cataract extraction and primary IOL implantation in both eyes two years apart. His postoperative period was uneventful, resulting in a final visual acuity of 20/400 in both eyes. Patient 7 (case 11). A4-year-old girl who had a history of unilateral microphthalmos and congenital cataract in the right eye. The visual acuity was hand motion in the right eye and 20/40 in the left eye. Because of the unilateral condition and the difficulties of fitting a contact lens in a microphthalmic eye, a cataract extraction with primary IOL implantation was performed. After the operation the patient developed posterior capsular opacification requiring a Nd:YAG laser posterior capsulotomy six months postoperatively. The final visual acuity was counting fingers. DISCUSSION Microphthalmos is a developmental disorder of the eye consisting of a smaller than normal eye. 1 It can present itself as an isolated condition, as occurred in patients 1, 2, and 7, or related to hereditary transmission following an autosomal dominant pattern,2 as occurred in patients 3, 4, 5, and 6. None of our patients had systemic abnormalities associated with their ocular condition. It is not uncommon for patients with microphthalmos to have congenital cataracts and nystagmus, both of which preclude an excellent visual result. Most of the patients did not have improvement in the objective visual acuity but all reported better subjective vision. This finding is most likely related to the advantage that secondary IOL implantation provided to patients who could not wear
contact lenses and whose nystagmus worsened the impact of optical aberrations of aphakic lenses, such as ring scotoma and image jump. Implantation of an IOL appears to be a good alternative in these patients, provided it can be done with relative safety. We also believe that the IOL increases the peripheral vision. It was not necessary to have smaller sized IOLs . The powers required were within the usual range (12.5 to 30.0 diopters). The flexibility of the modified J loops permitted easy insertion in the sulcus or bag without folding back onto the optic. We have observed that IOL insertion is the most critical part of the operation. The J loop and modified C loop configurations are more difficult to implant than the modified J loop. In three cases cortical material filled the visual axis postoperatively, requiring a secondary aspiration. When freeing up the posterior synechias the encapsulated cortical material was exposed to aqueous, causing it to flocculate and migrate into the pupillary area. SUMMARY Four primary cataract extractions with posterior chamber IOL implantation and seven secondary implantations were performed in microphthalmic eyes. Sinskey-style lenses of 13.5 mm or 14.0 mm overall diameter with 6.0 mm or 6.5 mm optics were used without complications referrable to the IOL. Three secondary implantation cases required a second surgical procedure to remove the residual cortical material. All cases reported subjective visual improvement. Microphthalmic eyes with cataracts and no other detectable abnormalities should be considered for IOL implantation as a primary procedure to improve visual function. Microphthalmic eyes that had a previous cataract extraction with enough residual posterior capsule to support a posterior chamber lens should also be considered for a secondary implantation if the patient cannot function adequately with aphakic spectacles or contact lenses. Nystagmus is not a contraindication for an IOL. We believe that improvement in objective visual acuity is not the only criterion for judging postoperative results in these patients. REFERENCES l. Duke-Elder S, ed. System of Ophthalmology. Vol III
Normal and Abnormal Development. Part 2: Congenital Deformities. London, Henry Kimpton, 1963; 488494 2. Francois J. Heredity in Ophthalmology. CV Mosby, St Louis, 1961 3. Ginsberg J, Bove KE. Ocular Pathology of Trisomy 13.
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER 1992
483
Ann Ophthalmol1974; 6:113-122 4. Sugar A, Bigger JF, Podos SM. Hallermann-StreiffFrancois syndrome. J Pediatr Ophthalmol 1971; 8: 234-238 5. Meyer-Schwickerath G, Gruterich E, Weyers H. Mikrophthalmussyndrome. Klin Monatsbl Augenheilkd 1957; 131:18-30 6. Warburg M. The heterogeneity of microphthalmia in
484
the mentally retarded. In: Bergsma D, ed, Birth defects: Original article series. Vol 7, No 3, March 1971. Baltimore, Williams and Wilkins, 1971; 146 7. MacRaeDW, HowardRO, AlbertDM, Hsia YE. Ocular manifestations of the Meckel syndrome. Arch Ophthalmol1972; 88:106-113 8. Boniuk V, Boniuk M. The congenital rubella syndrome. Int Ophthalmol Clin 1968; 8(2):487-514
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER 1992
Microphthalmos is a developmental disorder of the eye consisting of a smaller than normal eye. l This disorder can present as an isolated condition or related to hereditary transmission following an autosomal dominant or autosomal recessive pattern,2 but it can also be associated with other systemic abnormalities such as in trisomy 13,3 Hallermann-Streiff syndrome,4 Meyer-Schwickenath syndrome, 5 Sjogren-Larsson, 6 Galtz,6 Cornelia de Lange,6 Mickel's 7 syndromes, and congenital rubella syndrome,8 among others. It is not uncommon for patients with microphthalmos to have congenital cataracts and nystagmus. These cases are a challenge to the ophthalmologist because there is not much in the modern literature that can guide us in managing cataracts in these patients. The most conservative approach would be extraction of the cataract followed by visual rehabilitation using spectacles or contact lenses, but the optical correction of aphakia in these patients is difficult since contact lens fitting is complicated by
the anatomy of the eye. The contact lens is often poorly tolerated. For patients unable to use a contact lens, nystagmus exacerbates the optical aberrations produced by aphakic spectacles. All this makes the implantation of an intraocular lens (IOL) a reasonable rehabilitation alternative in these patients. SUBJECTS AND METHODS Between 1985 and 1991, 11 IOLs were implanted in seven microphthalmic patients. The patients' ages ranged from 21/2 years to 47 years. Four had primary implantation following cataract extraction and seven had secondary implantation with sulcus-fixated posterior chamber IOLs. None of the secondary implantation patients were able to wear contact lenses because of problems with fitting or tolerance. All 11 eyes were less than 9.5 mm in diameter measured from white to white. Seven eyes had nystagmus. All patients 18 years of age or
Reprint requests to Robert M. Sinskey, M.D., 2232 Santa Monica Boulevard, P.O. Box 4031, Santa Monica, California 90404-0031.
