Clinical Investigations on Squint. C. Schweigger
the following table the refraction of the fixing eye and the visual acuteness of the squinting eye are given. In alternating squint the refraction of the emmetropic eye was taken, as determining it for insertion in the lower division of the statistics.
A. Convergent squint with myopia:
1. Slight myopia to M. = 1·75 D.
(a) Permanent squint 11 cases (3 previously operated on). Anisometropia in 2 cases (one with M. 1·25 D. of the fixing, M. 4 D. of the squinting eye; the other with M. 1·25 D. of the fixing, H. 4 D. and V. = 1 of the squinting eye). The examination of the visual acuteness of the squinting eye showed:
| V. more than 1/7 | 4 cases. |
| V. 1/12 - 1/18 | 1 case. |
| V. ½4 - ⅓6 | 1 case. |
| V. Less than ⅓6 | 4 cases (among them one with H. 2 D. in the squinting eye.) |
| V. indeterminable | 1 case. |
(b) Periodic squint 2 cases with very slight anisometropia and good vision.
2. M. 2 D. to M. 3 D. 11 cases, all permanent (6 cases previously operated on), anisometropia with good vision in both eyes in 2 cases (in both, the less myopic eye squints). V. of the squinting eye more than 1/7 in 6 cases.
| V. 1/12 - 1/18 | 1 case. | |
| V. ½4 - ⅓6 | 2 cases. | |
| V. less than ⅓6 | 2 cases (one with H = 5 D). |
3. M. 3·5 D. to 6 D.
(a) Permanent 11 cases (one previously operated on). Anisometropia in 2 cases, of which one consisted of alternating squint, while the other possessed in the fixing eye M. 4 D., in the squinting one M. 7·5 D. with good vision on both sides.
| V. more than 1/7 | 7 cases. |
| V. ½4 | 1 case. |
| V. ⅓6 | 1 case (in fixation with this eye; the visual axis shows a linear deviation of 2 mm. The presence of emmetropia is detected with the ophthalmoscope). |
Two cases were excluded from the statistics of vision, one on account of congenital capsular cataract, covering almost the whole pupil area, the other on account of choroiditis of the macula lutea.
(b) Periodic squint 4 cases with good vision, anisometropia in 2 cases.
4. M. 6·5 D. and more.
(a) Permanent 11 cases, among them 9 with V. more than 1/7, 2 excluded from the statistics, one on account of complication with corneal nebulæ, cataract, &c., the other possessed in the fixing eye M. 6·5 D. V. = 10/70 and slight nystagmus, in the squinting eye a smaller amount of sight not accurately noted, and strong nystagmus in fixing with this eye.
(b) Periodic squint in 4 cases with good vision.
5. Myopia with nystagmus and congenital amblyopia on both sides, 2 cases (not included in the statistics of vision). Altogether 56 cases, among them 10 with periodic squint.
B. Convergent squint in emmetropia, including simple myopic astigmatism, 98 cases.
(a) Permanent 81 cases (13 previously operated on). Visual acuteness more than 1/7 in 44 cases. V. less than 1/7 to V. = 1/12 6 cases; V. less than 1/12 to V. = ⅓6 20 cases; V. less than ⅓6 7. Excluded from statistics of vision 4 (3 on account of complications, 1 on account of lack of accurate information).
(b) Alternating convergent squint with emmetropia in one, myopia in the other eye, 4 cases. The degree of the myopia was 3·75 D., 5 D., 6 D., 12 D. Vision good on both sides.
(c) Periodic squint 13 cases (in 6 of them the refraction was objectively and subjectively determined in mydriasis by atropine). No anisometropia worth mentioning was present in any of these cases. Visual acuteness more than 1/7 9 cases. V. < 1/7 to V. = 1/12 2. V. < 1/12 to V. = ⅓6 1; one case with choroiditis excluded.
C. Convergent squint with doubtful hypermetropia to H. = 1 D., including simple hypermetropic astigmatism, 38 cases.
(a) Permanent 30 cases (5 previously operated on). Visual acuteness more than 1/7 7 cases. V < 1/7 to V. = 1/12 2. V. < 1/12 to V. = ⅓6 5. V. < ⅓6 2 cases. 4 excluded (3 complicated with cataract, one on account of impossibility of a trial of vision).
(b) Periodic squint 8 cases. V. more than 1/7 7. V. < 1/7 to V. = 1/12 1 case.
D. Hypermetropia 1 D. to 1·5 D. 37 cases.
(a) Permanent 23 (4 cases previously operated on). V. more than 1/7 13, V. < 1/7 to V. = 1/12 3. V. < 1/12 to V. = ⅓6 3. V. < ⅓6 3. One case excluded (choroiditis of the macula lutea).
(b) Periodic squint 14 cases. V. more than 1/7 12. V. < 1/12 to V. = ⅓6 1 case. One excluded on account of choroiditis.
E. Hypermetropia 1·5 D. to 2 D. 61 cases.
(a) Permanent 41 (3 previously operated on). V. more than 1/7 26 cases. V. < 1/7 to V. = 1/12 3; V. < 1/12 to V. = ⅓6 3; V. < ⅓6 2; (7 cases excluded, 2 as complicated, 5 on account of the impossibility of testing the vision).
(b) Periodic 20 cases. V. more than 1/7 16; V. < 1/7 to V. = 1/12 2; V. < 1/12 to ⅓6 1; V. < ⅓6 1 case.
F. Hypermetropia 2 D. to 3 D. 88 cases.
(a) Permanent 58 cases. V. more than 1/7 26 cases; V. < 1/7 to V. = 1/12 5 cases (among them one with V. = 1/12 in both eyes); V. < 1/12 to V. = ⅓6 17; V. < ⅓6 4 cases. Six cases excluded as indeterminable.
(b) Periodic 30 cases. V. to 1/7 24; V < 1/7 to V. = 1/12 3; V. < 1/12 to V. = ⅓6 1; V < ⅓6 1. One case excluded as indeterminable.
G. Hypermetropia 3 D. to 4·5 D. 54 cases.
(a) Permanent 35 cases (9 previously operated on). V. more than 1/7 18 cases; V. < 1/7 to V. = 1/12 1 case; V. < 1/12 to ⅓6 9; 7 cases excluded.
(b) Periodic 19 cases. V. more than 1/7 14; V. < 1/7 to V. = 1/12 1; V. < 1/12 to V. = ⅓6 3; V. < ⅓6 1 case.
H. H. 5 D. and more, 16 cases.
(a) Permanent 9; V. to 1/7 3; V. < 1/7 to V. = 1/12 3; V. < 1/12 to V. = ⅓6 2; V. < ⅓6 1 case.
(b) Periodic 7; V. to 1/7 4; V. < 1/7 to V. = 1/12 3 cases.
Table of Refraction and Acuity of Vision in Convergent Strabismus.
| Convergent strabismus. | Permanent | V. to 1/7. | V. < 1/7 to V 1/12. | V. < 1/12 to V. ⅓6. |
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