480
J CATARACT REFRACT SURG-VOL 18,
SEPTEMBER 1992
less were approved by the Institutional Review Committee for IOL implantation. Intraocular lens measurements were performed under general anesthesia when patients were too young to cooperate. The IOL powers were selected to achieve emmetropia.
Surgical Technique The surgical technique in microphthalmic cases is basically the same as in other pediatric or adult cases without microphthalmos. One must be careful to measure the incision size required since the smaller cornea changes the spatial relationship. The incision appears larger and the lenses seem bigger. In primary cases a modified capsulorhexis (combination of can opener and capsulorhexis) was performed with a viscoelastic-filled anterior chamber. We were unable to remove the cataracts by irrigation and aspiration alone because they were too firm; an ultrasound needle was used for removal. In secondary implantation cases the anterior and posterior synechias were broken with the Sinskey hook or Vannas scissors before IOL placement. The IOL used in ten cases was a 6.0 mm planoconvex poly(methyl methacrylate) (PMMA) optic (Sinskey-style lens model UI02E, GI07E, 3260S IOLAB) with polypropylene loops. In the remaining case a 6.5 mm biconvex, three-piece, all-PMMA lens was used (3161B IOLAB). The overall diameter of all the lenses was 13.5 mm or 14.0 mm. The lenses selected for emmetropia were between 13.5 and 30.0 diopters. The lenses with the Sins keytype (modified J) loops were placed in the posterior chamber, either in the sulcus or in the bag, without experiencing difficulties with insertion. In five cases the posterior capsule was left intact and in one of these cases there was a thick plaque which was peeled off with a bent 30-gauge needle after the lens was inserted. In performing this technique the capsule opened without vitreous loss. At the end of the procedure the IOL was tested for stability and rotated with the Sinskey hook so the loops lay at the 3 o'clock and 9 o'clock positions. The anterior chamber was irrigated with balanced salt solution and the wound was sutured. We did not use intracameral miotics at the end of the procedure because they cause a reaction. Betamethasone sodium phosphate and betamethasone acetate (Celestone® Soluspan®) and Cephalosporin were injected subconjunctivally and an eye shield without an eye pad was taped over the eye. Postoperative Care Dilating drops were not used in children over 22 months of age. A mobile pupil is preferred over a
fixed dilated pupil to prevent synechial formation. Tobradex eyedrops were prescribed four times a day for three days and then prednisolone acetate (Pred Forte®) was given four times a day for one month. In younger patients it is extremely important to watch the parents actually put the drops into the eye to make sure that the medication is being administered properly. RESULTS The results in 11 eyes of seven patients are reported in this paper. They include six males and one female, with a mean age of 15 years (range 2112 to 47 years). The mean follow-up was 22 months (range three to 60 months). The mean interval between cataract extraction and secondary lens implantation was 23 years (range 2 to 46 years). The mean lens power implanted was 20 diopters (range 12.5 to 30.0 diopters). The clinical findings and postoperative results in 11 cases of microphthalmos are summarized in Table 1. Four of the 11 cases had primary implantation following cataract extraction and seven had secondary implantation. Many of these cases did not have marked improvement in the objective visual acuity but all of them reported better subjective visual acuity.
Case Reports Patient 1 (cases 1, 2). A 23-year-old man who had a history of bilateral microphthalmos and congenital cataracts with no other systemic abnormalities nor family history. He had a total of seven ocular surgical procedures in both eyes in the previous 22 years. He could not wear contact Ie rises because of fitting problems so secondary IOL implantation was considered. During the surgical procedure we observed that he had tightly encapsulated cortical material which we left undisturbed. Four days after the surgery on his right eye he noted a sudden loss of vision but no inflammation. The cortical material had expanded, filling the pupillary area behind the IOL. After watching for about three weeks, the patient was taken back to surgery and the cortical material was removed easily with mechanical irrigation/aspiration without complications. We attempted to prevent the same problem from occurring by removing as much of the cortical material as possible without tearing the posterior capsule when the left eye was operated on eight months later. The postoperative course was the same as the first eye and cortical material filled up the pupillary area behind the IOL, necessitating another surgical intervention. Apparently in freeing up the posterior synechias the encapsulated
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER 1992
481
Table l. Data from 11 microphthalmic cases.
Corneal Diameter Associated (mm) Condition Case Sex /Age Eye Bilat. condo nys1 R 9.S M/23 tagmus, aphakia previous eye surg. 2 Bilat. condo nysL 9 .S M/23 tagmus, aphakia previous eye surg.
Interval Between Cataract Surgery and 2° ImplantaVisual Acuity tion (years) Preop Postop Procedure Complication 22 C2° IOL with synech. Cortex in visual CF 400 axis re-surg cortical clean up 3161B 12.S
FollowUp 9 mon
400
200
23
2° IOL with synech. GI07E 13.S
6 mon
2 yrs
3
M/47
L
9 .0
Bilat condo aphakia, nystagmus
200
200
46
2° IOL UI02E 22 .0
4
M/47
R
9.0
Bilat condo aphakia, nystagmus
100
100
46
Capsular opacity/YAG
S
M/IS
L
9.0
Bilat. condo aphakia, nystagmus
SO
70
13
2° IOL 3161B 21.0 2° IOL 3260A 23 .S
6
M/lS
R
9.0
Bilat. condo aphakia, nystagmus
80
100
13
2° IOL 3260A 23.0
Cortex visual axis/re-surg
3 mon
7
M/21f2
L
9.0
Aphakia/bilat. condo
40
30
2
2° IOL UI02E 30.0
Cortex visual axis/re-surg
6 mon
8
M/9
L
9.0
Congo cataract, nystagmus
CF
80
Phaco IOL GI07E 15 .0 PC
5 yrs
9
M/3
L
9.0
Congo cataract
HM
400
4 yrs
10
M /5
R
9.0
Congo cataract
HM
400
Phaco IOL GI07E 19.5 PC Phaco IOL GI07E 19.5 PC
11
F /4
R
9.0
Congo cataract
HM
CF
cortical material was exposed to aqueous, causing it to flocculate and migrate into the pupillary area. Patient 2 (cases 3, 4). A 46-year-old space engineer who had a history of bilateral microphthalmos, cataracts, and nystagmus. He had bilateral cataract surgery 46 years previously. He was unable to wear contacts and in spite of his impaired visual acuity had a strong desire to free himself from the thick aphakic spectacles. Although the objective visual acuity did not change postoperatively, subjectively he was improved. Patient 3 (cases 5, 6). A I5-year-old boy who had a family history of microphthalmos and congenital cataracts (father, grandfather, and brother). He had bilateral cataract surgery 13 years earlier. He could not wear contact lenses because of fitting problems and because of the nystagmus did not feel 482
Phaco IOL Ul02E 19.5
2 yrs 1 yr
4 yrs PC cloudy, YAG posterior capsulotomy 6 mos
9 mon
comfortable with the aphakic spectacles. After the experience of treating patient 1, we attempted to remove the large amount of encapsulated cortical material. It was necessary to use the cystotome to expose the cortical material and the ultrasonic needle to break up the very hard nuclear-like cortical material and remove it. Despite this attention the patient had cortical material in the visual axis of his right eye postoperatively, requiring a second aspiration. Patient 4 (case 7). A 21J2-year-old child with a family history of microphthalmos and congenital cataracts (grandfather, father, and brother) who had bilateral cataract surgery two years earlier. He could not wear contact lenses because of allergy problems. A secondary implantation was done without complications. During the postoperative
J CATARACT REFRACT SURG-VOL 18,
SEPTEMBER 1992
period cortical material was found to occupy the visual axis, requiring a second aspiration. Patient 5 (case 8). A 9-year-old boy who had a history of familial microphthalmos, congenital cataracts, and nystagmus. He had surgery on his right eye eight years before in his native country, which resulted in phthisis bulbi . The examination of his left eye showed microphthalmos with a corneal diameter of 9 mm, nystagmus, and cataract (no red reflex), and a visual acuity of counting fingers at 11 inches. We decided to perform a cataract extraction with a primary IOL implantation because his socioeconomic condition would not enable him to buy contact lenses on a continuing basis. The surgery was uneventful. He did not have any postoperative problems. The visual acuity was objectively unchanged but subjectively improved. Patient 6 (cases 9,10). A 3-year-old boy who had a family history of microphthalmos, congenital cataracts, and nystagmus. His corneal diameter was 9 mm and his visual acuity in each eye was hand motion. He had cataract extraction and primary IOL implantation in both eyes two years apart. His postoperative period was uneventful, resulting in a final visual acuity of 20/400 in both eyes. Patient 7 (case 11). A4-year-old girl who had a history of unilateral microphthalmos and congenital cataract in the right eye. The visual acuity was hand motion in the right eye and 20/40 in the left eye. Because of the unilateral condition and the difficulties of fitting a contact lens in a microphthalmic eye, a cataract extraction with primary IOL implantation was performed. After the operation the patient developed posterior capsular opacification requiring a Nd:YAG laser posterior capsulotomy six months postoperatively. The final visual acuity was counting fingers. DISCUSSION Microphthalmos is a developmental disorder of the eye consisting of a smaller than normal eye. 1 It can present itself as an isolated condition, as occurred in patients 1, 2, and 7, or related to hereditary transmission following an autosomal dominant pattern,2 as occurred in patients 3, 4, 5, and 6. None of our patients had systemic abnormalities associated with their ocular condition. It is not uncommon for patients with microphthalmos to have congenital cataracts and nystagmus, both of which preclude an excellent visual result. Most of the patients did not have improvement in the objective visual acuity but all reported better subjective vision. This finding is most likely related to the advantage that secondary IOL implantation provided to patients who could not wear
contact lenses and whose nystagmus worsened the impact of optical aberrations of aphakic lenses, such as ring scotoma and image jump. Implantation of an IOL appears to be a good alternative in these patients, provided it can be done with relative safety. We also believe that the IOL increases the peripheral vision. It was not necessary to have smaller sized IOLs . The powers required were within the usual range (12.5 to 30.0 diopters). The flexibility of the modified J loops permitted easy insertion in the sulcus or bag without folding back onto the optic. We have observed that IOL insertion is the most critical part of the operation. The J loop and modified C loop configurations are more difficult to implant than the modified J loop. In three cases cortical material filled the visual axis postoperatively, requiring a secondary aspiration. When freeing up the posterior synechias the encapsulated cortical material was exposed to aqueous, causing it to flocculate and migrate into the pupillary area. SUMMARY Four primary cataract extractions with posterior chamber IOL implantation and seven secondary implantations were performed in microphthalmic eyes. Sinskey-style lenses of 13.5 mm or 14.0 mm overall diameter with 6.0 mm or 6.5 mm optics were used without complications referrable to the IOL. Three secondary implantation cases required a second surgical procedure to remove the residual cortical material. All cases reported subjective visual improvement. Microphthalmic eyes with cataracts and no other detectable abnormalities should be considered for IOL implantation as a primary procedure to improve visual function. Microphthalmic eyes that had a previous cataract extraction with enough residual posterior capsule to support a posterior chamber lens should also be considered for a secondary implantation if the patient cannot function adequately with aphakic spectacles or contact lenses. Nystagmus is not a contraindication for an IOL. We believe that improvement in objective visual acuity is not the only criterion for judging postoperative results in these patients. REFERENCES l. Duke-Elder S, ed. System of Ophthalmology. Vol III
Normal and Abnormal Development. Part 2: Congenital Deformities. London, Henry Kimpton, 1963; 488494 2. Francois J. Heredity in Ophthalmology. CV Mosby, St Louis, 1961 3. Ginsberg J, Bove KE. Ocular Pathology of Trisomy 13.
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER 1992
483
Ann Ophthalmol1974; 6:113-122 4. Sugar A, Bigger JF, Podos SM. Hallermann-StreiffFrancois syndrome. J Pediatr Ophthalmol 1971; 8: 234-238 5. Meyer-Schwickerath G, Gruterich E, Weyers H. Mikrophthalmussyndrome. Klin Monatsbl Augenheilkd 1957; 131:18-30 6. Warburg M. The heterogeneity of microphthalmia in
484
the mentally retarded. In: Bergsma D, ed, Birth defects: Original article series. Vol 7, No 3, March 1971. Baltimore, Williams and Wilkins, 1971; 146 7. MacRaeDW, HowardRO, AlbertDM, Hsia YE. Ocular manifestations of the Meckel syndrome. Arch Ophthalmol1972; 88:106-113 8. Boniuk V, Boniuk M. The congenital rubella syndrome. Int Ophthalmol Clin 1968; 8(2):487-514
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER 1992